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Commit | Line | Data |
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1 | /* | |
2 | * linux/mm/page_alloc.c | |
3 | * | |
4 | * Manages the free list, the system allocates free pages here. | |
5 | * Note that kmalloc() lives in slab.c | |
6 | * | |
7 | * Copyright (C) 1991, 1992, 1993, 1994 Linus Torvalds | |
8 | * Swap reorganised 29.12.95, Stephen Tweedie | |
9 | * Support of BIGMEM added by Gerhard Wichert, Siemens AG, July 1999 | |
10 | * Reshaped it to be a zoned allocator, Ingo Molnar, Red Hat, 1999 | |
11 | * Discontiguous memory support, Kanoj Sarcar, SGI, Nov 1999 | |
12 | * Zone balancing, Kanoj Sarcar, SGI, Jan 2000 | |
13 | * Per cpu hot/cold page lists, bulk allocation, Martin J. Bligh, Sept 2002 | |
14 | * (lots of bits borrowed from Ingo Molnar & Andrew Morton) | |
15 | */ | |
16 | ||
17 | #include <linux/stddef.h> | |
18 | #include <linux/mm.h> | |
19 | #include <linux/swap.h> | |
20 | #include <linux/interrupt.h> | |
21 | #include <linux/pagemap.h> | |
22 | #include <linux/jiffies.h> | |
23 | #include <linux/bootmem.h> | |
24 | #include <linux/memblock.h> | |
25 | #include <linux/compiler.h> | |
26 | #include <linux/kernel.h> | |
27 | #include <linux/kmemcheck.h> | |
28 | #include <linux/kasan.h> | |
29 | #include <linux/module.h> | |
30 | #include <linux/suspend.h> | |
31 | #include <linux/pagevec.h> | |
32 | #include <linux/blkdev.h> | |
33 | #include <linux/slab.h> | |
34 | #include <linux/ratelimit.h> | |
35 | #include <linux/oom.h> | |
36 | #include <linux/notifier.h> | |
37 | #include <linux/topology.h> | |
38 | #include <linux/sysctl.h> | |
39 | #include <linux/cpu.h> | |
40 | #include <linux/cpuset.h> | |
41 | #include <linux/memory_hotplug.h> | |
42 | #include <linux/nodemask.h> | |
43 | #include <linux/vmalloc.h> | |
44 | #include <linux/vmstat.h> | |
45 | #include <linux/mempolicy.h> | |
46 | #include <linux/memremap.h> | |
47 | #include <linux/stop_machine.h> | |
48 | #include <linux/sort.h> | |
49 | #include <linux/pfn.h> | |
50 | #include <linux/backing-dev.h> | |
51 | #include <linux/fault-inject.h> | |
52 | #include <linux/page-isolation.h> | |
53 | #include <linux/page_ext.h> | |
54 | #include <linux/debugobjects.h> | |
55 | #include <linux/kmemleak.h> | |
56 | #include <linux/compaction.h> | |
57 | #include <trace/events/kmem.h> | |
58 | #include <trace/events/oom.h> | |
59 | #include <linux/prefetch.h> | |
60 | #include <linux/mm_inline.h> | |
61 | #include <linux/migrate.h> | |
62 | #include <linux/hugetlb.h> | |
63 | #include <linux/sched/rt.h> | |
64 | #include <linux/sched/mm.h> | |
65 | #include <linux/page_owner.h> | |
66 | #include <linux/kthread.h> | |
67 | #include <linux/memcontrol.h> | |
68 | #include <linux/ftrace.h> | |
69 | #include <linux/nmi.h> | |
70 | ||
71 | #include <asm/sections.h> | |
72 | #include <asm/tlbflush.h> | |
73 | #include <asm/div64.h> | |
74 | #include "internal.h" | |
75 | ||
76 | /* prevent >1 _updater_ of zone percpu pageset ->high and ->batch fields */ | |
77 | static DEFINE_MUTEX(pcp_batch_high_lock); | |
78 | #define MIN_PERCPU_PAGELIST_FRACTION (8) | |
79 | ||
80 | #ifdef CONFIG_USE_PERCPU_NUMA_NODE_ID | |
81 | DEFINE_PER_CPU(int, numa_node); | |
82 | EXPORT_PER_CPU_SYMBOL(numa_node); | |
83 | #endif | |
84 | ||
85 | #ifdef CONFIG_HAVE_MEMORYLESS_NODES | |
86 | /* | |
87 | * N.B., Do NOT reference the '_numa_mem_' per cpu variable directly. | |
88 | * It will not be defined when CONFIG_HAVE_MEMORYLESS_NODES is not defined. | |
89 | * Use the accessor functions set_numa_mem(), numa_mem_id() and cpu_to_mem() | |
90 | * defined in <linux/topology.h>. | |
91 | */ | |
92 | DEFINE_PER_CPU(int, _numa_mem_); /* Kernel "local memory" node */ | |
93 | EXPORT_PER_CPU_SYMBOL(_numa_mem_); | |
94 | int _node_numa_mem_[MAX_NUMNODES]; | |
95 | #endif | |
96 | ||
97 | /* work_structs for global per-cpu drains */ | |
98 | DEFINE_MUTEX(pcpu_drain_mutex); | |
99 | DEFINE_PER_CPU(struct work_struct, pcpu_drain); | |
100 | ||
101 | #ifdef CONFIG_GCC_PLUGIN_LATENT_ENTROPY | |
102 | volatile unsigned long latent_entropy __latent_entropy; | |
103 | EXPORT_SYMBOL(latent_entropy); | |
104 | #endif | |
105 | ||
106 | /* | |
107 | * Array of node states. | |
108 | */ | |
109 | nodemask_t node_states[NR_NODE_STATES] __read_mostly = { | |
110 | [N_POSSIBLE] = NODE_MASK_ALL, | |
111 | [N_ONLINE] = { { [0] = 1UL } }, | |
112 | #ifndef CONFIG_NUMA | |
113 | [N_NORMAL_MEMORY] = { { [0] = 1UL } }, | |
114 | #ifdef CONFIG_HIGHMEM | |
115 | [N_HIGH_MEMORY] = { { [0] = 1UL } }, | |
116 | #endif | |
117 | [N_MEMORY] = { { [0] = 1UL } }, | |
118 | [N_CPU] = { { [0] = 1UL } }, | |
119 | #endif /* NUMA */ | |
120 | }; | |
121 | EXPORT_SYMBOL(node_states); | |
122 | ||
123 | /* Protect totalram_pages and zone->managed_pages */ | |
124 | static DEFINE_SPINLOCK(managed_page_count_lock); | |
125 | ||
126 | unsigned long totalram_pages __read_mostly; | |
127 | unsigned long totalreserve_pages __read_mostly; | |
128 | unsigned long totalcma_pages __read_mostly; | |
129 | ||
130 | int percpu_pagelist_fraction; | |
131 | gfp_t gfp_allowed_mask __read_mostly = GFP_BOOT_MASK; | |
132 | ||
133 | /* | |
134 | * A cached value of the page's pageblock's migratetype, used when the page is | |
135 | * put on a pcplist. Used to avoid the pageblock migratetype lookup when | |
136 | * freeing from pcplists in most cases, at the cost of possibly becoming stale. | |
137 | * Also the migratetype set in the page does not necessarily match the pcplist | |
138 | * index, e.g. page might have MIGRATE_CMA set but be on a pcplist with any | |
139 | * other index - this ensures that it will be put on the correct CMA freelist. | |
140 | */ | |
141 | static inline int get_pcppage_migratetype(struct page *page) | |
142 | { | |
143 | return page->index; | |
144 | } | |
145 | ||
146 | static inline void set_pcppage_migratetype(struct page *page, int migratetype) | |
147 | { | |
148 | page->index = migratetype; | |
149 | } | |
150 | ||
151 | #ifdef CONFIG_PM_SLEEP | |
152 | /* | |
153 | * The following functions are used by the suspend/hibernate code to temporarily | |
154 | * change gfp_allowed_mask in order to avoid using I/O during memory allocations | |
155 | * while devices are suspended. To avoid races with the suspend/hibernate code, | |
156 | * they should always be called with pm_mutex held (gfp_allowed_mask also should | |
157 | * only be modified with pm_mutex held, unless the suspend/hibernate code is | |
158 | * guaranteed not to run in parallel with that modification). | |
159 | */ | |
160 | ||
161 | static gfp_t saved_gfp_mask; | |
162 | ||
163 | void pm_restore_gfp_mask(void) | |
164 | { | |
165 | WARN_ON(!mutex_is_locked(&pm_mutex)); | |
166 | if (saved_gfp_mask) { | |
167 | gfp_allowed_mask = saved_gfp_mask; | |
168 | saved_gfp_mask = 0; | |
169 | } | |
170 | } | |
171 | ||
172 | void pm_restrict_gfp_mask(void) | |
173 | { | |
174 | WARN_ON(!mutex_is_locked(&pm_mutex)); | |
175 | WARN_ON(saved_gfp_mask); | |
176 | saved_gfp_mask = gfp_allowed_mask; | |
177 | gfp_allowed_mask &= ~(__GFP_IO | __GFP_FS); | |
178 | } | |
179 | ||
180 | bool pm_suspended_storage(void) | |
181 | { | |
182 | if ((gfp_allowed_mask & (__GFP_IO | __GFP_FS)) == (__GFP_IO | __GFP_FS)) | |
183 | return false; | |
184 | return true; | |
185 | } | |
186 | #endif /* CONFIG_PM_SLEEP */ | |
187 | ||
188 | #ifdef CONFIG_HUGETLB_PAGE_SIZE_VARIABLE | |
189 | unsigned int pageblock_order __read_mostly; | |
190 | #endif | |
191 | ||
192 | static void __free_pages_ok(struct page *page, unsigned int order); | |
193 | ||
194 | /* | |
195 | * results with 256, 32 in the lowmem_reserve sysctl: | |
196 | * 1G machine -> (16M dma, 800M-16M normal, 1G-800M high) | |
197 | * 1G machine -> (16M dma, 784M normal, 224M high) | |
198 | * NORMAL allocation will leave 784M/256 of ram reserved in the ZONE_DMA | |
199 | * HIGHMEM allocation will leave 224M/32 of ram reserved in ZONE_NORMAL | |
200 | * HIGHMEM allocation will leave (224M+784M)/256 of ram reserved in ZONE_DMA | |
201 | * | |
202 | * TBD: should special case ZONE_DMA32 machines here - in those we normally | |
203 | * don't need any ZONE_NORMAL reservation | |
204 | */ | |
205 | int sysctl_lowmem_reserve_ratio[MAX_NR_ZONES-1] = { | |
206 | #ifdef CONFIG_ZONE_DMA | |
207 | 256, | |
208 | #endif | |
209 | #ifdef CONFIG_ZONE_DMA32 | |
210 | 256, | |
211 | #endif | |
212 | #ifdef CONFIG_HIGHMEM | |
213 | 32, | |
214 | #endif | |
215 | 32, | |
216 | }; | |
217 | ||
218 | EXPORT_SYMBOL(totalram_pages); | |
219 | ||
220 | static char * const zone_names[MAX_NR_ZONES] = { | |
221 | #ifdef CONFIG_ZONE_DMA | |
222 | "DMA", | |
223 | #endif | |
224 | #ifdef CONFIG_ZONE_DMA32 | |
225 | "DMA32", | |
226 | #endif | |
227 | "Normal", | |
228 | #ifdef CONFIG_HIGHMEM | |
229 | "HighMem", | |
230 | #endif | |
231 | "Movable", | |
232 | #ifdef CONFIG_ZONE_DEVICE | |
233 | "Device", | |
234 | #endif | |
235 | }; | |
236 | ||
237 | char * const migratetype_names[MIGRATE_TYPES] = { | |
238 | "Unmovable", | |
239 | "Movable", | |
240 | "Reclaimable", | |
241 | "HighAtomic", | |
242 | #ifdef CONFIG_CMA | |
243 | "CMA", | |
244 | #endif | |
245 | #ifdef CONFIG_MEMORY_ISOLATION | |
246 | "Isolate", | |
247 | #endif | |
248 | }; | |
249 | ||
250 | compound_page_dtor * const compound_page_dtors[] = { | |
251 | NULL, | |
252 | free_compound_page, | |
253 | #ifdef CONFIG_HUGETLB_PAGE | |
254 | free_huge_page, | |
255 | #endif | |
256 | #ifdef CONFIG_TRANSPARENT_HUGEPAGE | |
257 | free_transhuge_page, | |
258 | #endif | |
259 | }; | |
260 | ||
261 | int min_free_kbytes = 1024; | |
262 | int user_min_free_kbytes = -1; | |
263 | int watermark_scale_factor = 10; | |
264 | ||
265 | static unsigned long __meminitdata nr_kernel_pages; | |
266 | static unsigned long __meminitdata nr_all_pages; | |
267 | static unsigned long __meminitdata dma_reserve; | |
268 | ||
269 | #ifdef CONFIG_HAVE_MEMBLOCK_NODE_MAP | |
270 | static unsigned long __meminitdata arch_zone_lowest_possible_pfn[MAX_NR_ZONES]; | |
271 | static unsigned long __meminitdata arch_zone_highest_possible_pfn[MAX_NR_ZONES]; | |
272 | static unsigned long __initdata required_kernelcore; | |
273 | static unsigned long __initdata required_movablecore; | |
274 | static unsigned long __meminitdata zone_movable_pfn[MAX_NUMNODES]; | |
275 | static bool mirrored_kernelcore; | |
276 | ||
277 | /* movable_zone is the "real" zone pages in ZONE_MOVABLE are taken from */ | |
278 | int movable_zone; | |
279 | EXPORT_SYMBOL(movable_zone); | |
280 | #endif /* CONFIG_HAVE_MEMBLOCK_NODE_MAP */ | |
281 | ||
282 | #if MAX_NUMNODES > 1 | |
283 | int nr_node_ids __read_mostly = MAX_NUMNODES; | |
284 | int nr_online_nodes __read_mostly = 1; | |
285 | EXPORT_SYMBOL(nr_node_ids); | |
286 | EXPORT_SYMBOL(nr_online_nodes); | |
287 | #endif | |
288 | ||
289 | int page_group_by_mobility_disabled __read_mostly; | |
290 | ||
291 | #ifdef CONFIG_DEFERRED_STRUCT_PAGE_INIT | |
292 | static inline void reset_deferred_meminit(pg_data_t *pgdat) | |
293 | { | |
294 | unsigned long max_initialise; | |
295 | unsigned long reserved_lowmem; | |
296 | ||
297 | /* | |
298 | * Initialise at least 2G of a node but also take into account that | |
299 | * two large system hashes that can take up 1GB for 0.25TB/node. | |
300 | */ | |
301 | max_initialise = max(2UL << (30 - PAGE_SHIFT), | |
302 | (pgdat->node_spanned_pages >> 8)); | |
303 | ||
304 | /* | |
305 | * Compensate the all the memblock reservations (e.g. crash kernel) | |
306 | * from the initial estimation to make sure we will initialize enough | |
307 | * memory to boot. | |
308 | */ | |
309 | reserved_lowmem = memblock_reserved_memory_within(pgdat->node_start_pfn, | |
310 | pgdat->node_start_pfn + max_initialise); | |
311 | max_initialise += reserved_lowmem; | |
312 | ||
313 | pgdat->static_init_size = min(max_initialise, pgdat->node_spanned_pages); | |
314 | pgdat->first_deferred_pfn = ULONG_MAX; | |
315 | } | |
316 | ||
317 | /* Returns true if the struct page for the pfn is uninitialised */ | |
318 | static inline bool __meminit early_page_uninitialised(unsigned long pfn) | |
319 | { | |
320 | int nid = early_pfn_to_nid(pfn); | |
321 | ||
322 | if (node_online(nid) && pfn >= NODE_DATA(nid)->first_deferred_pfn) | |
323 | return true; | |
324 | ||
325 | return false; | |
326 | } | |
327 | ||
328 | /* | |
329 | * Returns false when the remaining initialisation should be deferred until | |
330 | * later in the boot cycle when it can be parallelised. | |
331 | */ | |
332 | static inline bool update_defer_init(pg_data_t *pgdat, | |
333 | unsigned long pfn, unsigned long zone_end, | |
334 | unsigned long *nr_initialised) | |
335 | { | |
336 | /* Always populate low zones for address-contrained allocations */ | |
337 | if (zone_end < pgdat_end_pfn(pgdat)) | |
338 | return true; | |
339 | (*nr_initialised)++; | |
340 | if ((*nr_initialised > pgdat->static_init_size) && | |
341 | (pfn & (PAGES_PER_SECTION - 1)) == 0) { | |
342 | pgdat->first_deferred_pfn = pfn; | |
343 | return false; | |
344 | } | |
345 | ||
346 | return true; | |
347 | } | |
348 | #else | |
349 | static inline void reset_deferred_meminit(pg_data_t *pgdat) | |
350 | { | |
351 | } | |
352 | ||
353 | static inline bool early_page_uninitialised(unsigned long pfn) | |
354 | { | |
355 | return false; | |
356 | } | |
357 | ||
358 | static inline bool update_defer_init(pg_data_t *pgdat, | |
359 | unsigned long pfn, unsigned long zone_end, | |
360 | unsigned long *nr_initialised) | |
361 | { | |
362 | return true; | |
363 | } | |
364 | #endif | |
365 | ||
366 | /* Return a pointer to the bitmap storing bits affecting a block of pages */ | |
367 | static inline unsigned long *get_pageblock_bitmap(struct page *page, | |
368 | unsigned long pfn) | |
369 | { | |
370 | #ifdef CONFIG_SPARSEMEM | |
371 | return __pfn_to_section(pfn)->pageblock_flags; | |
372 | #else | |
373 | return page_zone(page)->pageblock_flags; | |
374 | #endif /* CONFIG_SPARSEMEM */ | |
375 | } | |
376 | ||
377 | static inline int pfn_to_bitidx(struct page *page, unsigned long pfn) | |
378 | { | |
379 | #ifdef CONFIG_SPARSEMEM | |
380 | pfn &= (PAGES_PER_SECTION-1); | |
381 | return (pfn >> pageblock_order) * NR_PAGEBLOCK_BITS; | |
382 | #else | |
383 | pfn = pfn - round_down(page_zone(page)->zone_start_pfn, pageblock_nr_pages); | |
384 | return (pfn >> pageblock_order) * NR_PAGEBLOCK_BITS; | |
385 | #endif /* CONFIG_SPARSEMEM */ | |
386 | } | |
387 | ||
388 | /** | |
389 | * get_pfnblock_flags_mask - Return the requested group of flags for the pageblock_nr_pages block of pages | |
390 | * @page: The page within the block of interest | |
391 | * @pfn: The target page frame number | |
392 | * @end_bitidx: The last bit of interest to retrieve | |
393 | * @mask: mask of bits that the caller is interested in | |
394 | * | |
395 | * Return: pageblock_bits flags | |
396 | */ | |
397 | static __always_inline unsigned long __get_pfnblock_flags_mask(struct page *page, | |
398 | unsigned long pfn, | |
399 | unsigned long end_bitidx, | |
400 | unsigned long mask) | |
401 | { | |
402 | unsigned long *bitmap; | |
403 | unsigned long bitidx, word_bitidx; | |
404 | unsigned long word; | |
405 | ||
406 | bitmap = get_pageblock_bitmap(page, pfn); | |
407 | bitidx = pfn_to_bitidx(page, pfn); | |
408 | word_bitidx = bitidx / BITS_PER_LONG; | |
409 | bitidx &= (BITS_PER_LONG-1); | |
410 | ||
411 | word = bitmap[word_bitidx]; | |
412 | bitidx += end_bitidx; | |
413 | return (word >> (BITS_PER_LONG - bitidx - 1)) & mask; | |
414 | } | |
415 | ||
416 | unsigned long get_pfnblock_flags_mask(struct page *page, unsigned long pfn, | |
417 | unsigned long end_bitidx, | |
418 | unsigned long mask) | |
419 | { | |
420 | return __get_pfnblock_flags_mask(page, pfn, end_bitidx, mask); | |
421 | } | |
422 | ||
423 | static __always_inline int get_pfnblock_migratetype(struct page *page, unsigned long pfn) | |
424 | { | |
425 | return __get_pfnblock_flags_mask(page, pfn, PB_migrate_end, MIGRATETYPE_MASK); | |
426 | } | |
427 | ||
428 | /** | |
429 | * set_pfnblock_flags_mask - Set the requested group of flags for a pageblock_nr_pages block of pages | |
430 | * @page: The page within the block of interest | |
431 | * @flags: The flags to set | |
432 | * @pfn: The target page frame number | |
433 | * @end_bitidx: The last bit of interest | |
434 | * @mask: mask of bits that the caller is interested in | |
435 | */ | |
436 | void set_pfnblock_flags_mask(struct page *page, unsigned long flags, | |
437 | unsigned long pfn, | |
438 | unsigned long end_bitidx, | |
439 | unsigned long mask) | |
440 | { | |
441 | unsigned long *bitmap; | |
442 | unsigned long bitidx, word_bitidx; | |
443 | unsigned long old_word, word; | |
444 | ||
445 | BUILD_BUG_ON(NR_PAGEBLOCK_BITS != 4); | |
446 | ||
447 | bitmap = get_pageblock_bitmap(page, pfn); | |
448 | bitidx = pfn_to_bitidx(page, pfn); | |
449 | word_bitidx = bitidx / BITS_PER_LONG; | |
450 | bitidx &= (BITS_PER_LONG-1); | |
451 | ||
452 | VM_BUG_ON_PAGE(!zone_spans_pfn(page_zone(page), pfn), page); | |
453 | ||
454 | bitidx += end_bitidx; | |
455 | mask <<= (BITS_PER_LONG - bitidx - 1); | |
456 | flags <<= (BITS_PER_LONG - bitidx - 1); | |
457 | ||
458 | word = READ_ONCE(bitmap[word_bitidx]); | |
459 | for (;;) { | |
460 | old_word = cmpxchg(&bitmap[word_bitidx], word, (word & ~mask) | flags); | |
461 | if (word == old_word) | |
462 | break; | |
463 | word = old_word; | |
464 | } | |
465 | } | |
466 | ||
467 | void set_pageblock_migratetype(struct page *page, int migratetype) | |
468 | { | |
469 | if (unlikely(page_group_by_mobility_disabled && | |
470 | migratetype < MIGRATE_PCPTYPES)) | |
471 | migratetype = MIGRATE_UNMOVABLE; | |
472 | ||
473 | set_pageblock_flags_group(page, (unsigned long)migratetype, | |
474 | PB_migrate, PB_migrate_end); | |
475 | } | |
476 | ||
477 | #ifdef CONFIG_DEBUG_VM | |
478 | static int page_outside_zone_boundaries(struct zone *zone, struct page *page) | |
479 | { | |
480 | int ret = 0; | |
481 | unsigned seq; | |
482 | unsigned long pfn = page_to_pfn(page); | |
483 | unsigned long sp, start_pfn; | |
484 | ||
485 | do { | |
486 | seq = zone_span_seqbegin(zone); | |
487 | start_pfn = zone->zone_start_pfn; | |
488 | sp = zone->spanned_pages; | |
489 | if (!zone_spans_pfn(zone, pfn)) | |
490 | ret = 1; | |
491 | } while (zone_span_seqretry(zone, seq)); | |
492 | ||
493 | if (ret) | |
494 | pr_err("page 0x%lx outside node %d zone %s [ 0x%lx - 0x%lx ]\n", | |
495 | pfn, zone_to_nid(zone), zone->name, | |
496 | start_pfn, start_pfn + sp); | |
497 | ||
498 | return ret; | |
499 | } | |
500 | ||
501 | static int page_is_consistent(struct zone *zone, struct page *page) | |
502 | { | |
503 | if (!pfn_valid_within(page_to_pfn(page))) | |
504 | return 0; | |
505 | if (zone != page_zone(page)) | |
506 | return 0; | |
507 | ||
508 | return 1; | |
509 | } | |
510 | /* | |
511 | * Temporary debugging check for pages not lying within a given zone. | |
512 | */ | |
513 | static int __maybe_unused bad_range(struct zone *zone, struct page *page) | |
514 | { | |
515 | if (page_outside_zone_boundaries(zone, page)) | |
516 | return 1; | |
517 | if (!page_is_consistent(zone, page)) | |
518 | return 1; | |
519 | ||
520 | return 0; | |
521 | } | |
522 | #else | |
523 | static inline int __maybe_unused bad_range(struct zone *zone, struct page *page) | |
524 | { | |
525 | return 0; | |
526 | } | |
527 | #endif | |
528 | ||
529 | static void bad_page(struct page *page, const char *reason, | |
530 | unsigned long bad_flags) | |
531 | { | |
532 | static unsigned long resume; | |
533 | static unsigned long nr_shown; | |
534 | static unsigned long nr_unshown; | |
535 | ||
536 | /* | |
537 | * Allow a burst of 60 reports, then keep quiet for that minute; | |
538 | * or allow a steady drip of one report per second. | |
539 | */ | |
540 | if (nr_shown == 60) { | |
541 | if (time_before(jiffies, resume)) { | |
542 | nr_unshown++; | |
543 | goto out; | |
544 | } | |
545 | if (nr_unshown) { | |
546 | pr_alert( | |
547 | "BUG: Bad page state: %lu messages suppressed\n", | |
548 | nr_unshown); | |
549 | nr_unshown = 0; | |
550 | } | |
551 | nr_shown = 0; | |
552 | } | |
553 | if (nr_shown++ == 0) | |
554 | resume = jiffies + 60 * HZ; | |
555 | ||
556 | pr_alert("BUG: Bad page state in process %s pfn:%05lx\n", | |
557 | current->comm, page_to_pfn(page)); | |
558 | __dump_page(page, reason); | |
559 | bad_flags &= page->flags; | |
560 | if (bad_flags) | |
561 | pr_alert("bad because of flags: %#lx(%pGp)\n", | |
562 | bad_flags, &bad_flags); | |
563 | dump_page_owner(page); | |
564 | ||
565 | print_modules(); | |
566 | dump_stack(); | |
567 | out: | |
568 | /* Leave bad fields for debug, except PageBuddy could make trouble */ | |
569 | page_mapcount_reset(page); /* remove PageBuddy */ | |
570 | add_taint(TAINT_BAD_PAGE, LOCKDEP_NOW_UNRELIABLE); | |
571 | } | |
572 | ||
573 | /* | |
574 | * Higher-order pages are called "compound pages". They are structured thusly: | |
575 | * | |
576 | * The first PAGE_SIZE page is called the "head page" and have PG_head set. | |
577 | * | |
578 | * The remaining PAGE_SIZE pages are called "tail pages". PageTail() is encoded | |
579 | * in bit 0 of page->compound_head. The rest of bits is pointer to head page. | |
580 | * | |
581 | * The first tail page's ->compound_dtor holds the offset in array of compound | |
582 | * page destructors. See compound_page_dtors. | |
583 | * | |
584 | * The first tail page's ->compound_order holds the order of allocation. | |
585 | * This usage means that zero-order pages may not be compound. | |
586 | */ | |
587 | ||
588 | void free_compound_page(struct page *page) | |
589 | { | |
590 | __free_pages_ok(page, compound_order(page)); | |
591 | } | |
592 | ||
593 | void prep_compound_page(struct page *page, unsigned int order) | |
594 | { | |
595 | int i; | |
596 | int nr_pages = 1 << order; | |
597 | ||
598 | set_compound_page_dtor(page, COMPOUND_PAGE_DTOR); | |
599 | set_compound_order(page, order); | |
600 | __SetPageHead(page); | |
601 | for (i = 1; i < nr_pages; i++) { | |
602 | struct page *p = page + i; | |
603 | set_page_count(p, 0); | |
604 | p->mapping = TAIL_MAPPING; | |
605 | set_compound_head(p, page); | |
606 | } | |
607 | atomic_set(compound_mapcount_ptr(page), -1); | |
608 | } | |
609 | ||
610 | #ifdef CONFIG_DEBUG_PAGEALLOC | |
611 | unsigned int _debug_guardpage_minorder; | |
612 | bool _debug_pagealloc_enabled __read_mostly | |
613 | = IS_ENABLED(CONFIG_DEBUG_PAGEALLOC_ENABLE_DEFAULT); | |
614 | EXPORT_SYMBOL(_debug_pagealloc_enabled); | |
615 | bool _debug_guardpage_enabled __read_mostly; | |
616 | ||
617 | static int __init early_debug_pagealloc(char *buf) | |
618 | { | |
619 | if (!buf) | |
620 | return -EINVAL; | |
621 | return kstrtobool(buf, &_debug_pagealloc_enabled); | |
622 | } | |
623 | early_param("debug_pagealloc", early_debug_pagealloc); | |
624 | ||
625 | static bool need_debug_guardpage(void) | |
626 | { | |
627 | /* If we don't use debug_pagealloc, we don't need guard page */ | |
628 | if (!debug_pagealloc_enabled()) | |
629 | return false; | |
630 | ||
631 | if (!debug_guardpage_minorder()) | |
632 | return false; | |
633 | ||
634 | return true; | |
635 | } | |
636 | ||
637 | static void init_debug_guardpage(void) | |
638 | { | |
639 | if (!debug_pagealloc_enabled()) | |
640 | return; | |
641 | ||
642 | if (!debug_guardpage_minorder()) | |
643 | return; | |
644 | ||
645 | _debug_guardpage_enabled = true; | |
646 | } | |
647 | ||
648 | struct page_ext_operations debug_guardpage_ops = { | |
649 | .need = need_debug_guardpage, | |
650 | .init = init_debug_guardpage, | |
651 | }; | |
652 | ||
653 | static int __init debug_guardpage_minorder_setup(char *buf) | |
654 | { | |
655 | unsigned long res; | |
656 | ||
657 | if (kstrtoul(buf, 10, &res) < 0 || res > MAX_ORDER / 2) { | |
658 | pr_err("Bad debug_guardpage_minorder value\n"); | |
659 | return 0; | |
660 | } | |
661 | _debug_guardpage_minorder = res; | |
662 | pr_info("Setting debug_guardpage_minorder to %lu\n", res); | |
663 | return 0; | |
664 | } | |
665 | early_param("debug_guardpage_minorder", debug_guardpage_minorder_setup); | |
666 | ||
667 | static inline bool set_page_guard(struct zone *zone, struct page *page, | |
668 | unsigned int order, int migratetype) | |
669 | { | |
670 | struct page_ext *page_ext; | |
671 | ||
672 | if (!debug_guardpage_enabled()) | |
673 | return false; | |
674 | ||
675 | if (order >= debug_guardpage_minorder()) | |
676 | return false; | |
677 | ||
678 | page_ext = lookup_page_ext(page); | |
679 | if (unlikely(!page_ext)) | |
680 | return false; | |
681 | ||
682 | __set_bit(PAGE_EXT_DEBUG_GUARD, &page_ext->flags); | |
683 | ||
684 | INIT_LIST_HEAD(&page->lru); | |
685 | set_page_private(page, order); | |
686 | /* Guard pages are not available for any usage */ | |
687 | __mod_zone_freepage_state(zone, -(1 << order), migratetype); | |
688 | ||
689 | return true; | |
690 | } | |
691 | ||
692 | static inline void clear_page_guard(struct zone *zone, struct page *page, | |
693 | unsigned int order, int migratetype) | |
694 | { | |
695 | struct page_ext *page_ext; | |
696 | ||
697 | if (!debug_guardpage_enabled()) | |
698 | return; | |
699 | ||
700 | page_ext = lookup_page_ext(page); | |
701 | if (unlikely(!page_ext)) | |
702 | return; | |
703 | ||
704 | __clear_bit(PAGE_EXT_DEBUG_GUARD, &page_ext->flags); | |
705 | ||
706 | set_page_private(page, 0); | |
707 | if (!is_migrate_isolate(migratetype)) | |
708 | __mod_zone_freepage_state(zone, (1 << order), migratetype); | |
709 | } | |
710 | #else | |
711 | struct page_ext_operations debug_guardpage_ops; | |
712 | static inline bool set_page_guard(struct zone *zone, struct page *page, | |
713 | unsigned int order, int migratetype) { return false; } | |
714 | static inline void clear_page_guard(struct zone *zone, struct page *page, | |
715 | unsigned int order, int migratetype) {} | |
716 | #endif | |
717 | ||
718 | static inline void set_page_order(struct page *page, unsigned int order) | |
719 | { | |
720 | set_page_private(page, order); | |
721 | __SetPageBuddy(page); | |
722 | } | |
723 | ||
724 | static inline void rmv_page_order(struct page *page) | |
725 | { | |
726 | __ClearPageBuddy(page); | |
727 | set_page_private(page, 0); | |
728 | } | |
729 | ||
730 | /* | |
731 | * This function checks whether a page is free && is the buddy | |
732 | * we can do coalesce a page and its buddy if | |
733 | * (a) the buddy is not in a hole (check before calling!) && | |
734 | * (b) the buddy is in the buddy system && | |
735 | * (c) a page and its buddy have the same order && | |
736 | * (d) a page and its buddy are in the same zone. | |
737 | * | |
738 | * For recording whether a page is in the buddy system, we set ->_mapcount | |
739 | * PAGE_BUDDY_MAPCOUNT_VALUE. | |
740 | * Setting, clearing, and testing _mapcount PAGE_BUDDY_MAPCOUNT_VALUE is | |
741 | * serialized by zone->lock. | |
742 | * | |
743 | * For recording page's order, we use page_private(page). | |
744 | */ | |
745 | static inline int page_is_buddy(struct page *page, struct page *buddy, | |
746 | unsigned int order) | |
747 | { | |
748 | if (page_is_guard(buddy) && page_order(buddy) == order) { | |
749 | if (page_zone_id(page) != page_zone_id(buddy)) | |
750 | return 0; | |
751 | ||
752 | VM_BUG_ON_PAGE(page_count(buddy) != 0, buddy); | |
753 | ||
754 | return 1; | |
755 | } | |
756 | ||
757 | if (PageBuddy(buddy) && page_order(buddy) == order) { | |
758 | /* | |
759 | * zone check is done late to avoid uselessly | |
760 | * calculating zone/node ids for pages that could | |
761 | * never merge. | |
762 | */ | |
763 | if (page_zone_id(page) != page_zone_id(buddy)) | |
764 | return 0; | |
765 | ||
766 | VM_BUG_ON_PAGE(page_count(buddy) != 0, buddy); | |
767 | ||
768 | return 1; | |
769 | } | |
770 | return 0; | |
771 | } | |
772 | ||
773 | /* | |
774 | * Freeing function for a buddy system allocator. | |
775 | * | |
776 | * The concept of a buddy system is to maintain direct-mapped table | |
777 | * (containing bit values) for memory blocks of various "orders". | |
778 | * The bottom level table contains the map for the smallest allocatable | |
779 | * units of memory (here, pages), and each level above it describes | |
780 | * pairs of units from the levels below, hence, "buddies". | |
781 | * At a high level, all that happens here is marking the table entry | |
782 | * at the bottom level available, and propagating the changes upward | |
783 | * as necessary, plus some accounting needed to play nicely with other | |
784 | * parts of the VM system. | |
785 | * At each level, we keep a list of pages, which are heads of continuous | |
786 | * free pages of length of (1 << order) and marked with _mapcount | |
787 | * PAGE_BUDDY_MAPCOUNT_VALUE. Page's order is recorded in page_private(page) | |
788 | * field. | |
789 | * So when we are allocating or freeing one, we can derive the state of the | |
790 | * other. That is, if we allocate a small block, and both were | |
791 | * free, the remainder of the region must be split into blocks. | |
792 | * If a block is freed, and its buddy is also free, then this | |
793 | * triggers coalescing into a block of larger size. | |
794 | * | |
795 | * -- nyc | |
796 | */ | |
797 | ||
798 | static inline void __free_one_page(struct page *page, | |
799 | unsigned long pfn, | |
800 | struct zone *zone, unsigned int order, | |
801 | int migratetype) | |
802 | { | |
803 | unsigned long combined_pfn; | |
804 | unsigned long uninitialized_var(buddy_pfn); | |
805 | struct page *buddy; | |
806 | unsigned int max_order; | |
807 | ||
808 | max_order = min_t(unsigned int, MAX_ORDER, pageblock_order + 1); | |
809 | ||
810 | VM_BUG_ON(!zone_is_initialized(zone)); | |
811 | VM_BUG_ON_PAGE(page->flags & PAGE_FLAGS_CHECK_AT_PREP, page); | |
812 | ||
813 | VM_BUG_ON(migratetype == -1); | |
814 | if (likely(!is_migrate_isolate(migratetype))) | |
815 | __mod_zone_freepage_state(zone, 1 << order, migratetype); | |
816 | ||
817 | VM_BUG_ON_PAGE(pfn & ((1 << order) - 1), page); | |
818 | VM_BUG_ON_PAGE(bad_range(zone, page), page); | |
819 | ||
820 | continue_merging: | |
821 | while (order < max_order - 1) { | |
822 | buddy_pfn = __find_buddy_pfn(pfn, order); | |
823 | buddy = page + (buddy_pfn - pfn); | |
824 | ||
825 | if (!pfn_valid_within(buddy_pfn)) | |
826 | goto done_merging; | |
827 | if (!page_is_buddy(page, buddy, order)) | |
828 | goto done_merging; | |
829 | /* | |
830 | * Our buddy is free or it is CONFIG_DEBUG_PAGEALLOC guard page, | |
831 | * merge with it and move up one order. | |
832 | */ | |
833 | if (page_is_guard(buddy)) { | |
834 | clear_page_guard(zone, buddy, order, migratetype); | |
835 | } else { | |
836 | list_del(&buddy->lru); | |
837 | zone->free_area[order].nr_free--; | |
838 | rmv_page_order(buddy); | |
839 | } | |
840 | combined_pfn = buddy_pfn & pfn; | |
841 | page = page + (combined_pfn - pfn); | |
842 | pfn = combined_pfn; | |
843 | order++; | |
844 | } | |
845 | if (max_order < MAX_ORDER) { | |
846 | /* If we are here, it means order is >= pageblock_order. | |
847 | * We want to prevent merge between freepages on isolate | |
848 | * pageblock and normal pageblock. Without this, pageblock | |
849 | * isolation could cause incorrect freepage or CMA accounting. | |
850 | * | |
851 | * We don't want to hit this code for the more frequent | |
852 | * low-order merging. | |
853 | */ | |
854 | if (unlikely(has_isolate_pageblock(zone))) { | |
855 | int buddy_mt; | |
856 | ||
857 | buddy_pfn = __find_buddy_pfn(pfn, order); | |
858 | buddy = page + (buddy_pfn - pfn); | |
859 | buddy_mt = get_pageblock_migratetype(buddy); | |
860 | ||
861 | if (migratetype != buddy_mt | |
862 | && (is_migrate_isolate(migratetype) || | |
863 | is_migrate_isolate(buddy_mt))) | |
864 | goto done_merging; | |
865 | } | |
866 | max_order++; | |
867 | goto continue_merging; | |
868 | } | |
869 | ||
870 | done_merging: | |
871 | set_page_order(page, order); | |
872 | ||
873 | /* | |
874 | * If this is not the largest possible page, check if the buddy | |
875 | * of the next-highest order is free. If it is, it's possible | |
876 | * that pages are being freed that will coalesce soon. In case, | |
877 | * that is happening, add the free page to the tail of the list | |
878 | * so it's less likely to be used soon and more likely to be merged | |
879 | * as a higher order page | |
880 | */ | |
881 | if ((order < MAX_ORDER-2) && pfn_valid_within(buddy_pfn)) { | |
882 | struct page *higher_page, *higher_buddy; | |
883 | combined_pfn = buddy_pfn & pfn; | |
884 | higher_page = page + (combined_pfn - pfn); | |
885 | buddy_pfn = __find_buddy_pfn(combined_pfn, order + 1); | |
886 | higher_buddy = higher_page + (buddy_pfn - combined_pfn); | |
887 | if (pfn_valid_within(buddy_pfn) && | |
888 | page_is_buddy(higher_page, higher_buddy, order + 1)) { | |
889 | list_add_tail(&page->lru, | |
890 | &zone->free_area[order].free_list[migratetype]); | |
891 | goto out; | |
892 | } | |
893 | } | |
894 | ||
895 | list_add(&page->lru, &zone->free_area[order].free_list[migratetype]); | |
896 | out: | |
897 | zone->free_area[order].nr_free++; | |
898 | } | |
899 | ||
900 | /* | |
901 | * A bad page could be due to a number of fields. Instead of multiple branches, | |
902 | * try and check multiple fields with one check. The caller must do a detailed | |
903 | * check if necessary. | |
904 | */ | |
905 | static inline bool page_expected_state(struct page *page, | |
906 | unsigned long check_flags) | |
907 | { | |
908 | if (unlikely(atomic_read(&page->_mapcount) != -1)) | |
909 | return false; | |
910 | ||
911 | if (unlikely((unsigned long)page->mapping | | |
912 | page_ref_count(page) | | |
913 | #ifdef CONFIG_MEMCG | |
914 | (unsigned long)page->mem_cgroup | | |
915 | #endif | |
916 | (page->flags & check_flags))) | |
917 | return false; | |
918 | ||
919 | return true; | |
920 | } | |
921 | ||
922 | static void free_pages_check_bad(struct page *page) | |
923 | { | |
924 | const char *bad_reason; | |
925 | unsigned long bad_flags; | |
926 | ||
927 | bad_reason = NULL; | |
928 | bad_flags = 0; | |
929 | ||
930 | if (unlikely(atomic_read(&page->_mapcount) != -1)) | |
931 | bad_reason = "nonzero mapcount"; | |
932 | if (unlikely(page->mapping != NULL)) | |
933 | bad_reason = "non-NULL mapping"; | |
934 | if (unlikely(page_ref_count(page) != 0)) | |
935 | bad_reason = "nonzero _refcount"; | |
936 | if (unlikely(page->flags & PAGE_FLAGS_CHECK_AT_FREE)) { | |
937 | bad_reason = "PAGE_FLAGS_CHECK_AT_FREE flag(s) set"; | |
938 | bad_flags = PAGE_FLAGS_CHECK_AT_FREE; | |
939 | } | |
940 | #ifdef CONFIG_MEMCG | |
941 | if (unlikely(page->mem_cgroup)) | |
942 | bad_reason = "page still charged to cgroup"; | |
943 | #endif | |
944 | bad_page(page, bad_reason, bad_flags); | |
945 | } | |
946 | ||
947 | static inline int free_pages_check(struct page *page) | |
948 | { | |
949 | if (likely(page_expected_state(page, PAGE_FLAGS_CHECK_AT_FREE))) | |
950 | return 0; | |
951 | ||
952 | /* Something has gone sideways, find it */ | |
953 | free_pages_check_bad(page); | |
954 | return 1; | |
955 | } | |
956 | ||
957 | static int free_tail_pages_check(struct page *head_page, struct page *page) | |
958 | { | |
959 | int ret = 1; | |
960 | ||
961 | /* | |
962 | * We rely page->lru.next never has bit 0 set, unless the page | |
963 | * is PageTail(). Let's make sure that's true even for poisoned ->lru. | |
964 | */ | |
965 | BUILD_BUG_ON((unsigned long)LIST_POISON1 & 1); | |
966 | ||
967 | if (!IS_ENABLED(CONFIG_DEBUG_VM)) { | |
968 | ret = 0; | |
969 | goto out; | |
970 | } | |
971 | switch (page - head_page) { | |
972 | case 1: | |
973 | /* the first tail page: ->mapping is compound_mapcount() */ | |
974 | if (unlikely(compound_mapcount(page))) { | |
975 | bad_page(page, "nonzero compound_mapcount", 0); | |
976 | goto out; | |
977 | } | |
978 | break; | |
979 | case 2: | |
980 | /* | |
981 | * the second tail page: ->mapping is | |
982 | * page_deferred_list().next -- ignore value. | |
983 | */ | |
984 | break; | |
985 | default: | |
986 | if (page->mapping != TAIL_MAPPING) { | |
987 | bad_page(page, "corrupted mapping in tail page", 0); | |
988 | goto out; | |
989 | } | |
990 | break; | |
991 | } | |
992 | if (unlikely(!PageTail(page))) { | |
993 | bad_page(page, "PageTail not set", 0); | |
994 | goto out; | |
995 | } | |
