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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/rwsem.h> | |
22 | #include <linux/pagemap.h> | |
23 | #include <linux/jiffies.h> | |
24 | #include <linux/bootmem.h> | |
25 | #include <linux/memblock.h> | |
26 | #include <linux/compiler.h> | |
27 | #include <linux/kernel.h> | |
28 | #include <linux/kmemcheck.h> | |
29 | #include <linux/kasan.h> | |
30 | #include <linux/module.h> | |
31 | #include <linux/suspend.h> | |
32 | #include <linux/pagevec.h> | |
33 | #include <linux/blkdev.h> | |
34 | #include <linux/slab.h> | |
35 | #include <linux/ratelimit.h> | |
36 | #include <linux/oom.h> | |
37 | #include <linux/notifier.h> | |
38 | #include <linux/topology.h> | |
39 | #include <linux/sysctl.h> | |
40 | #include <linux/cpu.h> | |
41 | #include <linux/cpuset.h> | |
42 | #include <linux/memory_hotplug.h> | |
43 | #include <linux/nodemask.h> | |
44 | #include <linux/vmalloc.h> | |
45 | #include <linux/vmstat.h> | |
46 | #include <linux/mempolicy.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 <linux/prefetch.h> | |
59 | #include <linux/mm_inline.h> | |
60 | #include <linux/migrate.h> | |
61 | #include <linux/page_ext.h> | |
62 | #include <linux/hugetlb.h> | |
63 | #include <linux/sched/rt.h> | |
64 | #include <linux/page_owner.h> | |
65 | #include <linux/kthread.h> | |
66 | ||
67 | #include <asm/sections.h> | |
68 | #include <asm/tlbflush.h> | |
69 | #include <asm/div64.h> | |
70 | #include "internal.h" | |
71 | ||
72 | /* prevent >1 _updater_ of zone percpu pageset ->high and ->batch fields */ | |
73 | static DEFINE_MUTEX(pcp_batch_high_lock); | |
74 | #define MIN_PERCPU_PAGELIST_FRACTION (8) | |
75 | ||
76 | #ifdef CONFIG_USE_PERCPU_NUMA_NODE_ID | |
77 | DEFINE_PER_CPU(int, numa_node); | |
78 | EXPORT_PER_CPU_SYMBOL(numa_node); | |
79 | #endif | |
80 | ||
81 | #ifdef CONFIG_HAVE_MEMORYLESS_NODES | |
82 | /* | |
83 | * N.B., Do NOT reference the '_numa_mem_' per cpu variable directly. | |
84 | * It will not be defined when CONFIG_HAVE_MEMORYLESS_NODES is not defined. | |
85 | * Use the accessor functions set_numa_mem(), numa_mem_id() and cpu_to_mem() | |
86 | * defined in <linux/topology.h>. | |
87 | */ | |
88 | DEFINE_PER_CPU(int, _numa_mem_); /* Kernel "local memory" node */ | |
89 | EXPORT_PER_CPU_SYMBOL(_numa_mem_); | |
90 | int _node_numa_mem_[MAX_NUMNODES]; | |
91 | #endif | |
92 | ||
93 | /* | |
94 | * Array of node states. | |
95 | */ | |
96 | nodemask_t node_states[NR_NODE_STATES] __read_mostly = { | |
97 | [N_POSSIBLE] = NODE_MASK_ALL, | |
98 | [N_ONLINE] = { { [0] = 1UL } }, | |
99 | #ifndef CONFIG_NUMA | |
100 | [N_NORMAL_MEMORY] = { { [0] = 1UL } }, | |
101 | #ifdef CONFIG_HIGHMEM | |
102 | [N_HIGH_MEMORY] = { { [0] = 1UL } }, | |
103 | #endif | |
104 | #ifdef CONFIG_MOVABLE_NODE | |
105 | [N_MEMORY] = { { [0] = 1UL } }, | |
106 | #endif | |
107 | [N_CPU] = { { [0] = 1UL } }, | |
108 | #endif /* NUMA */ | |
109 | }; | |
110 | EXPORT_SYMBOL(node_states); | |
111 | ||
112 | /* Protect totalram_pages and zone->managed_pages */ | |
113 | static DEFINE_SPINLOCK(managed_page_count_lock); | |
114 | ||
115 | unsigned long totalram_pages __read_mostly; | |
116 | unsigned long totalreserve_pages __read_mostly; | |
117 | unsigned long totalcma_pages __read_mostly; | |
118 | /* | |
119 | * When calculating the number of globally allowed dirty pages, there | |
120 | * is a certain number of per-zone reserves that should not be | |
121 | * considered dirtyable memory. This is the sum of those reserves | |
122 | * over all existing zones that contribute dirtyable memory. | |
123 | */ | |
124 | unsigned long dirty_balance_reserve __read_mostly; | |
125 | ||
126 | int percpu_pagelist_fraction; | |
127 | gfp_t gfp_allowed_mask __read_mostly = GFP_BOOT_MASK; | |
128 | ||
129 | #ifdef CONFIG_PM_SLEEP | |
130 | /* | |
131 | * The following functions are used by the suspend/hibernate code to temporarily | |
132 | * change gfp_allowed_mask in order to avoid using I/O during memory allocations | |
133 | * while devices are suspended. To avoid races with the suspend/hibernate code, | |
134 | * they should always be called with pm_mutex held (gfp_allowed_mask also should | |
135 | * only be modified with pm_mutex held, unless the suspend/hibernate code is | |
136 | * guaranteed not to run in parallel with that modification). | |
137 | */ | |
138 | ||
139 | static gfp_t saved_gfp_mask; | |
140 | ||
141 | void pm_restore_gfp_mask(void) | |
142 | { | |
143 | WARN_ON(!mutex_is_locked(&pm_mutex)); | |
144 | if (saved_gfp_mask) { | |
145 | gfp_allowed_mask = saved_gfp_mask; | |
146 | saved_gfp_mask = 0; | |
147 | } | |
148 | } | |
149 | ||
150 | void pm_restrict_gfp_mask(void) | |
151 | { | |
152 | WARN_ON(!mutex_is_locked(&pm_mutex)); | |
153 | WARN_ON(saved_gfp_mask); | |
154 | saved_gfp_mask = gfp_allowed_mask; | |
155 | gfp_allowed_mask &= ~GFP_IOFS; | |
156 | } | |
157 | ||
158 | bool pm_suspended_storage(void) | |
159 | { | |
160 | if ((gfp_allowed_mask & GFP_IOFS) == GFP_IOFS) | |
161 | return false; | |
162 | return true; | |
163 | } | |
164 | #endif /* CONFIG_PM_SLEEP */ | |
165 | ||
166 | #ifdef CONFIG_HUGETLB_PAGE_SIZE_VARIABLE | |
167 | int pageblock_order __read_mostly; | |
168 | #endif | |
169 | ||
170 | static void __free_pages_ok(struct page *page, unsigned int order); | |
171 | ||
172 | /* | |
173 | * results with 256, 32 in the lowmem_reserve sysctl: | |
174 | * 1G machine -> (16M dma, 800M-16M normal, 1G-800M high) | |
175 | * 1G machine -> (16M dma, 784M normal, 224M high) | |
176 | * NORMAL allocation will leave 784M/256 of ram reserved in the ZONE_DMA | |
177 | * HIGHMEM allocation will leave 224M/32 of ram reserved in ZONE_NORMAL | |
178 | * HIGHMEM allocation will leave (224M+784M)/256 of ram reserved in ZONE_DMA | |
179 | * | |
180 | * TBD: should special case ZONE_DMA32 machines here - in those we normally | |
181 | * don't need any ZONE_NORMAL reservation | |
182 | */ | |
183 | int sysctl_lowmem_reserve_ratio[MAX_NR_ZONES-1] = { | |
184 | #ifdef CONFIG_ZONE_DMA | |
185 | 256, | |
186 | #endif | |
187 | #ifdef CONFIG_ZONE_DMA32 | |
188 | 256, | |
189 | #endif | |
190 | #ifdef CONFIG_HIGHMEM | |
191 | 32, | |
192 | #endif | |
193 | 32, | |
194 | }; | |
195 | ||
196 | EXPORT_SYMBOL(totalram_pages); | |
197 | ||
198 | static char * const zone_names[MAX_NR_ZONES] = { | |
199 | #ifdef CONFIG_ZONE_DMA | |
200 | "DMA", | |
201 | #endif | |
202 | #ifdef CONFIG_ZONE_DMA32 | |
203 | "DMA32", | |
204 | #endif | |
205 | "Normal", | |
206 | #ifdef CONFIG_HIGHMEM | |
207 | "HighMem", | |
208 | #endif | |
209 | "Movable", | |
210 | }; | |
211 | ||
212 | int min_free_kbytes = 1024; | |
213 | int user_min_free_kbytes = -1; | |
214 | ||
215 | static unsigned long __meminitdata nr_kernel_pages; | |
216 | static unsigned long __meminitdata nr_all_pages; | |
217 | static unsigned long __meminitdata dma_reserve; | |
218 | ||
219 | #ifdef CONFIG_HAVE_MEMBLOCK_NODE_MAP | |
220 | static unsigned long __meminitdata arch_zone_lowest_possible_pfn[MAX_NR_ZONES]; | |
221 | static unsigned long __meminitdata arch_zone_highest_possible_pfn[MAX_NR_ZONES]; | |
222 | static unsigned long __initdata required_kernelcore; | |
223 | static unsigned long __initdata required_movablecore; | |
224 | static unsigned long __meminitdata zone_movable_pfn[MAX_NUMNODES]; | |
225 | ||
226 | /* movable_zone is the "real" zone pages in ZONE_MOVABLE are taken from */ | |
227 | int movable_zone; | |
228 | EXPORT_SYMBOL(movable_zone); | |
229 | #endif /* CONFIG_HAVE_MEMBLOCK_NODE_MAP */ | |
230 | ||
231 | #if MAX_NUMNODES > 1 | |
232 | int nr_node_ids __read_mostly = MAX_NUMNODES; | |
233 | int nr_online_nodes __read_mostly = 1; | |
234 | EXPORT_SYMBOL(nr_node_ids); | |
235 | EXPORT_SYMBOL(nr_online_nodes); | |
236 | #endif | |
237 | ||
238 | int page_group_by_mobility_disabled __read_mostly; | |
239 | ||
240 | #ifdef CONFIG_DEFERRED_STRUCT_PAGE_INIT | |
241 | static inline void reset_deferred_meminit(pg_data_t *pgdat) | |
242 | { | |
243 | pgdat->first_deferred_pfn = ULONG_MAX; | |
244 | } | |
245 | ||
246 | /* Returns true if the struct page for the pfn is uninitialised */ | |
247 | static inline bool __meminit early_page_uninitialised(unsigned long pfn) | |
248 | { | |
249 | if (pfn >= NODE_DATA(early_pfn_to_nid(pfn))->first_deferred_pfn) | |
250 | return true; | |
251 | ||
252 | return false; | |
253 | } | |
254 | ||
255 | static inline bool early_page_nid_uninitialised(unsigned long pfn, int nid) | |
256 | { | |
257 | if (pfn >= NODE_DATA(nid)->first_deferred_pfn) | |
258 | return true; | |
259 | ||
260 | return false; | |
261 | } | |
262 | ||
263 | /* | |
264 | * Returns false when the remaining initialisation should be deferred until | |
265 | * later in the boot cycle when it can be parallelised. | |
266 | */ | |
267 | static inline bool update_defer_init(pg_data_t *pgdat, | |
268 | unsigned long pfn, unsigned long zone_end, | |
269 | unsigned long *nr_initialised) | |
270 | { | |
271 | /* Always populate low zones for address-contrained allocations */ | |
272 | if (zone_end < pgdat_end_pfn(pgdat)) | |
273 | return true; | |
274 | ||
275 | /* Initialise at least 2G of the highest zone */ | |
276 | (*nr_initialised)++; | |
277 | if (*nr_initialised > (2UL << (30 - PAGE_SHIFT)) && | |
278 | (pfn & (PAGES_PER_SECTION - 1)) == 0) { | |
279 | pgdat->first_deferred_pfn = pfn; | |
280 | return false; | |
281 | } | |
282 | ||
283 | return true; | |
284 | } | |
285 | #else | |
286 | static inline void reset_deferred_meminit(pg_data_t *pgdat) | |
287 | { | |
288 | } | |
289 | ||
290 | static inline bool early_page_uninitialised(unsigned long pfn) | |
291 | { | |
292 | return false; | |
293 | } | |
294 | ||
295 | static inline bool early_page_nid_uninitialised(unsigned long pfn, int nid) | |
296 | { | |
297 | return false; | |
298 | } | |
299 | ||
300 | static inline bool update_defer_init(pg_data_t *pgdat, | |
301 | unsigned long pfn, unsigned long zone_end, | |
302 | unsigned long *nr_initialised) | |
303 | { | |
304 | return true; | |
305 | } | |
306 | #endif | |
307 | ||
308 | ||
309 | void set_pageblock_migratetype(struct page *page, int migratetype) | |
310 | { | |
311 | if (unlikely(page_group_by_mobility_disabled && | |
312 | migratetype < MIGRATE_PCPTYPES)) | |
313 | migratetype = MIGRATE_UNMOVABLE; | |
314 | ||
315 | set_pageblock_flags_group(page, (unsigned long)migratetype, | |
316 | PB_migrate, PB_migrate_end); | |
317 | } | |
318 | ||
319 | #ifdef CONFIG_DEBUG_VM | |
320 | static int page_outside_zone_boundaries(struct zone *zone, struct page *page) | |
321 | { | |
322 | int ret = 0; | |
323 | unsigned seq; | |
324 | unsigned long pfn = page_to_pfn(page); | |
325 | unsigned long sp, start_pfn; | |
326 | ||
327 | do { | |
328 | seq = zone_span_seqbegin(zone); | |
329 | start_pfn = zone->zone_start_pfn; | |
330 | sp = zone->spanned_pages; | |
331 | if (!zone_spans_pfn(zone, pfn)) | |
332 | ret = 1; | |
333 | } while (zone_span_seqretry(zone, seq)); | |
334 | ||
335 | if (ret) | |
336 | pr_err("page 0x%lx outside node %d zone %s [ 0x%lx - 0x%lx ]\n", | |
337 | pfn, zone_to_nid(zone), zone->name, | |
338 | start_pfn, start_pfn + sp); | |
339 | ||
340 | return ret; | |
341 | } | |
342 | ||
343 | static int page_is_consistent(struct zone *zone, struct page *page) | |
344 | { | |
345 | if (!pfn_valid_within(page_to_pfn(page))) | |
346 | return 0; | |
347 | if (zone != page_zone(page)) | |
348 | return 0; | |
349 | ||
350 | return 1; | |
351 | } | |
352 | /* | |
353 | * Temporary debugging check for pages not lying within a given zone. | |
354 | */ | |
355 | static int bad_range(struct zone *zone, struct page *page) | |
356 | { | |
357 | if (page_outside_zone_boundaries(zone, page)) | |
358 | return 1; | |
359 | if (!page_is_consistent(zone, page)) | |
360 | return 1; | |
361 | ||
362 | return 0; | |
363 | } | |
364 | #else | |
365 | static inline int bad_range(struct zone *zone, struct page *page) | |
366 | { | |
367 | return 0; | |
368 | } | |
369 | #endif | |
370 | ||
371 | static void bad_page(struct page *page, const char *reason, | |
372 | unsigned long bad_flags) | |
373 | { | |
374 | static unsigned long resume; | |
375 | static unsigned long nr_shown; | |
376 | static unsigned long nr_unshown; | |
377 | ||
378 | /* Don't complain about poisoned pages */ | |
379 | if (PageHWPoison(page)) { | |
380 | page_mapcount_reset(page); /* remove PageBuddy */ | |
381 | return; | |
382 | } | |
383 | ||
384 | /* | |
385 | * Allow a burst of 60 reports, then keep quiet for that minute; | |
386 | * or allow a steady drip of one report per second. | |
387 | */ | |
388 | if (nr_shown == 60) { | |
389 | if (time_before(jiffies, resume)) { | |
390 | nr_unshown++; | |
391 | goto out; | |
392 | } | |
393 | if (nr_unshown) { | |
394 | printk(KERN_ALERT | |
395 | "BUG: Bad page state: %lu messages suppressed\n", | |
396 | nr_unshown); | |
397 | nr_unshown = 0; | |
398 | } | |
399 | nr_shown = 0; | |
400 | } | |
401 | if (nr_shown++ == 0) | |
402 | resume = jiffies + 60 * HZ; | |
403 | ||
404 | printk(KERN_ALERT "BUG: Bad page state in process %s pfn:%05lx\n", | |
405 | current->comm, page_to_pfn(page)); | |
406 | dump_page_badflags(page, reason, bad_flags); | |
407 | ||
408 | print_modules(); | |
409 | dump_stack(); | |
410 | out: | |
411 | /* Leave bad fields for debug, except PageBuddy could make trouble */ | |
412 | page_mapcount_reset(page); /* remove PageBuddy */ | |
413 | add_taint(TAINT_BAD_PAGE, LOCKDEP_NOW_UNRELIABLE); | |
414 | } | |
415 | ||
416 | /* | |
417 | * Higher-order pages are called "compound pages". They are structured thusly: | |
418 | * | |
419 | * The first PAGE_SIZE page is called the "head page". | |
420 | * | |
421 | * The remaining PAGE_SIZE pages are called "tail pages". | |
422 | * | |
423 | * All pages have PG_compound set. All tail pages have their ->first_page | |
424 | * pointing at the head page. | |
425 | * | |
426 | * The first tail page's ->lru.next holds the address of the compound page's | |
427 | * put_page() function. Its ->lru.prev holds the order of allocation. | |
428 | * This usage means that zero-order pages may not be compound. | |
429 | */ | |
430 | ||
431 | static void free_compound_page(struct page *page) | |
432 | { | |
433 | __free_pages_ok(page, compound_order(page)); | |
434 | } | |
435 | ||
436 | void prep_compound_page(struct page *page, unsigned long order) | |
437 | { | |
438 | int i; | |
439 | int nr_pages = 1 << order; | |
440 | ||
441 | set_compound_page_dtor(page, free_compound_page); | |
442 | set_compound_order(page, order); | |
443 | __SetPageHead(page); | |
444 | for (i = 1; i < nr_pages; i++) { | |
445 | struct page *p = page + i; | |
446 | set_page_count(p, 0); | |
447 | p->first_page = page; | |
448 | /* Make sure p->first_page is always valid for PageTail() */ | |
449 | smp_wmb(); | |
450 | __SetPageTail(p); | |
451 | } | |
452 | } | |
453 | ||
454 | #ifdef CONFIG_DEBUG_PAGEALLOC | |
455 | unsigned int _debug_guardpage_minorder; | |
456 | bool _debug_pagealloc_enabled __read_mostly; | |
457 | bool _debug_guardpage_enabled __read_mostly; | |
458 | ||
459 | static int __init early_debug_pagealloc(char *buf) | |
460 | { | |
461 | if (!buf) | |
462 | return -EINVAL; | |
463 | ||
464 | if (strcmp(buf, "on") == 0) | |
465 | _debug_pagealloc_enabled = true; | |
466 | ||
467 | return 0; | |
468 | } | |
469 | early_param("debug_pagealloc", early_debug_pagealloc); | |
470 | ||
471 | static bool need_debug_guardpage(void) | |
472 | { | |
473 | /* If we don't use debug_pagealloc, we don't need guard page */ | |
474 | if (!debug_pagealloc_enabled()) | |
475 | return false; | |
476 | ||
477 | return true; | |
478 | } | |
479 | ||
480 | static void init_debug_guardpage(void) | |
481 | { | |
482 | if (!debug_pagealloc_enabled()) | |
483 | return; | |
484 | ||
485 | _debug_guardpage_enabled = true; | |
486 | } | |
487 | ||
488 | struct page_ext_operations debug_guardpage_ops = { | |
489 | .need = need_debug_guardpage, | |
490 | .init = init_debug_guardpage, | |
491 | }; | |
492 | ||
493 | static int __init debug_guardpage_minorder_setup(char *buf) | |
494 | { | |
495 | unsigned long res; | |
496 | ||
497 | if (kstrtoul(buf, 10, &res) < 0 || res > MAX_ORDER / 2) { | |
498 | printk(KERN_ERR "Bad debug_guardpage_minorder value\n"); | |
499 | return 0; | |
500 | } | |
501 | _debug_guardpage_minorder = res; | |
502 | printk(KERN_INFO "Setting debug_guardpage_minorder to %lu\n", res); | |
503 | return 0; | |
504 | } | |
505 | __setup("debug_guardpage_minorder=", debug_guardpage_minorder_setup); | |
506 | ||
507 | static inline void set_page_guard(struct zone *zone, struct page *page, | |
508 | unsigned int order, int migratetype) | |
509 | { | |
510 | struct page_ext *page_ext; | |
511 | ||
512 | if (!debug_guardpage_enabled()) | |
513 | return; | |
514 | ||
515 | page_ext = lookup_page_ext(page); | |
516 | __set_bit(PAGE_EXT_DEBUG_GUARD, &page_ext->flags); | |
517 | ||
518 | INIT_LIST_HEAD(&page->lru); | |
519 | set_page_private(page, order); | |
520 | /* Guard pages are not available for any usage */ | |
521 | __mod_zone_freepage_state(zone, -(1 << order), migratetype); | |
522 | } | |
523 | ||
524 | static inline void clear_page_guard(struct zone *zone, struct page *page, | |
525 | unsigned int order, int migratetype) | |
526 | { | |
527 | struct page_ext *page_ext; | |
528 | ||
529 | if (!debug_guardpage_enabled()) | |
530 | return; | |
531 | ||
532 | page_ext = lookup_page_ext(page); | |
533 | __clear_bit(PAGE_EXT_DEBUG_GUARD, &page_ext->flags); | |
534 | ||
535 | set_page_private(page, 0); | |
536 | if (!is_migrate_isolate(migratetype)) | |
537 | __mod_zone_freepage_state(zone, (1 << order), migratetype); | |
538 | } | |
539 | #else | |
540 | struct page_ext_operations debug_guardpage_ops = { NULL, }; | |
541 | static inline void set_page_guard(struct zone *zone, struct page *page, | |
542 | unsigned int order, int migratetype) {} | |
543 | static inline void clear_page_guard(struct zone *zone, struct page *page, | |
544 | unsigned int order, int migratetype) {} | |
545 | #endif | |
546 | ||
547 | static inline void set_page_order(struct page *page, unsigned int order) | |
548 | { | |
549 | set_page_private(page, order); | |
550 | __SetPageBuddy(page); | |
551 | } | |
552 | ||
553 | static inline void rmv_page_order(struct page *page) | |
554 | { | |
555 | __ClearPageBuddy(page); | |
556 | set_page_private(page, 0); | |
557 | } | |
558 | ||
559 | /* | |
560 | * This function checks whether a page is free && is the buddy | |