996 | if (unlikely(compound_head(page) != head_page)) { | |
997 | bad_page(page, "compound_head not consistent", 0); | |
998 | goto out; | |
999 | } | |
1000 | ret = 0; | |
1001 | out: | |
1002 | page->mapping = NULL; | |
1003 | clear_compound_head(page); | |
1004 | return ret; | |
1005 | } | |
1006 | ||
1007 | static __always_inline bool free_pages_prepare(struct page *page, | |
1008 | unsigned int order, bool check_free) | |
1009 | { | |
1010 | int bad = 0; | |
1011 | ||
1012 | VM_BUG_ON_PAGE(PageTail(page), page); | |
1013 | ||
1014 | trace_mm_page_free(page, order); | |
1015 | kmemcheck_free_shadow(page, order); | |
1016 | ||
1017 | /* | |
1018 | * Check tail pages before head page information is cleared to | |
1019 | * avoid checking PageCompound for order-0 pages. | |
1020 | */ | |
1021 | if (unlikely(order)) { | |
1022 | bool compound = PageCompound(page); | |
1023 | int i; | |
1024 | ||
1025 | VM_BUG_ON_PAGE(compound && compound_order(page) != order, page); | |
1026 | ||
1027 | if (compound) | |
1028 | ClearPageDoubleMap(page); | |
1029 | for (i = 1; i < (1 << order); i++) { | |
1030 | if (compound) | |
1031 | bad += free_tail_pages_check(page, page + i); | |
1032 | if (unlikely(free_pages_check(page + i))) { | |
1033 | bad++; | |
1034 | continue; | |
1035 | } | |
1036 | (page + i)->flags &= ~PAGE_FLAGS_CHECK_AT_PREP; | |
1037 | } | |
1038 | } | |
1039 | if (PageMappingFlags(page)) | |
1040 | page->mapping = NULL; | |
1041 | if (memcg_kmem_enabled() && PageKmemcg(page)) | |
1042 | memcg_kmem_uncharge(page, order); | |
1043 | if (check_free) | |
1044 | bad += free_pages_check(page); | |
1045 | if (bad) | |
1046 | return false; | |
1047 | ||
1048 | page_cpupid_reset_last(page); | |
1049 | page->flags &= ~PAGE_FLAGS_CHECK_AT_PREP; | |
1050 | reset_page_owner(page, order); | |
1051 | ||
1052 | if (!PageHighMem(page)) { | |
1053 | debug_check_no_locks_freed(page_address(page), | |
1054 | PAGE_SIZE << order); | |
1055 | debug_check_no_obj_freed(page_address(page), | |
1056 | PAGE_SIZE << order); | |
1057 | } | |
1058 | arch_free_page(page, order); | |
1059 | kernel_poison_pages(page, 1 << order, 0); | |
1060 | kernel_map_pages(page, 1 << order, 0); | |
1061 | kasan_free_pages(page, order); | |
1062 | ||
1063 | return true; | |
1064 | } | |
1065 | ||
1066 | #ifdef CONFIG_DEBUG_VM | |
1067 | static inline bool free_pcp_prepare(struct page *page) | |
1068 | { | |
1069 | return free_pages_prepare(page, 0, true); | |
1070 | } | |
1071 | ||
1072 | static inline bool bulkfree_pcp_prepare(struct page *page) | |
1073 | { | |
1074 | return false; | |
1075 | } | |
1076 | #else | |
1077 | static bool free_pcp_prepare(struct page *page) | |
1078 | { | |
1079 | return free_pages_prepare(page, 0, false); | |
1080 | } | |
1081 | ||
1082 | static bool bulkfree_pcp_prepare(struct page *page) | |
1083 | { | |
1084 | return free_pages_check(page); | |
1085 | } | |
1086 | #endif /* CONFIG_DEBUG_VM */ | |
1087 | ||
1088 | /* | |
1089 | * Frees a number of pages from the PCP lists | |
1090 | * Assumes all pages on list are in same zone, and of same order. | |
1091 | * count is the number of pages to free. | |
1092 | * | |
1093 | * If the zone was previously in an "all pages pinned" state then look to | |
1094 | * see if this freeing clears that state. | |
1095 | * | |
1096 | * And clear the zone's pages_scanned counter, to hold off the "all pages are | |
1097 | * pinned" detection logic. | |
1098 | */ | |
1099 | static void free_pcppages_bulk(struct zone *zone, int count, | |
1100 | struct per_cpu_pages *pcp) | |
1101 | { | |
1102 | int migratetype = 0; | |
1103 | int batch_free = 0; | |
1104 | bool isolated_pageblocks; | |
1105 | ||
1106 | spin_lock(&zone->lock); | |
1107 | isolated_pageblocks = has_isolate_pageblock(zone); | |
1108 | ||
1109 | while (count) { | |
1110 | struct page *page; | |
1111 | struct list_head *list; | |
1112 | ||
1113 | /* | |
1114 | * Remove pages from lists in a round-robin fashion. A | |
1115 | * batch_free count is maintained that is incremented when an | |
1116 | * empty list is encountered. This is so more pages are freed | |
1117 | * off fuller lists instead of spinning excessively around empty | |
1118 | * lists | |
1119 | */ | |
1120 | do { | |
1121 | batch_free++; | |
1122 | if (++migratetype == MIGRATE_PCPTYPES) | |
1123 | migratetype = 0; | |
1124 | list = &pcp->lists[migratetype]; | |
1125 | } while (list_empty(list)); | |
1126 | ||
1127 | /* This is the only non-empty list. Free them all. */ | |
1128 | if (batch_free == MIGRATE_PCPTYPES) | |
1129 | batch_free = count; | |
1130 | ||
1131 | do { | |
1132 | int mt; /* migratetype of the to-be-freed page */ | |
1133 | ||
1134 | page = list_last_entry(list, struct page, lru); | |
1135 | /* must delete as __free_one_page list manipulates */ | |
1136 | list_del(&page->lru); | |
1137 | ||
1138 | mt = get_pcppage_migratetype(page); | |
1139 | /* MIGRATE_ISOLATE page should not go to pcplists */ | |
1140 | VM_BUG_ON_PAGE(is_migrate_isolate(mt), page); | |
1141 | /* Pageblock could have been isolated meanwhile */ | |
1142 | if (unlikely(isolated_pageblocks)) | |
1143 | mt = get_pageblock_migratetype(page); | |
1144 | ||
1145 | if (bulkfree_pcp_prepare(page)) | |
1146 | continue; | |
1147 | ||
1148 | __free_one_page(page, page_to_pfn(page), zone, 0, mt); | |
1149 | trace_mm_page_pcpu_drain(page, 0, mt); | |
1150 | } while (--count && --batch_free && !list_empty(list)); | |
1151 | } | |
1152 | spin_unlock(&zone->lock); | |
1153 | } | |
1154 | ||
1155 | static void free_one_page(struct zone *zone, | |
1156 | struct page *page, unsigned long pfn, | |
1157 | unsigned int order, | |
1158 | int migratetype) | |
1159 | { | |
1160 | spin_lock(&zone->lock); | |
1161 | if (unlikely(has_isolate_pageblock(zone) || | |
1162 | is_migrate_isolate(migratetype))) { | |
1163 | migratetype = get_pfnblock_migratetype(page, pfn); | |
1164 | } | |
1165 | __free_one_page(page, pfn, zone, order, migratetype); | |
1166 | spin_unlock(&zone->lock); | |
1167 | } | |
1168 | ||
1169 | static void __meminit __init_single_page(struct page *page, unsigned long pfn, | |
1170 | unsigned long zone, int nid) | |
1171 | { | |
1172 | set_page_links(page, zone, nid, pfn); | |
1173 | init_page_count(page); | |
1174 | page_mapcount_reset(page); | |
1175 | page_cpupid_reset_last(page); | |
1176 | ||
1177 | INIT_LIST_HEAD(&page->lru); | |
1178 | #ifdef WANT_PAGE_VIRTUAL | |
1179 | /* The shift won't overflow because ZONE_NORMAL is below 4G. */ | |
1180 | if (!is_highmem_idx(zone)) | |
1181 | set_page_address(page, __va(pfn << PAGE_SHIFT)); | |
1182 | #endif | |
1183 | } | |
1184 | ||
1185 | static void __meminit __init_single_pfn(unsigned long pfn, unsigned long zone, | |
1186 | int nid) | |
1187 | { | |
1188 | return __init_single_page(pfn_to_page(pfn), pfn, zone, nid); | |
1189 | } | |
1190 | ||
1191 | #ifdef CONFIG_DEFERRED_STRUCT_PAGE_INIT | |
1192 | static void init_reserved_page(unsigned long pfn) | |
1193 | { | |
1194 | pg_data_t *pgdat; | |
1195 | int nid, zid; | |
1196 | ||
1197 | if (!early_page_uninitialised(pfn)) | |
1198 | return; | |
1199 | ||
1200 | nid = early_pfn_to_nid(pfn); | |
1201 | pgdat = NODE_DATA(nid); | |
1202 | ||
1203 | for (zid = 0; zid < MAX_NR_ZONES; zid++) { | |
1204 | struct zone *zone = &pgdat->node_zones[zid]; | |
1205 | ||
1206 | if (pfn >= zone->zone_start_pfn && pfn < zone_end_pfn(zone)) | |
1207 | break; | |
1208 | } | |
1209 | __init_single_pfn(pfn, zid, nid); | |
1210 | } | |
1211 | #else | |
1212 | static inline void init_reserved_page(unsigned long pfn) | |
1213 | { | |
1214 | } | |
1215 | #endif /* CONFIG_DEFERRED_STRUCT_PAGE_INIT */ | |
1216 | ||
1217 | /* | |
1218 | * Initialised pages do not have PageReserved set. This function is | |
1219 | * called for each range allocated by the bootmem allocator and | |
1220 | * marks the pages PageReserved. The remaining valid pages are later | |
1221 | * sent to the buddy page allocator. | |
1222 | */ | |
1223 | void __meminit reserve_bootmem_region(phys_addr_t start, phys_addr_t end) | |
1224 | { | |
1225 | unsigned long start_pfn = PFN_DOWN(start); | |
1226 | unsigned long end_pfn = PFN_UP(end); | |
1227 | ||
1228 | for (; start_pfn < end_pfn; start_pfn++) { | |
1229 | if (pfn_valid(start_pfn)) { | |
1230 | struct page *page = pfn_to_page(start_pfn); | |
1231 | ||
1232 | init_reserved_page(start_pfn); | |
1233 | ||
1234 | /* Avoid false-positive PageTail() */ | |
1235 | INIT_LIST_HEAD(&page->lru); | |
1236 | ||
1237 | SetPageReserved(page); | |
1238 | } | |
1239 | } | |
1240 | } | |
1241 | ||
1242 | static void __free_pages_ok(struct page *page, unsigned int order) | |
1243 | { | |
1244 | unsigned long flags; | |
1245 | int migratetype; | |
1246 | unsigned long pfn = page_to_pfn(page); | |
1247 | ||
1248 | if (!free_pages_prepare(page, order, true)) | |
1249 | return; | |
1250 | ||
1251 | migratetype = get_pfnblock_migratetype(page, pfn); | |
1252 | local_irq_save(flags); | |
1253 | __count_vm_events(PGFREE, 1 << order); | |
1254 | free_one_page(page_zone(page), page, pfn, order, migratetype); | |
1255 | local_irq_restore(flags); | |
1256 | } | |
1257 | ||
1258 | static void __init __free_pages_boot_core(struct page *page, unsigned int order) | |
1259 | { | |
1260 | unsigned int nr_pages = 1 << order; | |
1261 | struct page *p = page; | |
1262 | unsigned int loop; | |
1263 | ||
1264 | prefetchw(p); | |
1265 | for (loop = 0; loop < (nr_pages - 1); loop++, p++) { | |
1266 | prefetchw(p + 1); | |
1267 | __ClearPageReserved(p); | |
1268 | set_page_count(p, 0); | |
1269 | } | |
1270 | __ClearPageReserved(p); | |
1271 | set_page_count(p, 0); | |
1272 | ||
1273 | page_zone(page)->managed_pages += nr_pages; | |
1274 | set_page_refcounted(page); | |
1275 | __free_pages(page, order); | |
1276 | } | |
1277 | ||
1278 | #if defined(CONFIG_HAVE_ARCH_EARLY_PFN_TO_NID) || \ | |
1279 | defined(CONFIG_HAVE_MEMBLOCK_NODE_MAP) | |
1280 | ||
1281 | static struct mminit_pfnnid_cache early_pfnnid_cache __meminitdata; | |
1282 | ||
1283 | int __meminit early_pfn_to_nid(unsigned long pfn) | |
1284 | { | |
1285 | static DEFINE_SPINLOCK(early_pfn_lock); | |
1286 | int nid; | |
1287 | ||
1288 | spin_lock(&early_pfn_lock); | |
1289 | nid = __early_pfn_to_nid(pfn, &early_pfnnid_cache); | |
1290 | if (nid < 0) | |
1291 | nid = first_online_node; | |
1292 | spin_unlock(&early_pfn_lock); | |
1293 | ||
1294 | return nid; | |
1295 | } | |
1296 | #endif | |
1297 | ||
1298 | #ifdef CONFIG_NODES_SPAN_OTHER_NODES | |
1299 | static inline bool __meminit __maybe_unused | |
1300 | meminit_pfn_in_nid(unsigned long pfn, int node, | |
1301 | struct mminit_pfnnid_cache *state) | |
1302 | { | |
1303 | int nid; | |
1304 | ||
1305 | nid = __early_pfn_to_nid(pfn, state); | |
1306 | if (nid >= 0 && nid != node) | |
1307 | return false; | |
1308 | return true; | |
1309 | } | |
1310 | ||
1311 | /* Only safe to use early in boot when initialisation is single-threaded */ | |
1312 | static inline bool __meminit early_pfn_in_nid(unsigned long pfn, int node) | |
1313 | { | |
1314 | return meminit_pfn_in_nid(pfn, node, &early_pfnnid_cache); | |
1315 | } | |
1316 | ||
1317 | #else | |
1318 | ||
1319 | static inline bool __meminit early_pfn_in_nid(unsigned long pfn, int node) | |
1320 | { | |
1321 | return true; | |
1322 | } | |
1323 | static inline bool __meminit __maybe_unused | |
1324 | meminit_pfn_in_nid(unsigned long pfn, int node, | |
1325 | struct mminit_pfnnid_cache *state) | |
1326 | { | |
1327 | return true; | |
1328 | } | |
1329 | #endif | |
1330 | ||
1331 | ||
1332 | void __init __free_pages_bootmem(struct page *page, unsigned long pfn, | |
1333 | unsigned int order) | |
1334 | { | |
1335 | if (early_page_uninitialised(pfn)) | |
1336 | return; | |
1337 | return __free_pages_boot_core(page, order); | |
1338 | } | |
1339 | ||
1340 | /* | |
1341 | * Check that the whole (or subset of) a pageblock given by the interval of | |
1342 | * [start_pfn, end_pfn) is valid and within the same zone, before scanning it | |
1343 | * with the migration of free compaction scanner. The scanners then need to | |
1344 | * use only pfn_valid_within() check for arches that allow holes within | |
1345 | * pageblocks. | |
1346 | * | |
1347 | * Return struct page pointer of start_pfn, or NULL if checks were not passed. | |
1348 | * | |
1349 | * It's possible on some configurations to have a setup like node0 node1 node0 | |
1350 | * i.e. it's possible that all pages within a zones range of pages do not | |
1351 | * belong to a single zone. We assume that a border between node0 and node1 | |
1352 | * can occur within a single pageblock, but not a node0 node1 node0 | |
1353 | * interleaving within a single pageblock. It is therefore sufficient to check | |
1354 | * the first and last page of a pageblock and avoid checking each individual | |
1355 | * page in a pageblock. | |
1356 | */ | |
1357 | struct page *__pageblock_pfn_to_page(unsigned long start_pfn, | |
1358 | unsigned long end_pfn, struct zone *zone) | |
1359 | { | |
1360 | struct page *start_page; | |
1361 | struct page *end_page; | |
1362 | ||
1363 | /* end_pfn is one past the range we are checking */ | |
1364 | end_pfn--; | |
1365 | ||
1366 | if (!pfn_valid(start_pfn) || !pfn_valid(end_pfn)) | |
1367 | return NULL; | |
1368 | ||
1369 | start_page = pfn_to_online_page(start_pfn); | |
1370 | if (!start_page) | |
1371 | return NULL; | |
1372 | ||
1373 | if (page_zone(start_page) != zone) | |
1374 | return NULL; | |
1375 | ||
1376 | end_page = pfn_to_page(end_pfn); | |
1377 | ||
1378 | /* This gives a shorter code than deriving page_zone(end_page) */ | |
1379 | if (page_zone_id(start_page) != page_zone_id(end_page)) | |
1380 | return NULL; | |
1381 | ||
1382 | return start_page; | |
1383 | } | |
1384 | ||
1385 | void set_zone_contiguous(struct zone *zone) | |
1386 | { | |
1387 | unsigned long block_start_pfn = zone->zone_start_pfn; | |
1388 | unsigned long block_end_pfn; | |
1389 | ||
1390 | block_end_pfn = ALIGN(block_start_pfn + 1, pageblock_nr_pages); | |
1391 | for (; block_start_pfn < zone_end_pfn(zone); | |
1392 | block_start_pfn = block_end_pfn, | |
1393 | block_end_pfn += pageblock_nr_pages) { | |
1394 | ||
1395 | block_end_pfn = min(block_end_pfn, zone_end_pfn(zone)); | |
1396 | ||
1397 | if (!__pageblock_pfn_to_page(block_start_pfn, | |
1398 | block_end_pfn, zone)) | |
1399 | return; | |
1400 | } | |
1401 | ||
1402 | /* We confirm that there is no hole */ | |
1403 | zone->contiguous = true; | |
1404 | } | |
1405 | ||
1406 | void clear_zone_contiguous(struct zone *zone) | |
1407 | { | |
1408 | zone->contiguous = false; | |
1409 | } | |
1410 | ||
1411 | #ifdef CONFIG_DEFERRED_STRUCT_PAGE_INIT | |
1412 | static void __init deferred_free_range(struct page *page, | |
1413 | unsigned long pfn, int nr_pages) | |
1414 | { | |
1415 | int i; | |
1416 | ||
1417 | if (!page) | |
1418 | return; | |
1419 | ||
1420 | /* Free a large naturally-aligned chunk if possible */ | |
1421 | if (nr_pages == pageblock_nr_pages && | |
1422 | (pfn & (pageblock_nr_pages - 1)) == 0) { | |
1423 | set_pageblock_migratetype(page, MIGRATE_MOVABLE); | |
1424 | __free_pages_boot_core(page, pageblock_order); | |
1425 | return; | |
1426 | } | |
1427 | ||
1428 | for (i = 0; i < nr_pages; i++, page++, pfn++) { | |
1429 | if ((pfn & (pageblock_nr_pages - 1)) == 0) | |
1430 | set_pageblock_migratetype(page, MIGRATE_MOVABLE); | |
1431 | __free_pages_boot_core(page, 0); | |
1432 | } | |
1433 | } | |
1434 | ||
1435 | /* Completion tracking for deferred_init_memmap() threads */ | |
1436 | static atomic_t pgdat_init_n_undone __initdata; | |
1437 | static __initdata DECLARE_COMPLETION(pgdat_init_all_done_comp); | |
1438 | ||
1439 | static inline void __init pgdat_init_report_one_done(void) | |
1440 | { | |
1441 | if (atomic_dec_and_test(&pgdat_init_n_undone)) | |
1442 | complete(&pgdat_init_all_done_comp); | |
1443 | } | |
1444 | ||
1445 | /* Initialise remaining memory on a node */ | |
1446 | static int __init deferred_init_memmap(void *data) | |
1447 | { | |
1448 | pg_data_t *pgdat = data; | |
1449 | int nid = pgdat->node_id; | |
1450 | struct mminit_pfnnid_cache nid_init_state = { }; | |
1451 | unsigned long start = jiffies; | |
1452 | unsigned long nr_pages = 0; | |
1453 | unsigned long walk_start, walk_end; | |
1454 | int i, zid; | |
1455 | struct zone *zone; | |
1456 | unsigned long first_init_pfn = pgdat->first_deferred_pfn; | |
1457 | const struct cpumask *cpumask = cpumask_of_node(pgdat->node_id); | |
1458 | ||
1459 | if (first_init_pfn == ULONG_MAX) { | |
1460 | pgdat_init_report_one_done(); | |
1461 | return 0; | |
1462 | } | |
1463 | ||
1464 | /* Bind memory initialisation thread to a local node if possible */ | |
1465 | if (!cpumask_empty(cpumask)) | |
1466 | set_cpus_allowed_ptr(current, cpumask); | |
1467 | ||
1468 | /* Sanity check boundaries */ | |
1469 | BUG_ON(pgdat->first_deferred_pfn < pgdat->node_start_pfn); | |
1470 | BUG_ON(pgdat->first_deferred_pfn > pgdat_end_pfn(pgdat)); | |
1471 | pgdat->first_deferred_pfn = ULONG_MAX; | |
1472 | ||
1473 | /* Only the highest zone is deferred so find it */ | |
1474 | for (zid = 0; zid < MAX_NR_ZONES; zid++) { | |
1475 | zone = pgdat->node_zones + zid; | |
1476 | if (first_init_pfn < zone_end_pfn(zone)) | |
1477 | break; | |
1478 | } | |
1479 | ||
1480 | for_each_mem_pfn_range(i, nid, &walk_start, &walk_end, NULL) { | |
1481 | unsigned long pfn, end_pfn; | |
1482 | struct page *page = NULL; | |
1483 | struct page *free_base_page = NULL; | |
1484 | unsigned long free_base_pfn = 0; | |
1485 | int nr_to_free = 0; | |
1486 | ||
1487 | end_pfn = min(walk_end, zone_end_pfn(zone)); | |
1488 | pfn = first_init_pfn; | |
1489 | if (pfn < walk_start) | |
1490 | pfn = walk_start; | |
1491 | if (pfn < zone->zone_start_pfn) | |
1492 | pfn = zone->zone_start_pfn; | |
1493 | ||
1494 | for (; pfn < end_pfn; pfn++) { | |
1495 | if (!pfn_valid_within(pfn)) | |
1496 | goto free_range; | |
1497 | ||
1498 | /* | |
1499 | * Ensure pfn_valid is checked every | |
1500 | * pageblock_nr_pages for memory holes | |
1501 | */ | |
1502 | if ((pfn & (pageblock_nr_pages - 1)) == 0) { | |
1503 | if (!pfn_valid(pfn)) { | |
1504 | page = NULL; | |
1505 | goto free_range; | |
1506 | } | |
1507 | } | |
1508 | ||
1509 | if (!meminit_pfn_in_nid(pfn, nid, &nid_init_state)) { | |
1510 | page = NULL; | |
1511 | goto free_range; | |
1512 | } | |
1513 | ||
1514 | /* Minimise pfn page lookups and scheduler checks */ | |
1515 | if (page && (pfn & (pageblock_nr_pages - 1)) != 0) { | |
1516 | page++; | |
1517 | } else { | |
1518 | nr_pages += nr_to_free; | |
1519 | deferred_free_range(free_base_page, | |
1520 | free_base_pfn, nr_to_free); | |
1521 | free_base_page = NULL; | |
1522 | free_base_pfn = nr_to_free = 0; | |
1523 | ||
1524 | page = pfn_to_page(pfn); | |
1525 | cond_resched(); | |
1526 | } | |
1527 | ||
1528 | if (page->flags) { | |
1529 | VM_BUG_ON(page_zone(page) != zone); | |
1530 | goto free_range; | |
1531 | } | |
1532 | ||
1533 | __init_single_page(page, pfn, zid, nid); | |
1534 | if (!free_base_page) { | |
1535 | free_base_page = page; | |
1536 | free_base_pfn = pfn; | |
1537 | nr_to_free = 0; | |
1538 | } | |
1539 | nr_to_free++; | |
1540 | ||
1541 | /* Where possible, batch up pages for a single free */ | |
1542 | continue; | |
1543 | free_range: | |
1544 | /* Free the current block of pages to allocator */ | |
1545 | nr_pages += nr_to_free; | |
1546 | deferred_free_range(free_base_page, free_base_pfn, | |
1547 | nr_to_free); | |
1548 | free_base_page = NULL; | |
1549 | free_base_pfn = nr_to_free = 0; | |
1550 | } | |
1551 | /* Free the last block of pages to allocator */ | |
1552 | nr_pages += nr_to_free; | |
1553 | deferred_free_range(free_base_page, free_base_pfn, nr_to_free); | |
1554 | ||
1555 | first_init_pfn = max(end_pfn, first_init_pfn); | |
1556 | } | |
1557 | ||
1558 | /* Sanity check that the next zone really is unpopulated */ | |
1559 | WARN_ON(++zid < MAX_NR_ZONES && populated_zone(++zone)); | |
1560 | ||
1561 | pr_info("node %d initialised, %lu pages in %ums\n", nid, nr_pages, | |
1562 | jiffies_to_msecs(jiffies - start)); | |
1563 | ||
1564 | pgdat_init_report_one_done(); | |
1565 | return 0; | |
1566 | } | |
1567 | #endif /* CONFIG_DEFERRED_STRUCT_PAGE_INIT */ | |
1568 | ||
1569 | void __init page_alloc_init_late(void) | |
1570 | { | |
1571 | struct zone *zone; | |
1572 | ||
1573 | #ifdef CONFIG_DEFERRED_STRUCT_PAGE_INIT | |
1574 | int nid; | |
1575 | ||
1576 | /* There will be num_node_state(N_MEMORY) threads */ | |
1577 | atomic_set(&pgdat_init_n_undone, num_node_state(N_MEMORY)); | |
1578 | for_each_node_state(nid, N_MEMORY) { | |
1579 | kthread_run(deferred_init_memmap, NODE_DATA(nid), "pgdatinit%d", nid); | |
1580 | } | |
1581 | ||
1582 | /* Block until all are initialised */ | |
1583 | wait_for_completion(&pgdat_init_all_done_comp); | |
1584 | ||
1585 | /* Reinit limits that are based on free pages after the kernel is up */ | |
1586 | files_maxfiles_init(); | |
1587 | #endif | |
1588 | #ifdef CONFIG_ARCH_DISCARD_MEMBLOCK | |
1589 | /* Discard memblock private memory */ | |
1590 | memblock_discard(); | |
1591 | #endif | |
1592 | ||
1593 | for_each_populated_zone(zone) | |
1594 | set_zone_contiguous(zone); | |
1595 | } | |
1596 | ||
1597 | #ifdef CONFIG_CMA | |
1598 | /* Free whole pageblock and set its migration type to MIGRATE_CMA. */ | |
1599 | void __init init_cma_reserved_pageblock(struct page *page) | |
1600 | { | |
1601 | unsigned i = pageblock_nr_pages; | |
1602 | struct page *p = page; | |
1603 | ||
1604 | do { | |
1605 | __ClearPageReserved(p); | |
1606 | set_page_count(p, 0); | |
1607 | } while (++p, --i); | |
1608 | ||
1609 | set_pageblock_migratetype(page, MIGRATE_CMA); | |
1610 | ||
1611 | if (pageblock_order >= MAX_ORDER) { | |
1612 | i = pageblock_nr_pages; | |
1613 | p = page; | |
1614 | do { | |
1615 | set_page_refcounted(p); | |
1616 | __free_pages(p, MAX_ORDER - 1); | |
1617 | p += MAX_ORDER_NR_PAGES; | |
1618 | } while (i -= MAX_ORDER_NR_PAGES); | |
1619 | } else { | |
1620 | set_page_refcounted(page); | |
1621 | __free_pages(page, pageblock_order); | |
1622 | } | |
1623 | ||
1624 | adjust_managed_page_count(page, pageblock_nr_pages); | |
1625 | } | |
1626 | #endif | |
1627 | ||
1628 | /* | |
1629 | * The order of subdivision here is critical for the IO subsystem. | |
1630 | * Please do not alter this order without good reasons and regression | |
1631 | * testing. Specifically, as large blocks of memory are subdivided, | |
1632 | * the order in which smaller blocks are delivered depends on the order | |
1633 | * they're subdivided in this function. This is the primary factor | |
1634 | * influencing the order in which pages are delivered to the IO | |
1635 | * subsystem according to empirical testing, and this is also justified | |
1636 | * by considering the behavior of a buddy system containing a single | |
1637 | * large block of memory acted on by a series of small allocations. | |
1638 | * This behavior is a critical factor in sglist merging's success. | |
1639 | * | |
1640 | * -- nyc | |
1641 | */ | |
1642 | static inline void expand(struct zone *zone, struct page *page, | |
1643 | int low, int high, struct free_area *area, | |
1644 | int migratetype) | |
1645 | { | |
1646 | unsigned long size = 1 << high; | |
1647 | ||
1648 | while (high > low) { | |
1649 | area--; | |
1650 | high--; | |
1651 | size >>= 1; | |
1652 | VM_BUG_ON_PAGE(bad_range(zone, &page[size]), &page[size]); | |
1653 | ||
1654 | /* | |
1655 | * Mark as guard pages (or page), that will allow to | |
1656 | * merge back to allocator when buddy will be freed. | |
1657 | * Corresponding page table entries will not be touched, | |
1658 | * pages will stay not present in virtual address space | |
1659 | */ | |
1660 | if (set_page_guard(zone, &page[size], high, migratetype)) | |
1661 | continue; | |
1662 | ||
1663 | list_add(&page[size].lru, &area->free_list[migratetype]); | |
1664 | area->nr_free++; | |
1665 | set_page_order(&page[size], high); | |
1666 | } | |
1667 | } | |
1668 | ||
1669 | static void check_new_page_bad(struct page *page) | |
1670 | { | |
1671 | const char *bad_reason = NULL; | |
1672 | unsigned long bad_flags = 0; | |
1673 | ||
1674 | if (unlikely(atomic_read(&page->_mapcount) != -1)) | |
1675 | bad_reason = "nonzero mapcount"; | |
1676 | if (unlikely(page->mapping != NULL)) | |
1677 | bad_reason = "non-NULL mapping"; | |
1678 | if (unlikely(page_ref_count(page) != 0)) | |
1679 | bad_reason = "nonzero _count"; | |
1680 | if (unlikely(page->flags & __PG_HWPOISON)) { | |
1681 | bad_reason = "HWPoisoned (hardware-corrupted)"; | |
1682 | bad_flags = __PG_HWPOISON; | |
1683 | /* Don't complain about hwpoisoned pages */ | |
1684 | page_mapcount_reset(page); /* remove PageBuddy */ | |
1685 | return; | |
1686 | } | |
1687 | if (unlikely(page->flags & PAGE_FLAGS_CHECK_AT_PREP)) { | |
1688 | bad_reason = "PAGE_FLAGS_CHECK_AT_PREP flag set"; | |
1689 | bad_flags = PAGE_FLAGS_CHECK_AT_PREP; | |
1690 | } | |
1691 | #ifdef CONFIG_MEMCG | |
1692 | if (unlikely(page->mem_cgroup)) | |
1693 | bad_reason = "page still charged to cgroup"; | |
1694 | #endif | |
1695 | bad_page(page, bad_reason, bad_flags); | |
1696 | } | |
1697 | ||
1698 | /* | |
1699 | * This page is about to be returned from the page allocator | |
1700 | */ | |
1701 | static inline int check_new_page(struct page *page) | |
1702 | { | |
1703 | if (likely(page_expected_state(page, | |
1704 | PAGE_FLAGS_CHECK_AT_PREP|__PG_HWPOISON))) | |
1705 | return 0; | |
1706 | ||
1707 | check_new_page_bad(page); | |
1708 | return 1; | |
1709 | } | |
1710 | ||
1711 | static inline bool free_pages_prezeroed(void) | |
1712 | { | |
1713 | return IS_ENABLED(CONFIG_PAGE_POISONING_ZERO) && | |
1714 | page_poisoning_enabled(); | |
1715 | } | |
1716 | ||
1717 | #ifdef CONFIG_DEBUG_VM | |
1718 | static bool check_pcp_refill(struct page *page) | |
1719 | { | |
1720 | return false; | |
1721 | } | |
1722 | ||
1723 | static bool check_new_pcp(struct page *page) | |
1724 | { | |
1725 | return check_new_page(page); | |
1726 | } | |
1727 | #else | |
1728 | static bool check_pcp_refill(struct page *page) | |
1729 | { | |
1730 | return check_new_page(page); | |
1731 | } | |
1732 | static bool check_new_pcp(struct page *page) | |
1733 | { | |
1734 | return false; | |
1735 | } | |
1736 | #endif /* CONFIG_DEBUG_VM */ | |
1737 | ||
1738 | static bool check_new_pages(struct page *page, unsigned int order) | |
1739 | { | |
1740 | int i; | |
1741 | for (i = 0; i < (1 << order); i++) { | |
1742 | struct page *p = page + i; | |
1743 | ||
1744 | if (unlikely(check_new_page(p))) | |
1745 | return true; | |
1746 | } | |
1747 | ||
1748 | return false; | |
1749 | } | |
1750 | ||
1751 | inline void post_alloc_hook(struct page *page, unsigned int order, | |
1752 | gfp_t gfp_flags) | |
1753 | { | |
1754 | set_page_private(page, 0); | |
1755 | set_page_refcounted(page); | |
1756 | ||
1757 | arch_alloc_page(page, order); | |
1758 | kernel_map_pages(page, 1 << order, 1); | |
1759 | kernel_poison_pages(page, 1 << order, 1); | |
1760 | kasan_alloc_pages(page, order); | |
1761 | set_page_owner(page, order, gfp_flags); | |
1762 | } | |
1763 | ||
1764 | static void prep_new_page(struct page *page, unsigned int order, gfp_t gfp_flags, | |
1765 | unsigned int alloc_flags) | |
1766 | { | |
1767 | int i; | |
1768 | ||
1769 | post_alloc_hook(page, order, gfp_flags); | |
1770 | ||
1771 | if (!free_pages_prezeroed() && (gfp_flags & __GFP_ZERO)) | |
1772 | for (i = 0; i < (1 << order); i++) | |
1773 | clear_highpage(page + i); | |
1774 | ||
1775 | if (order && (gfp_flags & __GFP_COMP)) | |
1776 | prep_compound_page(page, order); | |
1777 | ||
1778 | /* | |
1779 | * page is set pfmemalloc when ALLOC_NO_WATERMARKS was necessary to | |
1780 | * allocate the page. The expectation is that the caller is taking | |
1781 | * steps that will free more memory. The caller should avoid the page | |
1782 | * being used for !PFMEMALLOC purposes. | |
1783 | */ | |
1784 | if (alloc_flags & ALLOC_NO_WATERMARKS) | |
1785 | set_page_pfmemalloc(page); | |
1786 | else | |
1787 | clear_page_pfmemalloc(page); | |
1788 | } | |
1789 | ||
1790 | /* | |
1791 | * Go through the free lists for the given migratetype and remove | |
1792 | * the smallest available page from the freelists | |
1793 | */ | |
1794 | static inline | |
1795 | struct page *__rmqueue_smallest(struct zone *zone, unsigned int order, | |
1796 | int migratetype) | |
1797 | { | |
1798 | unsigned int current_order; | |
1799 | struct free_area *area; | |
1800 | struct page *page; | |
1801 | ||
1802 | /* Find a page of the appropriate size in the preferred list */ | |
1803 | for (current_order = order; current_order < MAX_ORDER; ++current_order) { | |
1804 | area = &(zone->free_area[current_order]); | |
1805 | page = list_first_entry_or_null(&area->free_list[migratetype], | |
1806 | struct page, lru); | |
1807 | if (!page) | |
1808 | continue; | |
1809 | list_del(&page->lru); | |
1810 | rmv_page_order(page); | |
1811 | area->nr_free--; | |
1812 | expand(zone, page, order, current_order, area, migratetype); | |
1813 | set_pcppage_migratetype(page, migratetype); | |
1814 | return page; | |
1815 | } | |
1816 | ||
1817 | return NULL; | |
1818 | } | |
1819 | ||
1820 | ||
1821 | /* | |
1822 | * This array describes the order lists are fallen back to when | |
1823 | * the free lists for the desirable migrate type are depleted | |
1824 | */ | |
1825 | static int fallbacks[MIGRATE_TYPES][4] = { | |
1826 | [MIGRATE_UNMOVABLE] = { MIGRATE_RECLAIMABLE, MIGRATE_MOVABLE, MIGRATE_TYPES }, | |
1827 | [MIGRATE_RECLAIMABLE] = { MIGRATE_UNMOVABLE, MIGRATE_MOVABLE, MIGRATE_TYPES }, | |
1828 | [MIGRATE_MOVABLE] = { MIGRATE_RECLAIMABLE, MIGRATE_UNMOVABLE, MIGRATE_TYPES }, | |
1829 | #ifdef CONFIG_CMA | |
1830 | [MIGRATE_CMA] = { MIGRATE_TYPES }, /* Never used */ | |
1831 | #endif | |
1832 | #ifdef CONFIG_MEMORY_ISOLATION | |
1833 | [MIGRATE_ISOLATE] = { MIGRATE_TYPES }, /* Never used */ | |
1834 | #endif | |
1835 | }; | |
1836 | ||
1837 | #ifdef CONFIG_CMA | |
1838 | static struct page *__rmqueue_cma_fallback(struct zone *zone, | |
1839 | unsigned int order) | |
1840 | { | |
1841 | return __rmqueue_smallest(zone, order, MIGRATE_CMA); | |
1842 | } | |
1843 | #else | |
1844 | static inline struct page *__rmqueue_cma_fallback(struct zone *zone, | |
1845 | unsigned int order) { return NULL; } | |
1846 | #endif | |
1847 | ||
1848 | /* | |
1849 | * Move the free pages in a range to the free lists of the requested type. | |
1850 | * Note that start_page and end_pages are not aligned on a pageblock | |
1851 | * boundary. If alignment is required, use move_freepages_block() | |
1852 | */ | |
1853 | static int move_freepages(struct zone *zone, | |
1854 | struct page *start_page, struct page *end_page, | |
1855 | int migratetype, int *num_movable) | |
1856 | { | |
1857 | struct page *page; | |
1858 | unsigned int order; | |
1859 | int pages_moved = 0; | |
1860 | ||
1861 | #ifndef CONFIG_HOLES_IN_ZONE | |
1862 | /* | |
1863 | * page_zone is not safe to call in this context when | |
1864 | * CONFIG_HOLES_IN_ZONE is set. This bug check is probably redundant | |
1865 | * anyway as we check zone boundaries in move_freepages_block(). | |
1866 | * Remove at a later date when no bug reports exist related to | |
1867 | * grouping pages by mobility | |
1868 | */ | |
1869 | VM_BUG_ON(page_zone(start_page) != page_zone(end_page)); | |
1870 | #endif | |
1871 | ||
1872 | if (num_movable) | |
1873 | *num_movable = 0; | |
1874 | ||
1875 | for (page = start_page; page <= end_page;) { | |
1876 | if (!pfn_valid_within(page_to_pfn(page))) { | |
1877 | page++; | |
1878 | continue; | |
1879 | } | |
1880 | ||
1881 | /* Make sure we are not inadvertently changing nodes */ | |
1882 | VM_BUG_ON_PAGE(page_to_nid(page) != zone_to_nid(zone), page); | |
1883 | ||
1884 | if (!PageBuddy(page)) { | |
1885 | /* | |
1886 | * We assume that pages that could be isolated for | |
1887 | * migration are movable. But we don't actually try | |
1888 | * isolating, as that would be expensive. | |
1889 | */ | |
1890 | if (num_movable && | |
1891 | (PageLRU(page) || __PageMovable(page))) | |
1892 | (*num_movable)++; | |
1893 | ||
1894 | page++; | |
1895 | continue; | |
1896 | } | |
1897 | ||
1898 | order = page_order(page); | |
1899 | list_move(&page->lru, | |
1900 | &zone->free_area[order].free_list[migratetype]); | |
1901 | page += 1 << order; | |
1902 | pages_moved += 1 << order; | |
1903 | } | |
1904 | ||
1905 | return pages_moved; | |
1906 | } | |
1907 | ||
1908 | int move_freepages_block(struct zone *zone, struct page *page, | |
1909 | int migratetype, int *num_movable) | |
1910 | { | |
1911 | unsigned long start_pfn, end_pfn; | |
1912 | struct page *start_page, *end_page; | |
1913 | ||
1914 | start_pfn = page_to_pfn(page); | |
1915 | start_pfn = start_pfn & ~(pageblock_nr_pages-1); | |
1916 | start_page = pfn_to_page(start_pfn); | |
1917 | end_page = start_page + pageblock_nr_pages - 1; | |
1918 | end_pfn = start_pfn + pageblock_nr_pages - 1; | |
1919 | ||
1920 | /* Do not cross zone boundaries */ | |
1921 | if (!zone_spans_pfn(zone, start_pfn)) | |
1922 | start_page = page; | |
1923 | if (!zone_spans_pfn(zone, end_pfn)) | |
1924 | return 0; | |
1925 | ||
1926 | return move_freepages(zone, start_page, end_page, migratetype, | |
1927 | num_movable); | |
1928 | } | |
1929 | ||
1930 | static void change_pageblock_range(struct page *pageblock_page, | |
1931 | int start_order, int migratetype) | |
1932 | { | |
1933 | int nr_pageblocks = 1 << (start_order - pageblock_order); | |
1934 | ||
1935 | while (nr_pageblocks--) { | |
1936 | set_pageblock_migratetype(pageblock_page, migratetype); | |
1937 | pageblock_page += pageblock_nr_pages; | |
1938 | } | |
1939 | } | |
1940 | ||
1941 | /* | |
1942 | * When we are falling back to another migratetype during allocation, try to | |
1943 | * steal extra free pages from the same pageblocks to satisfy further | |
1944 | * allocations, instead of polluting multiple pageblocks. | |
1945 | * | |
1946 | * If we are stealing a relatively large buddy page, it is likely there will | |
1947 | * be more free pages in the pageblock, so try to steal them all. For | |
1948 | * reclaimable and unmovable allocations, we steal regardless of page size, | |
1949 | * as fragmentation caused by those allocations polluting movable pageblocks | |
1950 | * is worse than movable allocations stealing from unmovable and reclaimable | |
1951 | * pageblocks. | |
1952 | */ | |
1953 | static bool can_steal_fallback(unsigned int order, int start_mt) | |
1954 | { | |
1955 | /* | |
1956 | * Leaving this order check is intended, although there is | |
1957 | * relaxed order check in next check. The reason is that | |
1958 | * we can actually steal whole pageblock if this condition met, | |
1959 | * but, below check doesn't guarantee it and that is just heuristic | |
1960 | * so could be changed anytime. | |
1961 | */ | |
1962 | if (order >= pageblock_order) | |
1963 | return true; | |
1964 | ||
1965 | if (order >= pageblock_order / 2 || | |
1966 | start_mt == MIGRATE_RECLAIMABLE || | |
1967 | start_mt == MIGRATE_UNMOVABLE || | |
1968 | page_group_by_mobility_disabled) | |
1969 | return true; | |
1970 | ||
1971 | return false; | |
1972 | } | |
1973 | ||
1974 | /* | |
1975 | * This function implements actual steal behaviour. If order is large enough, | |
1976 | * we can steal whole pageblock. If not, we first move freepages in this | |
1977 | * pageblock to our migratetype and determine how many already-allocated pages | |
1978 | * are there in the pageblock with a compatible migratetype. If at least half | |
1979 | * of pages are free or compatible, we can change migratetype of the pageblock | |
1980 | * itself, so pages freed in the future will be put on the correct free list. | |
1981 | */ | |
1982 | static void steal_suitable_fallback(struct zone *zone, struct page *page, | |
1983 | int start_type, bool whole_block) | |
1984 | { | |
1985 | unsigned int current_order = page_order(page); | |
1986 | struct free_area *area; | |
1987 | int free_pages, movable_pages, alike_pages; | |
1988 | int old_block_type; | |
1989 | ||
1990 | old_block_type = get_pageblock_migratetype(page); | |
1991 | ||
1992 | /* | |
1993 | * This can happen due to races and we want to prevent broken | |
1994 | * highatomic accounting. | |
1995 | */ | |