561 | * we can do coalesce a page and its buddy if | |
562 | * (a) the buddy is not in a hole && | |
563 | * (b) the buddy is in the buddy system && | |
564 | * (c) a page and its buddy have the same order && | |
565 | * (d) a page and its buddy are in the same zone. | |
566 | * | |
567 | * For recording whether a page is in the buddy system, we set ->_mapcount | |
568 | * PAGE_BUDDY_MAPCOUNT_VALUE. | |
569 | * Setting, clearing, and testing _mapcount PAGE_BUDDY_MAPCOUNT_VALUE is | |
570 | * serialized by zone->lock. | |
571 | * | |
572 | * For recording page's order, we use page_private(page). | |
573 | */ | |
574 | static inline int page_is_buddy(struct page *page, struct page *buddy, | |
575 | unsigned int order) | |
576 | { | |
577 | if (!pfn_valid_within(page_to_pfn(buddy))) | |
578 | return 0; | |
579 | ||
580 | if (page_is_guard(buddy) && page_order(buddy) == order) { | |
581 | if (page_zone_id(page) != page_zone_id(buddy)) | |
582 | return 0; | |
583 | ||
584 | VM_BUG_ON_PAGE(page_count(buddy) != 0, buddy); | |
585 | ||
586 | return 1; | |
587 | } | |
588 | ||
589 | if (PageBuddy(buddy) && page_order(buddy) == order) { | |
590 | /* | |
591 | * zone check is done late to avoid uselessly | |
592 | * calculating zone/node ids for pages that could | |
593 | * never merge. | |
594 | */ | |
595 | if (page_zone_id(page) != page_zone_id(buddy)) | |
596 | return 0; | |
597 | ||
598 | VM_BUG_ON_PAGE(page_count(buddy) != 0, buddy); | |
599 | ||
600 | return 1; | |
601 | } | |
602 | return 0; | |
603 | } | |
604 | ||
605 | /* | |
606 | * Freeing function for a buddy system allocator. | |
607 | * | |
608 | * The concept of a buddy system is to maintain direct-mapped table | |
609 | * (containing bit values) for memory blocks of various "orders". | |
610 | * The bottom level table contains the map for the smallest allocatable | |
611 | * units of memory (here, pages), and each level above it describes | |
612 | * pairs of units from the levels below, hence, "buddies". | |
613 | * At a high level, all that happens here is marking the table entry | |
614 | * at the bottom level available, and propagating the changes upward | |
615 | * as necessary, plus some accounting needed to play nicely with other | |
616 | * parts of the VM system. | |
617 | * At each level, we keep a list of pages, which are heads of continuous | |
618 | * free pages of length of (1 << order) and marked with _mapcount | |
619 | * PAGE_BUDDY_MAPCOUNT_VALUE. Page's order is recorded in page_private(page) | |
620 | * field. | |
621 | * So when we are allocating or freeing one, we can derive the state of the | |
622 | * other. That is, if we allocate a small block, and both were | |
623 | * free, the remainder of the region must be split into blocks. | |
624 | * If a block is freed, and its buddy is also free, then this | |
625 | * triggers coalescing into a block of larger size. | |
626 | * | |
627 | * -- nyc | |
628 | */ | |
629 | ||
630 | static inline void __free_one_page(struct page *page, | |
631 | unsigned long pfn, | |
632 | struct zone *zone, unsigned int order, | |
633 | int migratetype) | |
634 | { | |
635 | unsigned long page_idx; | |
636 | unsigned long combined_idx; | |
637 | unsigned long uninitialized_var(buddy_idx); | |
638 | struct page *buddy; | |
639 | int max_order = MAX_ORDER; | |
640 | ||
641 | VM_BUG_ON(!zone_is_initialized(zone)); | |
642 | VM_BUG_ON_PAGE(page->flags & PAGE_FLAGS_CHECK_AT_PREP, page); | |
643 | ||
644 | VM_BUG_ON(migratetype == -1); | |
645 | if (is_migrate_isolate(migratetype)) { | |
646 | /* | |
647 | * We restrict max order of merging to prevent merge | |
648 | * between freepages on isolate pageblock and normal | |
649 | * pageblock. Without this, pageblock isolation | |
650 | * could cause incorrect freepage accounting. | |
651 | */ | |
652 | max_order = min(MAX_ORDER, pageblock_order + 1); | |
653 | } else { | |
654 | __mod_zone_freepage_state(zone, 1 << order, migratetype); | |
655 | } | |
656 | ||
657 | page_idx = pfn & ((1 << max_order) - 1); | |
658 | ||
659 | VM_BUG_ON_PAGE(page_idx & ((1 << order) - 1), page); | |
660 | VM_BUG_ON_PAGE(bad_range(zone, page), page); | |
661 | ||
662 | while (order < max_order - 1) { | |
663 | buddy_idx = __find_buddy_index(page_idx, order); | |
664 | buddy = page + (buddy_idx - page_idx); | |
665 | if (!page_is_buddy(page, buddy, order)) | |
666 | break; | |
667 | /* | |
668 | * Our buddy is free or it is CONFIG_DEBUG_PAGEALLOC guard page, | |
669 | * merge with it and move up one order. | |
670 | */ | |
671 | if (page_is_guard(buddy)) { | |
672 | clear_page_guard(zone, buddy, order, migratetype); | |
673 | } else { | |
674 | list_del(&buddy->lru); | |
675 | zone->free_area[order].nr_free--; | |
676 | rmv_page_order(buddy); | |
677 | } | |
678 | combined_idx = buddy_idx & page_idx; | |
679 | page = page + (combined_idx - page_idx); | |
680 | page_idx = combined_idx; | |
681 | order++; | |
682 | } | |
683 | set_page_order(page, order); | |
684 | ||
685 | /* | |
686 | * If this is not the largest possible page, check if the buddy | |
687 | * of the next-highest order is free. If it is, it's possible | |
688 | * that pages are being freed that will coalesce soon. In case, | |
689 | * that is happening, add the free page to the tail of the list | |
690 | * so it's less likely to be used soon and more likely to be merged | |
691 | * as a higher order page | |
692 | */ | |
693 | if ((order < MAX_ORDER-2) && pfn_valid_within(page_to_pfn(buddy))) { | |
694 | struct page *higher_page, *higher_buddy; | |
695 | combined_idx = buddy_idx & page_idx; | |
696 | higher_page = page + (combined_idx - page_idx); | |
697 | buddy_idx = __find_buddy_index(combined_idx, order + 1); | |
698 | higher_buddy = higher_page + (buddy_idx - combined_idx); | |
699 | if (page_is_buddy(higher_page, higher_buddy, order + 1)) { | |
700 | list_add_tail(&page->lru, | |
701 | &zone->free_area[order].free_list[migratetype]); | |
702 | goto out; | |
703 | } | |
704 | } | |
705 | ||
706 | list_add(&page->lru, &zone->free_area[order].free_list[migratetype]); | |
707 | out: | |
708 | zone->free_area[order].nr_free++; | |
709 | } | |
710 | ||
711 | static inline int free_pages_check(struct page *page) | |
712 | { | |
713 | const char *bad_reason = NULL; | |
714 | unsigned long bad_flags = 0; | |
715 | ||
716 | if (unlikely(page_mapcount(page))) | |
717 | bad_reason = "nonzero mapcount"; | |
718 | if (unlikely(page->mapping != NULL)) | |
719 | bad_reason = "non-NULL mapping"; | |
720 | if (unlikely(atomic_read(&page->_count) != 0)) | |
721 | bad_reason = "nonzero _count"; | |
722 | if (unlikely(page->flags & PAGE_FLAGS_CHECK_AT_FREE)) { | |
723 | bad_reason = "PAGE_FLAGS_CHECK_AT_FREE flag(s) set"; | |
724 | bad_flags = PAGE_FLAGS_CHECK_AT_FREE; | |
725 | } | |
726 | #ifdef CONFIG_MEMCG | |
727 | if (unlikely(page->mem_cgroup)) | |
728 | bad_reason = "page still charged to cgroup"; | |
729 | #endif | |
730 | if (unlikely(bad_reason)) { | |
731 | bad_page(page, bad_reason, bad_flags); | |
732 | return 1; | |
733 | } | |
734 | page_cpupid_reset_last(page); | |
735 | if (page->flags & PAGE_FLAGS_CHECK_AT_PREP) | |
736 | page->flags &= ~PAGE_FLAGS_CHECK_AT_PREP; | |
737 | return 0; | |
738 | } | |
739 | ||
740 | /* | |
741 | * Frees a number of pages from the PCP lists | |
742 | * Assumes all pages on list are in same zone, and of same order. | |
743 | * count is the number of pages to free. | |
744 | * | |
745 | * If the zone was previously in an "all pages pinned" state then look to | |
746 | * see if this freeing clears that state. | |
747 | * | |
748 | * And clear the zone's pages_scanned counter, to hold off the "all pages are | |
749 | * pinned" detection logic. | |
750 | */ | |
751 | static void free_pcppages_bulk(struct zone *zone, int count, | |
752 | struct per_cpu_pages *pcp) | |
753 | { | |
754 | int migratetype = 0; | |
755 | int batch_free = 0; | |
756 | int to_free = count; | |
757 | unsigned long nr_scanned; | |
758 | ||
759 | spin_lock(&zone->lock); | |
760 | nr_scanned = zone_page_state(zone, NR_PAGES_SCANNED); | |
761 | if (nr_scanned) | |
762 | __mod_zone_page_state(zone, NR_PAGES_SCANNED, -nr_scanned); | |
763 | ||
764 | while (to_free) { | |
765 | struct page *page; | |
766 | struct list_head *list; | |
767 | ||
768 | /* | |
769 | * Remove pages from lists in a round-robin fashion. A | |
770 | * batch_free count is maintained that is incremented when an | |
771 | * empty list is encountered. This is so more pages are freed | |
772 | * off fuller lists instead of spinning excessively around empty | |
773 | * lists | |
774 | */ | |
775 | do { | |
776 | batch_free++; | |
777 | if (++migratetype == MIGRATE_PCPTYPES) | |
778 | migratetype = 0; | |
779 | list = &pcp->lists[migratetype]; | |
780 | } while (list_empty(list)); | |
781 | ||
782 | /* This is the only non-empty list. Free them all. */ | |
783 | if (batch_free == MIGRATE_PCPTYPES) | |
784 | batch_free = to_free; | |
785 | ||
786 | do { | |
787 | int mt; /* migratetype of the to-be-freed page */ | |
788 | ||
789 | page = list_entry(list->prev, struct page, lru); | |
790 | /* must delete as __free_one_page list manipulates */ | |
791 | list_del(&page->lru); | |
792 | mt = get_freepage_migratetype(page); | |
793 | if (unlikely(has_isolate_pageblock(zone))) | |
794 | mt = get_pageblock_migratetype(page); | |
795 | ||
796 | /* MIGRATE_MOVABLE list may include MIGRATE_RESERVEs */ | |
797 | __free_one_page(page, page_to_pfn(page), zone, 0, mt); | |
798 | trace_mm_page_pcpu_drain(page, 0, mt); | |
799 | } while (--to_free && --batch_free && !list_empty(list)); | |
800 | } | |
801 | spin_unlock(&zone->lock); | |
802 | } | |
803 | ||
804 | static void free_one_page(struct zone *zone, | |
805 | struct page *page, unsigned long pfn, | |
806 | unsigned int order, | |
807 | int migratetype) | |
808 | { | |
809 | unsigned long nr_scanned; | |
810 | spin_lock(&zone->lock); | |
811 | nr_scanned = zone_page_state(zone, NR_PAGES_SCANNED); | |
812 | if (nr_scanned) | |
813 | __mod_zone_page_state(zone, NR_PAGES_SCANNED, -nr_scanned); | |
814 | ||
815 | if (unlikely(has_isolate_pageblock(zone) || | |
816 | is_migrate_isolate(migratetype))) { | |
817 | migratetype = get_pfnblock_migratetype(page, pfn); | |
818 | } | |
819 | __free_one_page(page, pfn, zone, order, migratetype); | |
820 | spin_unlock(&zone->lock); | |
821 | } | |
822 | ||
823 | static int free_tail_pages_check(struct page *head_page, struct page *page) | |
824 | { | |
825 | if (!IS_ENABLED(CONFIG_DEBUG_VM)) | |
826 | return 0; | |
827 | if (unlikely(!PageTail(page))) { | |
828 | bad_page(page, "PageTail not set", 0); | |
829 | return 1; | |
830 | } | |
831 | if (unlikely(page->first_page != head_page)) { | |
832 | bad_page(page, "first_page not consistent", 0); | |
833 | return 1; | |
834 | } | |
835 | return 0; | |
836 | } | |
837 | ||
838 | static void __meminit __init_single_page(struct page *page, unsigned long pfn, | |
839 | unsigned long zone, int nid) | |
840 | { | |
841 | set_page_links(page, zone, nid, pfn); | |
842 | init_page_count(page); | |
843 | page_mapcount_reset(page); | |
844 | page_cpupid_reset_last(page); | |
845 | ||
846 | INIT_LIST_HEAD(&page->lru); | |
847 | #ifdef WANT_PAGE_VIRTUAL | |
848 | /* The shift won't overflow because ZONE_NORMAL is below 4G. */ | |
849 | if (!is_highmem_idx(zone)) | |
850 | set_page_address(page, __va(pfn << PAGE_SHIFT)); | |
851 | #endif | |
852 | } | |
853 | ||
854 | static void __meminit __init_single_pfn(unsigned long pfn, unsigned long zone, | |
855 | int nid) | |
856 | { | |
857 | return __init_single_page(pfn_to_page(pfn), pfn, zone, nid); | |
858 | } | |
859 | ||
860 | #ifdef CONFIG_DEFERRED_STRUCT_PAGE_INIT | |
861 | static void init_reserved_page(unsigned long pfn) | |
862 | { | |
863 | pg_data_t *pgdat; | |
864 | int nid, zid; | |
865 | ||
866 | if (!early_page_uninitialised(pfn)) | |
867 | return; | |
868 | ||
869 | nid = early_pfn_to_nid(pfn); | |
870 | pgdat = NODE_DATA(nid); | |
871 | ||
872 | for (zid = 0; zid < MAX_NR_ZONES; zid++) { | |
873 | struct zone *zone = &pgdat->node_zones[zid]; | |
874 | ||
875 | if (pfn >= zone->zone_start_pfn && pfn < zone_end_pfn(zone)) | |
876 | break; | |
877 | } | |
878 | __init_single_pfn(pfn, zid, nid); | |
879 | } | |
880 | #else | |
881 | static inline void init_reserved_page(unsigned long pfn) | |
882 | { | |
883 | } | |
884 | #endif /* CONFIG_DEFERRED_STRUCT_PAGE_INIT */ | |
885 | ||
886 | /* | |
887 | * Initialised pages do not have PageReserved set. This function is | |
888 | * called for each range allocated by the bootmem allocator and | |
889 | * marks the pages PageReserved. The remaining valid pages are later | |
890 | * sent to the buddy page allocator. | |
891 | */ | |
892 | void __meminit reserve_bootmem_region(unsigned long start, unsigned long end) | |
893 | { | |
894 | unsigned long start_pfn = PFN_DOWN(start); | |
895 | unsigned long end_pfn = PFN_UP(end); | |
896 | ||
897 | for (; start_pfn < end_pfn; start_pfn++) { | |
898 | if (pfn_valid(start_pfn)) { | |
899 | struct page *page = pfn_to_page(start_pfn); | |
900 | ||
901 | init_reserved_page(start_pfn); | |
902 | SetPageReserved(page); | |
903 | } | |
904 | } | |
905 | } | |
906 | ||
907 | static bool free_pages_prepare(struct page *page, unsigned int order) | |
908 | { | |
909 | bool compound = PageCompound(page); | |
910 | int i, bad = 0; | |
911 | ||
912 | VM_BUG_ON_PAGE(PageTail(page), page); | |
913 | VM_BUG_ON_PAGE(compound && compound_order(page) != order, page); | |
914 | ||
915 | trace_mm_page_free(page, order); | |
916 | kmemcheck_free_shadow(page, order); | |
917 | kasan_free_pages(page, order); | |
918 | ||
919 | if (PageAnon(page)) | |
920 | page->mapping = NULL; | |
921 | bad += free_pages_check(page); | |
922 | for (i = 1; i < (1 << order); i++) { | |
923 | if (compound) | |
924 | bad += free_tail_pages_check(page, page + i); | |
925 | bad += free_pages_check(page + i); | |
926 | } | |
927 | if (bad) | |
928 | return false; | |
929 | ||
930 | reset_page_owner(page, order); | |
931 | ||
932 | if (!PageHighMem(page)) { | |
933 | debug_check_no_locks_freed(page_address(page), | |
934 | PAGE_SIZE << order); | |
935 | debug_check_no_obj_freed(page_address(page), | |
936 | PAGE_SIZE << order); | |
937 | } | |
938 | arch_free_page(page, order); | |
939 | kernel_map_pages(page, 1 << order, 0); | |
940 | ||
941 | return true; | |
942 | } | |
943 | ||
944 | static void __free_pages_ok(struct page *page, unsigned int order) | |
945 | { | |
946 | unsigned long flags; | |
947 | int migratetype; | |
948 | unsigned long pfn = page_to_pfn(page); | |
949 | ||
950 | if (!free_pages_prepare(page, order)) | |
951 | return; | |
952 | ||
953 | migratetype = get_pfnblock_migratetype(page, pfn); | |
954 | local_irq_save(flags); | |
955 | __count_vm_events(PGFREE, 1 << order); | |
956 | set_freepage_migratetype(page, migratetype); | |
957 | free_one_page(page_zone(page), page, pfn, order, migratetype); | |
958 | local_irq_restore(flags); | |
959 | } | |
960 | ||
961 | static void __init __free_pages_boot_core(struct page *page, | |
962 | unsigned long pfn, unsigned int order) | |
963 | { | |
964 | unsigned int nr_pages = 1 << order; | |
965 | struct page *p = page; | |
966 | unsigned int loop; | |
967 | ||
968 | prefetchw(p); | |
969 | for (loop = 0; loop < (nr_pages - 1); loop++, p++) { | |
970 | prefetchw(p + 1); | |
971 | __ClearPageReserved(p); | |
972 | set_page_count(p, 0); | |
973 | } | |
974 | __ClearPageReserved(p); | |
975 | set_page_count(p, 0); | |
976 | ||
977 | page_zone(page)->managed_pages += nr_pages; | |
978 | set_page_refcounted(page); | |
979 | __free_pages(page, order); | |
980 | } | |
981 | ||
982 | #if defined(CONFIG_HAVE_ARCH_EARLY_PFN_TO_NID) || \ | |
983 | defined(CONFIG_HAVE_MEMBLOCK_NODE_MAP) | |
984 | /* Only safe to use early in boot when initialisation is single-threaded */ | |
985 | static struct mminit_pfnnid_cache early_pfnnid_cache __meminitdata; | |
986 | ||
987 | int __meminit early_pfn_to_nid(unsigned long pfn) | |
988 | { | |
989 | int nid; | |
990 | ||
991 | /* The system will behave unpredictably otherwise */ | |
992 | BUG_ON(system_state != SYSTEM_BOOTING); | |
993 | ||
994 | nid = __early_pfn_to_nid(pfn, &early_pfnnid_cache); | |
995 | if (nid >= 0) | |
996 | return nid; | |
997 | /* just returns 0 */ | |
998 | return 0; | |
999 | } | |
1000 | #endif | |
1001 | ||
1002 | #ifdef CONFIG_NODES_SPAN_OTHER_NODES | |
1003 | static inline bool __meminit meminit_pfn_in_nid(unsigned long pfn, int node, | |
1004 | struct mminit_pfnnid_cache *state) | |
1005 | { | |
1006 | int nid; | |
1007 | ||
1008 | nid = __early_pfn_to_nid(pfn, state); | |
1009 | if (nid >= 0 && nid != node) | |
1010 | return false; | |
1011 | return true; | |
1012 | } | |
1013 | ||
1014 | /* Only safe to use early in boot when initialisation is single-threaded */ | |
1015 | static inline bool __meminit early_pfn_in_nid(unsigned long pfn, int node) | |
1016 | { | |
1017 | return meminit_pfn_in_nid(pfn, node, &early_pfnnid_cache); | |
1018 | } | |
1019 | ||
1020 | #else | |
1021 | ||
1022 | static inline bool __meminit early_pfn_in_nid(unsigned long pfn, int node) | |
1023 | { | |
1024 | return true; | |
1025 | } | |
1026 | static inline bool __meminit meminit_pfn_in_nid(unsigned long pfn, int node, | |
1027 | struct mminit_pfnnid_cache *state) | |
1028 | { | |
1029 | return true; | |
1030 | } | |
1031 | #endif | |
1032 | ||
1033 | ||
1034 | void __init __free_pages_bootmem(struct page *page, unsigned long pfn, | |
1035 | unsigned int order) | |
1036 | { | |
1037 | if (early_page_uninitialised(pfn)) | |
1038 | return; | |
1039 | return __free_pages_boot_core(page, pfn, order); | |
1040 | } | |
1041 | ||
1042 | #ifdef CONFIG_DEFERRED_STRUCT_PAGE_INIT | |
1043 | static void __init deferred_free_range(struct page *page, | |
1044 | unsigned long pfn, int nr_pages) | |
1045 | { | |
1046 | int i; | |
1047 | ||
1048 | if (!page) | |
1049 | return; | |
1050 | ||
1051 | /* Free a large naturally-aligned chunk if possible */ | |
1052 | if (nr_pages == MAX_ORDER_NR_PAGES && | |
1053 | (pfn & (MAX_ORDER_NR_PAGES-1)) == 0) { | |
1054 | set_pageblock_migratetype(page, MIGRATE_MOVABLE); | |
1055 | __free_pages_boot_core(page, pfn, MAX_ORDER-1); | |
1056 | return; | |
1057 | } | |
1058 | ||
1059 | for (i = 0; i < nr_pages; i++, page++, pfn++) | |
1060 | __free_pages_boot_core(page, pfn, 0); | |
1061 | } | |
1062 | ||
1063 | static __initdata DECLARE_RWSEM(pgdat_init_rwsem); | |