1996 | if (is_migrate_highatomic(old_block_type)) | |
1997 | goto single_page; | |
1998 | ||
1999 | /* Take ownership for orders >= pageblock_order */ | |
2000 | if (current_order >= pageblock_order) { | |
2001 | change_pageblock_range(page, current_order, start_type); | |
2002 | goto single_page; | |
2003 | } | |
2004 | ||
2005 | /* We are not allowed to try stealing from the whole block */ | |
2006 | if (!whole_block) | |
2007 | goto single_page; | |
2008 | ||
2009 | free_pages = move_freepages_block(zone, page, start_type, | |
2010 | &movable_pages); | |
2011 | /* | |
2012 | * Determine how many pages are compatible with our allocation. | |
2013 | * For movable allocation, it's the number of movable pages which | |
2014 | * we just obtained. For other types it's a bit more tricky. | |
2015 | */ | |
2016 | if (start_type == MIGRATE_MOVABLE) { | |
2017 | alike_pages = movable_pages; | |
2018 | } else { | |
2019 | /* | |
2020 | * If we are falling back a RECLAIMABLE or UNMOVABLE allocation | |
2021 | * to MOVABLE pageblock, consider all non-movable pages as | |
2022 | * compatible. If it's UNMOVABLE falling back to RECLAIMABLE or | |
2023 | * vice versa, be conservative since we can't distinguish the | |
2024 | * exact migratetype of non-movable pages. | |
2025 | */ | |
2026 | if (old_block_type == MIGRATE_MOVABLE) | |
2027 | alike_pages = pageblock_nr_pages | |
2028 | - (free_pages + movable_pages); | |
2029 | else | |
2030 | alike_pages = 0; | |
2031 | } | |
2032 | ||
2033 | /* moving whole block can fail due to zone boundary conditions */ | |
2034 | if (!free_pages) | |
2035 | goto single_page; | |
2036 | ||
2037 | /* | |
2038 | * If a sufficient number of pages in the block are either free or of | |
2039 | * comparable migratability as our allocation, claim the whole block. | |
2040 | */ | |
2041 | if (free_pages + alike_pages >= (1 << (pageblock_order-1)) || | |
2042 | page_group_by_mobility_disabled) | |
2043 | set_pageblock_migratetype(page, start_type); | |
2044 | ||
2045 | return; | |
2046 | ||
2047 | single_page: | |
2048 | area = &zone->free_area[current_order]; | |
2049 | list_move(&page->lru, &area->free_list[start_type]); | |
2050 | } | |
2051 | ||
2052 | /* | |
2053 | * Check whether there is a suitable fallback freepage with requested order. | |
2054 | * If only_stealable is true, this function returns fallback_mt only if | |
2055 | * we can steal other freepages all together. This would help to reduce | |
2056 | * fragmentation due to mixed migratetype pages in one pageblock. | |
2057 | */ | |
2058 | int find_suitable_fallback(struct free_area *area, unsigned int order, | |
2059 | int migratetype, bool only_stealable, bool *can_steal) | |
2060 | { | |
2061 | int i; | |
2062 | int fallback_mt; | |
2063 | ||
2064 | if (area->nr_free == 0) | |
2065 | return -1; | |
2066 | ||
2067 | *can_steal = false; | |
2068 | for (i = 0;; i++) { | |
2069 | fallback_mt = fallbacks[migratetype][i]; | |
2070 | if (fallback_mt == MIGRATE_TYPES) | |
2071 | break; | |
2072 | ||
2073 | if (list_empty(&area->free_list[fallback_mt])) | |
2074 | continue; | |
2075 | ||
2076 | if (can_steal_fallback(order, migratetype)) | |
2077 | *can_steal = true; | |
2078 | ||
2079 | if (!only_stealable) | |
2080 | return fallback_mt; | |
2081 | ||
2082 | if (*can_steal) | |
2083 | return fallback_mt; | |
2084 | } | |
2085 | ||
2086 | return -1; | |
2087 | } | |
2088 | ||
2089 | /* | |
2090 | * Reserve a pageblock for exclusive use of high-order atomic allocations if | |
2091 | * there are no empty page blocks that contain a page with a suitable order | |
2092 | */ | |
2093 | static void reserve_highatomic_pageblock(struct page *page, struct zone *zone, | |
2094 | unsigned int alloc_order) | |
2095 | { | |
2096 | int mt; | |
2097 | unsigned long max_managed, flags; | |
2098 | ||
2099 | /* | |
2100 | * Limit the number reserved to 1 pageblock or roughly 1% of a zone. | |
2101 | * Check is race-prone but harmless. | |
2102 | */ | |
2103 | max_managed = (zone->managed_pages / 100) + pageblock_nr_pages; | |
2104 | if (zone->nr_reserved_highatomic >= max_managed) | |
2105 | return; | |
2106 | ||
2107 | spin_lock_irqsave(&zone->lock, flags); | |
2108 | ||
2109 | /* Recheck the nr_reserved_highatomic limit under the lock */ | |
2110 | if (zone->nr_reserved_highatomic >= max_managed) | |
2111 | goto out_unlock; | |
2112 | ||
2113 | /* Yoink! */ | |
2114 | mt = get_pageblock_migratetype(page); | |
2115 | if (!is_migrate_highatomic(mt) && !is_migrate_isolate(mt) | |
2116 | && !is_migrate_cma(mt)) { | |
2117 | zone->nr_reserved_highatomic += pageblock_nr_pages; | |
2118 | set_pageblock_migratetype(page, MIGRATE_HIGHATOMIC); | |
2119 | move_freepages_block(zone, page, MIGRATE_HIGHATOMIC, NULL); | |
2120 | } | |
2121 | ||
2122 | out_unlock: | |
2123 | spin_unlock_irqrestore(&zone->lock, flags); | |
2124 | } | |
2125 | ||
2126 | /* | |
2127 | * Used when an allocation is about to fail under memory pressure. This | |
2128 | * potentially hurts the reliability of high-order allocations when under | |
2129 | * intense memory pressure but failed atomic allocations should be easier | |
2130 | * to recover from than an OOM. | |
2131 | * | |
2132 | * If @force is true, try to unreserve a pageblock even though highatomic | |
2133 | * pageblock is exhausted. | |
2134 | */ | |
2135 | static bool unreserve_highatomic_pageblock(const struct alloc_context *ac, | |
2136 | bool force) | |
2137 | { | |
2138 | struct zonelist *zonelist = ac->zonelist; | |
2139 | unsigned long flags; | |
2140 | struct zoneref *z; | |
2141 | struct zone *zone; | |
2142 | struct page *page; | |
2143 | int order; | |
2144 | bool ret; | |
2145 | ||
2146 | for_each_zone_zonelist_nodemask(zone, z, zonelist, ac->high_zoneidx, | |
2147 | ac->nodemask) { | |
2148 | /* | |
2149 | * Preserve at least one pageblock unless memory pressure | |
2150 | * is really high. | |
2151 | */ | |
2152 | if (!force && zone->nr_reserved_highatomic <= | |
2153 | pageblock_nr_pages) | |
2154 | continue; | |
2155 | ||
2156 | spin_lock_irqsave(&zone->lock, flags); | |
2157 | for (order = 0; order < MAX_ORDER; order++) { | |
2158 | struct free_area *area = &(zone->free_area[order]); | |
2159 | ||
2160 | page = list_first_entry_or_null( | |
2161 | &area->free_list[MIGRATE_HIGHATOMIC], | |
2162 | struct page, lru); | |
2163 | if (!page) | |
2164 | continue; | |
2165 | ||
2166 | /* | |
2167 | * In page freeing path, migratetype change is racy so | |
2168 | * we can counter several free pages in a pageblock | |
2169 | * in this loop althoug we changed the pageblock type | |
2170 | * from highatomic to ac->migratetype. So we should | |
2171 | * adjust the count once. | |
2172 | */ | |
2173 | if (is_migrate_highatomic_page(page)) { | |
2174 | /* | |
2175 | * It should never happen but changes to | |
2176 | * locking could inadvertently allow a per-cpu | |
2177 | * drain to add pages to MIGRATE_HIGHATOMIC | |
2178 | * while unreserving so be safe and watch for | |
2179 | * underflows. | |
2180 | */ | |
2181 | zone->nr_reserved_highatomic -= min( | |
2182 | pageblock_nr_pages, | |
2183 | zone->nr_reserved_highatomic); | |
2184 | } | |
2185 | ||
2186 | /* | |
2187 | * Convert to ac->migratetype and avoid the normal | |
2188 | * pageblock stealing heuristics. Minimally, the caller | |
2189 | * is doing the work and needs the pages. More | |
2190 | * importantly, if the block was always converted to | |
2191 | * MIGRATE_UNMOVABLE or another type then the number | |
2192 | * of pageblocks that cannot be completely freed | |
2193 | * may increase. | |
2194 | */ | |
2195 | set_pageblock_migratetype(page, ac->migratetype); | |
2196 | ret = move_freepages_block(zone, page, ac->migratetype, | |
2197 | NULL); | |
2198 | if (ret) { | |
2199 | spin_unlock_irqrestore(&zone->lock, flags); | |
2200 | return ret; | |
2201 | } | |
2202 | } | |
2203 | spin_unlock_irqrestore(&zone->lock, flags); | |
2204 | } | |
2205 | ||
2206 | return false; | |
2207 | } | |
2208 | ||
2209 | /* | |
2210 | * Try finding a free buddy page on the fallback list and put it on the free | |
2211 | * list of requested migratetype, possibly along with other pages from the same | |
2212 | * block, depending on fragmentation avoidance heuristics. Returns true if | |
2213 | * fallback was found so that __rmqueue_smallest() can grab it. | |
2214 | * | |
2215 | * The use of signed ints for order and current_order is a deliberate | |
2216 | * deviation from the rest of this file, to make the for loop | |
2217 | * condition simpler. | |
2218 | */ | |
2219 | static inline bool | |
2220 | __rmqueue_fallback(struct zone *zone, int order, int start_migratetype) | |
2221 | { | |
2222 | struct free_area *area; | |
2223 | int current_order; | |
2224 | struct page *page; | |
2225 | int fallback_mt; | |
2226 | bool can_steal; | |
2227 | ||
2228 | /* | |
2229 | * Find the largest available free page in the other list. This roughly | |
2230 | * approximates finding the pageblock with the most free pages, which | |
2231 | * would be too costly to do exactly. | |
2232 | */ | |
2233 | for (current_order = MAX_ORDER - 1; current_order >= order; | |
2234 | --current_order) { | |
2235 | area = &(zone->free_area[current_order]); | |
2236 | fallback_mt = find_suitable_fallback(area, current_order, | |
2237 | start_migratetype, false, &can_steal); | |
2238 | if (fallback_mt == -1) | |
2239 | continue; | |
2240 | ||
2241 | /* | |
2242 | * We cannot steal all free pages from the pageblock and the | |
2243 | * requested migratetype is movable. In that case it's better to | |
2244 | * steal and split the smallest available page instead of the | |
2245 | * largest available page, because even if the next movable | |
2246 | * allocation falls back into a different pageblock than this | |
2247 | * one, it won't cause permanent fragmentation. | |
2248 | */ | |
2249 | if (!can_steal && start_migratetype == MIGRATE_MOVABLE | |
2250 | && current_order > order) | |
2251 | goto find_smallest; | |
2252 | ||
2253 | goto do_steal; | |
2254 | } | |
2255 | ||
2256 | return false; | |
2257 | ||
2258 | find_smallest: | |
2259 | for (current_order = order; current_order < MAX_ORDER; | |
2260 | current_order++) { | |
2261 | area = &(zone->free_area[current_order]); | |
2262 | fallback_mt = find_suitable_fallback(area, current_order, | |
2263 | start_migratetype, false, &can_steal); | |
2264 | if (fallback_mt != -1) | |
2265 | break; | |
2266 | } | |
2267 | ||
2268 | /* | |
2269 | * This should not happen - we already found a suitable fallback | |
2270 | * when looking for the largest page. | |
2271 | */ | |
2272 | VM_BUG_ON(current_order == MAX_ORDER); | |
2273 | ||
2274 | do_steal: | |
2275 | page = list_first_entry(&area->free_list[fallback_mt], | |
2276 | struct page, lru); | |
2277 | ||
2278 | steal_suitable_fallback(zone, page, start_migratetype, can_steal); | |
2279 | ||
2280 | trace_mm_page_alloc_extfrag(page, order, current_order, | |
2281 | start_migratetype, fallback_mt); | |
2282 | ||
2283 | return true; | |
2284 | ||
2285 | } | |
2286 | ||
2287 | /* | |
2288 | * Do the hard work of removing an element from the buddy allocator. | |
2289 | * Call me with the zone->lock already held. | |
2290 | */ | |
2291 | static struct page *__rmqueue(struct zone *zone, unsigned int order, | |
2292 | int migratetype) | |
2293 | { | |
2294 | struct page *page; | |
2295 | ||
2296 | retry: | |
2297 | page = __rmqueue_smallest(zone, order, migratetype); | |
2298 | if (unlikely(!page)) { | |
2299 | if (migratetype == MIGRATE_MOVABLE) | |
2300 | page = __rmqueue_cma_fallback(zone, order); | |
2301 | ||
2302 | if (!page && __rmqueue_fallback(zone, order, migratetype)) | |
2303 | goto retry; | |
2304 | } | |
2305 | ||
2306 | trace_mm_page_alloc_zone_locked(page, order, migratetype); | |
2307 | return page; | |
2308 | } | |
2309 | ||
2310 | /* | |
2311 | * Obtain a specified number of elements from the buddy allocator, all under | |
2312 | * a single hold of the lock, for efficiency. Add them to the supplied list. | |
2313 | * Returns the number of new pages which were placed at *list. | |
2314 | */ | |
2315 | static int rmqueue_bulk(struct zone *zone, unsigned int order, | |
2316 | unsigned long count, struct list_head *list, | |
2317 | int migratetype, bool cold) | |
2318 | { | |
2319 | int i, alloced = 0; | |
2320 | ||
2321 | spin_lock(&zone->lock); | |
2322 | for (i = 0; i < count; ++i) { | |
2323 | struct page *page = __rmqueue(zone, order, migratetype); | |
2324 | if (unlikely(page == NULL)) | |
2325 | break; | |
2326 | ||
2327 | if (unlikely(check_pcp_refill(page))) | |
2328 | continue; | |
2329 | ||
2330 | /* | |
2331 | * Split buddy pages returned by expand() are received here | |
2332 | * in physical page order. The page is added to the callers and | |
2333 | * list and the list head then moves forward. From the callers | |
2334 | * perspective, the linked list is ordered by page number in | |
2335 | * some conditions. This is useful for IO devices that can | |
2336 | * merge IO requests if the physical pages are ordered | |
2337 | * properly. | |
2338 | */ | |
2339 | if (likely(!cold)) | |
2340 | list_add(&page->lru, list); | |
2341 | else | |
2342 | list_add_tail(&page->lru, list); | |
2343 | list = &page->lru; | |
2344 | alloced++; | |
2345 | if (is_migrate_cma(get_pcppage_migratetype(page))) | |
2346 | __mod_zone_page_state(zone, NR_FREE_CMA_PAGES, | |
2347 | -(1 << order)); | |
2348 | } | |
2349 | ||
2350 | /* | |
2351 | * i pages were removed from the buddy list even if some leak due | |
2352 | * to check_pcp_refill failing so adjust NR_FREE_PAGES based | |
2353 | * on i. Do not confuse with 'alloced' which is the number of | |
2354 | * pages added to the pcp list. | |
2355 | */ | |
2356 | __mod_zone_page_state(zone, NR_FREE_PAGES, -(i << order)); | |
2357 | spin_unlock(&zone->lock); | |
2358 | return alloced; | |
2359 | } | |
2360 | ||
2361 | #ifdef CONFIG_NUMA | |
2362 | /* | |
2363 | * Called from the vmstat counter updater to drain pagesets of this | |
2364 | * currently executing processor on remote nodes after they have | |
2365 | * expired. | |
2366 | * | |
2367 | * Note that this function must be called with the thread pinned to | |
2368 | * a single processor. | |
2369 | */ | |
2370 | void drain_zone_pages(struct zone *zone, struct per_cpu_pages *pcp) | |
2371 | { | |
2372 | unsigned long flags; | |
2373 | int to_drain, batch; | |
2374 | ||
2375 | local_irq_save(flags); | |
2376 | batch = READ_ONCE(pcp->batch); | |
2377 | to_drain = min(pcp->count, batch); | |
2378 | if (to_drain > 0) { | |
2379 | free_pcppages_bulk(zone, to_drain, pcp); | |
2380 | pcp->count -= to_drain; | |
2381 | } | |
2382 | local_irq_restore(flags); | |
2383 | } | |
2384 | #endif | |
2385 | ||
2386 | /* | |
2387 | * Drain pcplists of the indicated processor and zone. | |
2388 | * | |
2389 | * The processor must either be the current processor and the | |
2390 | * thread pinned to the current processor or a processor that | |
2391 | * is not online. | |
2392 | */ | |
2393 | static void drain_pages_zone(unsigned int cpu, struct zone *zone) | |
2394 | { | |
2395 | unsigned long flags; | |
2396 | struct per_cpu_pageset *pset; | |
2397 | struct per_cpu_pages *pcp; | |
2398 | ||
2399 | local_irq_save(flags); | |
2400 | pset = per_cpu_ptr(zone->pageset, cpu); | |
2401 | ||
2402 | pcp = &pset->pcp; | |
2403 | if (pcp->count) { | |
2404 | free_pcppages_bulk(zone, pcp->count, pcp); | |
2405 | pcp->count = 0; | |
2406 | } | |
2407 | local_irq_restore(flags); | |
2408 | } | |
2409 | ||
2410 | /* | |
2411 | * Drain pcplists of all zones on the indicated processor. | |
2412 | * | |
2413 | * The processor must either be the current processor and the | |
2414 | * thread pinned to the current processor or a processor that | |
2415 | * is not online. | |
2416 | */ | |
2417 | static void drain_pages(unsigned int cpu) | |
2418 | { | |
2419 | struct zone *zone; | |
2420 | ||
2421 | for_each_populated_zone(zone) { | |
2422 | drain_pages_zone(cpu, zone); | |
2423 | } | |
2424 | } | |
2425 | ||
2426 | /* | |
2427 | * Spill all of this CPU's per-cpu pages back into the buddy allocator. | |
2428 | * | |
2429 | * The CPU has to be pinned. When zone parameter is non-NULL, spill just | |
2430 | * the single zone's pages. | |
2431 | */ | |
2432 | void drain_local_pages(struct zone *zone) | |
2433 | { | |
2434 | int cpu = smp_processor_id(); | |
2435 | ||
2436 | if (zone) | |
2437 | drain_pages_zone(cpu, zone); | |
2438 | else | |
2439 | drain_pages(cpu); | |
2440 | } | |
2441 | ||
2442 | static void drain_local_pages_wq(struct work_struct *work) | |
2443 | { | |
2444 | /* | |
2445 | * drain_all_pages doesn't use proper cpu hotplug protection so | |
2446 | * we can race with cpu offline when the WQ can move this from | |
2447 | * a cpu pinned worker to an unbound one. We can operate on a different | |
2448 | * cpu which is allright but we also have to make sure to not move to | |
2449 | * a different one. | |
2450 | */ | |
2451 | preempt_disable(); | |
2452 | drain_local_pages(NULL); | |
2453 | preempt_enable(); | |
2454 | } | |
2455 | ||
2456 | /* | |
2457 | * Spill all the per-cpu pages from all CPUs back into the buddy allocator. | |
2458 | * | |
2459 | * When zone parameter is non-NULL, spill just the single zone's pages. | |
2460 | * | |
2461 | * Note that this can be extremely slow as the draining happens in a workqueue. | |
2462 | */ | |
2463 | void drain_all_pages(struct zone *zone) | |
2464 | { | |
2465 | int cpu; | |
2466 | ||
2467 | /* | |
2468 | * Allocate in the BSS so we wont require allocation in | |
2469 | * direct reclaim path for CONFIG_CPUMASK_OFFSTACK=y | |
2470 | */ | |
2471 | static cpumask_t cpus_with_pcps; | |
2472 | ||
2473 | /* | |
2474 | * Make sure nobody triggers this path before mm_percpu_wq is fully | |
2475 | * initialized. | |
2476 | */ | |
2477 | if (WARN_ON_ONCE(!mm_percpu_wq)) | |
2478 | return; | |
2479 | ||
2480 | /* Workqueues cannot recurse */ | |
2481 | if (current->flags & PF_WQ_WORKER) | |
2482 | return; | |
2483 | ||
2484 | /* | |
2485 | * Do not drain if one is already in progress unless it's specific to | |
2486 | * a zone. Such callers are primarily CMA and memory hotplug and need | |
2487 | * the drain to be complete when the call returns. | |
2488 | */ | |
2489 | if (unlikely(!mutex_trylock(&pcpu_drain_mutex))) { | |
2490 | if (!zone) | |
2491 | return; | |
2492 | mutex_lock(&pcpu_drain_mutex); | |
2493 | } | |
2494 | ||
2495 | /* | |
2496 | * We don't care about racing with CPU hotplug event | |
2497 | * as offline notification will cause the notified | |
2498 | * cpu to drain that CPU pcps and on_each_cpu_mask | |
2499 | * disables preemption as part of its processing | |
2500 | */ | |
2501 | for_each_online_cpu(cpu) { | |
2502 | struct per_cpu_pageset *pcp; | |
2503 | struct zone *z; | |
2504 | bool has_pcps = false; | |
2505 | ||
2506 | if (zone) { | |
2507 | pcp = per_cpu_ptr(zone->pageset, cpu); | |
2508 | if (pcp->pcp.count) | |
2509 | has_pcps = true; | |
2510 | } else { | |
2511 | for_each_populated_zone(z) { | |
2512 | pcp = per_cpu_ptr(z->pageset, cpu); | |
2513 | if (pcp->pcp.count) { | |
2514 | has_pcps = true; | |
2515 | break; | |
2516 | } | |
2517 | } | |
2518 | } | |
2519 | ||
2520 | if (has_pcps) | |
2521 | cpumask_set_cpu(cpu, &cpus_with_pcps); | |
2522 | else | |
2523 | cpumask_clear_cpu(cpu, &cpus_with_pcps); | |
2524 | } | |
2525 | ||
2526 | for_each_cpu(cpu, &cpus_with_pcps) { | |
2527 | struct work_struct *work = per_cpu_ptr(&pcpu_drain, cpu); | |
2528 | INIT_WORK(work, drain_local_pages_wq); | |
2529 | queue_work_on(cpu, mm_percpu_wq, work); | |
2530 | } | |
2531 | for_each_cpu(cpu, &cpus_with_pcps) | |
2532 | flush_work(per_cpu_ptr(&pcpu_drain, cpu)); | |
2533 | ||
2534 | mutex_unlock(&pcpu_drain_mutex); | |
2535 | } | |
2536 | ||
2537 | #ifdef CONFIG_HIBERNATION | |
2538 | ||
2539 | /* | |
2540 | * Touch the watchdog for every WD_PAGE_COUNT pages. | |
2541 | */ | |
2542 | #define WD_PAGE_COUNT (128*1024) | |
2543 | ||
2544 | void mark_free_pages(struct zone *zone) | |
2545 | { | |
2546 | unsigned long pfn, max_zone_pfn, page_count = WD_PAGE_COUNT; | |
2547 | unsigned long flags; | |
2548 | unsigned int order, t; | |
2549 | struct page *page; | |
2550 | ||
2551 | if (zone_is_empty(zone)) | |
2552 | return; | |
2553 | ||
2554 | spin_lock_irqsave(&zone->lock, flags); | |
2555 | ||
2556 | max_zone_pfn = zone_end_pfn(zone); | |
2557 | for (pfn = zone->zone_start_pfn; pfn < max_zone_pfn; pfn++) | |
2558 | if (pfn_valid(pfn)) { | |
2559 | page = pfn_to_page(pfn); | |
2560 | ||
2561 | if (!--page_count) { | |
2562 | touch_nmi_watchdog(); | |
2563 | page_count = WD_PAGE_COUNT; | |
2564 | } | |
2565 | ||
2566 | if (page_zone(page) != zone) | |
2567 | continue; | |
2568 | ||
2569 | if (!swsusp_page_is_forbidden(page)) | |
2570 | swsusp_unset_page_free(page); | |
2571 | } | |
2572 | ||
2573 | for_each_migratetype_order(order, t) { | |
2574 | list_for_each_entry(page, | |
2575 | &zone->free_area[order].free_list[t], lru) { | |
2576 | unsigned long i; | |
2577 | ||
2578 | pfn = page_to_pfn(page); | |
2579 | for (i = 0; i < (1UL << order); i++) { | |
2580 | if (!--page_count) { | |
2581 | touch_nmi_watchdog(); | |
2582 | page_count = WD_PAGE_COUNT; | |
2583 | } | |
2584 | swsusp_set_page_free(pfn_to_page(pfn + i)); | |
2585 | } | |
2586 | } | |
2587 | } | |
2588 | spin_unlock_irqrestore(&zone->lock, flags); | |
2589 | } | |
2590 | #endif /* CONFIG_PM */ | |
2591 | ||
2592 | /* | |
2593 | * Free a 0-order page | |
2594 | * cold == true ? free a cold page : free a hot page | |
2595 | */ | |
2596 | void free_hot_cold_page(struct page *page, bool cold) | |
2597 | { | |
2598 | struct zone *zone = page_zone(page); | |
2599 | struct per_cpu_pages *pcp; | |
2600 | unsigned long flags; | |
2601 | unsigned long pfn = page_to_pfn(page); | |
2602 | int migratetype; | |
2603 | ||
2604 | if (!free_pcp_prepare(page)) | |
2605 | return; | |
2606 | ||
2607 | migratetype = get_pfnblock_migratetype(page, pfn); | |
2608 | set_pcppage_migratetype(page, migratetype); | |
2609 | local_irq_save(flags); | |
2610 | __count_vm_event(PGFREE); | |
2611 | ||
2612 | /* | |
2613 | * We only track unmovable, reclaimable and movable on pcp lists. | |
2614 | * Free ISOLATE pages back to the allocator because they are being | |
2615 | * offlined but treat HIGHATOMIC as movable pages so we can get those | |
2616 | * areas back if necessary. Otherwise, we may have to free | |
2617 | * excessively into the page allocator | |
2618 | */ | |
2619 | if (migratetype >= MIGRATE_PCPTYPES) { | |
2620 | if (unlikely(is_migrate_isolate(migratetype))) { | |
2621 | free_one_page(zone, page, pfn, 0, migratetype); | |
2622 | goto out; | |
2623 | } | |
2624 | migratetype = MIGRATE_MOVABLE; | |
2625 | } | |
2626 | ||
2627 | pcp = &this_cpu_ptr(zone->pageset)->pcp; | |
2628 | if (!cold) | |
2629 | list_add(&page->lru, &pcp->lists[migratetype]); | |
2630 | else | |
2631 | list_add_tail(&page->lru, &pcp->lists[migratetype]); | |
2632 | pcp->count++; | |
2633 | if (pcp->count >= pcp->high) { | |
2634 | unsigned long batch = READ_ONCE(pcp->batch); | |
2635 | free_pcppages_bulk(zone, batch, pcp); | |
2636 | pcp->count -= batch; | |
2637 | } | |
2638 | ||
2639 | out: | |
2640 | local_irq_restore(flags); | |
2641 | } | |
2642 | ||
2643 | /* | |
2644 | * Free a list of 0-order pages | |
2645 | */ | |
2646 | void free_hot_cold_page_list(struct list_head *list, bool cold) | |
2647 | { | |
2648 | struct page *page, *next; | |
2649 | ||
2650 | list_for_each_entry_safe(page, next, list, lru) { | |
2651 | trace_mm_page_free_batched(page, cold); | |
2652 | free_hot_cold_page(page, cold); | |
2653 | } | |
2654 | } | |
2655 | ||
2656 | /* | |
2657 | * split_page takes a non-compound higher-order page, and splits it into | |
2658 | * n (1<<order) sub-pages: page[0..n] | |
2659 | * Each sub-page must be freed individually. | |
2660 | * | |
2661 | * Note: this is probably too low level an operation for use in drivers. | |
2662 | * Please consult with lkml before using this in your driver. | |
2663 | */ | |
2664 | void split_page(struct page *page, unsigned int order) | |
2665 | { | |
2666 | int i; | |
2667 | ||
2668 | VM_BUG_ON_PAGE(PageCompound(page), page); | |
2669 | VM_BUG_ON_PAGE(!page_count(page), page); | |
2670 | ||
2671 | #ifdef CONFIG_KMEMCHECK | |
2672 | /* | |
2673 | * Split shadow pages too, because free(page[0]) would | |
2674 | * otherwise free the whole shadow. | |
2675 | */ | |
2676 | if (kmemcheck_page_is_tracked(page)) | |
2677 | split_page(virt_to_page(page[0].shadow), order); | |
2678 | #endif | |
2679 | ||
2680 | for (i = 1; i < (1 << order); i++) | |
2681 | set_page_refcounted(page + i); | |
2682 | split_page_owner(page, order); | |
2683 | } | |
2684 | EXPORT_SYMBOL_GPL(split_page); | |
2685 | ||
2686 | int __isolate_free_page(struct page *page, unsigned int order) | |
2687 | { | |
2688 | unsigned long watermark; | |
2689 | struct zone *zone; | |
2690 | int mt; | |
2691 | ||
2692 | BUG_ON(!PageBuddy(page)); | |
2693 | ||
2694 | zone = page_zone(page); | |
2695 | mt = get_pageblock_migratetype(page); | |
2696 | ||
2697 | if (!is_migrate_isolate(mt)) { | |
2698 | /* | |
2699 | * Obey watermarks as if the page was being allocated. We can | |
2700 | * emulate a high-order watermark check with a raised order-0 | |
2701 | * watermark, because we already know our high-order page | |
2702 | * exists. | |
2703 | */ | |
2704 | watermark = min_wmark_pages(zone) + (1UL << order); | |
2705 | if (!zone_watermark_ok(zone, 0, watermark, 0, ALLOC_CMA)) | |
2706 | return 0; | |
2707 | ||
2708 | __mod_zone_freepage_state(zone, -(1UL << order), mt); | |
2709 | } | |
2710 | ||
2711 | /* Remove page from free list */ | |
2712 | list_del(&page->lru); | |
2713 | zone->free_area[order].nr_free--; | |
2714 | rmv_page_order(page); | |
2715 | ||
2716 | /* | |
2717 | * Set the pageblock if the isolated page is at least half of a | |
2718 | * pageblock | |
2719 | */ | |
2720 | if (order >= pageblock_order - 1) { | |
2721 | struct page *endpage = page + (1 << order) - 1; | |
2722 | for (; page < endpage; page += pageblock_nr_pages) { | |
2723 | int mt = get_pageblock_migratetype(page); | |
2724 | if (!is_migrate_isolate(mt) && !is_migrate_cma(mt) | |
2725 | && !is_migrate_highatomic(mt)) | |
2726 | set_pageblock_migratetype(page, | |
2727 | MIGRATE_MOVABLE); | |
2728 | } | |
2729 | } | |
2730 | ||
2731 | ||
2732 | return 1UL << order; | |
2733 | } | |
2734 | ||
2735 | /* | |
2736 | * Update NUMA hit/miss statistics | |
2737 | * | |
2738 | * Must be called with interrupts disabled. | |
2739 | */ | |
2740 | static inline void zone_statistics(struct zone *preferred_zone, struct zone *z) | |
2741 | { | |
2742 | #ifdef CONFIG_NUMA | |
2743 | enum zone_stat_item local_stat = NUMA_LOCAL; | |
2744 | ||
2745 | if (z->node != numa_node_id()) | |
2746 | local_stat = NUMA_OTHER; | |
2747 | ||
2748 | if (z->node == preferred_zone->node) | |
2749 | __inc_zone_state(z, NUMA_HIT); | |
2750 | else { | |
2751 | __inc_zone_state(z, NUMA_MISS); | |
2752 | __inc_zone_state(preferred_zone, NUMA_FOREIGN); | |
2753 | } | |
2754 | __inc_zone_state(z, local_stat); | |
2755 | #endif | |
2756 | } | |
2757 | ||
2758 | /* Remove page from the per-cpu list, caller must protect the list */ | |
2759 | static struct page *__rmqueue_pcplist(struct zone *zone, int migratetype, | |
2760 | bool cold, struct per_cpu_pages *pcp, | |
2761 | struct list_head *list) | |
2762 | { | |
2763 | struct page *page; | |
2764 | ||
2765 | do { | |
2766 | if (list_empty(list)) { | |
2767 | pcp->count += rmqueue_bulk(zone, 0, | |
2768 | pcp->batch, list, | |
2769 | migratetype, cold); | |
2770 | if (unlikely(list_empty(list))) | |
2771 | return NULL; | |
2772 | } | |
2773 | ||
2774 | if (cold) | |
2775 | page = list_last_entry(list, struct page, lru); | |
2776 | else | |
2777 | page = list_first_entry(list, struct page, lru); | |
2778 | ||
2779 | list_del(&page->lru); | |
2780 | pcp->count--; | |
2781 | } while (check_new_pcp(page)); | |
2782 | ||
2783 | return page; | |
2784 | } | |
2785 | ||
2786 | /* Lock and remove page from the per-cpu list */ | |
2787 | static struct page *rmqueue_pcplist(struct zone *preferred_zone, | |
2788 | struct zone *zone, unsigned int order, | |
2789 | gfp_t gfp_flags, int migratetype) | |
2790 | { | |
2791 | struct per_cpu_pages *pcp; | |
2792 | struct list_head *list; | |
2793 | bool cold = ((gfp_flags & __GFP_COLD) != 0); | |
2794 | struct page *page; | |
2795 | unsigned long flags; | |
2796 | ||
2797 | local_irq_save(flags); | |
2798 | pcp = &this_cpu_ptr(zone->pageset)->pcp; | |
2799 | list = &pcp->lists[migratetype]; | |
2800 | page = __rmqueue_pcplist(zone, migratetype, cold, pcp, list); | |
2801 | if (page) { | |
2802 | __count_zid_vm_events(PGALLOC, page_zonenum(page), 1 << order); | |
2803 | zone_statistics(preferred_zone, zone); | |
2804 | } | |
2805 | local_irq_restore(flags); | |
2806 | return page; | |
2807 | } | |
2808 | ||
2809 | /* | |
2810 | * Allocate a page from the given zone. Use pcplists for order-0 allocations. | |
2811 | */ | |
2812 | static inline | |
2813 | struct page *rmqueue(struct zone *preferred_zone, | |
2814 | struct zone *zone, unsigned int order, | |
2815 | gfp_t gfp_flags, unsigned int alloc_flags, | |
2816 | int migratetype) | |
2817 | { | |
2818 | unsigned long flags; | |
2819 | struct page *page; | |
2820 | ||
2821 | if (likely(order == 0)) { | |
2822 | page = rmqueue_pcplist(preferred_zone, zone, order, | |
2823 | gfp_flags, migratetype); | |
2824 | goto out; | |
2825 | } | |
2826 | ||
2827 | /* | |
2828 | * We most definitely don't want callers attempting to | |
2829 | * allocate greater than order-1 page units with __GFP_NOFAIL. | |
2830 | */ | |
2831 | WARN_ON_ONCE((gfp_flags & __GFP_NOFAIL) && (order > 1)); | |
2832 | spin_lock_irqsave(&zone->lock, flags); | |
2833 | ||
2834 | do { | |
2835 | page = NULL; | |
2836 | if (alloc_flags & ALLOC_HARDER) { | |
2837 | page = __rmqueue_smallest(zone, order, MIGRATE_HIGHATOMIC); | |
2838 | if (page) | |
2839 | trace_mm_page_alloc_zone_locked(page, order, migratetype); | |
2840 | } | |
2841 | if (!page) | |
2842 | page = __rmqueue(zone, order, migratetype); | |
2843 | } while (page && check_new_pages(page, order)); | |
2844 | spin_unlock(&zone->lock); | |
2845 | if (!page) | |
2846 | goto failed; | |
2847 | __mod_zone_freepage_state(zone, -(1 << order), | |
2848 | get_pcppage_migratetype(page)); | |
2849 | ||
2850 | __count_zid_vm_events(PGALLOC, page_zonenum(page), 1 << order); | |
2851 | zone_statistics(preferred_zone, zone); | |
2852 | local_irq_restore(flags); | |
2853 | ||
2854 | out: | |
2855 | VM_BUG_ON_PAGE(page && bad_range(zone, page), page); | |
2856 | return page; | |
2857 | ||
2858 | failed: | |
2859 | local_irq_restore(flags); | |
2860 | return NULL; | |
2861 | } | |
2862 | ||
2863 | #ifdef CONFIG_FAIL_PAGE_ALLOC | |
2864 | ||
2865 | static struct { | |
2866 | struct fault_attr attr; | |
2867 | ||
2868 | bool ignore_gfp_highmem; | |
2869 | bool ignore_gfp_reclaim; | |
2870 | u32 min_order; | |
2871 | } fail_page_alloc = { | |
2872 | .attr = FAULT_ATTR_INITIALIZER, | |
2873 | .ignore_gfp_reclaim = true, | |
2874 | .ignore_gfp_highmem = true, | |
2875 | .min_order = 1, | |
2876 | }; | |
2877 | ||
2878 | static int __init setup_fail_page_alloc(char *str) | |
2879 | { | |
2880 | return setup_fault_attr(&fail_page_alloc.attr, str); | |
2881 | } | |
2882 | __setup("fail_page_alloc=", setup_fail_page_alloc); | |
2883 | ||
2884 | static bool should_fail_alloc_page(gfp_t gfp_mask, unsigned int order) | |
2885 | { | |
2886 | if (order < fail_page_alloc.min_order) | |
2887 | return false; | |
2888 | if (gfp_mask & __GFP_NOFAIL) | |
2889 | return false; | |
2890 | if (fail_page_alloc.ignore_gfp_highmem && (gfp_mask & __GFP_HIGHMEM)) | |
2891 | return false; | |
2892 | if (fail_page_alloc.ignore_gfp_reclaim && | |
2893 | (gfp_mask & __GFP_DIRECT_RECLAIM)) | |
2894 | return false; | |
2895 | ||
2896 | return should_fail(&fail_page_alloc.attr, 1 << order); | |
2897 | } | |
2898 | ||
2899 | #ifdef CONFIG_FAULT_INJECTION_DEBUG_FS | |
2900 | ||
2901 | static int __init fail_page_alloc_debugfs(void) | |
2902 | { | |
2903 | umode_t mode = S_IFREG | S_IRUSR | S_IWUSR; | |
2904 | struct dentry *dir; | |
2905 | ||
2906 | dir = fault_create_debugfs_attr("fail_page_alloc", NULL, | |
2907 | &fail_page_alloc.attr); | |
2908 | if (IS_ERR(dir)) | |
2909 | return PTR_ERR(dir); | |
2910 | ||
2911 | if (!debugfs_create_bool("ignore-gfp-wait", mode, dir, | |
2912 | &fail_page_alloc.ignore_gfp_reclaim)) | |
2913 | goto fail; | |
2914 | if (!debugfs_create_bool("ignore-gfp-highmem", mode, dir, | |
2915 | &fail_page_alloc.ignore_gfp_highmem)) | |
2916 | goto fail; | |
2917 | if (!debugfs_create_u32("min-order", mode, dir, | |
2918 | &fail_page_alloc.min_order)) | |
2919 | goto fail; | |
2920 | ||
2921 | return 0; | |
2922 | fail: | |
2923 | debugfs_remove_recursive(dir); | |
2924 | ||
2925 | return -ENOMEM; | |
2926 | } | |
2927 | ||
2928 | late_initcall(fail_page_alloc_debugfs); | |
2929 | ||
2930 | #endif /* CONFIG_FAULT_INJECTION_DEBUG_FS */ | |
2931 | ||
2932 | #else /* CONFIG_FAIL_PAGE_ALLOC */ | |
2933 | ||
2934 | static inline bool should_fail_alloc_page(gfp_t gfp_mask, unsigned int order) | |
2935 | { | |
2936 | return false; | |
2937 | } | |
2938 | ||
2939 | #endif /* CONFIG_FAIL_PAGE_ALLOC */ | |
2940 | ||
2941 | /* | |
2942 | * Return true if free base pages are above 'mark'. For high-order checks it | |
2943 | * will return true of the order-0 watermark is reached and there is at least | |
2944 | * one free page of a suitable size. Checking now avoids taking the zone lock | |
2945 | * to check in the allocation paths if no pages are free. | |
2946 | */ | |
2947 | bool __zone_watermark_ok(struct zone *z, unsigned int order, unsigned long mark, | |
2948 | int classzone_idx, unsigned int alloc_flags, | |
2949 | long free_pages) | |
2950 | { | |
2951 | long min = mark; | |
2952 | int o; | |
2953 | const bool alloc_harder = (alloc_flags & ALLOC_HARDER); | |
2954 | ||
2955 | /* free_pages may go negative - that's OK */ | |
2956 | free_pages -= (1 << order) - 1; | |
2957 | ||
2958 | if (alloc_flags & ALLOC_HIGH) | |
2959 | min -= min / 2; | |
2960 | ||
2961 | /* | |
2962 | * If the caller does not have rights to ALLOC_HARDER then subtract | |
2963 | * the high-atomic reserves. This will over-estimate the size of the | |
2964 | * atomic reserve but it avoids a search. | |
2965 | */ | |
2966 | if (likely(!alloc_harder)) | |
2967 | free_pages -= z->nr_reserved_highatomic; | |
2968 | else | |
2969 | min -= min / 4; | |
2970 | ||
2971 | #ifdef CONFIG_CMA | |
2972 | /* If allocation can't use CMA areas don't use free CMA pages */ | |
2973 | if (!(alloc_flags & ALLOC_CMA)) | |
2974 | free_pages -= zone_page_state(z, NR_FREE_CMA_PAGES); | |
2975 | #endif | |
2976 | ||
2977 | /* | |
2978 | * Check watermarks for an order-0 allocation request. If these | |
2979 | * are not met, then a high-order request also cannot go ahead | |
2980 | * even if a suitable page happened to be free. | |
2981 | */ | |
2982 | if (free_pages <= min + z->lowmem_reserve[classzone_idx]) | |
2983 | return false; | |
2984 | ||
2985 | /* If this is an order-0 request then the watermark is fine */ | |
2986 | if (!order) | |
2987 | return true; | |
2988 | ||
2989 | /* For a high-order request, check at least one suitable page is free */ | |
2990 | for (o = order; o < MAX_ORDER; o++) { | |
2991 | struct free_area *area = &z->free_area[o]; | |
2992 | int mt; | |
2993 | ||
2994 | if (!area->nr_free) | |
2995 | continue; | |
2996 | ||
2997 | if (alloc_harder) | |
2998 | return true; | |
2999 | ||
3000 | for (mt = 0; mt < MIGRATE_PCPTYPES; mt++) { | |
3001 | if (!list_empty(&area->free_list[mt])) | |
3002 | return true; | |
3003 | } | |
3004 | ||
3005 | #ifdef CONFIG_CMA | |
3006 | if ((alloc_flags & ALLOC_CMA) && | |
3007 | !list_empty(&area->free_list[MIGRATE_CMA])) { | |
3008 | return true; | |
3009 | } | |
3010 | #endif | |
3011 | } | |
3012 | return false; | |
3013 | } | |
3014 | ||
3015 | bool zone_watermark_ok(struct zone *z, unsigned int order, unsigned long mark, | |
3016 | int classzone_idx, unsigned int alloc_flags) | |
3017 | { | |
3018 | return __zone_watermark_ok(z, order, mark, classzone_idx, alloc_flags, | |
3019 | zone_page_state(z, NR_FREE_PAGES)); | |