1064 | ||
1065 | /* Initialise remaining memory on a node */ | |
1066 | static int __init deferred_init_memmap(void *data) | |
1067 | { | |
1068 | pg_data_t *pgdat = data; | |
1069 | int nid = pgdat->node_id; | |
1070 | struct mminit_pfnnid_cache nid_init_state = { }; | |
1071 | unsigned long start = jiffies; | |
1072 | unsigned long nr_pages = 0; | |
1073 | unsigned long walk_start, walk_end; | |
1074 | int i, zid; | |
1075 | struct zone *zone; | |
1076 | unsigned long first_init_pfn = pgdat->first_deferred_pfn; | |
1077 | const struct cpumask *cpumask = cpumask_of_node(pgdat->node_id); | |
1078 | ||
1079 | if (first_init_pfn == ULONG_MAX) { | |
1080 | up_read(&pgdat_init_rwsem); | |
1081 | return 0; | |
1082 | } | |
1083 | ||
1084 | /* Bind memory initialisation thread to a local node if possible */ | |
1085 | if (!cpumask_empty(cpumask)) | |
1086 | set_cpus_allowed_ptr(current, cpumask); | |
1087 | ||
1088 | /* Sanity check boundaries */ | |
1089 | BUG_ON(pgdat->first_deferred_pfn < pgdat->node_start_pfn); | |
1090 | BUG_ON(pgdat->first_deferred_pfn > pgdat_end_pfn(pgdat)); | |
1091 | pgdat->first_deferred_pfn = ULONG_MAX; | |
1092 | ||
1093 | /* Only the highest zone is deferred so find it */ | |
1094 | for (zid = 0; zid < MAX_NR_ZONES; zid++) { | |
1095 | zone = pgdat->node_zones + zid; | |
1096 | if (first_init_pfn < zone_end_pfn(zone)) | |
1097 | break; | |
1098 | } | |
1099 | ||
1100 | for_each_mem_pfn_range(i, nid, &walk_start, &walk_end, NULL) { | |
1101 | unsigned long pfn, end_pfn; | |
1102 | struct page *page = NULL; | |
1103 | struct page *free_base_page = NULL; | |
1104 | unsigned long free_base_pfn = 0; | |
1105 | int nr_to_free = 0; | |
1106 | ||
1107 | end_pfn = min(walk_end, zone_end_pfn(zone)); | |
1108 | pfn = first_init_pfn; | |
1109 | if (pfn < walk_start) | |
1110 | pfn = walk_start; | |
1111 | if (pfn < zone->zone_start_pfn) | |
1112 | pfn = zone->zone_start_pfn; | |
1113 | ||
1114 | for (; pfn < end_pfn; pfn++) { | |
1115 | if (!pfn_valid_within(pfn)) | |
1116 | goto free_range; | |
1117 | ||
1118 | /* | |
1119 | * Ensure pfn_valid is checked every | |
1120 | * MAX_ORDER_NR_PAGES for memory holes | |
1121 | */ | |
1122 | if ((pfn & (MAX_ORDER_NR_PAGES - 1)) == 0) { | |
1123 | if (!pfn_valid(pfn)) { | |
1124 | page = NULL; | |
1125 | goto free_range; | |
1126 | } | |
1127 | } | |
1128 | ||
1129 | if (!meminit_pfn_in_nid(pfn, nid, &nid_init_state)) { | |
1130 | page = NULL; | |
1131 | goto free_range; | |
1132 | } | |
1133 | ||
1134 | /* Minimise pfn page lookups and scheduler checks */ | |
1135 | if (page && (pfn & (MAX_ORDER_NR_PAGES - 1)) != 0) { | |
1136 | page++; | |
1137 | } else { | |
1138 | nr_pages += nr_to_free; | |
1139 | deferred_free_range(free_base_page, | |
1140 | free_base_pfn, nr_to_free); | |
1141 | free_base_page = NULL; | |
1142 | free_base_pfn = nr_to_free = 0; | |
1143 | ||
1144 | page = pfn_to_page(pfn); | |
1145 | cond_resched(); | |
1146 | } | |
1147 | ||
1148 | if (page->flags) { | |
1149 | VM_BUG_ON(page_zone(page) != zone); | |
1150 | goto free_range; | |
1151 | } | |
1152 | ||
1153 | __init_single_page(page, pfn, zid, nid); | |
1154 | if (!free_base_page) { | |
1155 | free_base_page = page; | |
1156 | free_base_pfn = pfn; | |
1157 | nr_to_free = 0; | |
1158 | } | |
1159 | nr_to_free++; | |
1160 | ||
1161 | /* Where possible, batch up pages for a single free */ | |
1162 | continue; | |
1163 | free_range: | |
1164 | /* Free the current block of pages to allocator */ | |
1165 | nr_pages += nr_to_free; | |
1166 | deferred_free_range(free_base_page, free_base_pfn, | |
1167 | nr_to_free); | |
1168 | free_base_page = NULL; | |
1169 | free_base_pfn = nr_to_free = 0; | |
1170 | } | |
1171 | ||
1172 | first_init_pfn = max(end_pfn, first_init_pfn); | |
1173 | } | |
1174 | ||
1175 | /* Sanity check that the next zone really is unpopulated */ | |
1176 | WARN_ON(++zid < MAX_NR_ZONES && populated_zone(++zone)); | |
1177 | ||
1178 | pr_info("node %d initialised, %lu pages in %ums\n", nid, nr_pages, | |
1179 | jiffies_to_msecs(jiffies - start)); | |
1180 | up_read(&pgdat_init_rwsem); | |
1181 | return 0; | |
1182 | } | |
1183 | ||
1184 | void __init page_alloc_init_late(void) | |
1185 | { | |
1186 | int nid; | |
1187 | ||
1188 | for_each_node_state(nid, N_MEMORY) { | |
1189 | down_read(&pgdat_init_rwsem); | |
1190 | kthread_run(deferred_init_memmap, NODE_DATA(nid), "pgdatinit%d", nid); | |
1191 | } | |
1192 | ||
1193 | /* Block until all are initialised */ | |
1194 | down_write(&pgdat_init_rwsem); | |
1195 | up_write(&pgdat_init_rwsem); | |
1196 | } | |
1197 | #endif /* CONFIG_DEFERRED_STRUCT_PAGE_INIT */ | |
1198 | ||
1199 | #ifdef CONFIG_CMA | |
1200 | /* Free whole pageblock and set its migration type to MIGRATE_CMA. */ | |
1201 | void __init init_cma_reserved_pageblock(struct page *page) | |
1202 | { | |
1203 | unsigned i = pageblock_nr_pages; | |
1204 | struct page *p = page; | |
1205 | ||
1206 | do { | |
1207 | __ClearPageReserved(p); | |
1208 | set_page_count(p, 0); | |
1209 | } while (++p, --i); | |
1210 | ||
1211 | set_pageblock_migratetype(page, MIGRATE_CMA); | |
1212 | ||
1213 | if (pageblock_order >= MAX_ORDER) { | |
1214 | i = pageblock_nr_pages; | |
1215 | p = page; | |
1216 | do { | |
1217 | set_page_refcounted(p); | |
1218 | __free_pages(p, MAX_ORDER - 1); | |
1219 | p += MAX_ORDER_NR_PAGES; | |
1220 | } while (i -= MAX_ORDER_NR_PAGES); | |
1221 | } else { | |
1222 | set_page_refcounted(page); | |
1223 | __free_pages(page, pageblock_order); | |
1224 | } | |
1225 | ||
1226 | adjust_managed_page_count(page, pageblock_nr_pages); | |
1227 | } | |
1228 | #endif | |
1229 | ||
1230 | /* | |
1231 | * The order of subdivision here is critical for the IO subsystem. | |
1232 | * Please do not alter this order without good reasons and regression | |
1233 | * testing. Specifically, as large blocks of memory are subdivided, | |
1234 | * the order in which smaller blocks are delivered depends on the order | |
1235 | * they're subdivided in this function. This is the primary factor | |
1236 | * influencing the order in which pages are delivered to the IO | |
1237 | * subsystem according to empirical testing, and this is also justified | |
1238 | * by considering the behavior of a buddy system containing a single | |
1239 | * large block of memory acted on by a series of small allocations. | |
1240 | * This behavior is a critical factor in sglist merging's success. | |
1241 | * | |
1242 | * -- nyc | |
1243 | */ | |
1244 | static inline void expand(struct zone *zone, struct page *page, | |
1245 | int low, int high, struct free_area *area, | |
1246 | int migratetype) | |
1247 | { | |
1248 | unsigned long size = 1 << high; | |
1249 | ||
1250 | while (high > low) { | |
1251 | area--; | |
1252 | high--; | |
1253 | size >>= 1; | |
1254 | VM_BUG_ON_PAGE(bad_range(zone, &page[size]), &page[size]); | |
1255 | ||
1256 | if (IS_ENABLED(CONFIG_DEBUG_PAGEALLOC) && | |
1257 | debug_guardpage_enabled() && | |
1258 | high < debug_guardpage_minorder()) { | |
1259 | /* | |
1260 | * Mark as guard pages (or page), that will allow to | |
1261 | * merge back to allocator when buddy will be freed. | |
1262 | * Corresponding page table entries will not be touched, | |
1263 | * pages will stay not present in virtual address space | |
1264 | */ | |
1265 | set_page_guard(zone, &page[size], high, migratetype); | |
1266 | continue; | |
1267 | } | |
1268 | list_add(&page[size].lru, &area->free_list[migratetype]); | |
1269 | area->nr_free++; | |
1270 | set_page_order(&page[size], high); | |
1271 | } | |
1272 | } | |
1273 | ||
1274 | /* | |
1275 | * This page is about to be returned from the page allocator | |
1276 | */ | |
1277 | static inline int check_new_page(struct page *page) | |
1278 | { | |
1279 | const char *bad_reason = NULL; | |
1280 | unsigned long bad_flags = 0; | |
1281 | ||
1282 | if (unlikely(page_mapcount(page))) | |
1283 | bad_reason = "nonzero mapcount"; | |
1284 | if (unlikely(page->mapping != NULL)) | |
1285 | bad_reason = "non-NULL mapping"; | |
1286 | if (unlikely(atomic_read(&page->_count) != 0)) | |
1287 | bad_reason = "nonzero _count"; | |
1288 | if (unlikely(page->flags & PAGE_FLAGS_CHECK_AT_PREP)) { | |
1289 | bad_reason = "PAGE_FLAGS_CHECK_AT_PREP flag set"; | |
1290 | bad_flags = PAGE_FLAGS_CHECK_AT_PREP; | |
1291 | } | |
1292 | #ifdef CONFIG_MEMCG | |
1293 | if (unlikely(page->mem_cgroup)) | |
1294 | bad_reason = "page still charged to cgroup"; | |
1295 | #endif | |
1296 | if (unlikely(bad_reason)) { | |
1297 | bad_page(page, bad_reason, bad_flags); | |
1298 | return 1; | |
1299 | } | |
1300 | return 0; | |
1301 | } | |
1302 | ||
1303 | static int prep_new_page(struct page *page, unsigned int order, gfp_t gfp_flags, | |
1304 | int alloc_flags) | |
1305 | { | |
1306 | int i; | |
1307 | ||
1308 | for (i = 0; i < (1 << order); i++) { | |
1309 | struct page *p = page + i; | |
1310 | if (unlikely(check_new_page(p))) | |
1311 | return 1; | |
1312 | } | |
1313 | ||
1314 | set_page_private(page, 0); | |
1315 | set_page_refcounted(page); | |
1316 | ||
1317 | arch_alloc_page(page, order); | |
1318 | kernel_map_pages(page, 1 << order, 1); | |
1319 | kasan_alloc_pages(page, order); | |
1320 | ||
1321 | if (gfp_flags & __GFP_ZERO) | |
1322 | for (i = 0; i < (1 << order); i++) | |
1323 | clear_highpage(page + i); | |
1324 | ||
1325 | if (order && (gfp_flags & __GFP_COMP)) | |
1326 | prep_compound_page(page, order); | |
1327 | ||
1328 | set_page_owner(page, order, gfp_flags); | |
1329 | ||
1330 | /* | |
1331 | * page->pfmemalloc is set when ALLOC_NO_WATERMARKS was necessary to | |
1332 | * allocate the page. The expectation is that the caller is taking | |
1333 | * steps that will free more memory. The caller should avoid the page | |
1334 | * being used for !PFMEMALLOC purposes. | |
1335 | */ | |
1336 | page->pfmemalloc = !!(alloc_flags & ALLOC_NO_WATERMARKS); | |
1337 | ||
1338 | return 0; | |
1339 | } | |
1340 | ||
1341 | /* | |
1342 | * Go through the free lists for the given migratetype and remove | |
1343 | * the smallest available page from the freelists | |
1344 | */ | |
1345 | static inline | |
1346 | struct page *__rmqueue_smallest(struct zone *zone, unsigned int order, | |
1347 | int migratetype) | |
1348 | { | |
1349 | unsigned int current_order; | |
1350 | struct free_area *area; | |
1351 | struct page *page; | |
1352 | ||
1353 | /* Find a page of the appropriate size in the preferred list */ | |
1354 | for (current_order = order; current_order < MAX_ORDER; ++current_order) { | |
1355 | area = &(zone->free_area[current_order]); | |
1356 | if (list_empty(&area->free_list[migratetype])) | |
1357 | continue; | |
1358 | ||
1359 | page = list_entry(area->free_list[migratetype].next, | |
1360 | struct page, lru); | |
1361 | list_del(&page->lru); | |
1362 | rmv_page_order(page); | |
1363 | area->nr_free--; | |
1364 | expand(zone, page, order, current_order, area, migratetype); | |
1365 | set_freepage_migratetype(page, migratetype); | |
1366 | return page; | |
1367 | } | |
1368 | ||
1369 | return NULL; | |
1370 | } | |
1371 | ||
1372 | ||
1373 | /* | |
1374 | * This array describes the order lists are fallen back to when | |
1375 | * the free lists for the desirable migrate type are depleted | |
1376 | */ | |
1377 | static int fallbacks[MIGRATE_TYPES][4] = { | |
1378 | [MIGRATE_UNMOVABLE] = { MIGRATE_RECLAIMABLE, MIGRATE_MOVABLE, MIGRATE_RESERVE }, | |
1379 | [MIGRATE_RECLAIMABLE] = { MIGRATE_UNMOVABLE, MIGRATE_MOVABLE, MIGRATE_RESERVE }, | |
1380 | [MIGRATE_MOVABLE] = { MIGRATE_RECLAIMABLE, MIGRATE_UNMOVABLE, MIGRATE_RESERVE }, | |
1381 | #ifdef CONFIG_CMA | |
1382 | [MIGRATE_CMA] = { MIGRATE_RESERVE }, /* Never used */ | |
1383 | #endif | |
1384 | [MIGRATE_RESERVE] = { MIGRATE_RESERVE }, /* Never used */ | |
1385 | #ifdef CONFIG_MEMORY_ISOLATION | |
1386 | [MIGRATE_ISOLATE] = { MIGRATE_RESERVE }, /* Never used */ | |
1387 | #endif | |
1388 | }; | |
1389 | ||
1390 | #ifdef CONFIG_CMA | |
1391 | static struct page *__rmqueue_cma_fallback(struct zone *zone, | |
1392 | unsigned int order) | |
1393 | { | |
1394 | return __rmqueue_smallest(zone, order, MIGRATE_CMA); | |
1395 | } | |
1396 | #else | |
1397 | static inline struct page *__rmqueue_cma_fallback(struct zone *zone, | |
1398 | unsigned int order) { return NULL; } | |
1399 | #endif | |
1400 | ||
1401 | /* | |
1402 | * Move the free pages in a range to the free lists of the requested type. | |
1403 | * Note that start_page and end_pages are not aligned on a pageblock | |
1404 | * boundary. If alignment is required, use move_freepages_block() | |
1405 | */ | |
1406 | int move_freepages(struct zone *zone, | |
1407 | struct page *start_page, struct page *end_page, | |
1408 | int migratetype) | |
1409 | { | |
1410 | struct page *page; | |
1411 | unsigned long order; | |
1412 | int pages_moved = 0; | |
1413 | ||
1414 | #ifndef CONFIG_HOLES_IN_ZONE | |
1415 | /* | |
1416 | * page_zone is not safe to call in this context when | |
1417 | * CONFIG_HOLES_IN_ZONE is set. This bug check is probably redundant | |
1418 | * anyway as we check zone boundaries in move_freepages_block(). | |
1419 | * Remove at a later date when no bug reports exist related to | |
1420 | * grouping pages by mobility | |
1421 | */ | |
1422 | VM_BUG_ON(page_zone(start_page) != page_zone(end_page)); | |
1423 | #endif | |
1424 | ||
1425 | for (page = start_page; page <= end_page;) { | |
1426 | /* Make sure we are not inadvertently changing nodes */ | |
1427 | VM_BUG_ON_PAGE(page_to_nid(page) != zone_to_nid(zone), page); | |
1428 | ||
1429 | if (!pfn_valid_within(page_to_pfn(page))) { | |
1430 | page++; | |
1431 | continue; | |
1432 | } | |
1433 | ||
1434 | if (!PageBuddy(page)) { | |
1435 | page++; | |
1436 | continue; | |
1437 | } | |
1438 | ||
1439 | order = page_order(page); | |
1440 | list_move(&page->lru, | |
1441 | &zone->free_area[order].free_list[migratetype]); | |
1442 | set_freepage_migratetype(page, migratetype); | |
1443 | page += 1 << order; | |
1444 | pages_moved += 1 << order; | |
1445 | } | |
1446 | ||
1447 | return pages_moved; | |
1448 | } | |
1449 | ||
1450 | int move_freepages_block(struct zone *zone, struct page *page, | |
1451 | int migratetype) | |
1452 | { | |
1453 | unsigned long start_pfn, end_pfn; | |
1454 | struct page *start_page, *end_page; | |
1455 | ||
1456 | start_pfn = page_to_pfn(page); | |
1457 | start_pfn = start_pfn & ~(pageblock_nr_pages-1); | |
1458 | start_page = pfn_to_page(start_pfn); | |
1459 | end_page = start_page + pageblock_nr_pages - 1; | |
1460 | end_pfn = start_pfn + pageblock_nr_pages - 1; | |
1461 | ||
1462 | /* Do not cross zone boundaries */ | |
1463 | if (!zone_spans_pfn(zone, start_pfn)) | |
1464 | start_page = page; | |
1465 | if (!zone_spans_pfn(zone, end_pfn)) | |
1466 | return 0; | |
1467 | ||
1468 | return move_freepages(zone, start_page, end_page, migratetype); | |
1469 | } | |
1470 | ||
1471 | static void change_pageblock_range(struct page *pageblock_page, | |
1472 | int start_order, int migratetype) | |
1473 | { | |
1474 | int nr_pageblocks = 1 << (start_order - pageblock_order); | |
1475 | ||
1476 | while (nr_pageblocks--) { | |
1477 | set_pageblock_migratetype(pageblock_page, migratetype); | |
1478 | pageblock_page += pageblock_nr_pages; | |
1479 | } | |
1480 | } | |
1481 | ||
1482 | /* | |
1483 | * When we are falling back to another migratetype during allocation, try to | |
1484 | * steal extra free pages from the same pageblocks to satisfy further | |
1485 | * allocations, instead of polluting multiple pageblocks. | |
1486 | * | |
1487 | * If we are stealing a relatively large buddy page, it is likely there will | |
1488 | * be more free pages in the pageblock, so try to steal them all. For | |
1489 | * reclaimable and unmovable allocations, we steal regardless of page size, | |
1490 | * as fragmentation caused by those allocations polluting movable pageblocks | |
1491 | * is worse than movable allocations stealing from unmovable and reclaimable | |
1492 | * pageblocks. | |
1493 | */ | |
1494 | static bool can_steal_fallback(unsigned int order, int start_mt) | |
1495 | { | |
1496 | /* | |
1497 | * Leaving this order check is intended, although there is | |
1498 | * relaxed order check in next check. The reason is that | |
1499 | * we can actually steal whole pageblock if this condition met, | |
1500 | * but, below check doesn't guarantee it and that is just heuristic | |
1501 | * so could be changed anytime. | |
1502 | */ | |
1503 | if (order >= pageblock_order) | |
1504 | return true; | |
1505 | ||
1506 | if (order >= pageblock_order / 2 || | |
1507 | start_mt == MIGRATE_RECLAIMABLE || | |
1508 | start_mt == MIGRATE_UNMOVABLE || | |
1509 | page_group_by_mobility_disabled) | |
1510 | return true; | |
1511 | ||
1512 | return false; | |
1513 | } | |
1514 | ||
1515 | /* | |
1516 | * This function implements actual steal behaviour. If order is large enough, | |
1517 | * we can steal whole pageblock. If not, we first move freepages in this | |
1518 | * pageblock and check whether half of pages are moved or not. If half of | |
1519 | * pages are moved, we can change migratetype of pageblock and permanently | |
1520 | * use it's pages as requested migratetype in the future. | |
1521 | */ | |
1522 | static void steal_suitable_fallback(struct zone *zone, struct page *page, | |
1523 | int start_type) | |
1524 | { | |
1525 | int current_order = page_order(page); | |
1526 | int pages; | |
1527 | ||
1528 | /* Take ownership for orders >= pageblock_order */ | |
1529 | if (current_order >= pageblock_order) { | |
1530 | change_pageblock_range(page, current_order, start_type); | |
1531 | return; | |
1532 | } | |
1533 | ||
1534 | pages = move_freepages_block(zone, page, start_type); | |
1535 | ||
1536 | /* Claim the whole block if over half of it is free */ | |
1537 | if (pages >= (1 << (pageblock_order-1)) || | |
1538 | page_group_by_mobility_disabled) | |
1539 | set_pageblock_migratetype(page, start_type); | |
1540 | } | |
1541 | ||
1542 | /* | |
1543 | * Check whether there is a suitable fallback freepage with requested order. | |
1544 | * If only_stealable is true, this function returns fallback_mt only if | |
1545 | * we can steal other freepages all together. This would help to reduce | |
1546 | * fragmentation due to mixed migratetype pages in one pageblock. | |
1547 | */ | |
1548 | int find_suitable_fallback(struct free_area *area, unsigned int order, | |
1549 | int migratetype, bool only_stealable, bool *can_steal) | |
1550 | { | |
1551 | int i; | |