3020 | } | |
3021 | ||
3022 | static inline bool zone_watermark_fast(struct zone *z, unsigned int order, | |
3023 | unsigned long mark, int classzone_idx, unsigned int alloc_flags) | |
3024 | { | |
3025 | long free_pages = zone_page_state(z, NR_FREE_PAGES); | |
3026 | long cma_pages = 0; | |
3027 | ||
3028 | #ifdef CONFIG_CMA | |
3029 | /* If allocation can't use CMA areas don't use free CMA pages */ | |
3030 | if (!(alloc_flags & ALLOC_CMA)) | |
3031 | cma_pages = zone_page_state(z, NR_FREE_CMA_PAGES); | |
3032 | #endif | |
3033 | ||
3034 | /* | |
3035 | * Fast check for order-0 only. If this fails then the reserves | |
3036 | * need to be calculated. There is a corner case where the check | |
3037 | * passes but only the high-order atomic reserve are free. If | |
3038 | * the caller is !atomic then it'll uselessly search the free | |
3039 | * list. That corner case is then slower but it is harmless. | |
3040 | */ | |
3041 | if (!order && (free_pages - cma_pages) > mark + z->lowmem_reserve[classzone_idx]) | |
3042 | return true; | |
3043 | ||
3044 | return __zone_watermark_ok(z, order, mark, classzone_idx, alloc_flags, | |
3045 | free_pages); | |
3046 | } | |
3047 | ||
3048 | bool zone_watermark_ok_safe(struct zone *z, unsigned int order, | |
3049 | unsigned long mark, int classzone_idx) | |
3050 | { | |
3051 | long free_pages = zone_page_state(z, NR_FREE_PAGES); | |
3052 | ||
3053 | if (z->percpu_drift_mark && free_pages < z->percpu_drift_mark) | |
3054 | free_pages = zone_page_state_snapshot(z, NR_FREE_PAGES); | |
3055 | ||
3056 | return __zone_watermark_ok(z, order, mark, classzone_idx, 0, | |
3057 | free_pages); | |
3058 | } | |
3059 | ||
3060 | #ifdef CONFIG_NUMA | |
3061 | static bool zone_allows_reclaim(struct zone *local_zone, struct zone *zone) | |
3062 | { | |
3063 | return node_distance(zone_to_nid(local_zone), zone_to_nid(zone)) <= | |
3064 | RECLAIM_DISTANCE; | |
3065 | } | |
3066 | #else /* CONFIG_NUMA */ | |
3067 | static bool zone_allows_reclaim(struct zone *local_zone, struct zone *zone) | |
3068 | { | |
3069 | return true; | |
3070 | } | |
3071 | #endif /* CONFIG_NUMA */ | |
3072 | ||
3073 | /* | |
3074 | * get_page_from_freelist goes through the zonelist trying to allocate | |
3075 | * a page. | |
3076 | */ | |
3077 | static struct page * | |
3078 | get_page_from_freelist(gfp_t gfp_mask, unsigned int order, int alloc_flags, | |
3079 | const struct alloc_context *ac) | |
3080 | { | |
3081 | struct zoneref *z = ac->preferred_zoneref; | |
3082 | struct zone *zone; | |
3083 | struct pglist_data *last_pgdat_dirty_limit = NULL; | |
3084 | ||
3085 | /* | |
3086 | * Scan zonelist, looking for a zone with enough free. | |
3087 | * See also __cpuset_node_allowed() comment in kernel/cpuset.c. | |
3088 | */ | |
3089 | for_next_zone_zonelist_nodemask(zone, z, ac->zonelist, ac->high_zoneidx, | |
3090 | ac->nodemask) { | |
3091 | struct page *page; | |
3092 | unsigned long mark; | |
3093 | ||
3094 | if (cpusets_enabled() && | |
3095 | (alloc_flags & ALLOC_CPUSET) && | |
3096 | !__cpuset_zone_allowed(zone, gfp_mask)) | |
3097 | continue; | |
3098 | /* | |
3099 | * When allocating a page cache page for writing, we | |
3100 | * want to get it from a node that is within its dirty | |
3101 | * limit, such that no single node holds more than its | |
3102 | * proportional share of globally allowed dirty pages. | |
3103 | * The dirty limits take into account the node's | |
3104 | * lowmem reserves and high watermark so that kswapd | |
3105 | * should be able to balance it without having to | |
3106 | * write pages from its LRU list. | |
3107 | * | |
3108 | * XXX: For now, allow allocations to potentially | |
3109 | * exceed the per-node dirty limit in the slowpath | |
3110 | * (spread_dirty_pages unset) before going into reclaim, | |
3111 | * which is important when on a NUMA setup the allowed | |
3112 | * nodes are together not big enough to reach the | |
3113 | * global limit. The proper fix for these situations | |
3114 | * will require awareness of nodes in the | |
3115 | * dirty-throttling and the flusher threads. | |
3116 | */ | |
3117 | if (ac->spread_dirty_pages) { | |
3118 | if (last_pgdat_dirty_limit == zone->zone_pgdat) | |
3119 | continue; | |
3120 | ||
3121 | if (!node_dirty_ok(zone->zone_pgdat)) { | |
3122 | last_pgdat_dirty_limit = zone->zone_pgdat; | |
3123 | continue; | |
3124 | } | |
3125 | } | |
3126 | ||
3127 | mark = zone->watermark[alloc_flags & ALLOC_WMARK_MASK]; | |
3128 | if (!zone_watermark_fast(zone, order, mark, | |
3129 | ac_classzone_idx(ac), alloc_flags)) { | |
3130 | int ret; | |
3131 | ||
3132 | /* Checked here to keep the fast path fast */ | |
3133 | BUILD_BUG_ON(ALLOC_NO_WATERMARKS < NR_WMARK); | |
3134 | if (alloc_flags & ALLOC_NO_WATERMARKS) | |
3135 | goto try_this_zone; | |
3136 | ||
3137 | if (node_reclaim_mode == 0 || | |
3138 | !zone_allows_reclaim(ac->preferred_zoneref->zone, zone)) | |
3139 | continue; | |
3140 | ||
3141 | ret = node_reclaim(zone->zone_pgdat, gfp_mask, order); | |
3142 | switch (ret) { | |
3143 | case NODE_RECLAIM_NOSCAN: | |
3144 | /* did not scan */ | |
3145 | continue; | |
3146 | case NODE_RECLAIM_FULL: | |
3147 | /* scanned but unreclaimable */ | |
3148 | continue; | |
3149 | default: | |
3150 | /* did we reclaim enough */ | |
3151 | if (zone_watermark_ok(zone, order, mark, | |
3152 | ac_classzone_idx(ac), alloc_flags)) | |
3153 | goto try_this_zone; | |
3154 | ||
3155 | continue; | |
3156 | } | |
3157 | } | |
3158 | ||
3159 | try_this_zone: | |
3160 | page = rmqueue(ac->preferred_zoneref->zone, zone, order, | |
3161 | gfp_mask, alloc_flags, ac->migratetype); | |
3162 | if (page) { | |
3163 | prep_new_page(page, order, gfp_mask, alloc_flags); | |
3164 | ||
3165 | /* | |
3166 | * If this is a high-order atomic allocation then check | |
3167 | * if the pageblock should be reserved for the future | |
3168 | */ | |
3169 | if (unlikely(order && (alloc_flags & ALLOC_HARDER))) | |
3170 | reserve_highatomic_pageblock(page, zone, order); | |
3171 | ||
3172 | return page; | |
3173 | } | |
3174 | } | |
3175 | ||
3176 | return NULL; | |
3177 | } | |
3178 | ||
3179 | /* | |
3180 | * Large machines with many possible nodes should not always dump per-node | |
3181 | * meminfo in irq context. | |
3182 | */ | |
3183 | static inline bool should_suppress_show_mem(void) | |
3184 | { | |
3185 | bool ret = false; | |
3186 | ||
3187 | #if NODES_SHIFT > 8 | |
3188 | ret = in_interrupt(); | |
3189 | #endif | |
3190 | return ret; | |
3191 | } | |
3192 | ||
3193 | static void warn_alloc_show_mem(gfp_t gfp_mask, nodemask_t *nodemask) | |
3194 | { | |
3195 | unsigned int filter = SHOW_MEM_FILTER_NODES; | |
3196 | static DEFINE_RATELIMIT_STATE(show_mem_rs, HZ, 1); | |
3197 | ||
3198 | if (should_suppress_show_mem() || !__ratelimit(&show_mem_rs)) | |
3199 | return; | |
3200 | ||
3201 | /* | |
3202 | * This documents exceptions given to allocations in certain | |
3203 | * contexts that are allowed to allocate outside current's set | |
3204 | * of allowed nodes. | |
3205 | */ | |
3206 | if (!(gfp_mask & __GFP_NOMEMALLOC)) | |
3207 | if (test_thread_flag(TIF_MEMDIE) || | |
3208 | (current->flags & (PF_MEMALLOC | PF_EXITING))) | |
3209 | filter &= ~SHOW_MEM_FILTER_NODES; | |
3210 | if (in_interrupt() || !(gfp_mask & __GFP_DIRECT_RECLAIM)) | |
3211 | filter &= ~SHOW_MEM_FILTER_NODES; | |
3212 | ||
3213 | show_mem(filter, nodemask); | |
3214 | } | |
3215 | ||
3216 | void warn_alloc(gfp_t gfp_mask, nodemask_t *nodemask, const char *fmt, ...) | |
3217 | { | |
3218 | struct va_format vaf; | |
3219 | va_list args; | |
3220 | static DEFINE_RATELIMIT_STATE(nopage_rs, DEFAULT_RATELIMIT_INTERVAL, | |
3221 | DEFAULT_RATELIMIT_BURST); | |
3222 | ||
3223 | if ((gfp_mask & __GFP_NOWARN) || !__ratelimit(&nopage_rs)) | |
3224 | return; | |
3225 | ||
3226 | pr_warn("%s: ", current->comm); | |
3227 | ||
3228 | va_start(args, fmt); | |
3229 | vaf.fmt = fmt; | |
3230 | vaf.va = &args; | |
3231 | pr_cont("%pV", &vaf); | |
3232 | va_end(args); | |
3233 | ||
3234 | pr_cont(", mode:%#x(%pGg), nodemask=", gfp_mask, &gfp_mask); | |
3235 | if (nodemask) | |
3236 | pr_cont("%*pbl\n", nodemask_pr_args(nodemask)); | |
3237 | else | |
3238 | pr_cont("(null)\n"); | |
3239 | ||
3240 | cpuset_print_current_mems_allowed(); | |
3241 | ||
3242 | dump_stack(); | |
3243 | warn_alloc_show_mem(gfp_mask, nodemask); | |
3244 | } | |
3245 | ||
3246 | static inline struct page * | |
3247 | __alloc_pages_cpuset_fallback(gfp_t gfp_mask, unsigned int order, | |
3248 | unsigned int alloc_flags, | |
3249 | const struct alloc_context *ac) | |
3250 | { | |
3251 | struct page *page; | |
3252 | ||
3253 | page = get_page_from_freelist(gfp_mask, order, | |
3254 | alloc_flags|ALLOC_CPUSET, ac); | |
3255 | /* | |
3256 | * fallback to ignore cpuset restriction if our nodes | |
3257 | * are depleted | |
3258 | */ | |
3259 | if (!page) | |
3260 | page = get_page_from_freelist(gfp_mask, order, | |
3261 | alloc_flags, ac); | |
3262 | ||
3263 | return page; | |
3264 | } | |
3265 | ||
3266 | static inline struct page * | |
3267 | __alloc_pages_may_oom(gfp_t gfp_mask, unsigned int order, | |
3268 | const struct alloc_context *ac, unsigned long *did_some_progress) | |
3269 | { | |
3270 | struct oom_control oc = { | |
3271 | .zonelist = ac->zonelist, | |
3272 | .nodemask = ac->nodemask, | |
3273 | .memcg = NULL, | |
3274 | .gfp_mask = gfp_mask, | |
3275 | .order = order, | |
3276 | }; | |
3277 | struct page *page; | |
3278 | ||
3279 | *did_some_progress = 0; | |
3280 | ||
3281 | /* | |
3282 | * Acquire the oom lock. If that fails, somebody else is | |
3283 | * making progress for us. | |
3284 | */ | |
3285 | if (!mutex_trylock(&oom_lock)) { | |
3286 | *did_some_progress = 1; | |
3287 | schedule_timeout_uninterruptible(1); | |
3288 | return NULL; | |
3289 | } | |
3290 | ||
3291 | /* | |
3292 | * Go through the zonelist yet one more time, keep very high watermark | |
3293 | * here, this is only to catch a parallel oom killing, we must fail if | |
3294 | * we're still under heavy pressure. But make sure that this reclaim | |
3295 | * attempt shall not depend on __GFP_DIRECT_RECLAIM && !__GFP_NORETRY | |
3296 | * allocation which will never fail due to oom_lock already held. | |
3297 | */ | |
3298 | page = get_page_from_freelist((gfp_mask | __GFP_HARDWALL) & | |
3299 | ~__GFP_DIRECT_RECLAIM, order, | |
3300 | ALLOC_WMARK_HIGH|ALLOC_CPUSET, ac); | |
3301 | if (page) | |
3302 | goto out; | |
3303 | ||
3304 | /* Coredumps can quickly deplete all memory reserves */ | |
3305 | if (current->flags & PF_DUMPCORE) | |
3306 | goto out; | |
3307 | /* The OOM killer will not help higher order allocs */ | |
3308 | if (order > PAGE_ALLOC_COSTLY_ORDER) | |
3309 | goto out; | |
3310 | /* | |
3311 | * We have already exhausted all our reclaim opportunities without any | |
3312 | * success so it is time to admit defeat. We will skip the OOM killer | |
3313 | * because it is very likely that the caller has a more reasonable | |
3314 | * fallback than shooting a random task. | |
3315 | */ | |
3316 | if (gfp_mask & __GFP_RETRY_MAYFAIL) | |
3317 | goto out; | |
3318 | /* The OOM killer does not needlessly kill tasks for lowmem */ | |
3319 | if (ac->high_zoneidx < ZONE_NORMAL) | |
3320 | goto out; | |
3321 | if (pm_suspended_storage()) | |
3322 | goto out; | |
3323 | /* | |
3324 | * XXX: GFP_NOFS allocations should rather fail than rely on | |
3325 | * other request to make a forward progress. | |
3326 | * We are in an unfortunate situation where out_of_memory cannot | |
3327 | * do much for this context but let's try it to at least get | |
3328 | * access to memory reserved if the current task is killed (see | |
3329 | * out_of_memory). Once filesystems are ready to handle allocation | |
3330 | * failures more gracefully we should just bail out here. | |
3331 | */ | |
3332 | ||
3333 | /* The OOM killer may not free memory on a specific node */ | |
3334 | if (gfp_mask & __GFP_THISNODE) | |
3335 | goto out; | |
3336 | ||
3337 | /* Exhausted what can be done so it's blamo time */ | |
3338 | if (out_of_memory(&oc) || WARN_ON_ONCE(gfp_mask & __GFP_NOFAIL)) { | |
3339 | *did_some_progress = 1; | |
3340 | ||
3341 | /* | |
3342 | * Help non-failing allocations by giving them access to memory | |
3343 | * reserves | |
3344 | */ | |
3345 | if (gfp_mask & __GFP_NOFAIL) | |
3346 | page = __alloc_pages_cpuset_fallback(gfp_mask, order, | |
3347 | ALLOC_NO_WATERMARKS, ac); | |
3348 | } | |
3349 | out: | |
3350 | mutex_unlock(&oom_lock); | |
3351 | return page; | |
3352 | } | |
3353 | ||
3354 | /* | |
3355 | * Maximum number of compaction retries wit a progress before OOM | |
3356 | * killer is consider as the only way to move forward. | |
3357 | */ | |
3358 | #define MAX_COMPACT_RETRIES 16 | |
3359 | ||
3360 | #ifdef CONFIG_COMPACTION | |
3361 | /* Try memory compaction for high-order allocations before reclaim */ | |
3362 | static struct page * | |
3363 | __alloc_pages_direct_compact(gfp_t gfp_mask, unsigned int order, | |
3364 | unsigned int alloc_flags, const struct alloc_context *ac, | |
3365 | enum compact_priority prio, enum compact_result *compact_result) | |
3366 | { | |
3367 | struct page *page; | |
3368 | unsigned int noreclaim_flag; | |
3369 | ||
3370 | if (!order) | |
3371 | return NULL; | |
3372 | ||
3373 | noreclaim_flag = memalloc_noreclaim_save(); | |
3374 | *compact_result = try_to_compact_pages(gfp_mask, order, alloc_flags, ac, | |
3375 | prio); | |
3376 | memalloc_noreclaim_restore(noreclaim_flag); | |
3377 | ||
3378 | if (*compact_result <= COMPACT_INACTIVE) | |
3379 | return NULL; | |
3380 | ||
3381 | /* | |
3382 | * At least in one zone compaction wasn't deferred or skipped, so let's | |
3383 | * count a compaction stall | |
3384 | */ | |
3385 | count_vm_event(COMPACTSTALL); | |
3386 | ||
3387 | page = get_page_from_freelist(gfp_mask, order, alloc_flags, ac); | |
3388 | ||
3389 | if (page) { | |
3390 | struct zone *zone = page_zone(page); | |
3391 | ||
3392 | zone->compact_blockskip_flush = false; | |
3393 | compaction_defer_reset(zone, order, true); | |
3394 | count_vm_event(COMPACTSUCCESS); | |
3395 | return page; | |
3396 | } | |
3397 | ||
3398 | /* | |
3399 | * It's bad if compaction run occurs and fails. The most likely reason | |
3400 | * is that pages exist, but not enough to satisfy watermarks. | |
3401 | */ | |
3402 | count_vm_event(COMPACTFAIL); | |
3403 | ||
3404 | cond_resched(); | |
3405 | ||
3406 | return NULL; | |
3407 | } | |
3408 | ||
3409 | static inline bool | |
3410 | should_compact_retry(struct alloc_context *ac, int order, int alloc_flags, | |
3411 | enum compact_result compact_result, | |
3412 | enum compact_priority *compact_priority, | |
3413 | int *compaction_retries) | |
3414 | { | |
3415 | int max_retries = MAX_COMPACT_RETRIES; | |
3416 | int min_priority; | |
3417 | bool ret = false; | |
3418 | int retries = *compaction_retries; | |
3419 | enum compact_priority priority = *compact_priority; | |
3420 | ||
3421 | if (!order) | |
3422 | return false; | |
3423 | ||
3424 | if (compaction_made_progress(compact_result)) | |
3425 | (*compaction_retries)++; | |
3426 | ||
3427 | /* | |
3428 | * compaction considers all the zone as desperately out of memory | |
3429 | * so it doesn't really make much sense to retry except when the | |
3430 | * failure could be caused by insufficient priority | |
3431 | */ | |
3432 | if (compaction_failed(compact_result)) | |
3433 | goto check_priority; | |
3434 | ||
3435 | /* | |
3436 | * make sure the compaction wasn't deferred or didn't bail out early | |
3437 | * due to locks contention before we declare that we should give up. | |
3438 | * But do not retry if the given zonelist is not suitable for | |
3439 | * compaction. | |
3440 | */ | |
3441 | if (compaction_withdrawn(compact_result)) { | |
3442 | ret = compaction_zonelist_suitable(ac, order, alloc_flags); | |
3443 | goto out; | |
3444 | } | |
3445 | ||
3446 | /* | |
3447 | * !costly requests are much more important than __GFP_RETRY_MAYFAIL | |
3448 | * costly ones because they are de facto nofail and invoke OOM | |
3449 | * killer to move on while costly can fail and users are ready | |
3450 | * to cope with that. 1/4 retries is rather arbitrary but we | |
3451 | * would need much more detailed feedback from compaction to | |
3452 | * make a better decision. | |
3453 | */ | |
3454 | if (order > PAGE_ALLOC_COSTLY_ORDER) | |
3455 | max_retries /= 4; | |
3456 | if (*compaction_retries <= max_retries) { | |
3457 | ret = true; | |
3458 | goto out; | |
3459 | } | |
3460 | ||
3461 | /* | |
3462 | * Make sure there are attempts at the highest priority if we exhausted | |
3463 | * all retries or failed at the lower priorities. | |
3464 | */ | |
3465 | check_priority: | |
3466 | min_priority = (order > PAGE_ALLOC_COSTLY_ORDER) ? | |
3467 | MIN_COMPACT_COSTLY_PRIORITY : MIN_COMPACT_PRIORITY; | |
3468 | ||
3469 | if (*compact_priority > min_priority) { | |
3470 | (*compact_priority)--; | |
3471 | *compaction_retries = 0; | |
3472 | ret = true; | |
3473 | } | |
3474 | out: | |
3475 | trace_compact_retry(order, priority, compact_result, retries, max_retries, ret); | |
3476 | return ret; | |
3477 | } | |
3478 | #else | |
3479 | static inline struct page * | |
3480 | __alloc_pages_direct_compact(gfp_t gfp_mask, unsigned int order, | |
3481 | unsigned int alloc_flags, const struct alloc_context *ac, | |
3482 | enum compact_priority prio, enum compact_result *compact_result) | |
3483 | { | |
3484 | *compact_result = COMPACT_SKIPPED; | |
3485 | return NULL; | |
3486 | } | |
3487 | ||
3488 | static inline bool | |
3489 | should_compact_retry(struct alloc_context *ac, unsigned int order, int alloc_flags, | |
3490 | enum compact_result compact_result, | |
3491 | enum compact_priority *compact_priority, | |
3492 | int *compaction_retries) | |
3493 | { | |
3494 | struct zone *zone; | |
3495 | struct zoneref *z; | |
3496 | ||
3497 | if (!order || order > PAGE_ALLOC_COSTLY_ORDER) | |
3498 | return false; | |
3499 | ||
3500 | /* | |
3501 | * There are setups with compaction disabled which would prefer to loop | |
3502 | * inside the allocator rather than hit the oom killer prematurely. | |
3503 | * Let's give them a good hope and keep retrying while the order-0 | |
3504 | * watermarks are OK. | |
3505 | */ | |
3506 | for_each_zone_zonelist_nodemask(zone, z, ac->zonelist, ac->high_zoneidx, | |
3507 | ac->nodemask) { | |
3508 | if (zone_watermark_ok(zone, 0, min_wmark_pages(zone), | |
3509 | ac_classzone_idx(ac), alloc_flags)) | |
3510 | return true; | |
3511 | } | |
3512 | return false; | |
3513 | } | |
3514 | #endif /* CONFIG_COMPACTION */ | |
3515 | ||
3516 | /* Perform direct synchronous page reclaim */ | |
3517 | static int | |
3518 | __perform_reclaim(gfp_t gfp_mask, unsigned int order, | |
3519 | const struct alloc_context *ac) | |
3520 | { | |
3521 | struct reclaim_state reclaim_state; | |
3522 | int progress; | |
3523 | unsigned int noreclaim_flag; | |
3524 | ||
3525 | cond_resched(); | |
3526 | ||
3527 | /* We now go into synchronous reclaim */ | |
3528 | cpuset_memory_pressure_bump(); | |
3529 | noreclaim_flag = memalloc_noreclaim_save(); | |
3530 | lockdep_set_current_reclaim_state(gfp_mask); | |
3531 | reclaim_state.reclaimed_slab = 0; | |
3532 | current->reclaim_state = &reclaim_state; | |
3533 | ||
3534 | progress = try_to_free_pages(ac->zonelist, order, gfp_mask, | |
3535 | ac->nodemask); | |
3536 | ||
3537 | current->reclaim_state = NULL; | |
3538 | lockdep_clear_current_reclaim_state(); | |
3539 | memalloc_noreclaim_restore(noreclaim_flag); | |
3540 | ||
3541 | cond_resched(); | |
3542 | ||
3543 | return progress; | |
3544 | } | |
3545 | ||
3546 | /* The really slow allocator path where we enter direct reclaim */ | |
3547 | static inline struct page * | |
3548 | __alloc_pages_direct_reclaim(gfp_t gfp_mask, unsigned int order, | |
3549 | unsigned int alloc_flags, const struct alloc_context *ac, | |
3550 | unsigned long *did_some_progress) | |
3551 | { | |
3552 | struct page *page = NULL; | |
3553 | bool drained = false; | |
3554 | ||
3555 | *did_some_progress = __perform_reclaim(gfp_mask, order, ac); | |
3556 | if (unlikely(!(*did_some_progress))) | |
3557 | return NULL; | |
3558 | ||
3559 | retry: | |
3560 | page = get_page_from_freelist(gfp_mask, order, alloc_flags, ac); | |
3561 | ||
3562 | /* | |
3563 | * If an allocation failed after direct reclaim, it could be because | |
3564 | * pages are pinned on the per-cpu lists or in high alloc reserves. | |
3565 | * Shrink them them and try again | |
3566 | */ | |
3567 | if (!page && !drained) { | |
3568 | unreserve_highatomic_pageblock(ac, false); | |
3569 | drain_all_pages(NULL); | |
3570 | drained = true; | |
3571 | goto retry; | |
3572 | } | |
3573 | ||
3574 | return page; | |
3575 | } | |
3576 | ||
3577 | static void wake_all_kswapds(unsigned int order, const struct alloc_context *ac) | |
3578 | { | |
3579 | struct zoneref *z; | |
3580 | struct zone *zone; | |
3581 | pg_data_t *last_pgdat = NULL; | |
3582 | ||
3583 | for_each_zone_zonelist_nodemask(zone, z, ac->zonelist, | |
3584 | ac->high_zoneidx, ac->nodemask) { | |
3585 | if (last_pgdat != zone->zone_pgdat) | |
3586 | wakeup_kswapd(zone, order, ac->high_zoneidx); | |
3587 | last_pgdat = zone->zone_pgdat; | |
3588 | } | |
3589 | } | |
3590 | ||
3591 | static inline unsigned int | |
3592 | gfp_to_alloc_flags(gfp_t gfp_mask) | |
3593 | { | |
3594 | unsigned int alloc_flags = ALLOC_WMARK_MIN | ALLOC_CPUSET; | |
3595 | ||
3596 | /* __GFP_HIGH is assumed to be the same as ALLOC_HIGH to save a branch. */ | |
3597 | BUILD_BUG_ON(__GFP_HIGH != (__force gfp_t) ALLOC_HIGH); | |
3598 | ||
3599 | /* | |
3600 | * The caller may dip into page reserves a bit more if the caller | |
3601 | * cannot run direct reclaim, or if the caller has realtime scheduling | |
3602 | * policy or is asking for __GFP_HIGH memory. GFP_ATOMIC requests will | |
3603 | * set both ALLOC_HARDER (__GFP_ATOMIC) and ALLOC_HIGH (__GFP_HIGH). | |
3604 | */ | |
3605 | alloc_flags |= (__force int) (gfp_mask & __GFP_HIGH); | |
3606 | ||
3607 | if (gfp_mask & __GFP_ATOMIC) { | |
3608 | /* | |
3609 | * Not worth trying to allocate harder for __GFP_NOMEMALLOC even | |
3610 | * if it can't schedule. | |
3611 | */ | |
3612 | if (!(gfp_mask & __GFP_NOMEMALLOC)) | |
3613 | alloc_flags |= ALLOC_HARDER; | |
3614 | /* | |
3615 | * Ignore cpuset mems for GFP_ATOMIC rather than fail, see the | |
3616 | * comment for __cpuset_node_allowed(). | |
3617 | */ | |
3618 | alloc_flags &= ~ALLOC_CPUSET; | |
3619 | } else if (unlikely(rt_task(current)) && !in_interrupt()) | |
3620 | alloc_flags |= ALLOC_HARDER; | |
3621 | ||
3622 | #ifdef CONFIG_CMA | |
3623 | if (gfpflags_to_migratetype(gfp_mask) == MIGRATE_MOVABLE) | |
3624 | alloc_flags |= ALLOC_CMA; | |
3625 | #endif | |
3626 | return alloc_flags; | |
3627 | } | |
3628 | ||
3629 | bool gfp_pfmemalloc_allowed(gfp_t gfp_mask) | |
3630 | { | |
3631 | if (unlikely(gfp_mask & __GFP_NOMEMALLOC)) | |
3632 | return false; | |
3633 | ||
3634 | if (gfp_mask & __GFP_MEMALLOC) | |
3635 | return true; | |
3636 | if (in_serving_softirq() && (current->flags & PF_MEMALLOC)) | |
3637 | return true; | |
3638 | if (!in_interrupt() && | |
3639 | ((current->flags & PF_MEMALLOC) || | |
3640 | unlikely(test_thread_flag(TIF_MEMDIE)))) | |
3641 | return true; | |
3642 | ||
3643 | return false; | |
3644 | } | |
3645 | ||
3646 | /* | |
3647 | * Checks whether it makes sense to retry the reclaim to make a forward progress | |
3648 | * for the given allocation request. | |
3649 | * | |
3650 | * We give up when we either have tried MAX_RECLAIM_RETRIES in a row | |
3651 | * without success, or when we couldn't even meet the watermark if we | |
3652 | * reclaimed all remaining pages on the LRU lists. | |
3653 | * | |
3654 | * Returns true if a retry is viable or false to enter the oom path. | |
3655 | */ | |
3656 | static inline bool | |
3657 | should_reclaim_retry(gfp_t gfp_mask, unsigned order, | |
3658 | struct alloc_context *ac, int alloc_flags, | |
3659 | bool did_some_progress, int *no_progress_loops) | |
3660 | { | |
3661 | struct zone *zone; | |
3662 | struct zoneref *z; | |
3663 | ||
3664 | /* | |
3665 | * Costly allocations might have made a progress but this doesn't mean | |
3666 | * their order will become available due to high fragmentation so | |
3667 | * always increment the no progress counter for them | |
3668 | */ | |
3669 | if (did_some_progress && order <= PAGE_ALLOC_COSTLY_ORDER) | |
3670 | *no_progress_loops = 0; | |
3671 | else | |
3672 | (*no_progress_loops)++; | |
3673 | ||
3674 | /* | |
3675 | * Make sure we converge to OOM if we cannot make any progress | |
3676 | * several times in the row. | |
3677 | */ | |
3678 | if (*no_progress_loops > MAX_RECLAIM_RETRIES) { | |
3679 | /* Before OOM, exhaust highatomic_reserve */ | |
3680 | return unreserve_highatomic_pageblock(ac, true); | |
3681 | } | |
3682 | ||
3683 | /* | |
3684 | * Keep reclaiming pages while there is a chance this will lead | |
3685 | * somewhere. If none of the target zones can satisfy our allocation | |
3686 | * request even if all reclaimable pages are considered then we are | |
3687 | * screwed and have to go OOM. | |
3688 | */ | |
3689 | for_each_zone_zonelist_nodemask(zone, z, ac->zonelist, ac->high_zoneidx, | |
3690 | ac->nodemask) { | |
3691 | unsigned long available; | |
3692 | unsigned long reclaimable; | |
3693 | unsigned long min_wmark = min_wmark_pages(zone); | |
3694 | bool wmark; | |
3695 | ||
3696 | available = reclaimable = zone_reclaimable_pages(zone); | |
3697 | available += zone_page_state_snapshot(zone, NR_FREE_PAGES); | |
3698 | ||
3699 | /* | |
3700 | * Would the allocation succeed if we reclaimed all | |
3701 | * reclaimable pages? | |
3702 | */ | |
3703 | wmark = __zone_watermark_ok(zone, order, min_wmark, | |
3704 | ac_classzone_idx(ac), alloc_flags, available); | |
3705 | trace_reclaim_retry_zone(z, order, reclaimable, | |
3706 | available, min_wmark, *no_progress_loops, wmark); | |
3707 | if (wmark) { | |
3708 | /* | |
3709 | * If we didn't make any progress and have a lot of | |
3710 | * dirty + writeback pages then we should wait for | |
3711 | * an IO to complete to slow down the reclaim and | |
3712 | * prevent from pre mature OOM | |
3713 | */ | |
3714 | if (!did_some_progress) { | |
3715 | unsigned long write_pending; | |
3716 | ||
3717 | write_pending = zone_page_state_snapshot(zone, | |
3718 | NR_ZONE_WRITE_PENDING); | |
3719 | ||
3720 | if (2 * write_pending > reclaimable) { | |
3721 | congestion_wait(BLK_RW_ASYNC, HZ/10); | |
3722 | return true; | |
3723 | } | |
3724 | } | |
3725 | ||
3726 | /* | |
3727 | * Memory allocation/reclaim might be called from a WQ | |
3728 | * context and the current implementation of the WQ | |
3729 | * concurrency control doesn't recognize that | |
3730 | * a particular WQ is congested if the worker thread is | |
3731 | * looping without ever sleeping. Therefore we have to | |
3732 | * do a short sleep here rather than calling | |
3733 | * cond_resched(). | |
3734 | */ | |
3735 | if (current->flags & PF_WQ_WORKER) | |
3736 | schedule_timeout_uninterruptible(1); | |
3737 | else | |
3738 | cond_resched(); | |
3739 | ||
3740 | return true; | |
3741 | } | |
3742 | } | |
3743 | ||
3744 | return false; | |
3745 | } | |
3746 | ||
3747 | static inline bool | |
3748 | check_retry_cpuset(int cpuset_mems_cookie, struct alloc_context *ac) | |
3749 | { | |
3750 | /* | |
3751 | * It's possible that cpuset's mems_allowed and the nodemask from | |
3752 | * mempolicy don't intersect. This should be normally dealt with by | |
3753 | * policy_nodemask(), but it's possible to race with cpuset update in | |
3754 | * such a way the check therein was true, and then it became false | |
3755 | * before we got our cpuset_mems_cookie here. | |
3756 | * This assumes that for all allocations, ac->nodemask can come only | |
3757 | * from MPOL_BIND mempolicy (whose documented semantics is to be ignored | |
3758 | * when it does not intersect with the cpuset restrictions) or the | |
3759 | * caller can deal with a violated nodemask. | |
3760 | */ | |
3761 | if (cpusets_enabled() && ac->nodemask && | |
3762 | !cpuset_nodemask_valid_mems_allowed(ac->nodemask)) { | |
3763 | ac->nodemask = NULL; | |
3764 | return true; | |
3765 | } | |
3766 | ||
3767 | /* | |
3768 | * When updating a task's mems_allowed or mempolicy nodemask, it is | |
3769 | * possible to race with parallel threads in such a way that our | |
3770 | * allocation can fail while the mask is being updated. If we are about | |
3771 | * to fail, check if the cpuset changed during allocation and if so, | |
3772 | * retry. | |
3773 | */ | |
3774 | if (read_mems_allowed_retry(cpuset_mems_cookie)) | |
3775 | return true; | |
3776 | ||
3777 | return false; | |
3778 | } | |
3779 | ||
3780 | static inline struct page * | |
3781 | __alloc_pages_slowpath(gfp_t gfp_mask, unsigned int order, | |
3782 | struct alloc_context *ac) | |
3783 | { | |
3784 | bool can_direct_reclaim = gfp_mask & __GFP_DIRECT_RECLAIM; | |
3785 | const bool costly_order = order > PAGE_ALLOC_COSTLY_ORDER; | |
3786 | struct page *page = NULL; | |
3787 | unsigned int alloc_flags; | |
3788 | unsigned long did_some_progress; | |
3789 | enum compact_priority compact_priority; | |
3790 | enum compact_result compact_result; | |
3791 | int compaction_retries; | |
3792 | int no_progress_loops; | |
3793 | unsigned long alloc_start = jiffies; | |
3794 | unsigned int stall_timeout = 10 * HZ; | |
3795 | unsigned int cpuset_mems_cookie; | |
3796 | ||
3797 | /* | |
3798 | * In the slowpath, we sanity check order to avoid ever trying to | |
3799 | * reclaim >= MAX_ORDER areas which will never succeed. Callers may | |
3800 | * be using allocators in order of preference for an area that is | |
3801 | * too large. | |
3802 | */ | |
3803 | if (order >= MAX_ORDER) { | |
3804 | WARN_ON_ONCE(!(gfp_mask & __GFP_NOWARN)); | |
3805 | return NULL; | |
3806 | } | |
3807 | ||
3808 | /* | |
3809 | * We also sanity check to catch abuse of atomic reserves being used by | |
3810 | * callers that are not in atomic context. | |
3811 | */ | |
3812 | if (WARN_ON_ONCE((gfp_mask & (__GFP_ATOMIC|__GFP_DIRECT_RECLAIM)) == | |
3813 | (__GFP_ATOMIC|__GFP_DIRECT_RECLAIM))) | |
3814 | gfp_mask &= ~__GFP_ATOMIC; | |
3815 | ||
3816 | retry_cpuset: | |
3817 | compaction_retries = 0; | |
3818 | no_progress_loops = 0; | |
3819 | compact_priority = DEF_COMPACT_PRIORITY; | |
3820 | cpuset_mems_cookie = read_mems_allowed_begin(); | |
3821 | ||
3822 | /* | |
3823 | * The fast path uses conservative alloc_flags to succeed only until | |
3824 | * kswapd needs to be woken up, and to avoid the cost of setting up | |
3825 | * alloc_flags precisely. So we do that now. | |
3826 | */ | |
3827 | alloc_flags = gfp_to_alloc_flags(gfp_mask); | |
3828 | ||
3829 | /* | |
3830 | * We need to recalculate the starting point for the zonelist iterator | |
3831 | * because we might have used different nodemask in the fast path, or | |
3832 | * there was a cpuset modification and we are retrying - otherwise we | |
3833 | * could end up iterating over non-eligible zones endlessly. | |
3834 | */ | |
3835 | ac->preferred_zoneref = first_zones_zonelist(ac->zonelist, | |
3836 | ac->high_zoneidx, ac->nodemask); | |
3837 | if (!ac->preferred_zoneref->zone) | |
3838 | goto nopage; | |
3839 | ||
3840 | if (gfp_mask & __GFP_KSWAPD_RECLAIM) | |
3841 | wake_all_kswapds(order, ac); | |
3842 | ||
3843 | /* | |
3844 | * The adjusted alloc_flags might result in immediate success, so try | |
3845 | * that first | |
3846 | */ | |
3847 | page = get_page_from_freelist(gfp_mask, order, alloc_flags, ac); | |
3848 | if (page) | |
3849 | goto got_pg; | |
3850 | ||
3851 | /* | |
3852 | * For costly allocations, try direct compaction first, as it's likely | |
3853 | * that we have enough base pages and don't need to reclaim. For non- | |
3854 | * movable high-order allocations, do that as well, as compaction will | |
3855 | * try prevent permanent fragmentation by migrating from blocks of the | |
3856 | * same migratetype. | |
3857 | * Don't try this for allocations that are allowed to ignore | |
3858 | * watermarks, as the ALLOC_NO_WATERMARKS attempt didn't yet happen. | |
3859 | */ | |
3860 | if (can_direct_reclaim && | |
3861 | (costly_order || | |
3862 | (order > 0 && ac->migratetype != MIGRATE_MOVABLE)) | |
3863 | && !gfp_pfmemalloc_allowed(gfp_mask)) { | |
3864 | page = __alloc_pages_direct_compact(gfp_mask, order, | |
3865 | alloc_flags, ac, | |
3866 | INIT_COMPACT_PRIORITY, | |
3867 | &compact_result); | |
3868 | if (page) | |
3869 | goto got_pg; | |
3870 | ||
3871 | /* | |
3872 | * Checks for costly allocations with __GFP_NORETRY, which | |
3873 | * includes THP page fault allocations | |
3874 | */ | |
3875 | if (costly_order && (gfp_mask & __GFP_NORETRY)) { | |
3876 | /* | |
3877 | * If compaction is deferred for high-order allocations, | |
3878 | * it is because sync compaction recently failed. If | |
3879 | * this is the case and the caller requested a THP | |
3880 | * allocation, we do not want to heavily disrupt the | |
3881 | * system, so we fail the allocation instead of entering | |
3882 | * direct reclaim. | |
3883 | */ | |
3884 | if (compact_result == COMPACT_DEFERRED) | |
3885 | goto nopage; | |
3886 | ||
3887 | /* | |
3888 | * Looks like reclaim/compaction is worth trying, but | |
3889 | * sync compaction could be very expensive, so keep | |
3890 | * using async compaction. | |
3891 | */ | |
3892 | compact_priority = INIT_COMPACT_PRIORITY; | |
3893 | } | |
3894 | } | |
3895 | ||
3896 | retry: | |
3897 | /* Ensure kswapd doesn't accidentally go to sleep as long as we loop */ | |
3898 | if (gfp_mask & __GFP_KSWAPD_RECLAIM) | |
3899 | wake_all_kswapds(order, ac); | |
3900 | ||
3901 | if (gfp_pfmemalloc_allowed(gfp_mask)) | |
3902 | alloc_flags = ALLOC_NO_WATERMARKS; | |
3903 | ||
3904 | /* | |
3905 | * Reset the zonelist iterators if memory policies can be ignored. | |
3906 | * These allocations are high priority and system rather than user | |
3907 | * orientated. | |
3908 | */ | |
3909 | if (!(alloc_flags & ALLOC_CPUSET) || (alloc_flags & ALLOC_NO_WATERMARKS)) { | |
3910 | ac->zonelist = node_zonelist(numa_node_id(), gfp_mask); | |
3911 | ac->preferred_zoneref = first_zones_zonelist(ac->zonelist, | |
3912 | ac->high_zoneidx, ac->nodemask); | |
3913 | } | |
3914 | ||
3915 | /* Attempt with potentially adjusted zonelist and alloc_flags */ | |
3916 | page = get_page_from_freelist(gfp_mask, order, alloc_flags, ac); | |
3917 | if (page) | |
3918 | goto got_pg; | |
3919 | ||
3920 | /* Caller is not willing to reclaim, we can't balance anything */ | |
3921 | if (!can_direct_reclaim) | |
3922 | goto nopage; | |
3923 | ||
3924 | /* Make sure we know about allocations which stall for too long */ | |
3925 | if (time_after(jiffies, alloc_start + stall_timeout)) { | |
3926 | warn_alloc(gfp_mask & ~__GFP_NOWARN, ac->nodemask, | |
3927 | "page allocation stalls for %ums, order:%u", | |
3928 | jiffies_to_msecs(jiffies-alloc_start), order); | |
3929 | stall_timeout += 10 * HZ; | |
3930 | } | |
3931 | ||
3932 | /* Avoid recursion of direct reclaim */ | |
3933 | if (current->flags & PF_MEMALLOC) | |
3934 | goto nopage; | |
3935 | ||
3936 | /* Try direct reclaim and then allocating */ | |
3937 | page = __alloc_pages_direct_reclaim(gfp_mask, order, alloc_flags, ac, | |
3938 | &did_some_progress); | |
3939 | if (page) | |
3940 | goto got_pg; | |
3941 | ||
3942 | /* Try direct compaction and then allocating */ | |
3943 | page = __alloc_pages_direct_compact(gfp_mask, order, alloc_flags, ac, | |
3944 | compact_priority, &compact_result); | |
3945 | if (page) | |
3946 | goto got_pg; | |
3947 | ||
3948 | /* Do not loop if specifically requested */ | |
3949 | if (gfp_mask & __GFP_NORETRY) | |
3950 | goto nopage; | |
3951 | ||
3952 | /* | |
3953 | * Do not retry costly high order allocations unless they are | |
3954 | * __GFP_RETRY_MAYFAIL | |
3955 | */ | |
3956 | if (costly_order && !(gfp_mask & __GFP_RETRY_MAYFAIL)) | |
3957 | goto nopage; | |
3958 | ||
3959 | if (should_reclaim_retry(gfp_mask, order, ac, alloc_flags, | |
3960 | did_some_progress > 0, &no_progress_loops)) | |
3961 | goto retry; | |
3962 | ||
3963 | /* | |
3964 | * It doesn't make any sense to retry for the compaction if the order-0 | |
3965 | * reclaim is not able to make any progress because the current | |
3966 | * implementation of the compaction depends on the sufficient amount | |
3967 | * of free memory (see __compaction_suitable) | |
3968 | */ | |
3969 | if (did_some_progress > 0 && | |
3970 | should_compact_retry(ac, order, alloc_flags, | |
3971 | compact_result, &compact_priority, | |
3972 | &compaction_retries)) | |
3973 | goto retry; | |
3974 | ||
3975 | ||
3976 | /* Deal with possible cpuset update races before we start OOM killing */ | |
3977 | if (check_retry_cpuset(cpuset_mems_cookie, ac)) | |
3978 | goto retry_cpuset; | |
3979 | ||
3980 | /* Reclaim has failed us, start killing things */ | |
3981 | page = __alloc_pages_may_oom(gfp_mask, order, ac, &did_some_progress); | |
3982 | if (page) | |
3983 | goto got_pg; | |
3984 | ||
3985 | /* Avoid allocations with no watermarks from looping endlessly */ | |
3986 | if (test_thread_flag(TIF_MEMDIE) && | |
3987 | (alloc_flags == ALLOC_NO_WATERMARKS || | |
3988 | (gfp_mask & __GFP_NOMEMALLOC))) | |
3989 | goto nopage; | |
3990 | ||
3991 | /* Retry as long as the OOM killer is making progress */ | |
3992 | if (did_some_progress) { | |
3993 | no_progress_loops = 0; | |
3994 | goto retry; | |
3995 | } | |
3996 | ||
3997 | nopage: | |
3998 | /* Deal with possible cpuset update races before we fail */ | |
3999 | if (check_retry_cpuset(cpuset_mems_cookie, ac)) | |
4000 | goto retry_cpuset; | |
4001 | ||
4002 | /* | |
4003 | * Make sure that __GFP_NOFAIL request doesn't leak out and make sure | |
4004 | * we always retry | |
4005 | */ | |
4006 | if (gfp_mask & __GFP_NOFAIL) { | |
4007 | /* | |
4008 | * All existing users of the __GFP_NOFAIL are blockable, so warn | |
4009 | * of any new users that actually require GFP_NOWAIT | |
4010 | */ | |
4011 | if (WARN_ON_ONCE(!can_direct_reclaim)) | |
4012 | goto fail; | |
4013 | ||
4014 | /* | |
4015 | * PF_MEMALLOC request from this context is rather bizarre | |
4016 | * because we cannot reclaim anything and only can loop waiting | |
4017 | * for somebody to do a work for us | |
4018 | */ | |
4019 | WARN_ON_ONCE(current->flags & PF_MEMALLOC); | |
4020 | ||
4021 | /* | |
4022 | * non failing costly orders are a hard requirement which we | |
4023 | * are not prepared for much so let's warn about these users | |
4024 | * so that we can identify them and convert them to something | |
4025 | * else. | |
4026 | */ | |
4027 | WARN_ON_ONCE(order > PAGE_ALLOC_COSTLY_ORDER); | |
4028 | ||
4029 | /* | |
4030 | * Help non-failing allocations by giving them access to memory | |
4031 | * reserves but do not use ALLOC_NO_WATERMARKS because this | |
4032 | * could deplete whole memory reserves which would just make | |
4033 | * the situation worse | |
4034 | */ | |
4035 | page = __alloc_pages_cpuset_fallback(gfp_mask, order, ALLOC_HARDER, ac); | |
4036 | if (page) | |
4037 | goto got_pg; | |
4038 | ||
4039 | cond_resched(); | |
4040 | goto retry; | |
4041 | } | |
4042 | fail: | |
4043 | warn_alloc(gfp_mask, ac->nodemask, | |
4044 | "page allocation failure: order:%u", order); | |
4045 | got_pg: | |
4046 | return page; | |
4047 | } | |
4048 | ||
4049 | static inline bool prepare_alloc_pages(gfp_t gfp_mask, unsigned int order, | |
4050 | int preferred_nid, nodemask_t *nodemask, | |
4051 | struct alloc_context *ac, gfp_t *alloc_mask, | |
4052 | unsigned int *alloc_flags) | |
4053 | { | |
4054 | ac->high_zoneidx = gfp_zone(gfp_mask); | |
4055 | ac->zonelist = node_zonelist(preferred_nid, gfp_mask); | |
4056 | ac->nodemask = nodemask; | |
4057 | ac->migratetype = gfpflags_to_migratetype(gfp_mask); | |
4058 | ||
4059 | if (cpusets_enabled()) { | |
4060 | *alloc_mask |= __GFP_HARDWALL; | |
4061 | if (!ac->nodemask) | |
4062 | ac->nodemask = &cpuset_current_mems_allowed; | |
4063 | else | |
4064 | *alloc_flags |= ALLOC_CPUSET; | |
4065 | } | |
4066 | ||
4067 | lockdep_trace_alloc(gfp_mask); | |
4068 | ||
4069 | might_sleep_if(gfp_mask & __GFP_DIRECT_RECLAIM); | |
4070 | ||
4071 | if (should_fail_alloc_page(gfp_mask, order)) | |
4072 | return false; | |
4073 | ||
4074 | if (IS_ENABLED(CONFIG_CMA) && ac->migratetype == MIGRATE_MOVABLE) | |
4075 | *alloc_flags |= ALLOC_CMA; | |
4076 | ||
4077 | return true; | |
4078 | } | |
4079 | ||
4080 | /* Determine whether to spread dirty pages and what the first usable zone */ | |
4081 | static inline void finalise_ac(gfp_t gfp_mask, | |
4082 | unsigned int order, struct alloc_context *ac) | |
4083 | { | |
4084 | /* Dirty zone balancing only done in the fast path */ | |
4085 | ac->spread_dirty_pages = (gfp_mask & __GFP_WRITE); | |
4086 | ||
4087 | /* | |
4088 | * The preferred zone is used for statistics but crucially it is | |
4089 | * also used as the starting point for the zonelist iterator. It | |
4090 | * may get reset for allocations that ignore memory policies. | |
4091 | */ | |
4092 | ac->preferred_zoneref = first_zones_zonelist(ac->zonelist, | |
4093 | ac->high_zoneidx, ac->nodemask); | |
4094 | } | |
4095 | ||
4096 | /* | |
4097 | * This is the 'heart' of the zoned buddy allocator. | |
4098 | */ | |
4099 | struct page * | |
4100 | __alloc_pages_nodemask(gfp_t gfp_mask, unsigned int order, int preferred_nid, | |
4101 | nodemask_t *nodemask) | |
4102 | { | |
4103 | struct page *page; | |
4104 | unsigned int alloc_flags = ALLOC_WMARK_LOW; | |
4105 | gfp_t alloc_mask = gfp_mask; /* The gfp_t that was actually used for allocation */ | |
4106 | struct alloc_context ac = { }; | |
4107 | ||
4108 | gfp_mask &= gfp_allowed_mask; | |
4109 | if (!prepare_alloc_pages(gfp_mask, order, preferred_nid, nodemask, &ac, &alloc_mask, &alloc_flags)) | |
4110 | return NULL; | |
4111 | ||
4112 | finalise_ac(gfp_mask, order, &ac); | |
4113 | ||
4114 | /* First allocation attempt */ | |
4115 | page = get_page_from_freelist(alloc_mask, order, alloc_flags, &ac); | |
4116 | if (likely(page)) | |
4117 | goto out; | |
4118 | ||
4119 | /* | |
4120 | * Apply scoped allocation constraints. This is mainly about GFP_NOFS | |
4121 | * resp. GFP_NOIO which has to be inherited for all allocation requests | |
4122 | * from a particular context which has been marked by | |
4123 | * memalloc_no{fs,io}_{save,restore}. | |
4124 | */ | |
4125 | alloc_mask = current_gfp_context(gfp_mask); | |
4126 | ac.spread_dirty_pages = false; | |
4127 | ||
4128 | /* | |
4129 | * Restore the original nodemask if it was potentially replaced with | |
4130 | * &cpuset_current_mems_allowed to optimize the fast-path attempt. | |
4131 | */ | |
4132 | if (unlikely(ac.nodemask != nodemask)) | |
4133 | ac.nodemask = nodemask; | |
4134 | ||
4135 | page = __alloc_pages_slowpath(alloc_mask, order, &ac); | |
4136 | ||
4137 | out: | |
4138 | if (memcg_kmem_enabled() && (gfp_mask & __GFP_ACCOUNT) && page && | |
4139 | unlikely(memcg_kmem_charge(page, gfp_mask, order) != 0)) { | |
4140 | __free_pages(page, order); | |
4141 | page = NULL; | |
4142 | } | |
4143 | ||
4144 | if (kmemcheck_enabled && page) | |
4145 | kmemcheck_pagealloc_alloc(page, order, gfp_mask); | |
4146 | ||
4147 | trace_mm_page_alloc(page, order, alloc_mask, ac.migratetype); | |
4148 | ||
4149 | return page; | |
4150 | } | |
4151 | EXPORT_SYMBOL(__alloc_pages_nodemask); | |
4152 | ||
4153 | /* | |
4154 | * Common helper functions. | |
4155 | */ | |
4156 | unsigned long __get_free_pages(gfp_t gfp_mask, unsigned int order) | |
4157 | { | |
4158 | struct page *page; | |
4159 | ||
4160 | /* | |
4161 | * __get_free_pages() returns a 32-bit address, which cannot represent | |
4162 | * a highmem page | |
4163 | */ | |
4164 | VM_BUG_ON((gfp_mask & __GFP_HIGHMEM) != 0); | |
4165 | ||
4166 | page = alloc_pages(gfp_mask, order); | |
4167 | if (!page) | |
4168 | return 0; | |
4169 | return (unsigned long) page_address(page); | |
4170 | } | |
4171 | EXPORT_SYMBOL(__get_free_pages); | |
4172 | ||
4173 | unsigned long get_zeroed_page(gfp_t gfp_mask) | |
4174 | { | |
4175 | return __get_free_pages(gfp_mask | __GFP_ZERO, 0); | |
4176 | } | |
4177 | EXPORT_SYMBOL(get_zeroed_page); | |
4178 | ||
4179 | void __free_pages(struct page *page, unsigned int order) | |
4180 | { | |
4181 | if (put_page_testzero(page)) { | |
4182 | if (order == 0) | |
4183 | free_hot_cold_page(page, false); | |
4184 | else | |
4185 | __free_pages_ok(page, order); | |
4186 | } | |
4187 | } | |
4188 | ||
4189 | EXPORT_SYMBOL(__free_pages); | |
4190 | ||
4191 | void free_pages(unsigned long addr, unsigned int order) | |
4192 | { | |
4193 | if (addr != 0) { | |
4194 | VM_BUG_ON(!virt_addr_valid((void *)addr)); | |
4195 | __free_pages(virt_to_page((void *)addr), order); | |
4196 | } | |
4197 | } | |
4198 | ||
4199 | EXPORT_SYMBOL(free_pages); | |
4200 | ||
4201 | /* | |
4202 | * Page Fragment: | |
4203 | * An arbitrary-length arbitrary-offset area of memory which resides | |
4204 | * within a 0 or higher order page. Multiple fragments within that page | |
4205 | * are individually refcounted, in the page's reference counter. | |
4206 | * | |
4207 | * The page_frag functions below provide a simple allocation framework for | |
4208 | * page fragments. This is used by the network stack and network device | |
4209 | * drivers to provide a backing region of memory for use as either an | |
4210 | * sk_buff->head, or to be used in the "frags" portion of skb_shared_info. | |
4211 | */ | |
4212 | static struct page *__page_frag_cache_refill(struct page_frag_cache *nc, | |
4213 | gfp_t gfp_mask) | |
4214 | { | |
4215 | struct page *page = NULL; | |
4216 | gfp_t gfp = gfp_mask; | |
4217 | ||
4218 | #if (PAGE_SIZE < PAGE_FRAG_CACHE_MAX_SIZE) | |
4219 | gfp_mask |= __GFP_COMP | __GFP_NOWARN | __GFP_NORETRY | | |
4220 | __GFP_NOMEMALLOC; | |
4221 | page = alloc_pages_node(NUMA_NO_NODE, gfp_mask, | |
4222 | PAGE_FRAG_CACHE_MAX_ORDER); | |
4223 | nc->size = page ? PAGE_FRAG_CACHE_MAX_SIZE : PAGE_SIZE; | |
4224 | #endif | |
4225 | if (unlikely(!page)) | |
4226 | page = alloc_pages_node(NUMA_NO_NODE, gfp, 0); | |
4227 | ||
4228 | nc->va = page ? page_address(page) : NULL; | |
4229 | ||
4230 | return page; | |
4231 | } | |
4232 | ||
4233 | void __page_frag_cache_drain(struct page *page, unsigned int count) | |
4234 | { | |
4235 | VM_BUG_ON_PAGE(page_ref_count(page) == 0, page); | |
4236 | ||
4237 | if (page_ref_sub_and_test(page, count)) { | |
4238 | unsigned int order = compound_order(page); | |
4239 | ||
4240 | if (order == 0) | |
4241 | free_hot_cold_page(page, false); | |
4242 | else | |
4243 | __free_pages_ok(page, order); | |
4244 | } | |
4245 | } | |
4246 | EXPORT_SYMBOL(__page_frag_cache_drain); | |
4247 | ||
4248 | void *page_frag_alloc(struct page_frag_cache *nc, | |
4249 | unsigned int fragsz, gfp_t gfp_mask) | |
4250 | { | |
4251 | unsigned int size = PAGE_SIZE; | |
4252 | struct page *page; | |
4253 | int offset; | |
4254 | ||
4255 | if (unlikely(!nc->va)) { | |
4256 | refill: | |
4257 | page = __page_frag_cache_refill(nc, gfp_mask); | |
4258 | if (!page) | |
4259 | return NULL; | |
4260 | ||
4261 | #if (PAGE_SIZE < PAGE_FRAG_CACHE_MAX_SIZE) | |
4262 | /* if size can vary use size else just use PAGE_SIZE */ | |
4263 | size = nc->size; | |
4264 | #endif | |
4265 | /* Even if we own the page, we do not use atomic_set(). | |
4266 | * This would break get_page_unless_zero() users. | |
4267 | */ | |
4268 | page_ref_add(page, size - 1); | |
4269 | ||
4270 | /* reset page count bias and offset to start of new frag */ | |
4271 | nc->pfmemalloc = page_is_pfmemalloc(page); | |
4272 | nc->pagecnt_bias = size; | |
4273 | nc->offset = size; | |
4274 | } | |
4275 | ||
4276 | offset = nc->offset - fragsz; | |
4277 | if (unlikely(offset < 0)) { | |
4278 | page = virt_to_page(nc->va); | |
4279 | ||
4280 | if (!page_ref_sub_and_test(page, nc->pagecnt_bias)) | |
4281 | goto refill; | |
4282 | ||
4283 | #if (PAGE_SIZE < PAGE_FRAG_CACHE_MAX_SIZE) | |
4284 | /* if size can vary use size else just use PAGE_SIZE */ | |
4285 | size = nc->size; | |
4286 | #endif | |
4287 | /* OK, page count is 0, we can safely set it */ | |
4288 | set_page_count(page, size); | |
4289 | ||
4290 | /* reset page count bias and offset to start of new frag */ | |
4291 | nc->pagecnt_bias = size; | |
4292 | offset = size - fragsz; | |
4293 | } | |
4294 | ||
4295 | nc->pagecnt_bias--; | |
4296 | nc->offset = offset; | |
4297 | ||
4298 | return nc->va + offset; | |
4299 | } | |
4300 | EXPORT_SYMBOL(page_frag_alloc); | |
4301 | ||
4302 | /* | |
4303 | * Frees a page fragment allocated out of either a compound or order 0 page. | |
4304 | */ | |
4305 | void page_frag_free(void *addr) | |
4306 | { | |
4307 | struct page *page = virt_to_head_page(addr); | |
4308 | ||
4309 | if (unlikely(put_page_testzero(page))) | |
4310 | __free_pages_ok(page, compound_order(page)); | |
4311 | } | |
4312 | EXPORT_SYMBOL(page_frag_free); | |
4313 | ||
4314 | static void *make_alloc_exact(unsigned long addr, unsigned int order, | |
4315 | size_t size) | |
4316 | { | |
4317 | if (addr) { | |
4318 | unsigned long alloc_end = addr + (PAGE_SIZE << order); | |
4319 | unsigned long used = addr + PAGE_ALIGN(size); | |
4320 | ||
4321 | split_page(virt_to_page((void *)addr), order); | |
4322 | while (used < alloc_end) { | |
4323 | free_page(used); | |
4324 | used += PAGE_SIZE; | |
4325 | } | |
4326 | } | |
4327 | return (void *)addr; | |
4328 | } | |
4329 | ||
4330 | /** | |
4331 | * alloc_pages_exact - allocate an exact number physically-contiguous pages. | |
4332 | * @size: the number of bytes to allocate | |
4333 | * @gfp_mask: GFP flags for the allocation | |
4334 | * | |
4335 | * This function is similar to alloc_pages(), except that it allocates the | |
4336 | * minimum number of pages to satisfy the request. alloc_pages() can only | |
4337 | * allocate memory in power-of-two pages. | |
4338 | * | |
4339 | * This function is also limited by MAX_ORDER. | |
4340 | * | |
4341 | * Memory allocated by this function must be released by free_pages_exact(). | |
4342 | */ | |
4343 | void *alloc_pages_exact(size_t size, gfp_t gfp_mask) | |
4344 | { | |
4345 | unsigned int order = get_order(size); | |
4346 | unsigned long addr; | |
4347 | ||
4348 | addr = __get_free_pages(gfp_mask, order); | |
4349 | return make_alloc_exact(addr, order, size); | |
4350 | } | |
4351 | EXPORT_SYMBOL(alloc_pages_exact); | |
4352 | ||
4353 | /** | |
4354 | * alloc_pages_exact_nid - allocate an exact number of physically-contiguous | |
4355 | * pages on a node. | |
4356 | * @nid: the preferred node ID where memory should be allocated | |
4357 | * @size: the number of bytes to allocate | |
4358 | * @gfp_mask: GFP flags for the allocation | |
4359 | * | |
4360 | * Like alloc_pages_exact(), but try to allocate on node nid first before falling | |
4361 | * back. | |
4362 | */ | |
4363 | void * __meminit alloc_pages_exact_nid(int nid, size_t size, gfp_t gfp_mask) | |
4364 | { | |
4365 | unsigned int order = get_order(size); | |
4366 | struct page *p = alloc_pages_node(nid, gfp_mask, order); | |
4367 | if (!p) | |
4368 | return NULL; | |
4369 | return make_alloc_exact((unsigned long)page_address(p), order, size); | |
4370 | } | |
4371 | ||
4372 | /** | |
4373 | * free_pages_exact - release memory allocated via alloc_pages_exact() | |
4374 | * @virt: the value returned by alloc_pages_exact. | |
4375 | * @size: size of allocation, same value as passed to alloc_pages_exact(). | |
4376 | * | |
4377 | * Release the memory allocated by a previous call to alloc_pages_exact. | |
4378 | */ | |
4379 | void free_pages_exact(void *virt, size_t size) | |
4380 | { | |
4381 | unsigned long addr = (unsigned long)virt; | |
4382 | unsigned long end = addr + PAGE_ALIGN(size); | |
4383 | ||
4384 | while (addr < end) { | |
4385 | free_page(addr); | |
4386 | addr += PAGE_SIZE; | |
4387 | } | |
4388 | } | |
4389 | EXPORT_SYMBOL(free_pages_exact); | |
4390 | ||
4391 | /** | |
4392 | * nr_free_zone_pages - count number of pages beyond high watermark | |
4393 | * @offset: The zone index of the highest zone | |
4394 | * | |
4395 | * nr_free_zone_pages() counts the number of counts pages which are beyond the | |
4396 | * high watermark within all zones at or below a given zone index. For each | |
4397 | * zone, the number of pages is calculated as: | |
4398 | * | |
4399 | * nr_free_zone_pages = managed_pages - high_pages | |
4400 | */ | |
4401 | static unsigned long nr_free_zone_pages(int offset) | |
4402 | { | |
4403 | struct zoneref *z; | |
4404 | struct zone *zone; | |
4405 | ||
4406 | /* Just pick one node, since fallback list is circular */ | |
4407 | unsigned long sum = 0; | |
4408 | ||
4409 | struct zonelist *zonelist = node_zonelist(numa_node_id(), GFP_KERNEL); | |
4410 | ||
4411 | for_each_zone_zonelist(zone, z, zonelist, offset) { | |
4412 | unsigned long size = zone->managed_pages; | |
4413 | unsigned long high = high_wmark_pages(zone); | |
4414 | if (size > high) | |
4415 | sum += size - high; | |
4416 | } | |
4417 | ||
4418 | return sum; | |
4419 | } | |
4420 | ||
4421 | /** | |
4422 | * nr_free_buffer_pages - count number of pages beyond high watermark | |
4423 | * | |
4424 | * nr_free_buffer_pages() counts the number of pages which are beyond the high | |
4425 | * watermark within ZONE_DMA and ZONE_NORMAL. | |
4426 | */ | |
4427 | unsigned long nr_free_buffer_pages(void) | |
4428 | { | |
4429 | return nr_free_zone_pages(gfp_zone(GFP_USER)); | |
4430 | } | |
4431 | EXPORT_SYMBOL_GPL(nr_free_buffer_pages); | |
4432 | ||
4433 | /** | |
4434 | * nr_free_pagecache_pages - count number of pages beyond high watermark | |
4435 | * | |
4436 | * nr_free_pagecache_pages() counts the number of pages which are beyond the | |
4437 | * high watermark within all zones. | |
4438 | */ | |
4439 | unsigned long nr_free_pagecache_pages(void) | |
4440 | { | |
4441 | return nr_free_zone_pages(gfp_zone(GFP_HIGHUSER_MOVABLE)); | |
4442 | } | |
4443 | ||
4444 | static inline void show_node(struct zone *zone) | |
4445 | { | |
4446 | if (IS_ENABLED(CONFIG_NUMA)) | |
4447 | printk("Node %d ", zone_to_nid(zone)); | |
4448 | } | |
4449 | ||
4450 | long si_mem_available(void) | |
4451 | { | |
4452 | long available; | |
4453 | unsigned long pagecache; | |
4454 | unsigned long wmark_low = 0; | |
4455 | unsigned long pages[NR_LRU_LISTS]; | |
4456 | struct zone *zone; | |
4457 | int lru; | |
4458 | ||
4459 | for (lru = LRU_BASE; lru < NR_LRU_LISTS; lru++) | |
4460 | pages[lru] = global_node_page_state(NR_LRU_BASE + lru); | |
4461 | ||
4462 | for_each_zone(zone) | |
4463 | wmark_low += zone->watermark[WMARK_LOW]; | |
4464 | ||
4465 | /* | |
4466 | * Estimate the amount of memory available for userspace allocations, | |
4467 | * without causing swapping. | |
4468 | */ | |
4469 | available = global_page_state(NR_FREE_PAGES) - totalreserve_pages; | |
4470 | ||
4471 | /* | |
4472 | * Not all the page cache can be freed, otherwise the system will | |
4473 | * start swapping. Assume at least half of the page cache, or the | |
4474 | * low watermark worth of cache, needs to stay. | |
4475 | */ | |
4476 | pagecache = pages[LRU_ACTIVE_FILE] + pages[LRU_INACTIVE_FILE]; | |
4477 | pagecache -= min(pagecache / 2, wmark_low); | |
4478 | available += pagecache; | |
4479 | ||
4480 | /* | |
4481 | * Part of the reclaimable slab consists of items that are in use, | |
4482 | * and cannot be freed. Cap this estimate at the low watermark. | |
4483 | */ | |
4484 | available += global_node_page_state(NR_SLAB_RECLAIMABLE) - | |
4485 | min(global_node_page_state(NR_SLAB_RECLAIMABLE) / 2, | |
4486 | wmark_low); | |
4487 | ||
4488 | if (available < 0) | |
4489 | available = 0; | |
4490 | return available; | |
4491 | } | |
4492 | EXPORT_SYMBOL_GPL(si_mem_available); | |
4493 | ||
4494 | void si_meminfo(struct sysinfo *val) | |
4495 | { | |
4496 | val->totalram = totalram_pages; | |
4497 | val->sharedram = global_node_page_state(NR_SHMEM); | |
4498 | val->freeram = global_page_state(NR_FREE_PAGES); | |
4499 | val->bufferram = nr_blockdev_pages(); | |
4500 | val->totalhigh = totalhigh_pages; | |
4501 | val->freehigh = nr_free_highpages(); | |
4502 | val->mem_unit = PAGE_SIZE; | |
4503 | } | |
4504 | ||
4505 | EXPORT_SYMBOL(si_meminfo); | |
4506 | ||
4507 | #ifdef CONFIG_NUMA | |
4508 | void si_meminfo_node(struct sysinfo *val, int nid) | |
4509 | { | |
4510 | int zone_type; /* needs to be signed */ | |
4511 | unsigned long managed_pages = 0; | |
4512 | unsigned long managed_highpages = 0; | |
4513 | unsigned long free_highpages = 0; | |
4514 | pg_data_t *pgdat = NODE_DATA(nid); | |
4515 | ||
4516 | for (zone_type = 0; zone_type < MAX_NR_ZONES; zone_type++) | |
4517 | managed_pages += pgdat->node_zones[zone_type].managed_pages; | |
4518 | val->totalram = managed_pages; | |
4519 | val->sharedram = node_page_state(pgdat, NR_SHMEM); | |
4520 | val->freeram = sum_zone_node_page_state(nid, NR_FREE_PAGES); | |
4521 | #ifdef CONFIG_HIGHMEM | |
4522 | for (zone_type = 0; zone_type < MAX_NR_ZONES; zone_type++) { | |
4523 | struct zone *zone = &pgdat->node_zones[zone_type]; | |
4524 | ||
4525 | if (is_highmem(zone)) { | |
4526 | managed_highpages += zone->managed_pages; | |
4527 | free_highpages += zone_page_state(zone, NR_FREE_PAGES); | |
4528 | } | |
4529 | } | |
4530 | val->totalhigh = managed_highpages; | |
4531 | val->freehigh = free_highpages; | |
4532 | #else | |
4533 | val->totalhigh = managed_highpages; | |
4534 | val->freehigh = free_highpages; | |
4535 | #endif | |
4536 | val->mem_unit = PAGE_SIZE; | |
4537 | } | |
4538 | #endif | |
4539 | ||
4540 | /* | |
4541 | * Determine whether the node should be displayed or not, depending on whether | |
4542 | * SHOW_MEM_FILTER_NODES was passed to show_free_areas(). | |
4543 | */ | |
4544 | static bool show_mem_node_skip(unsigned int flags, int nid, nodemask_t *nodemask) | |
4545 | { | |
4546 | if (!(flags & SHOW_MEM_FILTER_NODES)) | |
4547 | return false; | |
4548 | ||
4549 | /* | |
4550 | * no node mask - aka implicit memory numa policy. Do not bother with | |
4551 | * the synchronization - read_mems_allowed_begin - because we do not | |
4552 | * have to be precise here. | |
4553 | */ | |
4554 | if (!nodemask) | |
4555 | nodemask = &cpuset_current_mems_allowed; | |
4556 | ||
4557 | return !node_isset(nid, *nodemask); | |
4558 | } | |
4559 | ||
4560 | #define K(x) ((x) << (PAGE_SHIFT-10)) | |
4561 | ||
4562 | static void show_migration_types(unsigned char type) | |
4563 | { | |
4564 | static const char types[MIGRATE_TYPES] = { | |
4565 | [MIGRATE_UNMOVABLE] = 'U', | |
4566 | [MIGRATE_MOVABLE] = 'M', | |
4567 | [MIGRATE_RECLAIMABLE] = 'E', | |
4568 | [MIGRATE_HIGHATOMIC] = 'H', | |
4569 | #ifdef CONFIG_CMA | |
4570 | [MIGRATE_CMA] = 'C', | |
4571 | #endif | |
4572 | #ifdef CONFIG_MEMORY_ISOLATION | |
4573 | [MIGRATE_ISOLATE] = 'I', | |
4574 | #endif | |
4575 | }; | |
4576 | char tmp[MIGRATE_TYPES + 1]; | |
4577 | char *p = tmp; | |
4578 | int i; | |
4579 | ||
4580 | for (i = 0; i < MIGRATE_TYPES; i++) { | |
4581 | if (type & (1 << i)) | |
4582 | *p++ = types[i]; | |
4583 | } | |
4584 | ||
4585 | *p = '\0'; | |
4586 | printk(KERN_CONT "(%s) ", tmp); | |
4587 | } | |
4588 | ||
4589 | /* | |
4590 | * Show free area list (used inside shift_scroll-lock stuff) | |
4591 | * We also calculate the percentage fragmentation. We do this by counting the | |
4592 | * memory on each free list with the exception of the first item on the list. | |
4593 | * | |
4594 | * Bits in @filter: | |
4595 | * SHOW_MEM_FILTER_NODES: suppress nodes that are not allowed by current's | |
4596 | * cpuset. | |
4597 | */ | |
4598 | void show_free_areas(unsigned int filter, nodemask_t *nodemask) | |
4599 | { | |
4600 | unsigned long free_pcp = 0; | |
4601 | int cpu; | |
4602 | struct zone *zone; | |
4603 | pg_data_t *pgdat; | |
4604 | ||
4605 | for_each_populated_zone(zone) { | |
4606 | if (show_mem_node_skip(filter, zone_to_nid(zone), nodemask)) | |
4607 | continue; | |
4608 | ||
4609 | for_each_online_cpu(cpu) | |
4610 | free_pcp += per_cpu_ptr(zone->pageset, cpu)->pcp.count; | |
4611 | } | |
4612 | ||
4613 | printk("active_anon:%lu inactive_anon:%lu isolated_anon:%lu\n" | |
4614 | " active_file:%lu inactive_file:%lu isolated_file:%lu\n" | |
4615 | " unevictable:%lu dirty:%lu writeback:%lu unstable:%lu\n" | |
4616 | " slab_reclaimable:%lu slab_unreclaimable:%lu\n" | |
4617 | " mapped:%lu shmem:%lu pagetables:%lu bounce:%lu\n" | |
4618 | " free:%lu free_pcp:%lu free_cma:%lu\n", | |
4619 | global_node_page_state(NR_ACTIVE_ANON), | |
4620 | global_node_page_state(NR_INACTIVE_ANON), | |
4621 | global_node_page_state(NR_ISOLATED_ANON), | |
4622 | global_node_page_state(NR_ACTIVE_FILE), | |
4623 | global_node_page_state(NR_INACTIVE_FILE), | |
4624 | global_node_page_state(NR_ISOLATED_FILE), | |
4625 | global_node_page_state(NR_UNEVICTABLE), | |
4626 | global_node_page_state(NR_FILE_DIRTY), | |
4627 | global_node_page_state(NR_WRITEBACK), | |
4628 | global_node_page_state(NR_UNSTABLE_NFS), | |
4629 | global_node_page_state(NR_SLAB_RECLAIMABLE), | |
4630 | global_node_page_state(NR_SLAB_UNRECLAIMABLE), | |
4631 | global_node_page_state(NR_FILE_MAPPED), | |
4632 | global_node_page_state(NR_SHMEM), | |
4633 | global_page_state(NR_PAGETABLE), | |
4634 | global_page_state(NR_BOUNCE), | |
4635 | global_page_state(NR_FREE_PAGES), | |
4636 | free_pcp, | |
4637 | global_page_state(NR_FREE_CMA_PAGES)); | |
4638 | ||
4639 | for_each_online_pgdat(pgdat) { | |
4640 | if (show_mem_node_skip(filter, pgdat->node_id, nodemask)) | |
4641 | continue; | |
4642 | ||
4643 | printk("Node %d" | |
4644 | " active_anon:%lukB" | |
4645 | " inactive_anon:%lukB" | |
4646 | " active_file:%lukB" | |
4647 | " inactive_file:%lukB" | |
4648 | " unevictable:%lukB" | |
4649 | " isolated(anon):%lukB" | |
4650 | " isolated(file):%lukB" | |
4651 | " mapped:%lukB" | |
4652 | " dirty:%lukB" | |
4653 | " writeback:%lukB" | |
4654 | " shmem:%lukB" | |
4655 | #ifdef CONFIG_TRANSPARENT_HUGEPAGE | |
4656 | " shmem_thp: %lukB" | |
4657 | " shmem_pmdmapped: %lukB" | |
4658 | " anon_thp: %lukB" | |
4659 | #endif | |
4660 | " writeback_tmp:%lukB" | |
4661 | " unstable:%lukB" | |
4662 | " all_unreclaimable? %s" | |
4663 | "\n", | |
4664 | pgdat->node_id, | |
4665 | K(node_page_state(pgdat, NR_ACTIVE_ANON)), | |
4666 | K(node_page_state(pgdat, NR_INACTIVE_ANON)), | |
4667 | K(node_page_state(pgdat, NR_ACTIVE_FILE)), | |
4668 | K(node_page_state(pgdat, NR_INACTIVE_FILE)), | |
4669 | K(node_page_state(pgdat, NR_UNEVICTABLE)), | |
4670 | K(node_page_state(pgdat, NR_ISOLATED_ANON)), | |
4671 | K(node_page_state(pgdat, NR_ISOLATED_FILE)), | |
4672 | K(node_page_state(pgdat, NR_FILE_MAPPED)), | |
4673 | K(node_page_state(pgdat, NR_FILE_DIRTY)), | |
4674 | K(node_page_state(pgdat, NR_WRITEBACK)), | |
4675 | K(node_page_state(pgdat, NR_SHMEM)), | |
4676 | #ifdef CONFIG_TRANSPARENT_HUGEPAGE | |
4677 | K(node_page_state(pgdat, NR_SHMEM_THPS) * HPAGE_PMD_NR), | |
4678 | K(node_page_state(pgdat, NR_SHMEM_PMDMAPPED) | |
4679 | * HPAGE_PMD_NR), | |
4680 | K(node_page_state(pgdat, NR_ANON_THPS) * HPAGE_PMD_NR), | |
4681 | #endif | |
4682 | K(node_page_state(pgdat, NR_WRITEBACK_TEMP)), | |
4683 | K(node_page_state(pgdat, NR_UNSTABLE_NFS)), | |
4684 | pgdat->kswapd_failures >= MAX_RECLAIM_RETRIES ? | |
4685 | "yes" : "no"); | |
4686 | } | |
4687 | ||
4688 | for_each_populated_zone(zone) { | |
4689 | int i; | |
4690 | ||
4691 | if (show_mem_node_skip(filter, zone_to_nid(zone), nodemask)) | |
4692 | continue; | |
4693 | ||
4694 | free_pcp = 0; | |
4695 | for_each_online_cpu(cpu) | |
4696 | free_pcp += per_cpu_ptr(zone->pageset, cpu)->pcp.count; | |
4697 | ||
4698 | show_node(zone); | |
4699 | printk(KERN_CONT | |
4700 | "%s" | |
4701 | " free:%lukB" | |
4702 | " min:%lukB" | |
4703 | " low:%lukB" | |
4704 | " high:%lukB" | |
4705 | " active_anon:%lukB" | |
4706 | " inactive_anon:%lukB" | |
4707 | " active_file:%lukB" | |
4708 | " inactive_file:%lukB" | |
4709 | " unevictable:%lukB" | |
4710 | " writepending:%lukB" | |
4711 | " present:%lukB" | |
4712 | " managed:%lukB" | |
4713 | " mlocked:%lukB" | |
4714 | " kernel_stack:%lukB" | |
4715 | " pagetables:%lukB" | |
4716 | " bounce:%lukB" | |
4717 | " free_pcp:%lukB" | |
4718 | " local_pcp:%ukB" | |
4719 | " free_cma:%lukB" | |
4720 | "\n", | |
4721 | zone->name, | |
4722 | K(zone_page_state(zone, NR_FREE_PAGES)), | |
4723 | K(min_wmark_pages(zone)), | |
4724 | K(low_wmark_pages(zone)), | |
4725 | K(high_wmark_pages(zone)), | |
4726 | K(zone_page_state(zone, NR_ZONE_ACTIVE_ANON)), | |
4727 | K(zone_page_state(zone, NR_ZONE_INACTIVE_ANON)), | |
4728 | K(zone_page_state(zone, NR_ZONE_ACTIVE_FILE)), | |
4729 | K(zone_page_state(zone, NR_ZONE_INACTIVE_FILE)), | |
4730 | K(zone_page_state(zone, NR_ZONE_UNEVICTABLE)), | |
4731 | K(zone_page_state(zone, NR_ZONE_WRITE_PENDING)), | |
4732 | K(zone->present_pages), | |
4733 | K(zone->managed_pages), | |
4734 | K(zone_page_state(zone, NR_MLOCK)), | |
4735 | zone_page_state(zone, NR_KERNEL_STACK_KB), | |
4736 | K(zone_page_state(zone, NR_PAGETABLE)), | |
4737 | K(zone_page_state(zone, NR_BOUNCE)), | |
4738 | K(free_pcp), | |
4739 | K(this_cpu_read(zone->pageset->pcp.count)), | |
4740 | K(zone_page_state(zone, NR_FREE_CMA_PAGES))); | |
4741 | printk("lowmem_reserve[]:"); | |
4742 | for (i = 0; i < MAX_NR_ZONES; i++) | |
4743 | printk(KERN_CONT " %ld", zone->lowmem_reserve[i]); | |
4744 | printk(KERN_CONT "\n"); | |
4745 | } | |
4746 | ||
4747 | for_each_populated_zone(zone) { | |
4748 | unsigned int order; | |
4749 | unsigned long nr[MAX_ORDER], flags, total = 0; | |
4750 | unsigned char types[MAX_ORDER]; | |
4751 | ||
4752 | if (show_mem_node_skip(filter, zone_to_nid(zone), nodemask)) | |
4753 | continue; | |
4754 | show_node(zone); | |
4755 | printk(KERN_CONT "%s: ", zone->name); | |
4756 | ||
4757 | spin_lock_irqsave(&zone->lock, flags); | |
4758 | for (order = 0; order < MAX_ORDER; order++) { | |
4759 | struct free_area *area = &zone->free_area[order]; | |
4760 | int type; | |
4761 | ||
4762 | nr[order] = area->nr_free; | |
4763 | total += nr[order] << order; | |
4764 | ||
4765 | types[order] = 0; | |
4766 | for (type = 0; type < MIGRATE_TYPES; type++) { | |
4767 | if (!list_empty(&area->free_list[type])) | |
4768 | types[order] |= 1 << type; | |
4769 | } | |
4770 | } | |
4771 | spin_unlock_irqrestore(&zone->lock, flags); | |
4772 | for (order = 0; order < MAX_ORDER; order++) { | |
4773 | printk(KERN_CONT "%lu*%lukB ", | |
4774 | nr[order], K(1UL) << order); | |
4775 | if (nr[order]) | |
4776 | show_migration_types(types[order]); | |
4777 | } | |
4778 | printk(KERN_CONT "= %lukB\n", K(total)); | |
4779 | } | |
4780 | ||
4781 | hugetlb_show_meminfo(); | |
4782 | ||
4783 | printk("%ld total pagecache pages\n", global_node_page_state(NR_FILE_PAGES)); | |
4784 | ||
4785 | show_swap_cache_info(); | |
4786 | } | |
4787 | ||
4788 | static void zoneref_set_zone(struct zone *zone, struct zoneref *zoneref) | |
4789 | { | |
4790 | zoneref->zone = zone; | |
4791 | zoneref->zone_idx = zone_idx(zone); | |
4792 | } | |
4793 | ||
4794 | /* | |
4795 | * Builds allocation fallback zone lists. | |
4796 | * | |
4797 | * Add all populated zones of a node to the zonelist. | |
4798 | */ | |
4799 | static int build_zonelists_node(pg_data_t *pgdat, struct zonelist *zonelist, | |
4800 | int nr_zones) | |
4801 | { | |
4802 | struct zone *zone; | |
4803 | enum zone_type zone_type = MAX_NR_ZONES; | |
4804 | ||
4805 | do { | |
4806 | zone_type--; | |
4807 | zone = pgdat->node_zones + zone_type; | |
4808 | if (managed_zone(zone)) { | |
4809 | zoneref_set_zone(zone, | |
4810 | &zonelist->_zonerefs[nr_zones++]); | |
4811 | check_highest_zone(zone_type); | |
4812 | } | |
4813 | } while (zone_type); | |
4814 | ||
4815 | return nr_zones; | |
4816 | } | |
4817 | ||
4818 | ||
4819 | /* | |
4820 | * zonelist_order: | |
4821 | * 0 = automatic detection of better ordering. | |
4822 | * 1 = order by ([node] distance, -zonetype) | |
4823 | * 2 = order by (-zonetype, [node] distance) | |
4824 | * | |
4825 | * If not NUMA, ZONELIST_ORDER_ZONE and ZONELIST_ORDER_NODE will create | |
4826 | * the same zonelist. So only NUMA can configure this param. | |
4827 | */ | |
4828 | #define ZONELIST_ORDER_DEFAULT 0 | |
4829 | #define ZONELIST_ORDER_NODE 1 | |
4830 | #define ZONELIST_ORDER_ZONE 2 | |
4831 | ||
4832 | /* zonelist order in the kernel. | |
4833 | * set_zonelist_order() will set this to NODE or ZONE. | |
4834 | */ | |
4835 | static int current_zonelist_order = ZONELIST_ORDER_DEFAULT; | |
4836 | static char zonelist_order_name[3][8] = {"Default", "Node", "Zone"}; | |
4837 | ||
4838 | ||
4839 | #ifdef CONFIG_NUMA | |
4840 | /* The value user specified ....changed by config */ | |
4841 | static int user_zonelist_order = ZONELIST_ORDER_DEFAULT; | |
4842 | /* string for sysctl */ | |
4843 | #define NUMA_ZONELIST_ORDER_LEN 16 | |
4844 | char numa_zonelist_order[16] = "default"; | |
4845 | ||
4846 | /* | |
4847 | * interface for configure zonelist ordering. | |
4848 | * command line option "numa_zonelist_order" | |
4849 | * = "[dD]efault - default, automatic configuration. | |
4850 | * = "[nN]ode - order by node locality, then by zone within node | |
4851 | * = "[zZ]one - order by zone, then by locality within zone | |
4852 | */ | |
4853 | ||
4854 | static int __parse_numa_zonelist_order(char *s) | |
4855 | { | |
4856 | if (*s == 'd' || *s == 'D') { | |
4857 | user_zonelist_order = ZONELIST_ORDER_DEFAULT; | |
4858 | } else if (*s == 'n' || *s == 'N') { | |
4859 | user_zonelist_order = ZONELIST_ORDER_NODE; | |
4860 | } else if (*s == 'z' || *s == 'Z') { | |
4861 | user_zonelist_order = ZONELIST_ORDER_ZONE; | |
4862 | } else { | |
4863 | pr_warn("Ignoring invalid numa_zonelist_order value: %s\n", s); | |
4864 | return -EINVAL; | |
4865 | } | |
4866 | return 0; | |
4867 | } | |
4868 | ||
4869 | static __init int setup_numa_zonelist_order(char *s) | |
4870 | { | |
4871 | int ret; | |
4872 | ||
4873 | if (!s) | |
4874 | return 0; | |
4875 | ||
4876 | ret = __parse_numa_zonelist_order(s); | |
4877 | if (ret == 0) | |
4878 | strlcpy(numa_zonelist_order, s, NUMA_ZONELIST_ORDER_LEN); | |
4879 | ||
4880 | return ret; | |
4881 | } | |
4882 | early_param("numa_zonelist_order", setup_numa_zonelist_order); | |
4883 | ||
4884 | /* | |
4885 | * sysctl handler for numa_zonelist_order | |
4886 | */ | |
4887 | int numa_zonelist_order_handler(struct ctl_table *table, int write, | |
4888 | void __user *buffer, size_t *length, | |
4889 | loff_t *ppos) | |
4890 | { | |
4891 | char saved_string[NUMA_ZONELIST_ORDER_LEN]; | |
4892 | int ret; | |
4893 | static DEFINE_MUTEX(zl_order_mutex); | |
4894 | ||
4895 | mutex_lock(&zl_order_mutex); | |
4896 | if (write) { | |
4897 | if (strlen((char *)table->data) >= NUMA_ZONELIST_ORDER_LEN) { | |
4898 | ret = -EINVAL; | |
4899 | goto out; | |
4900 | } | |
4901 | strcpy(saved_string, (char *)table->data); | |
4902 | } | |
4903 | ret = proc_dostring(table, write, buffer, length, ppos); | |
4904 | if (ret) | |
4905 | goto out; | |
4906 | if (write) { | |
4907 | int oldval = user_zonelist_order; | |
4908 | ||
4909 | ret = __parse_numa_zonelist_order((char *)table->data); | |
4910 | if (ret) { | |
4911 | /* | |
4912 | * bogus value. restore saved string | |
4913 | */ | |
4914 | strncpy((char *)table->data, saved_string, | |
4915 | NUMA_ZONELIST_ORDER_LEN); | |
4916 | user_zonelist_order = oldval; | |
4917 | } else if (oldval != user_zonelist_order) { | |
4918 | mem_hotplug_begin(); | |
4919 | mutex_lock(&zonelists_mutex); | |
4920 | build_all_zonelists(NULL, NULL); | |
4921 | mutex_unlock(&zonelists_mutex); | |
4922 | mem_hotplug_done(); | |
4923 | } | |
4924 | } | |
4925 | out: | |
4926 | mutex_unlock(&zl_order_mutex); | |
4927 | return ret; | |
4928 | } | |
4929 | ||
4930 | ||
4931 | #define MAX_NODE_LOAD (nr_online_nodes) | |
4932 | static int node_load[MAX_NUMNODES]; | |
4933 | ||
4934 | /** | |
4935 | * find_next_best_node - find the next node that should appear in a given node's fallback list | |
4936 | * @node: node whose fallback list we're appending | |
4937 | * @used_node_mask: nodemask_t of already used nodes | |
4938 | * | |
4939 | * We use a number of factors to determine which is the next node that should | |
4940 | * appear on a given node's fallback list. The node should not have appeared | |
4941 | * already in @node's fallback list, and it should be the next closest node | |
4942 | * according to the distance array (which contains arbitrary distance values | |
4943 | * from each node to each node in the system), and should also prefer nodes | |
4944 | * with no CPUs, since presumably they'll have very little allocation pressure | |