1552 | int fallback_mt; | |
1553 | ||
1554 | if (area->nr_free == 0) | |
1555 | return -1; | |
1556 | ||
1557 | *can_steal = false; | |
1558 | for (i = 0;; i++) { | |
1559 | fallback_mt = fallbacks[migratetype][i]; | |
1560 | if (fallback_mt == MIGRATE_RESERVE) | |
1561 | break; | |
1562 | ||
1563 | if (list_empty(&area->free_list[fallback_mt])) | |
1564 | continue; | |
1565 | ||
1566 | if (can_steal_fallback(order, migratetype)) | |
1567 | *can_steal = true; | |
1568 | ||
1569 | if (!only_stealable) | |
1570 | return fallback_mt; | |
1571 | ||
1572 | if (*can_steal) | |
1573 | return fallback_mt; | |
1574 | } | |
1575 | ||
1576 | return -1; | |
1577 | } | |
1578 | ||
1579 | /* Remove an element from the buddy allocator from the fallback list */ | |
1580 | static inline struct page * | |
1581 | __rmqueue_fallback(struct zone *zone, unsigned int order, int start_migratetype) | |
1582 | { | |
1583 | struct free_area *area; | |
1584 | unsigned int current_order; | |
1585 | struct page *page; | |
1586 | int fallback_mt; | |
1587 | bool can_steal; | |
1588 | ||
1589 | /* Find the largest possible block of pages in the other list */ | |
1590 | for (current_order = MAX_ORDER-1; | |
1591 | current_order >= order && current_order <= MAX_ORDER-1; | |
1592 | --current_order) { | |
1593 | area = &(zone->free_area[current_order]); | |
1594 | fallback_mt = find_suitable_fallback(area, current_order, | |
1595 | start_migratetype, false, &can_steal); | |
1596 | if (fallback_mt == -1) | |
1597 | continue; | |
1598 | ||
1599 | page = list_entry(area->free_list[fallback_mt].next, | |
1600 | struct page, lru); | |
1601 | if (can_steal) | |
1602 | steal_suitable_fallback(zone, page, start_migratetype); | |
1603 | ||
1604 | /* Remove the page from the freelists */ | |
1605 | area->nr_free--; | |
1606 | list_del(&page->lru); | |
1607 | rmv_page_order(page); | |
1608 | ||
1609 | expand(zone, page, order, current_order, area, | |
1610 | start_migratetype); | |
1611 | /* | |
1612 | * The freepage_migratetype may differ from pageblock's | |
1613 | * migratetype depending on the decisions in | |
1614 | * try_to_steal_freepages(). This is OK as long as it | |
1615 | * does not differ for MIGRATE_CMA pageblocks. For CMA | |
1616 | * we need to make sure unallocated pages flushed from | |
1617 | * pcp lists are returned to the correct freelist. | |
1618 | */ | |
1619 | set_freepage_migratetype(page, start_migratetype); | |
1620 | ||
1621 | trace_mm_page_alloc_extfrag(page, order, current_order, | |
1622 | start_migratetype, fallback_mt); | |
1623 | ||
1624 | return page; | |
1625 | } | |
1626 | ||
1627 | return NULL; | |
1628 | } | |
1629 | ||
1630 | /* | |
1631 | * Do the hard work of removing an element from the buddy allocator. | |
1632 | * Call me with the zone->lock already held. | |
1633 | */ | |
1634 | static struct page *__rmqueue(struct zone *zone, unsigned int order, | |
1635 | int migratetype) | |
1636 | { | |
1637 | struct page *page; | |
1638 | ||
1639 | retry_reserve: | |
1640 | page = __rmqueue_smallest(zone, order, migratetype); | |
1641 | ||
1642 | if (unlikely(!page) && migratetype != MIGRATE_RESERVE) { | |
1643 | if (migratetype == MIGRATE_MOVABLE) | |
1644 | page = __rmqueue_cma_fallback(zone, order); | |
1645 | ||
1646 | if (!page) | |
1647 | page = __rmqueue_fallback(zone, order, migratetype); | |
1648 | ||
1649 | /* | |
1650 | * Use MIGRATE_RESERVE rather than fail an allocation. goto | |
1651 | * is used because __rmqueue_smallest is an inline function | |
1652 | * and we want just one call site | |
1653 | */ | |
1654 | if (!page) { | |
1655 | migratetype = MIGRATE_RESERVE; | |
1656 | goto retry_reserve; | |
1657 | } | |
1658 | } | |
1659 | ||
1660 | trace_mm_page_alloc_zone_locked(page, order, migratetype); | |
1661 | return page; | |
1662 | } | |
1663 | ||
1664 | /* | |
1665 | * Obtain a specified number of elements from the buddy allocator, all under | |
1666 | * a single hold of the lock, for efficiency. Add them to the supplied list. | |
1667 | * Returns the number of new pages which were placed at *list. | |
1668 | */ | |
1669 | static int rmqueue_bulk(struct zone *zone, unsigned int order, | |
1670 | unsigned long count, struct list_head *list, | |
1671 | int migratetype, bool cold) | |
1672 | { | |
1673 | int i; | |
1674 | ||
1675 | spin_lock(&zone->lock); | |
1676 | for (i = 0; i < count; ++i) { | |
1677 | struct page *page = __rmqueue(zone, order, migratetype); | |
1678 | if (unlikely(page == NULL)) | |
1679 | break; | |
1680 | ||
1681 | /* | |
1682 | * Split buddy pages returned by expand() are received here | |
1683 | * in physical page order. The page is added to the callers and | |
1684 | * list and the list head then moves forward. From the callers | |
1685 | * perspective, the linked list is ordered by page number in | |
1686 | * some conditions. This is useful for IO devices that can | |
1687 | * merge IO requests if the physical pages are ordered | |
1688 | * properly. | |
1689 | */ | |
1690 | if (likely(!cold)) | |
1691 | list_add(&page->lru, list); | |
1692 | else | |
1693 | list_add_tail(&page->lru, list); | |
1694 | list = &page->lru; | |
1695 | if (is_migrate_cma(get_freepage_migratetype(page))) | |
1696 | __mod_zone_page_state(zone, NR_FREE_CMA_PAGES, | |
1697 | -(1 << order)); | |
1698 | } | |
1699 | __mod_zone_page_state(zone, NR_FREE_PAGES, -(i << order)); | |
1700 | spin_unlock(&zone->lock); | |
1701 | return i; | |
1702 | } | |
1703 | ||
1704 | #ifdef CONFIG_NUMA | |
1705 | /* | |
1706 | * Called from the vmstat counter updater to drain pagesets of this | |
1707 | * currently executing processor on remote nodes after they have | |
1708 | * expired. | |
1709 | * | |
1710 | * Note that this function must be called with the thread pinned to | |
1711 | * a single processor. | |
1712 | */ | |
1713 | void drain_zone_pages(struct zone *zone, struct per_cpu_pages *pcp) | |
1714 | { | |
1715 | unsigned long flags; | |
1716 | int to_drain, batch; | |
1717 | ||
1718 | local_irq_save(flags); | |
1719 | batch = READ_ONCE(pcp->batch); | |
1720 | to_drain = min(pcp->count, batch); | |
1721 | if (to_drain > 0) { | |
1722 | free_pcppages_bulk(zone, to_drain, pcp); | |
1723 | pcp->count -= to_drain; | |
1724 | } | |
1725 | local_irq_restore(flags); | |
1726 | } | |
1727 | #endif | |
1728 | ||
1729 | /* | |
1730 | * Drain pcplists of the indicated processor and zone. | |
1731 | * | |
1732 | * The processor must either be the current processor and the | |
1733 | * thread pinned to the current processor or a processor that | |
1734 | * is not online. | |
1735 | */ | |
1736 | static void drain_pages_zone(unsigned int cpu, struct zone *zone) | |
1737 | { | |
1738 | unsigned long flags; | |
1739 | struct per_cpu_pageset *pset; | |
1740 | struct per_cpu_pages *pcp; | |
1741 | ||
1742 | local_irq_save(flags); | |
1743 | pset = per_cpu_ptr(zone->pageset, cpu); | |
1744 | ||
1745 | pcp = &pset->pcp; | |
1746 | if (pcp->count) { | |
1747 | free_pcppages_bulk(zone, pcp->count, pcp); | |
1748 | pcp->count = 0; | |
1749 | } | |
1750 | local_irq_restore(flags); | |
1751 | } | |
1752 | ||
1753 | /* | |
1754 | * Drain pcplists of all zones on the indicated processor. | |
1755 | * | |
1756 | * The processor must either be the current processor and the | |
1757 | * thread pinned to the current processor or a processor that | |
1758 | * is not online. | |
1759 | */ | |
1760 | static void drain_pages(unsigned int cpu) | |
1761 | { | |
1762 | struct zone *zone; | |
1763 | ||
1764 | for_each_populated_zone(zone) { | |
1765 | drain_pages_zone(cpu, zone); | |
1766 | } | |
1767 | } | |
1768 | ||
1769 | /* | |
1770 | * Spill all of this CPU's per-cpu pages back into the buddy allocator. | |
1771 | * | |
1772 | * The CPU has to be pinned. When zone parameter is non-NULL, spill just | |
1773 | * the single zone's pages. | |
1774 | */ | |
1775 | void drain_local_pages(struct zone *zone) | |
1776 | { | |
1777 | int cpu = smp_processor_id(); | |
1778 | ||
1779 | if (zone) | |
1780 | drain_pages_zone(cpu, zone); | |
1781 | else | |
1782 | drain_pages(cpu); | |
1783 | } | |
1784 | ||
1785 | /* | |
1786 | * Spill all the per-cpu pages from all CPUs back into the buddy allocator. | |
1787 | * | |
1788 | * When zone parameter is non-NULL, spill just the single zone's pages. | |
1789 | * | |
1790 | * Note that this code is protected against sending an IPI to an offline | |
1791 | * CPU but does not guarantee sending an IPI to newly hotplugged CPUs: | |
1792 | * on_each_cpu_mask() blocks hotplug and won't talk to offlined CPUs but | |
1793 | * nothing keeps CPUs from showing up after we populated the cpumask and | |
1794 | * before the call to on_each_cpu_mask(). | |
1795 | */ | |
1796 | void drain_all_pages(struct zone *zone) | |
1797 | { | |
1798 | int cpu; | |
1799 | ||
1800 | /* | |
1801 | * Allocate in the BSS so we wont require allocation in | |
1802 | * direct reclaim path for CONFIG_CPUMASK_OFFSTACK=y | |
1803 | */ | |
1804 | static cpumask_t cpus_with_pcps; | |
1805 | ||
1806 | /* | |
1807 | * We don't care about racing with CPU hotplug event | |
1808 | * as offline notification will cause the notified | |
1809 | * cpu to drain that CPU pcps and on_each_cpu_mask | |
1810 | * disables preemption as part of its processing | |