4945 | * on them otherwise. | |
4946 | * It returns -1 if no node is found. | |
4947 | */ | |
4948 | static int find_next_best_node(int node, nodemask_t *used_node_mask) | |
4949 | { | |
4950 | int n, val; | |
4951 | int min_val = INT_MAX; | |
4952 | int best_node = NUMA_NO_NODE; | |
4953 | const struct cpumask *tmp = cpumask_of_node(0); | |
4954 | ||
4955 | /* Use the local node if we haven't already */ | |
4956 | if (!node_isset(node, *used_node_mask)) { | |
4957 | node_set(node, *used_node_mask); | |
4958 | return node; | |
4959 | } | |
4960 | ||
4961 | for_each_node_state(n, N_MEMORY) { | |
4962 | ||
4963 | /* Don't want a node to appear more than once */ | |
4964 | if (node_isset(n, *used_node_mask)) | |
4965 | continue; | |
4966 | ||
4967 | /* Use the distance array to find the distance */ | |
4968 | val = node_distance(node, n); | |
4969 | ||
4970 | /* Penalize nodes under us ("prefer the next node") */ | |
4971 | val += (n < node); | |
4972 | ||
4973 | /* Give preference to headless and unused nodes */ | |
4974 | tmp = cpumask_of_node(n); | |
4975 | if (!cpumask_empty(tmp)) | |
4976 | val += PENALTY_FOR_NODE_WITH_CPUS; | |
4977 | ||
4978 | /* Slight preference for less loaded node */ | |
4979 | val *= (MAX_NODE_LOAD*MAX_NUMNODES); | |
4980 | val += node_load[n]; | |
4981 | ||
4982 | if (val < min_val) { | |
4983 | min_val = val; | |
4984 | best_node = n; | |
4985 | } | |
4986 | } | |
4987 | ||
4988 | if (best_node >= 0) | |
4989 | node_set(best_node, *used_node_mask); | |
4990 | ||
4991 | return best_node; | |
4992 | } | |
4993 | ||
4994 | ||
4995 | /* | |
4996 | * Build zonelists ordered by node and zones within node. | |
4997 | * This results in maximum locality--normal zone overflows into local | |
4998 | * DMA zone, if any--but risks exhausting DMA zone. | |
4999 | */ | |
5000 | static void build_zonelists_in_node_order(pg_data_t *pgdat, int node) | |
5001 | { | |
5002 | int j; | |
5003 | struct zonelist *zonelist; | |
5004 | ||
5005 | zonelist = &pgdat->node_zonelists[ZONELIST_FALLBACK]; | |
5006 | for (j = 0; zonelist->_zonerefs[j].zone != NULL; j++) | |
5007 | ; | |
5008 | j = build_zonelists_node(NODE_DATA(node), zonelist, j); | |
5009 | zonelist->_zonerefs[j].zone = NULL; | |
5010 | zonelist->_zonerefs[j].zone_idx = 0; | |
5011 | } | |
5012 | ||
5013 | /* | |
5014 | * Build gfp_thisnode zonelists | |
5015 | */ | |
5016 | static void build_thisnode_zonelists(pg_data_t *pgdat) | |
5017 | { | |
5018 | int j; | |
5019 | struct zonelist *zonelist; | |
5020 | ||
5021 | zonelist = &pgdat->node_zonelists[ZONELIST_NOFALLBACK]; | |
5022 | j = build_zonelists_node(pgdat, zonelist, 0); | |
5023 | zonelist->_zonerefs[j].zone = NULL; | |
5024 | zonelist->_zonerefs[j].zone_idx = 0; | |
5025 | } | |
5026 | ||
5027 | /* | |
5028 | * Build zonelists ordered by zone and nodes within zones. | |
5029 | * This results in conserving DMA zone[s] until all Normal memory is | |
5030 | * exhausted, but results in overflowing to remote node while memory | |
5031 | * may still exist in local DMA zone. | |
5032 | */ | |
5033 | static int node_order[MAX_NUMNODES]; | |
5034 | ||
5035 | static void build_zonelists_in_zone_order(pg_data_t *pgdat, int nr_nodes) | |
5036 | { | |
5037 | int pos, j, node; | |
5038 | int zone_type; /* needs to be signed */ | |
5039 | struct zone *z; | |
5040 | struct zonelist *zonelist; | |
5041 | ||
5042 | zonelist = &pgdat->node_zonelists[ZONELIST_FALLBACK]; | |
5043 | pos = 0; | |
5044 | for (zone_type = MAX_NR_ZONES - 1; zone_type >= 0; zone_type--) { | |
5045 | for (j = 0; j < nr_nodes; j++) { | |
5046 | node = node_order[j]; | |
5047 | z = &NODE_DATA(node)->node_zones[zone_type]; | |
5048 | if (managed_zone(z)) { | |
5049 | zoneref_set_zone(z, | |
5050 | &zonelist->_zonerefs[pos++]); | |
5051 | check_highest_zone(zone_type); | |
5052 | } | |
5053 | } | |
5054 | } | |
5055 | zonelist->_zonerefs[pos].zone = NULL; | |
5056 | zonelist->_zonerefs[pos].zone_idx = 0; | |
5057 | } | |
5058 | ||
5059 | #if defined(CONFIG_64BIT) | |
5060 | /* | |
5061 | * Devices that require DMA32/DMA are relatively rare and do not justify a | |
5062 | * penalty to every machine in case the specialised case applies. Default | |
5063 | * to Node-ordering on 64-bit NUMA machines | |
5064 | */ | |
5065 | static int default_zonelist_order(void) | |
5066 | { | |
5067 | return ZONELIST_ORDER_NODE; | |
5068 | } | |
5069 | #else | |
5070 | /* | |
5071 | * On 32-bit, the Normal zone needs to be preserved for allocations accessible | |
5072 | * by the kernel. If processes running on node 0 deplete the low memory zone | |
5073 | * then reclaim will occur more frequency increasing stalls and potentially | |
5074 | * be easier to OOM if a large percentage of the zone is under writeback or | |
5075 | * dirty. The problem is significantly worse if CONFIG_HIGHPTE is not set. | |
5076 | * Hence, default to zone ordering on 32-bit. | |
5077 | */ | |
5078 | static int default_zonelist_order(void) | |
5079 | { | |
5080 | return ZONELIST_ORDER_ZONE; | |
5081 | } | |
5082 | #endif /* CONFIG_64BIT */ | |
5083 | ||
5084 | static void set_zonelist_order(void) | |
5085 | { | |
5086 | if (user_zonelist_order == ZONELIST_ORDER_DEFAULT) | |
5087 | current_zonelist_order = default_zonelist_order(); | |
5088 | else | |
5089 | current_zonelist_order = user_zonelist_order; | |
5090 | } | |
5091 | ||
5092 | static void build_zonelists(pg_data_t *pgdat) | |
5093 | { | |
5094 | int i, node, load; | |
5095 | nodemask_t used_mask; | |
5096 | int local_node, prev_node; | |
5097 | struct zonelist *zonelist; | |
5098 | unsigned int order = current_zonelist_order; | |
5099 | ||
5100 | /* initialize zonelists */ | |
5101 | for (i = 0; i < MAX_ZONELISTS; i++) { | |
5102 | zonelist = pgdat->node_zonelists + i; | |
5103 | zonelist->_zonerefs[0].zone = NULL; | |
5104 | zonelist->_zonerefs[0].zone_idx = 0; | |
5105 | } | |
5106 | ||
5107 | /* NUMA-aware ordering of nodes */ | |
5108 | local_node = pgdat->node_id; | |
5109 | load = nr_online_nodes; | |
5110 | prev_node = local_node; | |
5111 | nodes_clear(used_mask); | |
5112 | ||
5113 | memset(node_order, 0, sizeof(node_order)); | |
5114 | i = 0; | |
5115 | ||
5116 | while ((node = find_next_best_node(local_node, &used_mask)) >= 0) { | |
5117 | /* | |
5118 | * We don't want to pressure a particular node. | |
5119 | * So adding penalty to the first node in same | |
5120 | * distance group to make it round-robin. | |
5121 | */ | |
5122 | if (node_distance(local_node, node) != | |
5123 | node_distance(local_node, prev_node)) | |
5124 | node_load[node] = load; | |
5125 | ||
5126 | prev_node = node; | |
5127 | load--; | |
5128 | if (order == ZONELIST_ORDER_NODE) | |
5129 | build_zonelists_in_node_order(pgdat, node); | |
5130 | else | |
5131 | node_order[i++] = node; /* remember order */ | |
5132 | } | |
5133 | ||
5134 | if (order == ZONELIST_ORDER_ZONE) { | |
5135 | /* calculate node order -- i.e., DMA last! */ | |
5136 | build_zonelists_in_zone_order(pgdat, i); | |
5137 | } | |
5138 | ||
5139 | build_thisnode_zonelists(pgdat); | |
5140 | } | |
5141 | ||
5142 | #ifdef CONFIG_HAVE_MEMORYLESS_NODES | |
5143 | /* | |
5144 | * Return node id of node used for "local" allocations. | |
5145 | * I.e., first node id of first zone in arg node's generic zonelist. | |
5146 | * Used for initializing percpu 'numa_mem', which is used primarily | |
5147 | * for kernel allocations, so use GFP_KERNEL flags to locate zonelist. | |
5148 | */ | |
5149 | int local_memory_node(int node) | |
5150 | { | |
5151 | struct zoneref *z; | |
5152 | ||
5153 | z = first_zones_zonelist(node_zonelist(node, GFP_KERNEL), | |
5154 | gfp_zone(GFP_KERNEL), | |
5155 | NULL); | |
5156 | return z->zone->node; | |
5157 | } | |
5158 | #endif | |
5159 | ||
5160 | static void setup_min_unmapped_ratio(void); | |
5161 | static void setup_min_slab_ratio(void); | |
5162 | #else /* CONFIG_NUMA */ | |
5163 | ||
5164 | static void set_zonelist_order(void) | |
5165 | { | |
5166 | current_zonelist_order = ZONELIST_ORDER_ZONE; | |
5167 | } | |
5168 | ||
5169 | static void build_zonelists(pg_data_t *pgdat) | |
5170 | { | |
5171 | int node, local_node; | |
5172 | enum zone_type j; | |
5173 | struct zonelist *zonelist; | |
5174 | ||
5175 | local_node = pgdat->node_id; | |
5176 | ||
5177 | zonelist = &pgdat->node_zonelists[ZONELIST_FALLBACK]; | |
5178 | j = build_zonelists_node(pgdat, zonelist, 0); | |
5179 | ||
5180 | /* | |
5181 | * Now we build the zonelist so that it contains the zones | |
5182 | * of all the other nodes. | |
5183 | * We don't want to pressure a particular node, so when | |
5184 | * building the zones for node N, we make sure that the | |
5185 | * zones coming right after the local ones are those from | |
5186 | * node N+1 (modulo N) | |
5187 | */ | |
5188 | for (node = local_node + 1; node < MAX_NUMNODES; node++) { | |
5189 | if (!node_online(node)) | |
5190 | continue; | |
5191 | j = build_zonelists_node(NODE_DATA(node), zonelist, j); | |
5192 | } | |
5193 | for (node = 0; node < local_node; node++) { | |
5194 | if (!node_online(node)) | |
5195 | continue; | |
5196 | j = build_zonelists_node(NODE_DATA(node), zonelist, j); | |
5197 | } | |
5198 | ||
5199 | zonelist->_zonerefs[j].zone = NULL; | |
5200 | zonelist->_zonerefs[j].zone_idx = 0; | |
5201 | } | |
5202 | ||
5203 | #endif /* CONFIG_NUMA */ | |
5204 | ||
5205 | /* | |
5206 | * Boot pageset table. One per cpu which is going to be used for all | |
5207 | * zones and all nodes. The parameters will be set in such a way | |
5208 | * that an item put on a list will immediately be handed over to | |
5209 | * the buddy list. This is safe since pageset manipulation is done | |
5210 | * with interrupts disabled. | |
5211 | * | |
5212 | * The boot_pagesets must be kept even after bootup is complete for | |
5213 | * unused processors and/or zones. They do play a role for bootstrapping | |
5214 | * hotplugged processors. | |
5215 | * | |
5216 | * zoneinfo_show() and maybe other functions do | |
5217 | * not check if the processor is online before following the pageset pointer. | |
5218 | * Other parts of the kernel may not check if the zone is available. | |
5219 | */ | |
5220 | static void setup_pageset(struct per_cpu_pageset *p, unsigned long batch); | |
5221 | static DEFINE_PER_CPU(struct per_cpu_pageset, boot_pageset); | |
5222 | static DEFINE_PER_CPU(struct per_cpu_nodestat, boot_nodestats); | |
5223 | static void setup_zone_pageset(struct zone *zone); | |
5224 | ||
5225 | /* | |
5226 | * Global mutex to protect against size modification of zonelists | |
5227 | * as well as to serialize pageset setup for the new populated zone. | |
5228 | */ | |
5229 | DEFINE_MUTEX(zonelists_mutex); | |
5230 | ||
5231 | /* return values int ....just for stop_machine() */ | |
5232 | static int __build_all_zonelists(void *data) | |
5233 | { | |
5234 | int nid; | |
5235 | int cpu; | |
5236 | pg_data_t *self = data; | |
5237 | ||
5238 | #ifdef CONFIG_NUMA | |
5239 | memset(node_load, 0, sizeof(node_load)); | |
5240 | #endif | |
5241 | ||
5242 | if (self && !node_online(self->node_id)) { | |
5243 | build_zonelists(self); | |
5244 | } | |
5245 | ||
5246 | for_each_online_node(nid) { | |
5247 | pg_data_t *pgdat = NODE_DATA(nid); | |
5248 | ||
5249 | build_zonelists(pgdat); | |
5250 | } | |
5251 | ||
5252 | /* | |
5253 | * Initialize the boot_pagesets that are going to be used | |
5254 | * for bootstrapping processors. The real pagesets for | |
5255 | * each zone will be allocated later when the per cpu | |
5256 | * allocator is available. | |
5257 | * | |
5258 | * boot_pagesets are used also for bootstrapping offline | |
5259 | * cpus if the system is already booted because the pagesets | |
5260 | * are needed to initialize allocators on a specific cpu too. | |
5261 | * F.e. the percpu allocator needs the page allocator which | |
5262 | * needs the percpu allocator in order to allocate its pagesets | |
5263 | * (a chicken-egg dilemma). | |
5264 | */ | |
5265 | for_each_possible_cpu(cpu) { | |
5266 | setup_pageset(&per_cpu(boot_pageset, cpu), 0); | |
5267 | ||
5268 | #ifdef CONFIG_HAVE_MEMORYLESS_NODES | |
5269 | /* | |
5270 | * We now know the "local memory node" for each node-- | |
5271 | * i.e., the node of the first zone in the generic zonelist. | |
5272 | * Set up numa_mem percpu variable for on-line cpus. During | |
5273 | * boot, only the boot cpu should be on-line; we'll init the | |
5274 | * secondary cpus' numa_mem as they come on-line. During | |
5275 | * node/memory hotplug, we'll fixup all on-line cpus. | |
5276 | */ | |
5277 | if (cpu_online(cpu)) | |
5278 | set_cpu_numa_mem(cpu, local_memory_node(cpu_to_node(cpu))); | |
5279 | #endif | |
5280 | } | |
5281 | ||
5282 | return 0; | |
5283 | } | |
5284 | ||
5285 | static noinline void __init | |
5286 | build_all_zonelists_init(void) | |
5287 | { | |
5288 | __build_all_zonelists(NULL); | |
5289 | mminit_verify_zonelist(); | |
5290 | cpuset_init_current_mems_allowed(); | |
5291 | } | |
5292 | ||
5293 | /* | |
5294 | * Called with zonelists_mutex held always | |
5295 | * unless system_state == SYSTEM_BOOTING. | |
5296 | * | |
5297 | * __ref due to (1) call of __meminit annotated setup_zone_pageset | |
5298 | * [we're only called with non-NULL zone through __meminit paths] and | |
5299 | * (2) call of __init annotated helper build_all_zonelists_init | |
5300 | * [protected by SYSTEM_BOOTING]. | |
5301 | */ | |
5302 | void __ref build_all_zonelists(pg_data_t *pgdat, struct zone *zone) | |
5303 | { | |
5304 | set_zonelist_order(); | |
5305 | ||
5306 | if (system_state == SYSTEM_BOOTING) { | |
5307 | build_all_zonelists_init(); | |
5308 | } else { | |
5309 | #ifdef CONFIG_MEMORY_HOTPLUG | |
5310 | if (zone) | |
5311 | setup_zone_pageset(zone); | |
5312 | #endif | |
5313 | /* we have to stop all cpus to guarantee there is no user | |
5314 | of zonelist */ | |
5315 | stop_machine_cpuslocked(__build_all_zonelists, pgdat, NULL); | |
5316 | /* cpuset refresh routine should be here */ | |
5317 | } | |
5318 | vm_total_pages = nr_free_pagecache_pages(); | |
5319 | /* | |
5320 | * Disable grouping by mobility if the number of pages in the | |
5321 | * system is too low to allow the mechanism to work. It would be | |
5322 | * more accurate, but expensive to check per-zone. This check is | |
5323 | * made on memory-hotadd so a system can start with mobility | |
5324 | * disabled and enable it later | |
5325 | */ | |
5326 | if (vm_total_pages < (pageblock_nr_pages * MIGRATE_TYPES)) | |
5327 | page_group_by_mobility_disabled = 1; | |
5328 | else | |
5329 | page_group_by_mobility_disabled = 0; | |
5330 | ||
5331 | pr_info("Built %i zonelists in %s order, mobility grouping %s. Total pages: %ld\n", | |
5332 | nr_online_nodes, | |
5333 | zonelist_order_name[current_zonelist_order], | |
5334 | page_group_by_mobility_disabled ? "off" : "on", | |
5335 | vm_total_pages); | |
5336 | #ifdef CONFIG_NUMA | |
5337 | pr_info("Policy zone: %s\n", zone_names[policy_zone]); | |
5338 | #endif | |
5339 | } | |
5340 | ||
5341 | /* | |
5342 | * Initially all pages are reserved - free ones are freed | |
5343 | * up by free_all_bootmem() once the early boot process is | |
5344 | * done. Non-atomic initialization, single-pass. | |
5345 | */ | |
5346 | void __meminit memmap_init_zone(unsigned long size, int nid, unsigned long zone, | |
5347 | unsigned long start_pfn, enum memmap_context context) | |
5348 | { | |
5349 | struct vmem_altmap *altmap = to_vmem_altmap(__pfn_to_phys(start_pfn)); | |
5350 | unsigned long end_pfn = start_pfn + size; | |
5351 | pg_data_t *pgdat = NODE_DATA(nid); | |
5352 | unsigned long pfn; | |
5353 | unsigned long nr_initialised = 0; | |
5354 | #ifdef CONFIG_HAVE_MEMBLOCK_NODE_MAP | |
5355 | struct memblock_region *r = NULL, *tmp; | |
5356 | #endif | |
5357 | ||
5358 | if (highest_memmap_pfn < end_pfn - 1) | |
5359 | highest_memmap_pfn = end_pfn - 1; | |
5360 | ||
5361 | /* | |
5362 | * Honor reservation requested by the driver for this ZONE_DEVICE | |
5363 | * memory | |
5364 | */ | |
5365 | if (altmap && start_pfn == altmap->base_pfn) | |
5366 | start_pfn += altmap->reserve; | |
5367 | ||
5368 | for (pfn = start_pfn; pfn < end_pfn; pfn++) { | |
5369 | /* | |
5370 | * There can be holes in boot-time mem_map[]s handed to this | |
5371 | * function. They do not exist on hotplugged memory. | |
5372 | */ | |
5373 | if (context != MEMMAP_EARLY) | |
5374 | goto not_early; | |
5375 | ||
5376 | if (!early_pfn_valid(pfn)) { | |
5377 | #ifdef CONFIG_HAVE_MEMBLOCK_NODE_MAP | |
5378 | /* | |
5379 | * Skip to the pfn preceding the next valid one (or | |
5380 | * end_pfn), such that we hit a valid pfn (or end_pfn) | |
5381 | * on our next iteration of the loop. | |
5382 | */ | |
5383 | pfn = memblock_next_valid_pfn(pfn, end_pfn) - 1; | |
5384 | #endif | |
5385 | continue; | |
5386 | } | |
5387 | if (!early_pfn_in_nid(pfn, nid)) | |
5388 | continue; | |
5389 | if (!update_defer_init(pgdat, pfn, end_pfn, &nr_initialised)) | |
5390 | break; | |
5391 | ||
5392 | #ifdef CONFIG_HAVE_MEMBLOCK_NODE_MAP | |
5393 | /* | |
5394 | * Check given memblock attribute by firmware which can affect | |
5395 | * kernel memory layout. If zone==ZONE_MOVABLE but memory is | |
5396 | * mirrored, it's an overlapped memmap init. skip it. | |
5397 | */ | |
5398 | if (mirrored_kernelcore && zone == ZONE_MOVABLE) { | |
5399 | if (!r || pfn >= memblock_region_memory_end_pfn(r)) { | |
5400 | for_each_memblock(memory, tmp) | |
5401 | if (pfn < memblock_region_memory_end_pfn(tmp)) | |
5402 | break; | |
5403 | r = tmp; | |
5404 | } | |
5405 | if (pfn >= memblock_region_memory_base_pfn(r) && | |
5406 | memblock_is_mirror(r)) { | |
5407 | /* already initialized as NORMAL */ | |
5408 | pfn = memblock_region_memory_end_pfn(r); | |
5409 | continue; | |
5410 | } | |
5411 | } | |
5412 | #endif | |
5413 | ||
5414 | not_early: | |
5415 | /* | |
5416 | * Mark the block movable so that blocks are reserved for | |
5417 | * movable at startup. This will force kernel allocations | |
5418 | * to reserve their blocks rather than leaking throughout | |
5419 | * the address space during boot when many long-lived | |
5420 | * kernel allocations are made. | |
5421 | * | |
5422 | * bitmap is created for zone's valid pfn range. but memmap | |
5423 | * can be created for invalid pages (for alignment) | |
5424 | * check here not to call set_pageblock_migratetype() against | |
5425 | * pfn out of zone. | |
5426 | */ | |
5427 | if (!(pfn & (pageblock_nr_pages - 1))) { | |
5428 | struct page *page = pfn_to_page(pfn); | |
5429 | ||
5430 | __init_single_page(page, pfn, zone, nid); | |
5431 | set_pageblock_migratetype(page, MIGRATE_MOVABLE); | |
5432 | } else { | |
5433 | __init_single_pfn(pfn, zone, nid); | |
5434 | } | |
5435 | } | |
5436 | } | |
5437 | ||
5438 | static void __meminit zone_init_free_lists(struct zone *zone) | |
5439 | { | |
5440 | unsigned int order, t; | |
5441 | for_each_migratetype_order(order, t) { | |
5442 | INIT_LIST_HEAD(&zone->free_area[order].free_list[t]); | |
5443 | zone->free_area[order].nr_free = 0; | |
5444 | } | |
5445 | } | |
5446 | ||
5447 | #ifndef __HAVE_ARCH_MEMMAP_INIT | |
5448 | #define memmap_init(size, nid, zone, start_pfn) \ | |
5449 | memmap_init_zone((size), (nid), (zone), (start_pfn), MEMMAP_EARLY) | |
5450 | #endif | |
5451 | ||
5452 | static int zone_batchsize(struct zone *zone) | |
5453 | { | |
5454 | #ifdef CONFIG_MMU | |
5455 | int batch; | |
5456 | ||
5457 | /* | |
5458 | * The per-cpu-pages pools are set to around 1000th of the | |
5459 | * size of the zone. But no more than 1/2 of a meg. | |
5460 | * | |
5461 | * OK, so we don't know how big the cache is. So guess. | |
5462 | */ | |
5463 | batch = zone->managed_pages / 1024; | |
5464 | if (batch * PAGE_SIZE > 512 * 1024) | |
5465 | batch = (512 * 1024) / PAGE_SIZE; | |
5466 | batch /= 4; /* We effectively *= 4 below */ | |
5467 | if (batch < 1) | |
5468 | batch = 1; | |
5469 | ||
5470 | /* | |
5471 | * Clamp the batch to a 2^n - 1 value. Having a power | |
5472 | * of 2 value was found to be more likely to have | |
5473 | * suboptimal cache aliasing properties in some cases. | |
5474 | * | |
5475 | * For example if 2 tasks are alternately allocating | |
5476 | * batches of pages, one task can end up with a lot | |
5477 | * of pages of one half of the possible page colors | |
5478 | * and the other with pages of the other colors. | |
5479 | */ | |
5480 | batch = rounddown_pow_of_two(batch + batch/2) - 1; | |
5481 | ||
5482 | return batch; | |
5483 | ||
5484 | #else | |
5485 | /* The deferral and batching of frees should be suppressed under NOMMU | |
5486 | * conditions. | |
5487 | * | |
5488 | * The problem is that NOMMU needs to be able to allocate large chunks | |
5489 | * of contiguous memory as there's no hardware page translation to | |
5490 | * assemble apparent contiguous memory from discontiguous pages. | |
5491 | * | |
5492 | * Queueing large contiguous runs of pages for batching, however, | |
5493 | * causes the pages to actually be freed in smaller chunks. As there | |
5494 | * can be a significant delay between the individual batches being | |
5495 | * recycled, this leads to the once large chunks of space being | |
5496 | * fragmented and becoming unavailable for high-order allocations. | |
5497 | */ | |
5498 | return 0; | |
5499 | #endif | |
5500 | } | |
5501 | ||
5502 | /* | |
5503 | * pcp->high and pcp->batch values are related and dependent on one another: | |
5504 | * ->batch must never be higher then ->high. | |
5505 | * The following function updates them in a safe manner without read side | |
5506 | * locking. | |
5507 | * | |
5508 | * Any new users of pcp->batch and pcp->high should ensure they can cope with | |
5509 | * those fields changing asynchronously (acording the the above rule). | |
5510 | * | |
5511 | * mutex_is_locked(&pcp_batch_high_lock) required when calling this function | |
5512 | * outside of boot time (or some other assurance that no concurrent updaters | |
5513 | * exist). | |
5514 | */ | |
5515 | static void pageset_update(struct per_cpu_pages *pcp, unsigned long high, | |
5516 | unsigned long batch) | |
5517 | { | |
5518 | /* start with a fail safe value for batch */ | |
5519 | pcp->batch = 1; | |
5520 | smp_wmb(); | |
5521 | ||
5522 | /* Update high, then batch, in order */ | |
5523 | pcp->high = high; | |
5524 | smp_wmb(); | |
5525 | ||
5526 | pcp->batch = batch; | |
5527 | } | |
5528 | ||
5529 | /* a companion to pageset_set_high() */ | |
5530 | static void pageset_set_batch(struct per_cpu_pageset *p, unsigned long batch) | |
5531 | { | |
5532 | pageset_update(&p->pcp, 6 * batch, max(1UL, 1 * batch)); | |
5533 | } | |
5534 | ||
5535 | static void pageset_init(struct per_cpu_pageset *p) | |
5536 | { | |
5537 | struct per_cpu_pages *pcp; | |
5538 | int migratetype; | |
5539 | ||
5540 | memset(p, 0, sizeof(*p)); | |
5541 | ||
5542 | pcp = &p->pcp; | |
5543 | pcp->count = 0; | |
5544 | for (migratetype = 0; migratetype < MIGRATE_PCPTYPES; migratetype++) | |
5545 | INIT_LIST_HEAD(&pcp->lists[migratetype]); | |
5546 | } | |
5547 | ||
5548 | static void setup_pageset(struct per_cpu_pageset *p, unsigned long batch) | |
5549 | { | |
5550 | pageset_init(p); | |
5551 | pageset_set_batch(p, batch); | |
5552 | } | |
5553 | ||
5554 | /* | |
5555 | * pageset_set_high() sets the high water mark for hot per_cpu_pagelist | |
5556 | * to the value high for the pageset p. | |
5557 | */ | |
5558 | static void pageset_set_high(struct per_cpu_pageset *p, | |
5559 | unsigned long high) | |
5560 | { | |
5561 | unsigned long batch = max(1UL, high / 4); | |
5562 | if ((high / 4) > (PAGE_SHIFT * 8)) | |
5563 | batch = PAGE_SHIFT * 8; | |
5564 | ||
5565 | pageset_update(&p->pcp, high, batch); | |
5566 | } | |
5567 | ||
5568 | static void pageset_set_high_and_batch(struct zone *zone, | |
5569 | struct per_cpu_pageset *pcp) | |
5570 | { | |
5571 | if (percpu_pagelist_fraction) | |
5572 | pageset_set_high(pcp, | |
5573 | (zone->managed_pages / | |
5574 | percpu_pagelist_fraction)); | |
5575 | else | |
5576 | pageset_set_batch(pcp, zone_batchsize(zone)); | |
5577 | } | |
5578 | ||
5579 | static void __meminit zone_pageset_init(struct zone *zone, int cpu) | |
5580 | { | |
5581 | struct per_cpu_pageset *pcp = per_cpu_ptr(zone->pageset, cpu); | |
5582 | ||
5583 | pageset_init(pcp); | |
5584 | pageset_set_high_and_batch(zone, pcp); | |
5585 | } | |
5586 | ||
5587 | static void __meminit setup_zone_pageset(struct zone *zone) | |
5588 | { | |
5589 | int cpu; | |
5590 | zone->pageset = alloc_percpu(struct per_cpu_pageset); | |
5591 | for_each_possible_cpu(cpu) | |
5592 | zone_pageset_init(zone, cpu); | |
5593 | } | |
5594 | ||
5595 | /* | |
5596 | * Allocate per cpu pagesets and initialize them. | |
5597 | * Before this call only boot pagesets were available. | |
5598 | */ | |
5599 | void __init setup_per_cpu_pageset(void) | |
5600 | { | |
5601 | struct pglist_data *pgdat; | |
5602 | struct zone *zone; | |
5603 | ||
5604 | for_each_populated_zone(zone) | |
5605 | setup_zone_pageset(zone); | |
5606 | ||
5607 | for_each_online_pgdat(pgdat) | |
5608 | pgdat->per_cpu_nodestats = | |
5609 | alloc_percpu(struct per_cpu_nodestat); | |
5610 | } | |
5611 | ||
5612 | static __meminit void zone_pcp_init(struct zone *zone) | |
5613 | { | |
5614 | /* | |
5615 | * per cpu subsystem is not up at this point. The following code | |
5616 | * relies on the ability of the linker to provide the | |
5617 | * offset of a (static) per cpu variable into the per cpu area. | |
5618 | */ | |
5619 | zone->pageset = &boot_pageset; | |
5620 | ||
5621 | if (populated_zone(zone)) | |
5622 | printk(KERN_DEBUG " %s zone: %lu pages, LIFO batch:%u\n", | |
5623 | zone->name, zone->present_pages, | |
5624 | zone_batchsize(zone)); | |
5625 | } | |
5626 | ||
5627 | void __meminit init_currently_empty_zone(struct zone *zone, | |
5628 | unsigned long zone_start_pfn, | |
5629 | unsigned long size) | |
5630 | { | |
5631 | struct pglist_data *pgdat = zone->zone_pgdat; | |
5632 | ||
5633 | pgdat->nr_zones = zone_idx(zone) + 1; | |
5634 | ||
5635 | zone->zone_start_pfn = zone_start_pfn; | |
5636 | ||
5637 | mminit_dprintk(MMINIT_TRACE, "memmap_init", | |
5638 | "Initialising map node %d zone %lu pfns %lu -> %lu\n", | |
5639 | pgdat->node_id, | |
5640 | (unsigned long)zone_idx(zone), | |
5641 | zone_start_pfn, (zone_start_pfn + size)); | |
5642 | ||
5643 | zone_init_free_lists(zone); | |
5644 | zone->initialized = 1; | |
5645 | } | |
5646 | ||
5647 | #ifdef CONFIG_HAVE_MEMBLOCK_NODE_MAP | |
5648 | #ifndef CONFIG_HAVE_ARCH_EARLY_PFN_TO_NID | |
5649 | ||
5650 | /* | |
5651 | * Required by SPARSEMEM. Given a PFN, return what node the PFN is on. | |
5652 | */ | |
5653 | int __meminit __early_pfn_to_nid(unsigned long pfn, | |
5654 | struct mminit_pfnnid_cache *state) | |
5655 | { | |
5656 | unsigned long start_pfn, end_pfn; | |
5657 | int nid; | |
5658 | ||
5659 | if (state->last_start <= pfn && pfn < state->last_end) | |
5660 | return state->last_nid; | |
5661 | ||
5662 | nid = memblock_search_pfn_nid(pfn, &start_pfn, &end_pfn); | |
5663 | if (nid != -1) { | |
5664 | state->last_start = start_pfn; | |
5665 | state->last_end = end_pfn; | |
5666 | state->last_nid = nid; | |
5667 | } | |
5668 | ||
5669 | return nid; | |
5670 | } | |
5671 | #endif /* CONFIG_HAVE_ARCH_EARLY_PFN_TO_NID */ | |
5672 | ||
5673 | /** | |
5674 | * free_bootmem_with_active_regions - Call memblock_free_early_nid for each active range | |
5675 | * @nid: The node to free memory on. If MAX_NUMNODES, all nodes are freed. | |
5676 | * @max_low_pfn: The highest PFN that will be passed to memblock_free_early_nid | |
5677 | * | |
5678 | * If an architecture guarantees that all ranges registered contain no holes | |
5679 | * and may be freed, this this function may be used instead of calling | |
5680 | * memblock_free_early_nid() manually. | |
5681 | */ | |
5682 | void __init free_bootmem_with_active_regions(int nid, unsigned long max_low_pfn) | |
5683 | { | |
5684 | unsigned long start_pfn, end_pfn; | |
5685 | int i, this_nid; | |
5686 | ||
5687 | for_each_mem_pfn_range(i, nid, &start_pfn, &end_pfn, &this_nid) { | |
5688 | start_pfn = min(start_pfn, max_low_pfn); | |
5689 | end_pfn = min(end_pfn, max_low_pfn); | |
5690 | ||
5691 | if (start_pfn < end_pfn) | |
5692 | memblock_free_early_nid(PFN_PHYS(start_pfn), | |
5693 | (end_pfn - start_pfn) << PAGE_SHIFT, | |
5694 | this_nid); | |
5695 | } | |
5696 | } | |
5697 | ||
5698 | /** | |
5699 | * sparse_memory_present_with_active_regions - Call memory_present for each active range | |
5700 | * @nid: The node to call memory_present for. If MAX_NUMNODES, all nodes will be used. | |
5701 | * | |
5702 | * If an architecture guarantees that all ranges registered contain no holes and may | |
5703 | * be freed, this function may be used instead of calling memory_present() manually. | |
5704 | */ | |
5705 | void __init sparse_memory_present_with_active_regions(int nid) | |
5706 | { | |
5707 | unsigned long start_pfn, end_pfn; | |
5708 | int i, this_nid; | |
5709 | ||
5710 | for_each_mem_pfn_range(i, nid, &start_pfn, &end_pfn, &this_nid) | |
5711 | memory_present(this_nid, start_pfn, end_pfn); | |
5712 | } | |
5713 | ||
5714 | /** | |
5715 | * get_pfn_range_for_nid - Return the start and end page frames for a node | |
5716 | * @nid: The nid to return the range for. If MAX_NUMNODES, the min and max PFN are returned. | |
5717 | * @start_pfn: Passed by reference. On return, it will have the node start_pfn. | |
5718 | * @end_pfn: Passed by reference. On return, it will have the node end_pfn. | |
5719 | * | |
5720 | * It returns the start and end page frame of a node based on information | |
5721 | * provided by memblock_set_node(). If called for a node | |
5722 | * with no available memory, a warning is printed and the start and end | |
5723 | * PFNs will be 0. | |
5724 | */ | |
5725 | void __meminit get_pfn_range_for_nid(unsigned int nid, | |
5726 | unsigned long *start_pfn, unsigned long *end_pfn) | |
5727 | { | |
5728 | unsigned long this_start_pfn, this_end_pfn; | |
5729 | int i; | |
5730 | ||
5731 | *start_pfn = -1UL; | |
5732 | *end_pfn = 0; | |
5733 | ||
5734 | for_each_mem_pfn_range(i, nid, &this_start_pfn, &this_end_pfn, NULL) { | |
5735 | *start_pfn = min(*start_pfn, this_start_pfn); | |
5736 | *end_pfn = max(*end_pfn, this_end_pfn); | |
5737 | } | |
5738 | ||
5739 | if (*start_pfn == -1UL) | |
5740 | *start_pfn = 0; | |
5741 | } | |
5742 | ||
5743 | /* | |
5744 | * This finds a zone that can be used for ZONE_MOVABLE pages. The | |
5745 | * assumption is made that zones within a node are ordered in monotonic | |
5746 | * increasing memory addresses so that the "highest" populated zone is used | |
5747 | */ | |
5748 | static void __init find_usable_zone_for_movable(void) | |
5749 | { | |
5750 | int zone_index; | |
5751 | for (zone_index = MAX_NR_ZONES - 1; zone_index >= 0; zone_index--) { | |
5752 | if (zone_index == ZONE_MOVABLE) | |
5753 | continue; | |
5754 | ||
5755 | if (arch_zone_highest_possible_pfn[zone_index] > | |
5756 | arch_zone_lowest_possible_pfn[zone_index]) | |
5757 | break; | |
5758 | } | |
5759 | ||
5760 | VM_BUG_ON(zone_index == -1); | |
5761 | movable_zone = zone_index; | |
5762 | } | |
5763 | ||
5764 | /* | |
5765 | * The zone ranges provided by the architecture do not include ZONE_MOVABLE | |
5766 | * because it is sized independent of architecture. Unlike the other zones, | |
5767 | * the starting point for ZONE_MOVABLE is not fixed. It may be different | |
5768 | * in each node depending on the size of each node and how evenly kernelcore | |
5769 | * is distributed. This helper function adjusts the zone ranges | |
5770 | * provided by the architecture for a given node by using the end of the | |
5771 | * highest usable zone for ZONE_MOVABLE. This preserves the assumption that | |
5772 | * zones within a node are in order of monotonic increases memory addresses | |
5773 | */ | |
5774 | static void __meminit adjust_zone_range_for_zone_movable(int nid, | |
5775 | unsigned long zone_type, | |
5776 | unsigned long node_start_pfn, | |
5777 | unsigned long node_end_pfn, | |
5778 | unsigned long *zone_start_pfn, | |
5779 | unsigned long *zone_end_pfn) | |
5780 | { | |
5781 | /* Only adjust if ZONE_MOVABLE is on this node */ | |
5782 | if (zone_movable_pfn[nid]) { | |
5783 | /* Size ZONE_MOVABLE */ | |
5784 | if (zone_type == ZONE_MOVABLE) { | |
5785 | *zone_start_pfn = zone_movable_pfn[nid]; | |
5786 | *zone_end_pfn = min(node_end_pfn, | |
5787 | arch_zone_highest_possible_pfn[movable_zone]); | |
5788 | ||
5789 | /* Adjust for ZONE_MOVABLE starting within this range */ | |
5790 | } else if (!mirrored_kernelcore && | |
5791 | *zone_start_pfn < zone_movable_pfn[nid] && | |
5792 | *zone_end_pfn > zone_movable_pfn[nid]) { | |
5793 | *zone_end_pfn = zone_movable_pfn[nid]; | |
5794 | ||
5795 | /* Check if this whole range is within ZONE_MOVABLE */ | |
5796 | } else if (*zone_start_pfn >= zone_movable_pfn[nid]) | |
5797 | *zone_start_pfn = *zone_end_pfn; | |
5798 | } | |
5799 | } | |
5800 | ||
5801 | /* | |
5802 | * Return the number of pages a zone spans in a node, including holes | |
5803 | * present_pages = zone_spanned_pages_in_node() - zone_absent_pages_in_node() | |
5804 | */ | |
5805 | static unsigned long __meminit zone_spanned_pages_in_node(int nid, | |
5806 | unsigned long zone_type, | |
5807 | unsigned long node_start_pfn, | |
5808 | unsigned long node_end_pfn, | |
5809 | unsigned long *zone_start_pfn, | |
5810 | unsigned long *zone_end_pfn, | |
5811 | unsigned long *ignored) | |
5812 | { | |
5813 | /* When hotadd a new node from cpu_up(), the node should be empty */ | |
5814 | if (!node_start_pfn && !node_end_pfn) | |
5815 | return 0; | |
5816 | ||
5817 | /* Get the start and end of the zone */ | |
5818 | *zone_start_pfn = arch_zone_lowest_possible_pfn[zone_type]; | |
5819 | *zone_end_pfn = arch_zone_highest_possible_pfn[zone_type]; | |
5820 | adjust_zone_range_for_zone_movable(nid, zone_type, | |
5821 | node_start_pfn, node_end_pfn, | |
5822 | zone_start_pfn, zone_end_pfn); | |
5823 | ||
5824 | /* Check that this node has pages within the zone's required range */ | |
5825 | if (*zone_end_pfn < node_start_pfn || *zone_start_pfn > node_end_pfn) | |
5826 | return 0; | |
5827 | ||
5828 | /* Move the zone boundaries inside the node if necessary */ | |
5829 | *zone_end_pfn = min(*zone_end_pfn, node_end_pfn); | |
5830 | *zone_start_pfn = max(*zone_start_pfn, node_start_pfn); | |
5831 | ||
5832 | /* Return the spanned pages */ | |
5833 | return *zone_end_pfn - *zone_start_pfn; | |
5834 | } | |
5835 | ||
5836 | /* | |
5837 | * Return the number of holes in a range on a node. If nid is MAX_NUMNODES, | |
5838 | * then all holes in the requested range will be accounted for. | |
5839 | */ | |
5840 | unsigned long __meminit __absent_pages_in_range(int nid, | |
5841 | unsigned long range_start_pfn, | |
5842 | unsigned long range_end_pfn) | |
5843 | { | |
5844 | unsigned long nr_absent = range_end_pfn - range_start_pfn; | |
5845 | unsigned long start_pfn, end_pfn; | |
5846 | int i; | |
5847 | ||
5848 | for_each_mem_pfn_range(i, nid, &start_pfn, &end_pfn, NULL) { | |
5849 | start_pfn = clamp(start_pfn, range_start_pfn, range_end_pfn); | |
5850 | end_pfn = clamp(end_pfn, range_start_pfn, range_end_pfn); | |
5851 | nr_absent -= end_pfn - start_pfn; | |
5852 | } | |
5853 | return nr_absent; | |
5854 | } | |
5855 | ||
5856 | /** | |
5857 | * absent_pages_in_range - Return number of page frames in holes within a range | |
5858 | * @start_pfn: The start PFN to start searching for holes | |
5859 | * @end_pfn: The end PFN to stop searching for holes | |
5860 | * | |
5861 | * It returns the number of pages frames in memory holes within a range. | |
5862 | */ | |
5863 | unsigned long __init absent_pages_in_range(unsigned long start_pfn, | |
5864 | unsigned long end_pfn) | |
5865 | { | |
5866 | return __absent_pages_in_range(MAX_NUMNODES, start_pfn, end_pfn); | |
5867 | } | |
5868 | ||
5869 | /* Return the number of page frames in holes in a zone on a node */ | |
5870 | static unsigned long __meminit zone_absent_pages_in_node(int nid, | |
5871 | unsigned long zone_type, | |
5872 | unsigned long node_start_pfn, | |
5873 | unsigned long node_end_pfn, | |
5874 | unsigned long *ignored) | |
5875 | { | |
5876 | unsigned long zone_low = arch_zone_lowest_possible_pfn[zone_type]; | |
5877 | unsigned long zone_high = arch_zone_highest_possible_pfn[zone_type]; | |
5878 | unsigned long zone_start_pfn, zone_end_pfn; | |
5879 | unsigned long nr_absent; | |
5880 | ||
5881 | /* When hotadd a new node from cpu_up(), the node should be empty */ | |
5882 | if (!node_start_pfn && !node_end_pfn) | |
5883 | return 0; | |
5884 | ||
5885 | zone_start_pfn = clamp(node_start_pfn, zone_low, zone_high); | |
5886 | zone_end_pfn = clamp(node_end_pfn, zone_low, zone_high); | |
5887 | ||
5888 | adjust_zone_range_for_zone_movable(nid, zone_type, | |
5889 | node_start_pfn, node_end_pfn, | |
5890 | &zone_start_pfn, &zone_end_pfn); | |
5891 | nr_absent = __absent_pages_in_range(nid, zone_start_pfn, zone_end_pfn); | |
5892 | ||
5893 | /* | |
5894 | * ZONE_MOVABLE handling. | |
5895 | * Treat pages to be ZONE_MOVABLE in ZONE_NORMAL as absent pages | |
5896 | * and vice versa. | |
5897 | */ | |
5898 | if (mirrored_kernelcore && zone_movable_pfn[nid]) { | |
5899 | unsigned long start_pfn, end_pfn; | |
5900 | struct memblock_region *r; | |
5901 | ||
5902 | for_each_memblock(memory, r) { | |
5903 | start_pfn = clamp(memblock_region_memory_base_pfn(r), | |
5904 | zone_start_pfn, zone_end_pfn); | |
5905 | end_pfn = clamp(memblock_region_memory_end_pfn(r), | |
5906 | zone_start_pfn, zone_end_pfn); | |
5907 | ||
5908 | if (zone_type == ZONE_MOVABLE && | |
5909 | memblock_is_mirror(r)) | |
5910 | nr_absent += end_pfn - start_pfn; | |
5911 | ||
5912 | if (zone_type == ZONE_NORMAL && | |
5913 | !memblock_is_mirror(r)) | |
5914 | nr_absent += end_pfn - start_pfn; | |
5915 | } | |
5916 | } | |
5917 | ||
5918 | return nr_absent; | |
5919 | } | |
5920 | ||
5921 | #else /* CONFIG_HAVE_MEMBLOCK_NODE_MAP */ | |
5922 | static inline unsigned long __meminit zone_spanned_pages_in_node(int nid, | |
5923 | unsigned long zone_type, | |
5924 | unsigned long node_start_pfn, | |
5925 | unsigned long node_end_pfn, | |
5926 | unsigned long *zone_start_pfn, | |
5927 | unsigned long *zone_end_pfn, | |
5928 | unsigned long *zones_size) | |
5929 | { | |
5930 | unsigned int zone; | |
5931 | ||
5932 | *zone_start_pfn = node_start_pfn; | |
5933 | for (zone = 0; zone < zone_type; zone++) | |
5934 | *zone_start_pfn += zones_size[zone]; | |
5935 | ||
5936 | *zone_end_pfn = *zone_start_pfn + zones_size[zone_type]; | |
5937 | ||
5938 | return zones_size[zone_type]; | |
5939 | } | |
5940 | ||
5941 | static inline unsigned long __meminit zone_absent_pages_in_node(int nid, | |
5942 | unsigned long zone_type, | |
5943 | unsigned long node_start_pfn, | |
5944 | unsigned long node_end_pfn, | |
5945 | unsigned long *zholes_size) | |
5946 | { | |
5947 | if (!zholes_size) | |
5948 | return 0; | |
5949 | ||
5950 | return zholes_size[zone_type]; | |
5951 | } | |
5952 | ||
5953 | #endif /* CONFIG_HAVE_MEMBLOCK_NODE_MAP */ | |
5954 | ||
5955 | static void __meminit calculate_node_totalpages(struct pglist_data *pgdat, | |
5956 | unsigned long node_start_pfn, | |
5957 | unsigned long node_end_pfn, | |
5958 | unsigned long *zones_size, | |
5959 | unsigned long *zholes_size) | |
5960 | { | |
5961 | unsigned long realtotalpages = 0, totalpages = 0; | |
5962 | enum zone_type i; | |
5963 | ||
5964 | for (i = 0; i < MAX_NR_ZONES; i++) { | |
5965 | struct zone *zone = pgdat->node_zones + i; | |
5966 | unsigned long zone_start_pfn, zone_end_pfn; | |
5967 | unsigned long size, real_size; | |
5968 | ||
5969 | size = zone_spanned_pages_in_node(pgdat->node_id, i, | |
5970 | node_start_pfn, | |
5971 | node_end_pfn, | |
5972 | &zone_start_pfn, | |
5973 | &zone_end_pfn, | |
5974 | zones_size); | |
5975 | real_size = size - zone_absent_pages_in_node(pgdat->node_id, i, | |
5976 | node_start_pfn, node_end_pfn, | |
5977 | zholes_size); | |
5978 | if (size) | |
5979 | zone->zone_start_pfn = zone_start_pfn; | |
5980 | else | |
5981 | zone->zone_start_pfn = 0; | |
5982 | zone->spanned_pages = size; | |
5983 | zone->present_pages = real_size; | |
5984 | ||
5985 | totalpages += size; | |
5986 | realtotalpages += real_size; | |
5987 | } | |
5988 | ||
5989 | pgdat->node_spanned_pages = totalpages; | |
5990 | pgdat->node_present_pages = realtotalpages; | |
5991 | printk(KERN_DEBUG "On node %d totalpages: %lu\n", pgdat->node_id, | |
5992 | realtotalpages); | |
5993 | } | |
5994 | ||
5995 | #ifndef CONFIG_SPARSEMEM | |
5996 | /* | |
5997 | * Calculate the size of the zone->blockflags rounded to an unsigned long | |
5998 | * Start by making sure zonesize is a multiple of pageblock_order by rounding | |
5999 | * up. Then use 1 NR_PAGEBLOCK_BITS worth of bits per pageblock, finally | |
6000 | * round what is now in bits to nearest long in bits, then return it in | |
6001 | * bytes. | |
6002 | */ | |
6003 | static unsigned long __init usemap_size(unsigned long zone_start_pfn, unsigned long zonesize) | |
6004 | { | |
6005 | unsigned long usemapsize; | |
6006 | ||
6007 | zonesize += zone_start_pfn & (pageblock_nr_pages-1); | |
6008 | usemapsize = roundup(zonesize, pageblock_nr_pages); | |
6009 | usemapsize = usemapsize >> pageblock_order; | |
6010 | usemapsize *= NR_PAGEBLOCK_BITS; | |
6011 | usemapsize = roundup(usemapsize, 8 * sizeof(unsigned long)); | |
6012 | ||
6013 | return usemapsize / 8; | |
6014 | } | |
6015 | ||
6016 | static void __init setup_usemap(struct pglist_data *pgdat, | |
6017 | struct zone *zone, | |
6018 | unsigned long zone_start_pfn, | |
6019 | unsigned long zonesize) | |
6020 | { | |
6021 | unsigned long usemapsize = usemap_size(zone_start_pfn, zonesize); | |
6022 | zone->pageblock_flags = NULL; | |
6023 | if (usemapsize) | |
6024 | zone->pageblock_flags = | |
6025 | memblock_virt_alloc_node_nopanic(usemapsize, | |
6026 | pgdat->node_id); | |
6027 | } | |
6028 | #else | |
6029 | static inline void setup_usemap(struct pglist_data *pgdat, struct zone *zone, | |
6030 | unsigned long zone_start_pfn, unsigned long zonesize) {} | |
6031 | #endif /* CONFIG_SPARSEMEM */ | |
6032 | ||
6033 | #ifdef CONFIG_HUGETLB_PAGE_SIZE_VARIABLE | |
6034 | ||
6035 | /* Initialise the number of pages represented by NR_PAGEBLOCK_BITS */ | |
6036 | void __paginginit set_pageblock_order(void) | |
6037 | { | |
6038 | unsigned int order; | |
6039 | ||
6040 | /* Check that pageblock_nr_pages has not already been setup */ | |
6041 | if (pageblock_order) | |
6042 | return; | |
6043 | ||
6044 | if (HPAGE_SHIFT > PAGE_SHIFT) | |
6045 | order = HUGETLB_PAGE_ORDER; | |
6046 | else | |
6047 | order = MAX_ORDER - 1; | |
6048 | ||
6049 | /* | |
6050 | * Assume the largest contiguous order of interest is a huge page. | |
6051 | * This value may be variable depending on boot parameters on IA64 and | |
6052 | * powerpc. | |
6053 | */ | |
6054 | pageblock_order = order; | |
6055 | } | |
6056 | #else /* CONFIG_HUGETLB_PAGE_SIZE_VARIABLE */ | |
6057 | ||
6058 | /* | |
6059 | * When CONFIG_HUGETLB_PAGE_SIZE_VARIABLE is not set, set_pageblock_order() | |
6060 | * is unused as pageblock_order is set at compile-time. See | |
6061 | * include/linux/pageblock-flags.h for the values of pageblock_order based on | |
6062 | * the kernel config | |
6063 | */ | |
6064 | void __paginginit set_pageblock_order(void) | |
6065 | { | |
6066 | } | |
6067 | ||
6068 | #endif /* CONFIG_HUGETLB_PAGE_SIZE_VARIABLE */ | |
6069 | ||
6070 | static unsigned long __paginginit calc_memmap_size(unsigned long spanned_pages, | |
6071 | unsigned long present_pages) | |
6072 | { | |
6073 | unsigned long pages = spanned_pages; | |
6074 | ||
6075 | /* | |
6076 | * Provide a more accurate estimation if there are holes within | |
6077 | * the zone and SPARSEMEM is in use. If there are holes within the | |
6078 | * zone, each populated memory region may cost us one or two extra | |
6079 | * memmap pages due to alignment because memmap pages for each | |
6080 | * populated regions may not be naturally aligned on page boundary. | |
6081 | * So the (present_pages >> 4) heuristic is a tradeoff for that. | |
6082 | */ | |
6083 | if (spanned_pages > present_pages + (present_pages >> 4) && | |
6084 | IS_ENABLED(CONFIG_SPARSEMEM)) | |
6085 | pages = present_pages; | |
6086 | ||
6087 | return PAGE_ALIGN(pages * sizeof(struct page)) >> PAGE_SHIFT; | |
6088 | } | |
6089 | ||
6090 | /* | |
6091 | * Set up the zone data structures: | |
6092 | * - mark all pages reserved | |
6093 | * - mark all memory queues empty | |
6094 | * - clear the memory bitmaps | |
6095 | * | |
6096 | * NOTE: pgdat should get zeroed by caller. | |
6097 | */ | |
6098 | static void __paginginit free_area_init_core(struct pglist_data *pgdat) | |
6099 | { | |
6100 | enum zone_type j; | |
6101 | int nid = pgdat->node_id; | |
6102 | ||
6103 | pgdat_resize_init(pgdat); | |
6104 | #ifdef CONFIG_NUMA_BALANCING | |
6105 | spin_lock_init(&pgdat->numabalancing_migrate_lock); | |
6106 | pgdat->numabalancing_migrate_nr_pages = 0; | |
6107 | pgdat->numabalancing_migrate_next_window = jiffies; | |
6108 | #endif | |
6109 | #ifdef CONFIG_TRANSPARENT_HUGEPAGE | |
6110 | spin_lock_init(&pgdat->split_queue_lock); | |
6111 | INIT_LIST_HEAD(&pgdat->split_queue); | |
6112 | pgdat->split_queue_len = 0; | |
6113 | #endif | |
6114 | init_waitqueue_head(&pgdat->kswapd_wait); | |
6115 | init_waitqueue_head(&pgdat->pfmemalloc_wait); | |
6116 | #ifdef CONFIG_COMPACTION | |
6117 | init_waitqueue_head(&pgdat->kcompactd_wait); | |
6118 | #endif | |
6119 | pgdat_page_ext_init(pgdat); | |
6120 | spin_lock_init(&pgdat->lru_lock); | |
6121 | lruvec_init(node_lruvec(pgdat)); | |
6122 | ||
6123 | pgdat->per_cpu_nodestats = &boot_nodestats; | |
6124 | ||
6125 | for (j = 0; j < MAX_NR_ZONES; j++) { | |
6126 | struct zone *zone = pgdat->node_zones + j; | |
6127 | unsigned long size, realsize, freesize, memmap_pages; | |
6128 | unsigned long zone_start_pfn = zone->zone_start_pfn; | |
6129 | ||
6130 | size = zone->spanned_pages; | |
6131 | realsize = freesize = zone->present_pages; | |
6132 | ||
6133 | /* | |
6134 | * Adjust freesize so that it accounts for how much memory | |
6135 | * is used by this zone for memmap. This affects the watermark | |
6136 | * and per-cpu initialisations | |
6137 | */ | |
6138 | memmap_pages = calc_memmap_size(size, realsize); | |
6139 | if (!is_highmem_idx(j)) { | |
6140 | if (freesize >= memmap_pages) { | |
6141 | freesize -= memmap_pages; | |
6142 | if (memmap_pages) | |
6143 | printk(KERN_DEBUG | |
6144 | " %s zone: %lu pages used for memmap\n", | |
6145 | zone_names[j], memmap_pages); | |
6146 | } else | |
6147 | pr_warn(" %s zone: %lu pages exceeds freesize %lu\n", | |
6148 | zone_names[j], memmap_pages, freesize); | |
6149 | } | |
6150 | ||
6151 | /* Account for reserved pages */ | |
6152 | if (j == 0 && freesize > dma_reserve) { | |
6153 | freesize -= dma_reserve; | |
6154 | printk(KERN_DEBUG " %s zone: %lu pages reserved\n", | |
6155 | zone_names[0], dma_reserve); | |
6156 | } | |
6157 | ||
6158 | if (!is_highmem_idx(j)) | |
6159 | nr_kernel_pages += freesize; | |
6160 | /* Charge for highmem memmap if there are enough kernel pages */ | |
6161 | else if (nr_kernel_pages > memmap_pages * 2) | |
6162 | nr_kernel_pages -= memmap_pages; | |
6163 | nr_all_pages += freesize; | |
6164 | ||
6165 | /* | |
6166 | * Set an approximate value for lowmem here, it will be adjusted | |
6167 | * when the bootmem allocator frees pages into the buddy system. | |
6168 | * And all highmem pages will be managed by the buddy system. | |
6169 | */ | |
6170 | zone->managed_pages = is_highmem_idx(j) ? realsize : freesize; | |
6171 | #ifdef CONFIG_NUMA | |
6172 | zone->node = nid; | |
6173 | #endif | |
6174 | zone->name = zone_names[j]; | |
6175 | zone->zone_pgdat = pgdat; | |
6176 | spin_lock_init(&zone->lock); | |
6177 | zone_seqlock_init(zone); | |
6178 | zone_pcp_init(zone); | |
6179 | ||
6180 | if (!size) | |
6181 | continue; | |
6182 | ||
6183 | set_pageblock_order(); | |
6184 | setup_usemap(pgdat, zone, zone_start_pfn, size); | |
6185 | init_currently_empty_zone(zone, zone_start_pfn, size); | |
6186 | memmap_init(size, nid, j, zone_start_pfn); | |
6187 | } | |
6188 | } | |
6189 | ||
6190 | static void __ref alloc_node_mem_map(struct pglist_data *pgdat) | |
6191 | { | |
6192 | unsigned long __maybe_unused start = 0; | |
6193 | unsigned long __maybe_unused offset = 0; | |
6194 | ||
6195 | /* Skip empty nodes */ | |
6196 | if (!pgdat->node_spanned_pages) | |
6197 | return; | |
6198 | ||
6199 | #ifdef CONFIG_FLAT_NODE_MEM_MAP | |
6200 | start = pgdat->node_start_pfn & ~(MAX_ORDER_NR_PAGES - 1); | |
6201 | offset = pgdat->node_start_pfn - start; | |
6202 | /* ia64 gets its own node_mem_map, before this, without bootmem */ | |
6203 | if (!pgdat->node_mem_map) { | |
6204 | unsigned long size, end; | |
6205 | struct page *map; | |
6206 | ||
6207 | /* | |
6208 | * The zone's endpoints aren't required to be MAX_ORDER | |
6209 | * aligned but the node_mem_map endpoints must be in order | |
6210 | * for the buddy allocator to function correctly. | |
6211 | */ | |
6212 | end = pgdat_end_pfn(pgdat); | |
6213 | end = ALIGN(end, MAX_ORDER_NR_PAGES); | |
6214 | size = (end - start) * sizeof(struct page); | |
6215 | map = alloc_remap(pgdat->node_id, size); | |
6216 | if (!map) | |
6217 | map = memblock_virt_alloc_node_nopanic(size, | |
6218 | pgdat->node_id); | |
6219 | pgdat->node_mem_map = map + offset; | |
6220 | } | |
6221 | #ifndef CONFIG_NEED_MULTIPLE_NODES | |
6222 | /* | |
6223 | * With no DISCONTIG, the global mem_map is just set as node 0's | |
6224 | */ | |
6225 | if (pgdat == NODE_DATA(0)) { | |
6226 | mem_map = NODE_DATA(0)->node_mem_map; | |
6227 | #if defined(CONFIG_HAVE_MEMBLOCK_NODE_MAP) || defined(CONFIG_FLATMEM) | |
6228 | if (page_to_pfn(mem_map) != pgdat->node_start_pfn) | |
6229 | mem_map -= offset; | |
6230 | #endif /* CONFIG_HAVE_MEMBLOCK_NODE_MAP */ | |
6231 | } | |
6232 | #endif | |
6233 | #endif /* CONFIG_FLAT_NODE_MEM_MAP */ | |
6234 | } | |
6235 | ||
6236 | void __paginginit free_area_init_node(int nid, unsigned long *zones_size, | |
6237 | unsigned long node_start_pfn, unsigned long *zholes_size) | |
6238 | { | |
6239 | pg_data_t *pgdat = NODE_DATA(nid); | |
6240 | unsigned long start_pfn = 0; | |
6241 | unsigned long end_pfn = 0; | |
6242 | ||
6243 | /* pg_data_t should be reset to zero when it's allocated */ | |
6244 | WARN_ON(pgdat->nr_zones || pgdat->kswapd_classzone_idx); | |
6245 | ||
6246 | pgdat->node_id = nid; | |
6247 | pgdat->node_start_pfn = node_start_pfn; | |
6248 | pgdat->per_cpu_nodestats = NULL; | |
6249 | #ifdef CONFIG_HAVE_MEMBLOCK_NODE_MAP | |
6250 | get_pfn_range_for_nid(nid, &start_pfn, &end_pfn); | |
6251 | pr_info("Initmem setup node %d [mem %#018Lx-%#018Lx]\n", nid, | |
6252 | (u64)start_pfn << PAGE_SHIFT, | |
6253 | end_pfn ? ((u64)end_pfn << PAGE_SHIFT) - 1 : 0); | |
6254 | #else | |
6255 | start_pfn = node_start_pfn; | |
6256 | #endif | |
6257 | calculate_node_totalpages(pgdat, start_pfn, end_pfn, | |
6258 | zones_size, zholes_size); | |
6259 | ||
6260 | alloc_node_mem_map(pgdat); | |
6261 | #ifdef CONFIG_FLAT_NODE_MEM_MAP | |
6262 | printk(KERN_DEBUG "free_area_init_node: node %d, pgdat %08lx, node_mem_map %08lx\n", | |
6263 | nid, (unsigned long)pgdat, | |
6264 | (unsigned long)pgdat->node_mem_map); | |
6265 | #endif | |
6266 | ||
6267 | reset_deferred_meminit(pgdat); | |
6268 | free_area_init_core(pgdat); | |
6269 | } | |
6270 | ||
6271 | #ifdef CONFIG_HAVE_MEMBLOCK_NODE_MAP | |
6272 | ||
6273 | #if MAX_NUMNODES > 1 | |
6274 | /* | |
6275 | * Figure out the number of possible node ids. | |
6276 | */ | |
6277 | void __init setup_nr_node_ids(void) | |
6278 | { | |
6279 | unsigned int highest; | |
6280 | ||
6281 | highest = find_last_bit(node_possible_map.bits, MAX_NUMNODES); | |
6282 | nr_node_ids = highest + 1; | |
6283 | } | |
6284 | #endif | |
6285 | ||
6286 | /** | |
6287 | * node_map_pfn_alignment - determine the maximum internode alignment | |
6288 | * | |
6289 | * This function should be called after node map is populated and sorted. | |
6290 | * It calculates the maximum power of two alignment which can distinguish | |
6291 | * all the nodes. | |
6292 | * | |
6293 | * For example, if all nodes are 1GiB and aligned to 1GiB, the return value | |
6294 | * would indicate 1GiB alignment with (1 << (30 - PAGE_SHIFT)). If the | |
6295 | * nodes are shifted by 256MiB, 256MiB. Note that if only the last node is | |
6296 | * shifted, 1GiB is enough and this function will indicate so. | |
6297 | * | |
6298 | * This is used to test whether pfn -> nid mapping of the chosen memory | |
6299 | * model has fine enough granularity to avoid incorrect mapping for the | |
6300 | * populated node map. | |
6301 | * | |
6302 | * Returns the determined alignment in pfn's. 0 if there is no alignment | |
6303 | * requirement (single node). | |
6304 | */ | |
6305 | unsigned long __init node_map_pfn_alignment(void) | |
6306 | { | |
6307 | unsigned long accl_mask = 0, last_end = 0; | |
6308 | unsigned long start, end, mask; | |
6309 | int last_nid = -1; | |
6310 | int i, nid; | |
6311 | ||
6312 | for_each_mem_pfn_range(i, MAX_NUMNODES, &start, &end, &nid) { | |
6313 | if (!start || last_nid < 0 || last_nid == nid) { | |
6314 | last_nid = nid; | |
6315 | last_end = end; | |
6316 | continue; | |
6317 | } | |
6318 | ||
6319 | /* | |
6320 | * Start with a mask granular enough to pin-point to the | |
6321 | * start pfn and tick off bits one-by-one until it becomes | |
6322 | * too coarse to separate the current node from the last. | |
6323 | */ | |
6324 | mask = ~((1 << __ffs(start)) - 1); | |
6325 | while (mask && last_end <= (start & (mask << 1))) | |
6326 | mask <<= 1; | |
6327 | ||
6328 | /* accumulate all internode masks */ | |
6329 | accl_mask |= mask; | |
6330 | } | |
6331 | ||
6332 | /* convert mask to number of pages */ | |
6333 | return ~accl_mask + 1; | |
6334 | } | |
6335 | ||
6336 | /* Find the lowest pfn for a node */ | |
6337 | static unsigned long __init find_min_pfn_for_node(int nid) | |
6338 | { | |
6339 | unsigned long min_pfn = ULONG_MAX; | |
6340 | unsigned long start_pfn; | |
6341 | int i; | |
6342 | ||
6343 | for_each_mem_pfn_range(i, nid, &start_pfn, NULL, NULL) | |
6344 | min_pfn = min(min_pfn, start_pfn); | |
6345 | ||
6346 | if (min_pfn == ULONG_MAX) { | |
6347 | pr_warn("Could not find start_pfn for node %d\n", nid); | |
6348 | return 0; | |
6349 | } | |
6350 | ||
6351 | return min_pfn; | |
6352 | } | |
6353 | ||
6354 | /** | |
6355 | * find_min_pfn_with_active_regions - Find the minimum PFN registered | |
6356 | * | |
6357 | * It returns the minimum PFN based on information provided via | |
6358 | * memblock_set_node(). | |
6359 | */ | |
6360 | unsigned long __init find_min_pfn_with_active_regions(void) | |
6361 | { | |
6362 | return find_min_pfn_for_node(MAX_NUMNODES); | |
6363 | } | |
6364 | ||
6365 | /* | |
6366 | * early_calculate_totalpages() | |
6367 | * Sum pages in active regions for movable zone. | |
6368 | * Populate N_MEMORY for calculating usable_nodes. | |
6369 | */ | |
6370 | static unsigned long __init early_calculate_totalpages(void) | |
6371 | { | |
6372 | unsigned long totalpages = 0; | |
6373 | unsigned long start_pfn, end_pfn; | |
6374 | int i, nid; | |
6375 | ||
6376 | for_each_mem_pfn_range(i, MAX_NUMNODES, &start_pfn, &end_pfn, &nid) { | |
6377 | unsigned long pages = end_pfn - start_pfn; | |
6378 | ||
6379 | totalpages += pages; | |
6380 | if (pages) | |
6381 | node_set_state(nid, N_MEMORY); | |
6382 | } | |
6383 | return totalpages; | |
6384 | } | |
6385 | ||
6386 | /* | |
6387 | * Find the PFN the Movable zone begins in each node. Kernel memory | |
6388 | * is spread evenly between nodes as long as the nodes have enough | |
6389 | * memory. When they don't, some nodes will have more kernelcore than | |
6390 | * others | |
6391 | */ | |
6392 | static void __init find_zone_movable_pfns_for_nodes(void) | |
6393 | { | |
6394 | int i, nid; | |
6395 | unsigned long usable_startpfn; | |
6396 | unsigned long kernelcore_node, kernelcore_remaining; | |
6397 | /* save the state before borrow the nodemask */ | |
6398 | nodemask_t saved_node_state = node_states[N_MEMORY]; | |
6399 | unsigned long totalpages = early_calculate_totalpages(); | |
6400 | int usable_nodes = nodes_weight(node_states[N_MEMORY]); | |
6401 | struct memblock_region *r; | |
6402 | ||
6403 | /* Need to find movable_zone earlier when movable_node is specified. */ | |
6404 | find_usable_zone_for_movable(); | |
6405 | ||
6406 | /* | |
6407 | * If movable_node is specified, ignore kernelcore and movablecore | |
6408 | * options. | |
6409 | */ | |
6410 | if (movable_node_is_enabled()) { | |
6411 | for_each_memblock(memory, r) { | |
6412 | if (!memblock_is_hotpluggable(r)) | |
6413 | continue; | |
6414 | ||
6415 | nid = r->nid; | |
6416 | ||
6417 | usable_startpfn = PFN_DOWN(r->base); | |
6418 | zone_movable_pfn[nid] = zone_movable_pfn[nid] ? | |
6419 | min(usable_startpfn, zone_movable_pfn[nid]) : | |
6420 | usable_startpfn; | |
6421 | } | |
6422 | ||
6423 | goto out2; | |
6424 | } | |
6425 | ||
6426 | /* | |
6427 | * If kernelcore=mirror is specified, ignore movablecore option | |
6428 | */ | |
6429 | if (mirrored_kernelcore) { | |
6430 | bool mem_below_4gb_not_mirrored = false; | |
6431 | ||
6432 | for_each_memblock(memory, r) { | |
6433 | if (memblock_is_mirror(r)) | |
6434 | continue; | |
6435 | ||
6436 | nid = r->nid; | |
6437 | ||
6438 | usable_startpfn = memblock_region_memory_base_pfn(r); | |
6439 | ||
6440 | if (usable_startpfn < 0x100000) { | |
6441 | mem_below_4gb_not_mirrored = true; | |
6442 | continue; | |
6443 | } | |
6444 | ||
6445 | zone_movable_pfn[nid] = zone_movable_pfn[nid] ? | |
6446 | min(usable_startpfn, zone_movable_pfn[nid]) : | |
6447 | usable_startpfn; | |
6448 | } | |
6449 | ||
6450 | if (mem_below_4gb_not_mirrored) | |
6451 | pr_warn("This configuration results in unmirrored kernel memory."); | |
6452 | ||
6453 | goto out2; | |
6454 | } | |
6455 | ||
6456 | /* | |
6457 | * If movablecore=nn[KMG] was specified, calculate what size of | |
6458 | * kernelcore that corresponds so that memory usable for | |
6459 | * any allocation type is evenly spread. If both kernelcore | |
6460 | * and movablecore are specified, then the value of kernelcore | |
6461 | * will be used for required_kernelcore if it's greater than | |
6462 | * what movablecore would have allowed. | |
6463 | */ | |
6464 | if (required_movablecore) { | |
6465 | unsigned long corepages; | |
6466 | ||
6467 | /* | |
6468 | * Round-up so that ZONE_MOVABLE is at least as large as what | |
6469 | * was requested by the user | |
6470 | */ | |
6471 | required_movablecore = | |
6472 | roundup(required_movablecore, MAX_ORDER_NR_PAGES); | |
6473 | required_movablecore = min(totalpages, required_movablecore); | |
6474 | corepages = totalpages - required_movablecore; | |
6475 | ||
6476 | required_kernelcore = max(required_kernelcore, corepages); | |
6477 | } | |
6478 | ||
6479 | /* | |
6480 | * If kernelcore was not specified or kernelcore size is larger | |
6481 | * than totalpages, there is no ZONE_MOVABLE. | |
6482 | */ | |
6483 | if (!required_kernelcore || required_kernelcore >= totalpages) | |
6484 | goto out; | |
6485 | ||
6486 | /* usable_startpfn is the lowest possible pfn ZONE_MOVABLE can be at */ | |
6487 | usable_startpfn = arch_zone_lowest_possible_pfn[movable_zone]; | |
6488 | ||
6489 | restart: | |
6490 | /* Spread kernelcore memory as evenly as possible throughout nodes */ | |
6491 | kernelcore_node = required_kernelcore / usable_nodes; | |
6492 | for_each_node_state(nid, N_MEMORY) { | |
6493 | unsigned long start_pfn, end_pfn; | |
6494 | ||
6495 | /* | |
6496 | * Recalculate kernelcore_node if the division per node | |
6497 | * now exceeds what is necessary to satisfy the requested | |
6498 | * amount of memory for the kernel | |
6499 | */ | |
6500 | if (required_kernelcore < kernelcore_node) | |
6501 | kernelcore_node = required_kernelcore / usable_nodes; | |
6502 | ||
6503 | /* | |
6504 | * As the map is walked, we track how much memory is usable | |
6505 | * by the kernel using kernelcore_remaining. When it is | |
6506 | * 0, the rest of the node is usable by ZONE_MOVABLE | |
6507 | */ | |
6508 | kernelcore_remaining = kernelcore_node; | |
6509 | ||
6510 | /* Go through each range of PFNs within this node */ | |
6511 | for_each_mem_pfn_range(i, nid, &start_pfn, &end_pfn, NULL) { | |
6512 | unsigned long size_pages; | |
6513 | ||
6514 | start_pfn = max(start_pfn, zone_movable_pfn[nid]); | |
6515 | if (start_pfn >= end_pfn) | |
6516 | continue; | |
6517 | ||
6518 | /* Account for what is only usable for kernelcore */ | |
6519 | if (start_pfn < usable_startpfn) { | |
6520 | unsigned long kernel_pages; | |
6521 | kernel_pages = min(end_pfn, usable_startpfn) | |
6522 | - start_pfn; | |
6523 | ||
6524 | kernelcore_remaining -= min(kernel_pages, | |
6525 | kernelcore_remaining); | |
6526 | required_kernelcore -= min(kernel_pages, | |
6527 | required_kernelcore); | |
6528 | ||
6529 | /* Continue if range is now fully accounted */ | |
6530 | if (end_pfn <= usable_startpfn) { | |
6531 | ||
6532 | /* | |
6533 | * Push zone_movable_pfn to the end so | |
6534 | * that if we have to rebalance | |
6535 | * kernelcore across nodes, we will | |
6536 | * not double account here | |
6537 | */ | |
6538 | zone_movable_pfn[nid] = end_pfn; | |
6539 | continue; | |
6540 | } | |
6541 | start_pfn = usable_startpfn; | |
6542 | } | |
6543 | ||
6544 | /* | |
6545 | * The usable PFN range for ZONE_MOVABLE is from | |
6546 | * start_pfn->end_pfn. Calculate size_pages as the | |
6547 | * number of pages used as kernelcore | |
6548 | */ | |
6549 | size_pages = end_pfn - start_pfn; | |
6550 | if (size_pages > kernelcore_remaining) | |
6551 | size_pages = kernelcore_remaining; | |
6552 | zone_movable_pfn[nid] = start_pfn + size_pages; | |
6553 | ||
6554 | /* | |
6555 | * Some kernelcore has been met, update counts and | |
6556 | * break if the kernelcore for this node has been | |
6557 | * satisfied | |
6558 | */ | |
6559 | required_kernelcore -= min(required_kernelcore, | |
6560 | size_pages); | |
6561 | kernelcore_remaining -= size_pages; | |
6562 | if (!kernelcore_remaining) | |
6563 | break; | |
6564 | } | |
6565 | } | |
6566 | ||
6567 | /* | |
6568 | * If there is still required_kernelcore, we do another pass with one | |
6569 | * less node in the count. This will push zone_movable_pfn[nid] further | |
6570 | * along on the nodes that still have memory until kernelcore is | |
6571 | * satisfied | |
6572 | */ | |
6573 | usable_nodes--; | |
6574 | if (usable_nodes && required_kernelcore > usable_nodes) | |
6575 | goto restart; | |
6576 | ||
6577 | out2: | |
6578 | /* Align start of ZONE_MOVABLE on all nids to MAX_ORDER_NR_PAGES */ | |
6579 | for (nid = 0; nid < MAX_NUMNODES; nid++) | |
6580 | zone_movable_pfn[nid] = | |
6581 | roundup(zone_movable_pfn[nid], MAX_ORDER_NR_PAGES); | |
6582 | ||
6583 | out: | |
6584 | /* restore the node_state */ | |
6585 | node_states[N_MEMORY] = saved_node_state; | |
6586 | } | |
6587 | ||
6588 | /* Any regular or high memory on that node ? */ | |
6589 | static void check_for_memory(pg_data_t *pgdat, int nid) | |
6590 | { | |
6591 | enum zone_type zone_type; | |
6592 | ||
6593 | if (N_MEMORY == N_NORMAL_MEMORY) | |
6594 | return; | |
6595 | ||
6596 | for (zone_type = 0; zone_type <= ZONE_MOVABLE - 1; zone_type++) { | |
6597 | struct zone *zone = &pgdat->node_zones[zone_type]; | |
6598 | if (populated_zone(zone)) { | |
6599 | node_set_state(nid, N_HIGH_MEMORY); | |
6600 | if (N_NORMAL_MEMORY != N_HIGH_MEMORY && | |
6601 | zone_type <= ZONE_NORMAL) | |
6602 | node_set_state(nid, N_NORMAL_MEMORY); | |
6603 | break; | |
6604 | } | |
6605 | } | |
6606 | } | |
6607 | ||
6608 | /** | |
6609 | * free_area_init_nodes - Initialise all pg_data_t and zone data | |
6610 | * @max_zone_pfn: an array of max PFNs for each zone | |
6611 | * | |
6612 | * This will call free_area_init_node() for each active node in the system. | |
6613 | * Using the page ranges provided by memblock_set_node(), the size of each | |
6614 | * zone in each node and their holes is calculated. If the maximum PFN | |
6615 | * between two adjacent zones match, it is assumed that the zone is empty. | |
6616 | * For example, if arch_max_dma_pfn == arch_max_dma32_pfn, it is assumed | |
6617 | * that arch_max_dma32_pfn has no pages. It is also assumed that a zone | |
6618 | * starts where the previous one ended. For example, ZONE_DMA32 starts | |
6619 | * at arch_max_dma_pfn. | |
6620 | */ | |
6621 | void __init free_area_init_nodes(unsigned long *max_zone_pfn) | |
6622 | { | |
6623 | unsigned long start_pfn, end_pfn; | |
6624 | int i, nid; | |
6625 | ||
6626 | /* Record where the zone boundaries are */ | |
6627 | memset(arch_zone_lowest_possible_pfn, 0, | |
6628 | sizeof(arch_zone_lowest_possible_pfn)); | |
6629 | memset(arch_zone_highest_possible_pfn, 0, | |
6630 | sizeof(arch_zone_highest_possible_pfn)); | |
6631 | ||
6632 | start_pfn = find_min_pfn_with_active_regions(); | |
6633 | ||
6634 | for (i = 0; i < MAX_NR_ZONES; i++) { | |
6635 | if (i == ZONE_MOVABLE) | |
6636 | continue; | |
6637 | ||
6638 | end_pfn = max(max_zone_pfn[i], start_pfn); | |
6639 | arch_zone_lowest_possible_pfn[i] = start_pfn; | |
6640 | arch_zone_highest_possible_pfn[i] = end_pfn; | |
6641 | ||
6642 | start_pfn = end_pfn; | |
6643 | } | |
6644 | ||
6645 | /* Find the PFNs that ZONE_MOVABLE begins at in each node */ | |
6646 | memset(zone_movable_pfn, 0, sizeof(zone_movable_pfn)); | |
6647 | find_zone_movable_pfns_for_nodes(); | |
6648 | ||
6649 | /* Print out the zone ranges */ | |
6650 | pr_info("Zone ranges:\n"); | |
6651 | for (i = 0; i < MAX_NR_ZONES; i++) { | |
6652 | if (i == ZONE_MOVABLE) | |
6653 | continue; | |
6654 | pr_info(" %-8s ", zone_names[i]); | |
6655 | if (arch_zone_lowest_possible_pfn[i] == | |
6656 | arch_zone_highest_possible_pfn[i]) | |
6657 | pr_cont("empty\n"); | |
6658 | else | |
6659 | pr_cont("[mem %#018Lx-%#018Lx]\n", | |
6660 | (u64)arch_zone_lowest_possible_pfn[i] | |
6661 | << PAGE_SHIFT, | |
6662 | ((u64)arch_zone_highest_possible_pfn[i] | |
6663 | << PAGE_SHIFT) - 1); | |
6664 | } | |
6665 | ||
6666 | /* Print out the PFNs ZONE_MOVABLE begins at in each node */ | |
6667 | pr_info("Movable zone start for each node\n"); | |
6668 | for (i = 0; i < MAX_NUMNODES; i++) { | |
6669 | if (zone_movable_pfn[i]) | |
6670 | pr_info(" Node %d: %#018Lx\n", i, | |
6671 | (u64)zone_movable_pfn[i] << PAGE_SHIFT); | |
6672 | } | |
6673 | ||
6674 | /* Print out the early node map */ | |
6675 | pr_info("Early memory node ranges\n"); | |
6676 | for_each_mem_pfn_range(i, MAX_NUMNODES, &start_pfn, &end_pfn, &nid) | |
6677 | pr_info(" node %3d: [mem %#018Lx-%#018Lx]\n", nid, | |
6678 | (u64)start_pfn << PAGE_SHIFT, | |
6679 | ((u64)end_pfn << PAGE_SHIFT) - 1); | |
6680 | ||
6681 | /* Initialise every node */ | |
6682 | mminit_verify_pageflags_layout(); | |
6683 | setup_nr_node_ids(); | |
6684 | for_each_online_node(nid) { | |
6685 | pg_data_t *pgdat = NODE_DATA(nid); | |
6686 | free_area_init_node(nid, NULL, | |
6687 | find_min_pfn_for_node(nid), NULL); | |
6688 | ||
6689 | /* Any memory on that node */ | |
6690 | if (pgdat->node_present_pages) | |
6691 | node_set_state(nid, N_MEMORY); | |
6692 | check_for_memory(pgdat, nid); | |
6693 | } | |
6694 | } | |
6695 | ||
6696 | static int __init cmdline_parse_core(char *p, unsigned long *core) | |
6697 | { | |
6698 | unsigned long long coremem; | |
6699 | if (!p) | |
6700 | return -EINVAL; | |
6701 | ||
6702 | coremem = memparse(p, &p); | |
6703 | *core = coremem >> PAGE_SHIFT; | |
6704 | ||
6705 | /* Paranoid check that UL is enough for the coremem value */ | |
6706 | WARN_ON((coremem >> PAGE_SHIFT) > ULONG_MAX); | |
6707 | ||
6708 | return 0; | |
6709 | } | |
6710 | ||
6711 | /* | |
6712 | * kernelcore=size sets the amount of memory for use for allocations that | |
6713 | * cannot be reclaimed or migrated. | |
6714 | */ | |
6715 | static int __init cmdline_parse_kernelcore(char *p) | |
6716 | { | |
6717 | /* parse kernelcore=mirror */ | |
6718 | if (parse_option_str(p, "mirror")) { | |
6719 | mirrored_kernelcore = true; | |
6720 | return 0; | |
6721 | } | |
6722 | ||
6723 | return cmdline_parse_core(p, &required_kernelcore); | |
6724 | } | |
6725 | ||
6726 | /* | |
6727 | * movablecore=size sets the amount of memory for use for allocations that | |
6728 | * can be reclaimed or migrated. | |
6729 | */ | |
6730 | static int __init cmdline_parse_movablecore(char *p) | |
6731 | { | |
6732 | return cmdline_parse_core(p, &required_movablecore); | |
6733 | } | |
6734 | ||
6735 | early_param("kernelcore", cmdline_parse_kernelcore); | |
6736 | early_param("movablecore", cmdline_parse_movablecore); | |
6737 | ||
6738 | #endif /* CONFIG_HAVE_MEMBLOCK_NODE_MAP */ | |
6739 | ||
6740 | void adjust_managed_page_count(struct page *page, long count) | |
6741 | { | |
6742 | spin_lock(&managed_page_count_lock); | |
6743 | page_zone(page)->managed_pages += count; | |
6744 | totalram_pages += count; | |
6745 | #ifdef CONFIG_HIGHMEM | |
6746 | if (PageHighMem(page)) | |
6747 | totalhigh_pages += count; | |
6748 | #endif | |
6749 | spin_unlock(&managed_page_count_lock); | |
6750 | } | |
6751 | EXPORT_SYMBOL(adjust_managed_page_count); | |
6752 | ||
6753 | unsigned long free_reserved_area(void *start, void *end, int poison, char *s) | |
6754 | { | |
6755 | void *pos; | |
6756 | unsigned long pages = 0; | |
6757 | ||
6758 | start = (void *)PAGE_ALIGN((unsigned long)start); | |
6759 | end = (void *)((unsigned long)end & PAGE_MASK); | |
6760 | for (pos = start; pos < end; pos += PAGE_SIZE, pages++) { | |
6761 | if ((unsigned int)poison <= 0xFF) | |
6762 | memset(pos, poison, PAGE_SIZE); | |
6763 | free_reserved_page(virt_to_page(pos)); | |
6764 | } | |
6765 | ||
6766 | if (pages && s) | |
6767 | pr_info("Freeing %s memory: %ldK\n", | |
6768 | s, pages << (PAGE_SHIFT - 10)); | |
6769 | ||
6770 | return pages; | |
6771 | } | |
6772 | EXPORT_SYMBOL(free_reserved_area); | |
6773 | ||
6774 | #ifdef CONFIG_HIGHMEM | |
6775 | void free_highmem_page(struct page *page) | |
6776 | { | |
6777 | __free_reserved_page(page); | |
6778 | totalram_pages++; | |
6779 | page_zone(page)->managed_pages++; | |
6780 | totalhigh_pages++; | |
6781 | } | |
6782 | #endif | |
6783 | ||
6784 | ||
6785 | void __init mem_init_print_info(const char *str) | |
6786 | { | |
6787 | unsigned long physpages, codesize, datasize, rosize, bss_size; | |
6788 | unsigned long init_code_size, init_data_size; | |
6789 | ||
6790 | physpages = get_num_physpages(); | |
6791 | codesize = _etext - _stext; | |
6792 | datasize = _edata - _sdata; | |
6793 | rosize = __end_rodata - __start_rodata; | |
6794 | bss_size = __bss_stop - __bss_start; | |
6795 | init_data_size = __init_end - __init_begin; | |
6796 | init_code_size = _einittext - _sinittext; | |
6797 | ||
6798 | /* | |
6799 | * Detect special cases and adjust section sizes accordingly: | |
6800 | * 1) .init.* may be embedded into .data sections | |
6801 | * 2) .init.text.* may be out of [__init_begin, __init_end], | |
6802 | * please refer to arch/tile/kernel/vmlinux.lds.S. | |
6803 | * 3) .rodata.* may be embedded into .text or .data sections. | |
6804 | */ | |
6805 | #define adj_init_size(start, end, size, pos, adj) \ | |
6806 | do { \ | |
6807 | if (start <= pos && pos < end && size > adj) \ | |
6808 | size -= adj; \ | |
6809 | } while (0) | |
6810 | ||
6811 | adj_init_size(__init_begin, __init_end, init_data_size, | |
6812 | _sinittext, init_code_size); | |
6813 | adj_init_size(_stext, _etext, codesize, _sinittext, init_code_size); | |
6814 | adj_init_size(_sdata, _edata, datasize, __init_begin, init_data_size); | |
6815 | adj_init_size(_stext, _etext, codesize, __start_rodata, rosize); | |
6816 | adj_init_size(_sdata, _edata, datasize, __start_rodata, rosize); | |
6817 | ||
6818 | #undef adj_init_size | |
6819 | ||
6820 | pr_info("Memory: %luK/%luK available (%luK kernel code, %luK rwdata, %luK rodata, %luK init, %luK bss, %luK reserved, %luK cma-reserved" | |
6821 | #ifdef CONFIG_HIGHMEM | |
6822 | ", %luK highmem" | |
6823 | #endif | |
6824 | "%s%s)\n", | |
6825 | nr_free_pages() << (PAGE_SHIFT - 10), | |
6826 | physpages << (PAGE_SHIFT - 10), | |
6827 | codesize >> 10, datasize >> 10, rosize >> 10, | |
6828 | (init_data_size + init_code_size) >> 10, bss_size >> 10, | |
6829 | (physpages - totalram_pages - totalcma_pages) << (PAGE_SHIFT - 10), | |
6830 | totalcma_pages << (PAGE_SHIFT - 10), | |
6831 | #ifdef CONFIG_HIGHMEM | |
6832 | totalhigh_pages << (PAGE_SHIFT - 10), | |
6833 | #endif | |
6834 | str ? ", " : "", str ? str : ""); | |
6835 | } | |
6836 | ||
6837 | /** | |
6838 | * set_dma_reserve - set the specified number of pages reserved in the first zone | |
6839 | * @new_dma_reserve: The number of pages to mark reserved | |
6840 | * | |
6841 | * The per-cpu batchsize and zone watermarks are determined by managed_pages. | |
6842 | * In the DMA zone, a significant percentage may be consumed by kernel image | |
6843 | * and other unfreeable allocations which can skew the watermarks badly. This | |
6844 | * function may optionally be used to account for unfreeable pages in the | |
6845 | * first zone (e.g., ZONE_DMA). The effect will be lower watermarks and | |
6846 | * smaller per-cpu batchsize. | |
6847 | */ | |
6848 | void __init set_dma_reserve(unsigned long new_dma_reserve) | |
6849 | { | |
6850 | dma_reserve = new_dma_reserve; | |
6851 | } | |
6852 | ||
6853 | void __init free_area_init(unsigned long *zones_size) | |
6854 | { | |
6855 | free_area_init_node(0, zones_size, | |
6856 | __pa(PAGE_OFFSET) >> PAGE_SHIFT, NULL); | |
6857 | } | |
6858 | ||
6859 | static int page_alloc_cpu_dead(unsigned int cpu) | |
6860 | { | |
6861 | ||
6862 | lru_add_drain_cpu(cpu); | |
6863 | drain_pages(cpu); | |
6864 | ||
6865 | /* | |
6866 | * Spill the event counters of the dead processor | |
6867 | * into the current processors event counters. | |
6868 | * This artificially elevates the count of the current | |
6869 | * processor. | |
6870 | */ | |
6871 | vm_events_fold_cpu(cpu); | |
6872 | ||
6873 | /* | |
6874 | * Zero the differential counters of the dead processor | |
6875 | * so that the vm statistics are consistent. | |
6876 | * | |
6877 | * This is only okay since the processor is dead and cannot | |
6878 | * race with what we are doing. | |
6879 | */ | |
6880 | cpu_vm_stats_fold(cpu); | |
6881 | return 0; | |
6882 | } | |
6883 | ||
6884 | void __init page_alloc_init(void) | |
6885 | { | |
6886 | int ret; | |
6887 | ||
6888 | ret = cpuhp_setup_state_nocalls(CPUHP_PAGE_ALLOC_DEAD, | |
6889 | "mm/page_alloc:dead", NULL, | |
6890 | page_alloc_cpu_dead); | |
6891 | WARN_ON(ret < 0); | |
6892 | } | |
6893 | ||
6894 | /* | |
6895 | * calculate_totalreserve_pages - called when sysctl_lowmem_reserve_ratio | |
6896 | * or min_free_kbytes changes. | |
6897 | */ | |
6898 | static void calculate_totalreserve_pages(void) | |
6899 | { | |
6900 | struct pglist_data *pgdat; | |
6901 | unsigned long reserve_pages = 0; | |
6902 | enum zone_type i, j; | |
6903 | ||
6904 | for_each_online_pgdat(pgdat) { | |
6905 | ||
6906 | pgdat->totalreserve_pages = 0; | |
6907 | ||
6908 | for (i = 0; i < MAX_NR_ZONES; i++) { | |
6909 | struct zone *zone = pgdat->node_zones + i; | |
6910 | long max = 0; | |
6911 | ||
6912 | /* Find valid and maximum lowmem_reserve in the zone */ | |
6913 | for (j = i; j < MAX_NR_ZONES; j++) { | |
6914 | if (zone->lowmem_reserve[j] > max) | |
6915 | max = zone->lowmem_reserve[j]; | |
6916 | } | |
6917 | ||
6918 | /* we treat the high watermark as reserved pages. */ | |
6919 | max += high_wmark_pages(zone); | |
6920 | ||
6921 | if (max > zone->managed_pages) | |
6922 | max = zone->managed_pages; | |
6923 | ||
6924 | pgdat->totalreserve_pages += max; | |
6925 | ||
6926 | reserve_pages += max; | |
6927 | } | |
6928 | } | |
6929 | totalreserve_pages = reserve_pages; | |
6930 | } | |
6931 | ||
6932 | /* | |
6933 | * setup_per_zone_lowmem_reserve - called whenever | |
6934 | * sysctl_lowmem_reserve_ratio changes. Ensures that each zone | |
6935 | * has a correct pages reserved value, so an adequate number of | |
6936 | * pages are left in the zone after a successful __alloc_pages(). | |
6937 | */ | |
6938 | static void setup_per_zone_lowmem_reserve(void) | |
6939 | { | |
6940 | struct pglist_data *pgdat; | |
6941 | enum zone_type j, idx; | |
6942 | ||
6943 | for_each_online_pgdat(pgdat) { | |
6944 | for (j = 0; j < MAX_NR_ZONES; j++) { | |
6945 | struct zone *zone = pgdat->node_zones + j; | |
6946 | unsigned long managed_pages = zone->managed_pages; | |
6947 | ||
6948 | zone->lowmem_reserve[j] = 0; | |
6949 | ||
6950 | idx = j; | |
6951 | while (idx) { | |
6952 | struct zone *lower_zone; | |
6953 | ||
6954 | idx--; | |
6955 | ||
6956 | if (sysctl_lowmem_reserve_ratio[idx] < 1) | |
6957 | sysctl_lowmem_reserve_ratio[idx] = 1; | |
6958 | ||
6959 | lower_zone = pgdat->node_zones + idx; | |
6960 | lower_zone->lowmem_reserve[j] = managed_pages / | |
6961 | sysctl_lowmem_reserve_ratio[idx]; | |
6962 | managed_pages += lower_zone->managed_pages; | |
6963 | } | |
6964 | } | |
6965 | } | |
6966 | ||
6967 | /* update totalreserve_pages */ | |
6968 | calculate_totalreserve_pages(); | |
6969 | } | |
6970 | ||
6971 | static void __setup_per_zone_wmarks(void) | |
6972 | { | |
6973 | unsigned long pages_min = min_free_kbytes >> (PAGE_SHIFT - 10); | |
6974 | unsigned long lowmem_pages = 0; | |
6975 | struct zone *zone; | |
6976 | unsigned long flags; | |
6977 | ||
6978 | /* Calculate total number of !ZONE_HIGHMEM pages */ | |
6979 | for_each_zone(zone) { | |
6980 | if (!is_highmem(zone)) | |
6981 | lowmem_pages += zone->managed_pages; | |
6982 | } | |
6983 | ||
6984 | for_each_zone(zone) { | |
6985 | u64 tmp; | |
6986 | ||
6987 | spin_lock_irqsave(&zone->lock, flags); | |
6988 | tmp = (u64)pages_min * zone->managed_pages; | |
6989 | do_div(tmp, lowmem_pages); | |
6990 | if (is_highmem(zone)) { | |
6991 | /* | |
6992 | * __GFP_HIGH and PF_MEMALLOC allocations usually don't | |
6993 | * need highmem pages, so cap pages_min to a small | |
6994 | * value here. | |
6995 | * | |
6996 | * The WMARK_HIGH-WMARK_LOW and (WMARK_LOW-WMARK_MIN) | |
6997 | * deltas control asynch page reclaim, and so should | |
6998 | * not be capped for highmem. | |
6999 | */ | |
7000 | unsigned long min_pages; | |
7001 | ||
7002 | min_pages = zone->managed_pages / 1024; | |
7003 | min_pages = clamp(min_pages, SWAP_CLUSTER_MAX, 128UL); | |
7004 | zone->watermark[WMARK_MIN] = min_pages; | |
7005 | } else { | |
7006 | /* | |
7007 | * If it's a lowmem zone, reserve a number of pages | |
7008 | * proportionate to the zone's size. | |
7009 | */ | |
7010 | zone->watermark[WMARK_MIN] = tmp; | |
7011 | } | |
7012 | ||
7013 | /* | |
7014 | * Set the kswapd watermarks distance according to the | |
7015 | * scale factor in proportion to available memory, but | |
7016 | * ensure a minimum size on small systems. | |
7017 | */ | |
7018 | tmp = max_t(u64, tmp >> 2, | |
7019 | mult_frac(zone->managed_pages, | |
7020 | watermark_scale_factor, 10000)); | |
7021 | ||
7022 | zone->watermark[WMARK_LOW] = min_wmark_pages(zone) + tmp; | |
7023 | zone->watermark[WMARK_HIGH] = min_wmark_pages(zone) + tmp * 2; | |
7024 | ||
7025 | spin_unlock_irqrestore(&zone->lock, flags); | |
7026 | } | |
7027 | ||
7028 | /* update totalreserve_pages */ | |
7029 | calculate_totalreserve_pages(); | |
7030 | } | |
7031 | ||
7032 | /** | |
7033 | * setup_per_zone_wmarks - called when min_free_kbytes changes | |
7034 | * or when memory is hot-{added|removed} | |
7035 | * | |
7036 | * Ensures that the watermark[min,low,high] values for each zone are set | |
7037 | * correctly with respect to min_free_kbytes. | |
7038 | */ | |
7039 | void setup_per_zone_wmarks(void) | |
7040 | { | |
7041 | mutex_lock(&zonelists_mutex); | |
7042 | __setup_per_zone_wmarks(); | |
7043 | mutex_unlock(&zonelists_mutex); | |
7044 | } | |
7045 | ||
7046 | /* | |
7047 | * Initialise min_free_kbytes. | |
7048 | * | |
7049 | * For small machines we want it small (128k min). For large machines | |
7050 | * we want it large (64MB max). But it is not linear, because network | |
7051 | * bandwidth does not increase linearly with machine size. We use | |
7052 | * | |
7053 | * min_free_kbytes = 4 * sqrt(lowmem_kbytes), for better accuracy: | |
7054 | * min_free_kbytes = sqrt(lowmem_kbytes * 16) | |
7055 | * | |
7056 | * which yields | |
7057 | * | |
7058 | * 16MB: 512k | |
7059 | * 32MB: 724k | |
7060 | * 64MB: 1024k | |
7061 | * 128MB: 1448k | |
7062 | * 256MB: 2048k | |
7063 | * 512MB: 2896k | |
7064 | * 1024MB: 4096k | |
7065 | * 2048MB: 5792k | |
7066 | * 4096MB: 8192k | |
7067 | * 8192MB: 11584k | |
7068 | * 16384MB: 16384k | |
7069 | */ | |
7070 | int __meminit init_per_zone_wmark_min(void) | |
7071 | { | |
7072 | unsigned long lowmem_kbytes; | |
7073 | int new_min_free_kbytes; | |
7074 | ||
7075 | lowmem_kbytes = nr_free_buffer_pages() * (PAGE_SIZE >> 10); | |
7076 | new_min_free_kbytes = int_sqrt(lowmem_kbytes * 16); | |
7077 | ||
7078 | if (new_min_free_kbytes > user_min_free_kbytes) { | |
7079 | min_free_kbytes = new_min_free_kbytes; | |
7080 | if (min_free_kbytes < 128) | |
7081 | min_free_kbytes = 128; | |
7082 | if (min_free_kbytes > 65536) | |
7083 | min_free_kbytes = 65536; | |
7084 | } else { | |
7085 | pr_warn("min_free_kbytes is not updated to %d because user defined value %d is preferred\n", | |
7086 | new_min_free_kbytes, user_min_free_kbytes); | |
7087 | } | |
7088 | setup_per_zone_wmarks(); | |
7089 | refresh_zone_stat_thresholds(); | |
7090 | setup_per_zone_lowmem_reserve(); | |
7091 | ||
7092 | #ifdef CONFIG_NUMA | |
7093 | setup_min_unmapped_ratio(); | |
7094 | setup_min_slab_ratio(); | |
7095 | #endif | |
7096 | ||
7097 | return 0; | |
7098 | } | |
7099 | core_initcall(init_per_zone_wmark_min) | |
7100 | ||
7101 | /* | |
7102 | * min_free_kbytes_sysctl_handler - just a wrapper around proc_dointvec() so | |
7103 | * that we can call two helper functions whenever min_free_kbytes | |
7104 | * changes. | |
7105 | */ | |
7106 | int min_free_kbytes_sysctl_handler(struct ctl_table *table, int write, | |
7107 | void __user *buffer, size_t *length, loff_t *ppos) | |
7108 | { | |
7109 | int rc; | |
7110 | ||
7111 | rc = proc_dointvec_minmax(table, write, buffer, length, ppos); | |
7112 | if (rc) | |
7113 | return rc; | |
7114 | ||
7115 | if (write) { | |
7116 | user_min_free_kbytes = min_free_kbytes; | |
7117 | setup_per_zone_wmarks(); | |
7118 | } | |
7119 | return 0; | |
7120 | } | |
7121 | ||
7122 | int watermark_scale_factor_sysctl_handler(struct ctl_table *table, int write, | |
7123 | void __user *buffer, size_t *length, loff_t *ppos) | |
7124 | { | |
7125 | int rc; | |
7126 | ||
7127 | rc = proc_dointvec_minmax(table, write, buffer, length, ppos); | |
7128 | if (rc) | |
7129 | return rc; | |
7130 | ||
7131 | if (write) | |
7132 | setup_per_zone_wmarks(); | |
7133 | ||
7134 | return 0; | |
7135 | } | |
7136 | ||
7137 | #ifdef CONFIG_NUMA | |
7138 | static void setup_min_unmapped_ratio(void) | |
7139 | { | |
7140 | pg_data_t *pgdat; | |
7141 | struct zone *zone; | |
7142 | ||
7143 | for_each_online_pgdat(pgdat) | |
7144 | pgdat->min_unmapped_pages = 0; | |
7145 | ||
7146 | for_each_zone(zone) | |
7147 | zone->zone_pgdat->min_unmapped_pages += (zone->managed_pages * | |
7148 | sysctl_min_unmapped_ratio) / 100; | |
7149 | } | |
7150 | ||
7151 | ||
7152 | int sysctl_min_unmapped_ratio_sysctl_handler(struct ctl_table *table, int write, | |
7153 | void __user *buffer, size_t *length, loff_t *ppos) | |
7154 | { | |
7155 | int rc; | |
7156 | ||
7157 | rc = proc_dointvec_minmax(table, write, buffer, length, ppos); | |
7158 | if (rc) | |
7159 | return rc; | |
7160 | ||
7161 | setup_min_unmapped_ratio(); | |
7162 | ||
7163 | return 0; | |
7164 | } | |
7165 | ||
7166 | static void setup_min_slab_ratio(void) | |
7167 | { | |
7168 | pg_data_t *pgdat; | |
7169 | struct zone *zone; | |
7170 | ||
7171 | for_each_online_pgdat(pgdat) | |
7172 | pgdat->min_slab_pages = 0; | |
7173 | ||
7174 | for_each_zone(zone) | |
7175 | zone->zone_pgdat->min_slab_pages += (zone->managed_pages * | |
7176 | sysctl_min_slab_ratio) / 100; | |
7177 | } | |
7178 | ||
7179 | int sysctl_min_slab_ratio_sysctl_handler(struct ctl_table *table, int write, | |
7180 | void __user *buffer, size_t *length, loff_t *ppos) | |
7181 | { | |
7182 | int rc; | |
7183 | ||
7184 | rc = proc_dointvec_minmax(table, write, buffer, length, ppos); | |
7185 | if (rc) | |
7186 | return rc; | |
7187 | ||
7188 | setup_min_slab_ratio(); | |
7189 | ||
7190 | return 0; | |
7191 | } | |
7192 | #endif | |
7193 | ||
7194 | /* | |
7195 | * lowmem_reserve_ratio_sysctl_handler - just a wrapper around | |
7196 | * proc_dointvec() so that we can call setup_per_zone_lowmem_reserve() | |
7197 | * whenever sysctl_lowmem_reserve_ratio changes. | |
7198 | * | |
7199 | * The reserve ratio obviously has absolutely no relation with the | |
7200 | * minimum watermarks. The lowmem reserve ratio can only make sense | |
7201 | * if in function of the boot time zone sizes. | |
7202 | */ | |
7203 | int lowmem_reserve_ratio_sysctl_handler(struct ctl_table *table, int write, | |
7204 | void __user *buffer, size_t *length, loff_t *ppos) | |
7205 | { | |
7206 | proc_dointvec_minmax(table, write, buffer, length, ppos); | |
7207 | setup_per_zone_lowmem_reserve(); | |
7208 | return 0; | |
7209 | } | |
7210 | ||
7211 | /* | |
7212 | * percpu_pagelist_fraction - changes the pcp->high for each zone on each | |
7213 | * cpu. It is the fraction of total pages in each zone that a hot per cpu | |
7214 | * pagelist can have before it gets flushed back to buddy allocator. | |
7215 | */ | |
7216 | int percpu_pagelist_fraction_sysctl_handler(struct ctl_table *table, int write, | |
7217 | void __user *buffer, size_t *length, loff_t *ppos) | |
7218 | { | |
7219 | struct zone *zone; | |
7220 | int old_percpu_pagelist_fraction; | |
7221 | int ret; | |
7222 | ||
7223 | mutex_lock(&pcp_batch_high_lock); | |
7224 | old_percpu_pagelist_fraction = percpu_pagelist_fraction; | |
7225 | ||
7226 | ret = proc_dointvec_minmax(table, write, buffer, length, ppos); | |
7227 | if (!write || ret < 0) | |
7228 | goto out; | |
7229 | ||
7230 | /* Sanity checking to avoid pcp imbalance */ | |
7231 | if (percpu_pagelist_fraction && | |
7232 | percpu_pagelist_fraction < MIN_PERCPU_PAGELIST_FRACTION) { | |
7233 | percpu_pagelist_fraction = old_percpu_pagelist_fraction; | |
7234 | ret = -EINVAL; | |
7235 | goto out; | |
7236 | } | |
7237 | ||
7238 | /* No change? */ | |
7239 | if (percpu_pagelist_fraction == old_percpu_pagelist_fraction) | |
7240 | goto out; | |
7241 | ||
7242 | for_each_populated_zone(zone) { | |
7243 | unsigned int cpu; | |
7244 | ||
7245 | for_each_possible_cpu(cpu) | |
7246 | pageset_set_high_and_batch(zone, | |
7247 | per_cpu_ptr(zone->pageset, cpu)); | |
7248 | } | |
7249 | out: | |
7250 | mutex_unlock(&pcp_batch_high_lock); | |
7251 | return ret; | |
7252 | } | |
7253 | ||
7254 | #ifdef CONFIG_NUMA | |
7255 | int hashdist = HASHDIST_DEFAULT; | |
7256 | ||
7257 | static int __init set_hashdist(char *str) | |
7258 | { | |
7259 | if (!str) | |
7260 | return 0; | |
7261 | hashdist = simple_strtoul(str, &str, 0); | |
7262 | return 1; | |
7263 | } | |
7264 | __setup("hashdist=", set_hashdist); | |
7265 | #endif | |
7266 | ||
7267 | #ifndef __HAVE_ARCH_RESERVED_KERNEL_PAGES | |
7268 | /* | |
7269 | * Returns the number of pages that arch has reserved but | |
7270 | * is not known to alloc_large_system_hash(). | |
7271 | */ | |
7272 | static unsigned long __init arch_reserved_kernel_pages(void) | |
7273 | { | |
7274 | return 0; | |
7275 | } | |
7276 | #endif | |
7277 | ||
7278 | /* | |
7279 | * Adaptive scale is meant to reduce sizes of hash tables on large memory | |
7280 | * machines. As memory size is increased the scale is also increased but at | |
7281 | * slower pace. Starting from ADAPT_SCALE_BASE (64G), every time memory | |
7282 | * quadruples the scale is increased by one, which means the size of hash table | |
7283 | * only doubles, instead of quadrupling as well. | |
7284 | * Because 32-bit systems cannot have large physical memory, where this scaling | |
7285 | * makes sense, it is disabled on such platforms. | |
7286 | */ | |
7287 | #if __BITS_PER_LONG > 32 | |
7288 | #define ADAPT_SCALE_BASE (64ul << 30) | |
7289 | #define ADAPT_SCALE_SHIFT 2 | |
7290 | #define ADAPT_SCALE_NPAGES (ADAPT_SCALE_BASE >> PAGE_SHIFT) | |
7291 | #endif | |
7292 | ||
7293 | /* | |
7294 | * allocate a large system hash table from bootmem | |
7295 | * - it is assumed that the hash table must contain an exact power-of-2 | |
7296 | * quantity of entries | |
7297 | * - limit is the number of hash buckets, not the total allocation size | |
7298 | */ | |
7299 | void *__init alloc_large_system_hash(const char *tablename, | |
7300 | unsigned long bucketsize, | |
7301 | unsigned long numentries, | |
7302 | int scale, | |
7303 | int flags, | |
7304 | unsigned int *_hash_shift, | |
7305 | unsigned int *_hash_mask, | |
7306 | unsigned long low_limit, | |
7307 | unsigned long high_limit) | |
7308 | { | |
7309 | unsigned long long max = high_limit; | |
7310 | unsigned long log2qty, size; | |
7311 | void *table = NULL; | |
7312 | gfp_t gfp_flags; | |
7313 | ||
7314 | /* allow the kernel cmdline to have a say */ | |
7315 | if (!numentries) { | |
7316 | /* round applicable memory size up to nearest megabyte */ | |
7317 | numentries = nr_kernel_pages; | |
7318 | numentries -= arch_reserved_kernel_pages(); | |
7319 | ||
7320 | /* It isn't necessary when PAGE_SIZE >= 1MB */ | |
7321 | if (PAGE_SHIFT < 20) | |
7322 | numentries = round_up(numentries, (1<<20)/PAGE_SIZE); | |
7323 | ||
7324 | #if __BITS_PER_LONG > 32 | |
7325 | if (!high_limit) { | |
7326 | unsigned long adapt; | |
7327 | ||
7328 | for (adapt = ADAPT_SCALE_NPAGES; adapt < numentries; | |
7329 | adapt <<= ADAPT_SCALE_SHIFT) | |
7330 | scale++; | |
7331 | } | |
7332 | #endif | |
7333 | ||
7334 | /* limit to 1 bucket per 2^scale bytes of low memory */ | |
7335 | if (scale > PAGE_SHIFT) | |
7336 | numentries >>= (scale - PAGE_SHIFT); | |
7337 | else | |
7338 | numentries <<= (PAGE_SHIFT - scale); | |
7339 | ||
7340 | /* Make sure we've got at least a 0-order allocation.. */ | |
7341 | if (unlikely(flags & HASH_SMALL)) { | |
7342 | /* Makes no sense without HASH_EARLY */ | |
7343 | WARN_ON(!(flags & HASH_EARLY)); | |
7344 | if (!(numentries >> *_hash_shift)) { | |
7345 | numentries = 1UL << *_hash_shift; | |
7346 | BUG_ON(!numentries); | |
7347 | } | |
7348 | } else if (unlikely((numentries * bucketsize) < PAGE_SIZE)) | |
7349 | numentries = PAGE_SIZE / bucketsize; | |
7350 | } | |
7351 | numentries = roundup_pow_of_two(numentries); | |
7352 | ||
7353 | /* limit allocation size to 1/16 total memory by default */ | |
7354 | if (max == 0) { | |
7355 | max = ((unsigned long long)nr_all_pages << PAGE_SHIFT) >> 4; | |
7356 | do_div(max, bucketsize); | |
7357 | } | |
7358 | max = min(max, 0x80000000ULL); | |
7359 | ||
7360 | if (numentries < low_limit) | |
7361 | numentries = low_limit; | |
7362 | if (numentries > max) | |
7363 | numentries = max; | |
7364 | ||
7365 | log2qty = ilog2(numentries); | |
7366 | ||
7367 | /* | |
7368 | * memblock allocator returns zeroed memory already, so HASH_ZERO is | |
7369 | * currently not used when HASH_EARLY is specified. | |
7370 | */ | |
7371 | gfp_flags = (flags & HASH_ZERO) ? GFP_ATOMIC | __GFP_ZERO : GFP_ATOMIC; | |
7372 | do { | |
7373 | size = bucketsize << log2qty; | |
7374 | if (flags & HASH_EARLY) | |
7375 | table = memblock_virt_alloc_nopanic(size, 0); | |
7376 | else if (hashdist) | |
7377 | table = __vmalloc(size, gfp_flags, PAGE_KERNEL); | |
7378 | else { | |
7379 | /* | |
7380 | * If bucketsize is not a power-of-two, we may free | |
7381 | * some pages at the end of hash table which | |
7382 | * alloc_pages_exact() automatically does | |
7383 | */ | |
7384 | if (get_order(size) < MAX_ORDER) { | |
7385 | table = alloc_pages_exact(size, gfp_flags); | |
7386 | kmemleak_alloc(table, size, 1, gfp_flags); | |
7387 | } | |
7388 | } | |
7389 | } while (!table && size > PAGE_SIZE && --log2qty); | |
7390 | ||
7391 | if (!table) | |
7392 | panic("Failed to allocate %s hash table\n", tablename); | |
7393 | ||
7394 | pr_info("%s hash table entries: %ld (order: %d, %lu bytes)\n", | |
7395 | tablename, 1UL << log2qty, ilog2(size) - PAGE_SHIFT, size); | |
7396 | ||
7397 | if (_hash_shift) | |
7398 | *_hash_shift = log2qty; | |
7399 | if (_hash_mask) | |
7400 | *_hash_mask = (1 << log2qty) - 1; | |
7401 | ||
7402 | return table; | |
7403 | } | |
7404 | ||
7405 | /* | |
7406 | * This function checks whether pageblock includes unmovable pages or not. | |
7407 | * If @count is not zero, it is okay to include less @count unmovable pages | |
7408 | * | |
7409 | * PageLRU check without isolation or lru_lock could race so that | |
7410 | * MIGRATE_MOVABLE block might include unmovable pages. And __PageMovable | |
7411 | * check without lock_page also may miss some movable non-lru pages at | |
7412 | * race condition. So you can't expect this function should be exact. | |
7413 | */ | |
7414 | bool has_unmovable_pages(struct zone *zone, struct page *page, int count, | |
7415 | bool skip_hwpoisoned_pages) | |
7416 | { | |
7417 | unsigned long pfn, iter, found; | |
7418 | int mt; | |
7419 | ||
7420 | /* | |
7421 | * For avoiding noise data, lru_add_drain_all() should be called | |
7422 | * If ZONE_MOVABLE, the zone never contains unmovable pages | |
7423 | */ | |
7424 | if (zone_idx(zone) == ZONE_MOVABLE) | |
7425 | return false; | |
7426 | mt = get_pageblock_migratetype(page); | |
7427 | if (mt == MIGRATE_MOVABLE || is_migrate_cma(mt)) | |
7428 | return false; | |
7429 | ||
7430 | pfn = page_to_pfn(page); | |
7431 | for (found = 0, iter = 0; iter < pageblock_nr_pages; iter++) { | |
7432 | unsigned long check = pfn + iter; | |
7433 | ||
7434 | if (!pfn_valid_within(check)) | |
7435 | continue; | |
7436 | ||
7437 | page = pfn_to_page(check); | |
7438 | ||
7439 | /* | |
7440 | * Hugepages are not in LRU lists, but they're movable. | |
7441 | * We need not scan over tail pages bacause we don't | |
7442 | * handle each tail page individually in migration. | |
7443 | */ | |
7444 | if (PageHuge(page)) { | |
7445 | iter = round_up(iter + 1, 1<<compound_order(page)) - 1; | |
7446 | continue; | |
7447 | } | |
7448 | ||
7449 | /* | |
7450 | * We can't use page_count without pin a page | |
7451 | * because another CPU can free compound page. | |
7452 | * This check already skips compound tails of THP | |
7453 | * because their page->_refcount is zero at all time. | |
7454 | */ | |
7455 | if (!page_ref_count(page)) { | |
7456 | if (PageBuddy(page)) | |
7457 | iter += (1 << page_order(page)) - 1; | |
7458 | continue; | |
7459 | } | |
7460 | ||
7461 | /* | |
7462 | * The HWPoisoned page may be not in buddy system, and | |
7463 | * page_count() is not 0. | |
7464 | */ | |
7465 | if (skip_hwpoisoned_pages && PageHWPoison(page)) | |
7466 | continue; | |
7467 | ||
7468 | if (__PageMovable(page)) | |
7469 | continue; | |
7470 | ||
7471 | if (!PageLRU(page)) | |
7472 | found++; | |
7473 | /* | |
7474 | * If there are RECLAIMABLE pages, we need to check | |
7475 | * it. But now, memory offline itself doesn't call | |
7476 | * shrink_node_slabs() and it still to be fixed. | |
7477 | */ | |
7478 | /* | |
7479 | * If the page is not RAM, page_count()should be 0. | |
7480 | * we don't need more check. This is an _used_ not-movable page. | |
7481 | * | |
7482 | * The problematic thing here is PG_reserved pages. PG_reserved | |
7483 | * is set to both of a memory hole page and a _used_ kernel | |
7484 | * page at boot. | |
7485 | */ | |
7486 | if (found > count) | |
7487 | return true; | |
7488 | } | |
7489 | return false; | |
7490 | } | |
7491 | ||
7492 | bool is_pageblock_removable_nolock(struct page *page) | |
7493 | { | |
7494 | struct zone *zone; | |
7495 | unsigned long pfn; | |
7496 | ||
7497 | /* | |
7498 | * We have to be careful here because we are iterating over memory | |
7499 | * sections which are not zone aware so we might end up outside of | |
7500 | * the zone but still within the section. | |
7501 | * We have to take care about the node as well. If the node is offline | |
7502 | * its NODE_DATA will be NULL - see page_zone. | |
7503 | */ | |
7504 | if (!node_online(page_to_nid(page))) | |
7505 | return false; | |
7506 | ||
7507 | zone = page_zone(page); | |
7508 | pfn = page_to_pfn(page); | |
7509 | if (!zone_spans_pfn(zone, pfn)) | |
7510 | return false; | |
7511 | ||
7512 | return !has_unmovable_pages(zone, page, 0, true); | |
7513 | } | |
7514 | ||
7515 | #if (defined(CONFIG_MEMORY_ISOLATION) && defined(CONFIG_COMPACTION)) || defined(CONFIG_CMA) | |
7516 | ||
7517 | static unsigned long pfn_max_align_down(unsigned long pfn) | |
7518 | { | |
7519 | return pfn & ~(max_t(unsigned long, MAX_ORDER_NR_PAGES, | |
7520 | pageblock_nr_pages) - 1); | |
7521 | } | |
7522 | ||
7523 | static unsigned long pfn_max_align_up(unsigned long pfn) | |
7524 | { | |
7525 | return ALIGN(pfn, max_t(unsigned long, MAX_ORDER_NR_PAGES, | |
7526 | pageblock_nr_pages)); | |
7527 | } | |
7528 | ||
7529 | /* [start, end) must belong to a single zone. */ | |
7530 | static int __alloc_contig_migrate_range(struct compact_control *cc, | |
7531 | unsigned long start, unsigned long end) | |
7532 | { | |
7533 | /* This function is based on compact_zone() from compaction.c. */ | |
7534 | unsigned long nr_reclaimed; | |
7535 | unsigned long pfn = start; | |
7536 | unsigned int tries = 0; | |
7537 | int ret = 0; | |
7538 | ||
7539 | migrate_prep(); | |
7540 | ||
7541 | while (pfn < end || !list_empty(&cc->migratepages)) { | |
7542 | if (fatal_signal_pending(current)) { | |
7543 | ret = -EINTR; | |
7544 | break; | |
7545 | } | |
7546 | ||
7547 | if (list_empty(&cc->migratepages)) { | |
7548 | cc->nr_migratepages = 0; | |
7549 | pfn = isolate_migratepages_range(cc, pfn, end); | |
7550 | if (!pfn) { | |
7551 | ret = -EINTR; | |
7552 | break; | |
7553 | } | |
7554 | tries = 0; | |
7555 | } else if (++tries == 5) { | |
7556 | ret = ret < 0 ? ret : -EBUSY; | |
7557 | break; | |
7558 | } | |
7559 | ||
7560 | nr_reclaimed = reclaim_clean_pages_from_list(cc->zone, | |
7561 | &cc->migratepages); | |
7562 | cc->nr_migratepages -= nr_reclaimed; | |
7563 | ||
7564 | ret = migrate_pages(&cc->migratepages, alloc_migrate_target, | |
7565 | NULL, 0, cc->mode, MR_CMA); | |
7566 | } | |
7567 | if (ret < 0) { | |
7568 | putback_movable_pages(&cc->migratepages); | |
7569 | return ret; | |
7570 | } | |
7571 | return 0; | |
7572 | } | |
7573 | ||
7574 | /** | |
7575 | * alloc_contig_range() -- tries to allocate given range of pages | |
7576 | * @start: start PFN to allocate | |
7577 | * @end: one-past-the-last PFN to allocate | |
7578 | * @migratetype: migratetype of the underlaying pageblocks (either | |
7579 | * #MIGRATE_MOVABLE or #MIGRATE_CMA). All pageblocks | |
7580 | * in range must have the same migratetype and it must | |
7581 | * be either of the two. | |
7582 | * @gfp_mask: GFP mask to use during compaction | |
7583 | * | |
7584 | * The PFN range does not have to be pageblock or MAX_ORDER_NR_PAGES | |
7585 | * aligned, however it's the caller's responsibility to guarantee that | |
7586 | * we are the only thread that changes migrate type of pageblocks the | |
7587 | * pages fall in. | |
7588 | * | |
7589 | * The PFN range must belong to a single zone. | |
7590 | * | |
7591 | * Returns zero on success or negative error code. On success all | |
7592 | * pages which PFN is in [start, end) are allocated for the caller and | |
7593 | * need to be freed with free_contig_range(). | |
7594 | */ | |
7595 | int alloc_contig_range(unsigned long start, unsigned long end, | |
7596 | unsigned migratetype, gfp_t gfp_mask) | |
7597 | { | |
7598 | unsigned long outer_start, outer_end; | |
7599 | unsigned int order; | |
7600 | int ret = 0; | |
7601 | ||
7602 | struct compact_control cc = { | |
7603 | .nr_migratepages = 0, | |
7604 | .order = -1, | |
7605 | .zone = page_zone(pfn_to_page(start)), | |
7606 | .mode = MIGRATE_SYNC, | |
7607 | .ignore_skip_hint = true, | |
7608 | .gfp_mask = current_gfp_context(gfp_mask), | |
7609 | }; | |
7610 | INIT_LIST_HEAD(&cc.migratepages); | |
7611 | ||
7612 | /* | |
7613 | * What we do here is we mark all pageblocks in range as | |
7614 | * MIGRATE_ISOLATE. Because pageblock and max order pages may | |
7615 | * have different sizes, and due to the way page allocator | |
7616 | * work, we align the range to biggest of the two pages so | |
7617 | * that page allocator won't try to merge buddies from | |
7618 | * different pageblocks and change MIGRATE_ISOLATE to some | |
7619 | * other migration type. | |
7620 | * | |
7621 | * Once the pageblocks are marked as MIGRATE_ISOLATE, we | |
7622 | * migrate the pages from an unaligned range (ie. pages that | |
7623 | * we are interested in). This will put all the pages in | |
7624 | * range back to page allocator as MIGRATE_ISOLATE. | |
7625 | * | |
7626 | * When this is done, we take the pages in range from page | |
7627 | * allocator removing them from the buddy system. This way | |
7628 | * page allocator will never consider using them. | |
7629 | * | |
7630 | * This lets us mark the pageblocks back as | |
7631 | * MIGRATE_CMA/MIGRATE_MOVABLE so that free pages in the | |
7632 | * aligned range but not in the unaligned, original range are | |
7633 | * put back to page allocator so that buddy can use them. | |
7634 | */ | |
7635 | ||
7636 | ret = start_isolate_page_range(pfn_max_align_down(start), | |
7637 | pfn_max_align_up(end), migratetype, | |
7638 | false); | |
7639 | if (ret) | |
7640 | return ret; | |
7641 | ||
7642 | /* | |
7643 | * In case of -EBUSY, we'd like to know which page causes problem. | |
7644 | * So, just fall through. We will check it in test_pages_isolated(). | |
7645 | */ | |
7646 | ret = __alloc_contig_migrate_range(&cc, start, end); | |
7647 | if (ret && ret != -EBUSY) | |
7648 | goto done; | |
7649 | ||
7650 | /* | |
7651 | * Pages from [start, end) are within a MAX_ORDER_NR_PAGES | |
7652 | * aligned blocks that are marked as MIGRATE_ISOLATE. What's | |
7653 | * more, all pages in [start, end) are free in page allocator. | |
7654 | * What we are going to do is to allocate all pages from | |
7655 | * [start, end) (that is remove them from page allocator). | |
7656 | * | |
7657 | * The only problem is that pages at the beginning and at the | |
7658 | * end of interesting range may be not aligned with pages that | |
7659 | * page allocator holds, ie. they can be part of higher order | |
7660 | * pages. Because of this, we reserve the bigger range and | |
7661 | * once this is done free the pages we are not interested in. | |
7662 | * | |
7663 | * We don't have to hold zone->lock here because the pages are | |
7664 | * isolated thus they won't get removed from buddy. | |
7665 | */ | |
7666 | ||
7667 | lru_add_drain_all(); | |
7668 | drain_all_pages(cc.zone); | |
7669 | ||
7670 | order = 0; | |
7671 | outer_start = start; | |
7672 | while (!PageBuddy(pfn_to_page(outer_start))) { | |
7673 | if (++order >= MAX_ORDER) { | |
7674 | outer_start = start; | |
7675 | break; | |
7676 | } | |
7677 | outer_start &= ~0UL << order; | |
7678 | } | |
7679 | ||
7680 | if (outer_start != start) { | |
7681 | order = page_order(pfn_to_page(outer_start)); | |
7682 | ||
7683 | /* | |
7684 | * outer_start page could be small order buddy page and | |
7685 | * it doesn't include start page. Adjust outer_start | |
7686 | * in this case to report failed page properly | |
7687 | * on tracepoint in test_pages_isolated() | |
7688 | */ | |
7689 | if (outer_start + (1UL << order) <= start) | |
7690 | outer_start = start; | |
7691 | } | |
7692 | ||
7693 | /* Make sure the range is really isolated. */ | |
7694 | if (test_pages_isolated(outer_start, end, false)) { | |
7695 | pr_info_ratelimited("%s: [%lx, %lx) PFNs busy\n", | |
7696 | __func__, outer_start, end); | |
7697 | ret = -EBUSY; | |
7698 | goto done; | |
7699 | } | |
7700 | ||
7701 | /* Grab isolated pages from freelists. */ | |
7702 | outer_end = isolate_freepages_range(&cc, outer_start, end); | |
7703 | if (!outer_end) { | |
7704 | ret = -EBUSY; | |
7705 | goto done; | |
7706 | } | |
7707 | ||
7708 | /* Free head and tail (if any) */ | |
7709 | if (start != outer_start) | |
7710 | free_contig_range(outer_start, start - outer_start); | |
7711 | if (end != outer_end) | |
7712 | free_contig_range(end, outer_end - end); | |
7713 | ||
7714 | done: | |
7715 | undo_isolate_page_range(pfn_max_align_down(start), | |
7716 | pfn_max_align_up(end), migratetype); | |
7717 | return ret; | |
7718 | } | |
7719 | ||
7720 | void free_contig_range(unsigned long pfn, unsigned nr_pages) | |
7721 | { | |
7722 | unsigned int count = 0; | |
7723 | ||
7724 | for (; nr_pages--; pfn++) { | |
7725 | struct page *page = pfn_to_page(pfn); | |
7726 | ||
7727 | count += page_count(page) != 1; | |
7728 | __free_page(page); | |
7729 | } | |
7730 | WARN(count != 0, "%d pages are still in use!\n", count); | |
7731 | } | |
7732 | #endif | |
7733 | ||
7734 | #ifdef CONFIG_MEMORY_HOTPLUG | |
7735 | /* | |
7736 | * The zone indicated has a new number of managed_pages; batch sizes and percpu | |
7737 | * page high values need to be recalulated. | |
7738 | */ | |
7739 | void __meminit zone_pcp_update(struct zone *zone) | |
7740 | { | |
7741 | unsigned cpu; | |
7742 | mutex_lock(&pcp_batch_high_lock); | |
7743 | for_each_possible_cpu(cpu) | |
7744 | pageset_set_high_and_batch(zone, | |
7745 | per_cpu_ptr(zone->pageset, cpu)); | |
7746 | mutex_unlock(&pcp_batch_high_lock); | |
7747 | } | |
7748 | #endif | |
7749 | ||
7750 | void zone_pcp_reset(struct zone *zone) | |
7751 | { | |
7752 | unsigned long flags; | |
7753 | int cpu; | |
7754 | struct per_cpu_pageset *pset; | |
7755 | ||
7756 | /* avoid races with drain_pages() */ | |
7757 | local_irq_save(flags); | |
7758 | if (zone->pageset != &boot_pageset) { | |
7759 | for_each_online_cpu(cpu) { | |
7760 | pset = per_cpu_ptr(zone->pageset, cpu); | |
7761 | drain_zonestat(zone, pset); | |
7762 | } | |
7763 | free_percpu(zone->pageset); | |
7764 | zone->pageset = &boot_pageset; | |
7765 | } | |
7766 | local_irq_restore(flags); | |
7767 | } | |
7768 | ||
7769 | #ifdef CONFIG_MEMORY_HOTREMOVE | |
7770 | /* | |
7771 | * All pages in the range must be in a single zone and isolated | |
7772 | * before calling this. | |
7773 | */ | |
7774 | void | |
7775 | __offline_isolated_pages(unsigned long start_pfn, unsigned long end_pfn) | |
7776 | { | |
7777 | struct page *page; | |
7778 | struct zone *zone; | |
7779 | unsigned int order, i; | |
7780 | unsigned long pfn; | |
7781 | unsigned long flags; | |
7782 | /* find the first valid pfn */ | |
7783 | for (pfn = start_pfn; pfn < end_pfn; pfn++) | |
7784 | if (pfn_valid(pfn)) | |
7785 | break; | |
7786 | if (pfn == end_pfn) | |
7787 | return; | |
7788 | offline_mem_sections(pfn, end_pfn); | |
7789 | zone = page_zone(pfn_to_page(pfn)); | |
7790 | spin_lock_irqsave(&zone->lock, flags); | |
7791 | pfn = start_pfn; | |
7792 | while (pfn < end_pfn) { | |
7793 | if (!pfn_valid(pfn)) { | |
7794 | pfn++; | |
7795 | continue; | |
7796 | } | |
7797 | page = pfn_to_page(pfn); | |
7798 | /* | |
7799 | * The HWPoisoned page may be not in buddy system, and | |
7800 | * page_count() is not 0. | |
7801 | */ | |
7802 | if (unlikely(!PageBuddy(page) && PageHWPoison(page))) { | |
7803 | pfn++; | |
7804 | SetPageReserved(page); | |
7805 | continue; | |
7806 | } | |
7807 | ||
7808 | BUG_ON(page_count(page)); | |
7809 | BUG_ON(!PageBuddy(page)); | |
7810 | order = page_order(page); | |
7811 | #ifdef CONFIG_DEBUG_VM | |
7812 | pr_info("remove from free list %lx %d %lx\n", | |
7813 | pfn, 1 << order, end_pfn); | |
7814 | #endif | |
7815 | list_del(&page->lru); | |
7816 | rmv_page_order(page); | |
7817 | zone->free_area[order].nr_free--; | |
7818 | for (i = 0; i < (1 << order); i++) | |
7819 | SetPageReserved((page+i)); | |
7820 | pfn += (1 << order); | |
7821 | } | |
7822 | spin_unlock_irqrestore(&zone->lock, flags); | |
7823 | } | |
7824 | #endif | |
7825 | ||
7826 | bool is_free_buddy_page(struct page *page) | |
7827 | { | |
7828 | struct zone *zone = page_zone(page); | |
7829 | unsigned long pfn = page_to_pfn(page); | |
7830 | unsigned long flags; | |
7831 | unsigned int order; | |
7832 | ||
7833 | spin_lock_irqsave(&zone->lock, flags); | |
7834 | for (order = 0; order < MAX_ORDER; order++) { | |
7835 | struct page *page_head = page - (pfn & ((1 << order) - 1)); | |
7836 | ||
7837 | if (PageBuddy(page_head) && page_order(page_head) >= order) | |
7838 | break; | |
7839 | } | |
7840 | spin_unlock_irqrestore(&zone->lock, flags); | |
7841 | ||
7842 | return order < MAX_ORDER; | |
7843 | } |