1811 | */ | |
1812 | for_each_online_cpu(cpu) { | |
1813 | struct per_cpu_pageset *pcp; | |
1814 | struct zone *z; | |
1815 | bool has_pcps = false; | |
1816 | ||
1817 | if (zone) { | |
1818 | pcp = per_cpu_ptr(zone->pageset, cpu); | |
1819 | if (pcp->pcp.count) | |
1820 | has_pcps = true; | |
1821 | } else { | |
1822 | for_each_populated_zone(z) { | |
1823 | pcp = per_cpu_ptr(z->pageset, cpu); | |
1824 | if (pcp->pcp.count) { | |
1825 | has_pcps = true; | |
1826 | break; | |
1827 | } | |
1828 | } | |
1829 | } | |
1830 | ||
1831 | if (has_pcps) | |
1832 | cpumask_set_cpu(cpu, &cpus_with_pcps); | |
1833 | else | |
1834 | cpumask_clear_cpu(cpu, &cpus_with_pcps); | |
1835 | } | |
1836 | on_each_cpu_mask(&cpus_with_pcps, (smp_call_func_t) drain_local_pages, | |
1837 | zone, 1); | |
1838 | } | |
1839 | ||
1840 | #ifdef CONFIG_HIBERNATION | |
1841 | ||
1842 | void mark_free_pages(struct zone *zone) | |
1843 | { | |
1844 | unsigned long pfn, max_zone_pfn; | |
1845 | unsigned long flags; | |
1846 | unsigned int order, t; | |
1847 | struct list_head *curr; | |
1848 | ||
1849 | if (zone_is_empty(zone)) | |
1850 | return; | |
1851 | ||
1852 | spin_lock_irqsave(&zone->lock, flags); | |
1853 | ||
1854 | max_zone_pfn = zone_end_pfn(zone); | |
1855 | for (pfn = zone->zone_start_pfn; pfn < max_zone_pfn; pfn++) | |
1856 | if (pfn_valid(pfn)) { | |
1857 | struct page *page = pfn_to_page(pfn); | |
1858 | ||
1859 | if (!swsusp_page_is_forbidden(page)) | |
1860 | swsusp_unset_page_free(page); | |
1861 | } | |
1862 | ||
1863 | for_each_migratetype_order(order, t) { | |
1864 | list_for_each(curr, &zone->free_area[order].free_list[t]) { | |
1865 | unsigned long i; | |
1866 | ||
1867 | pfn = page_to_pfn(list_entry(curr, struct page, lru)); | |
1868 | for (i = 0; i < (1UL << order); i++) | |
1869 | swsusp_set_page_free(pfn_to_page(pfn + i)); | |
1870 | } | |
1871 | } | |
1872 | spin_unlock_irqrestore(&zone->lock, flags); | |
1873 | } | |
1874 | #endif /* CONFIG_PM */ | |
1875 | ||
1876 | /* | |
1877 | * Free a 0-order page | |
1878 | * cold == true ? free a cold page : free a hot page | |
1879 | */ | |
1880 | void free_hot_cold_page(struct page *page, bool cold) | |
1881 | { | |
1882 | struct zone *zone = page_zone(page); | |
1883 | struct per_cpu_pages *pcp; | |
1884 | unsigned long flags; | |
1885 | unsigned long pfn = page_to_pfn(page); | |
1886 | int migratetype; | |
1887 | ||
1888 | if (!free_pages_prepare(page, 0)) | |
1889 | return; | |
1890 | ||
1891 | migratetype = get_pfnblock_migratetype(page, pfn); | |
1892 | set_freepage_migratetype(page, migratetype); | |
1893 | local_irq_save(flags); | |
1894 | __count_vm_event(PGFREE); | |
1895 | ||
1896 | /* | |
1897 | * We only track unmovable, reclaimable and movable on pcp lists. | |
1898 | * Free ISOLATE pages back to the allocator because they are being | |
1899 | * offlined but treat RESERVE as movable pages so we can get those | |
1900 | * areas back if necessary. Otherwise, we may have to free | |
1901 | * excessively into the page allocator | |
1902 | */ | |
1903 | if (migratetype >= MIGRATE_PCPTYPES) { | |
1904 | if (unlikely(is_migrate_isolate(migratetype))) { | |
1905 | free_one_page(zone, page, pfn, 0, migratetype); | |
1906 | goto out; | |
1907 | } | |
1908 | migratetype = MIGRATE_MOVABLE; | |
1909 | } | |
1910 | ||
1911 | pcp = &this_cpu_ptr(zone->pageset)->pcp; | |
1912 | if (!cold) | |
1913 | list_add(&page->lru, &pcp->lists[migratetype]); | |
1914 | else | |
1915 | list_add_tail(&page->lru, &pcp->lists[migratetype]); | |
1916 | pcp->count++; | |
1917 | if (pcp->count >= pcp->high) { | |
1918 | unsigned long batch = READ_ONCE(pcp->batch); | |
1919 | free_pcppages_bulk(zone, batch, pcp); | |
1920 | pcp->count -= batch; | |
1921 | } | |
1922 | ||
1923 | out: | |
1924 | local_irq_restore(flags); | |
1925 | } | |
1926 | ||
1927 | /* | |
1928 | * Free a list of 0-order pages | |
1929 | */ | |
1930 | void free_hot_cold_page_list(struct list_head *list, bool cold) | |
1931 | { | |
1932 | struct page *page, *next; | |
1933 | ||
1934 | list_for_each_entry_safe(page, next, list, lru) { | |
1935 | trace_mm_page_free_batched(page, cold); | |
1936 | free_hot_cold_page(page, cold); | |
1937 | } | |
1938 | } | |
1939 | ||
1940 | /* | |
1941 | * split_page takes a non-compound higher-order page, and splits it into | |
1942 | * n (1<<order) sub-pages: page[0..n] | |
1943 | * Each sub-page must be freed individually. | |
1944 | * | |
1945 | * Note: this is probably too low level an operation for use in drivers. | |
1946 | * Please consult with lkml before using this in your driver. | |
1947 | */ | |
1948 | void split_page(struct page *page, unsigned int order) | |
1949 | { | |
1950 | int i; | |
1951 | ||
1952 | VM_BUG_ON_PAGE(PageCompound(page), page); | |
1953 | VM_BUG_ON_PAGE(!page_count(page), page); | |
1954 | ||
1955 | #ifdef CONFIG_KMEMCHECK | |
1956 | /* | |
1957 | * Split shadow pages too, because free(page[0]) would | |
1958 | * otherwise free the whole shadow. | |
1959 | */ | |
1960 | if (kmemcheck_page_is_tracked(page)) | |
1961 | split_page(virt_to_page(page[0].shadow), order); | |
1962 | #endif | |
1963 | ||
1964 | set_page_owner(page, 0, 0); | |
1965 | for (i = 1; i < (1 << order); i++) { | |
1966 | set_page_refcounted(page + i); | |
1967 | set_page_owner(page + i, 0, 0); | |
1968 | } | |
1969 | } | |
1970 | EXPORT_SYMBOL_GPL(split_page); | |
1971 | ||
1972 | int __isolate_free_page(struct page *page, unsigned int order) | |
1973 | { | |
1974 | unsigned long watermark; | |
1975 | struct zone *zone; | |
1976 | int mt; | |
1977 | ||
1978 | BUG_ON(!PageBuddy(page)); | |
1979 | ||
1980 | zone = page_zone(page); | |
1981 | mt = get_pageblock_migratetype(page); | |
1982 | ||
1983 | if (!is_migrate_isolate(mt)) { | |
1984 | /* Obey watermarks as if the page was being allocated */ | |
1985 | watermark = low_wmark_pages(zone) + (1 << order); | |
1986 | if (!zone_watermark_ok(zone, 0, watermark, 0, 0)) | |
1987 | return 0; | |
1988 | ||
1989 | __mod_zone_freepage_state(zone, -(1UL << order), mt); | |
1990 | } | |
1991 | ||
1992 | /* Remove page from free list */ | |
1993 | list_del(&page->lru); | |
1994 | zone->free_area[order].nr_free--; | |
1995 | rmv_page_order(page); | |
1996 | ||
1997 | /* Set the pageblock if the isolated page is at least a pageblock */ | |
1998 | if (order >= pageblock_order - 1) { | |
1999 | struct page *endpage = page + (1 << order) - 1; | |
2000 | for (; page < endpage; page += pageblock_nr_pages) { | |
2001 | int mt = get_pageblock_migratetype(page); | |
2002 | if (!is_migrate_isolate(mt) && !is_migrate_cma(mt)) | |
2003 | set_pageblock_migratetype(page, | |
2004 | MIGRATE_MOVABLE); | |
2005 | } | |
2006 | } | |
2007 | ||
2008 | set_page_owner(page, order, 0); | |
2009 | return 1UL << order; | |
2010 | } | |
2011 | ||
2012 | /* | |
2013 | * Similar to split_page except the page is already free. As this is only | |
2014 | * being used for migration, the migratetype of the block also changes. | |
2015 | * As this is called with interrupts disabled, the caller is responsible | |
2016 | * for calling arch_alloc_page() and kernel_map_page() after interrupts | |
2017 | * are enabled. | |
2018 | * | |
2019 | * Note: this is probably too low level an operation for use in drivers. | |
2020 | * Please consult with lkml before using this in your driver. | |
2021 | */ | |
2022 | int split_free_page(struct page *page) | |
2023 | { | |
2024 | unsigned int order; | |
2025 | int nr_pages; | |
2026 | ||
2027 | order = page_order(page); | |
2028 | ||
2029 | nr_pages = __isolate_free_page(page, order); | |
2030 | if (!nr_pages) | |
2031 | return 0; | |
2032 | ||
2033 | /* Split into individual pages */ | |
2034 | set_page_refcounted(page); | |
2035 | split_page(page, order); | |
2036 | return nr_pages; | |
2037 | } | |
2038 | ||
2039 | /* | |
2040 | * Allocate a page from the given zone. Use pcplists for order-0 allocations. | |
2041 | */ | |
2042 | static inline | |
2043 | struct page *buffered_rmqueue(struct zone *preferred_zone, | |
2044 | struct zone *zone, unsigned int order, | |
2045 | gfp_t gfp_flags, int migratetype) | |
2046 | { | |
2047 | unsigned long flags; | |
2048 | struct page *page; | |
2049 | bool cold = ((gfp_flags & __GFP_COLD) != 0); | |
2050 | ||
2051 | if (likely(order == 0)) { | |
2052 | struct per_cpu_pages *pcp; | |
2053 | struct list_head *list; | |
2054 | ||
2055 | local_irq_save(flags); | |
2056 | pcp = &this_cpu_ptr(zone->pageset)->pcp; | |
2057 | list = &pcp->lists[migratetype]; | |
2058 | if (list_empty(list)) { | |
2059 | pcp->count += rmqueue_bulk(zone, 0, | |
2060 | pcp->batch, list, | |
2061 | migratetype, cold); | |
2062 | if (unlikely(list_empty(list))) | |
2063 | goto failed; | |
2064 | } | |
2065 | ||
2066 | if (cold) | |
2067 | page = list_entry(list->prev, struct page, lru); | |
2068 | else | |
2069 | page = list_entry(list->next, struct page, lru); | |
2070 | ||
2071 | list_del(&page->lru); | |
2072 | pcp->count--; | |
2073 | } else { | |
2074 | if (unlikely(gfp_flags & __GFP_NOFAIL)) { | |
2075 | /* | |
2076 | * __GFP_NOFAIL is not to be used in new code. | |
2077 | * | |
2078 | * All __GFP_NOFAIL callers should be fixed so that they | |
2079 | * properly detect and handle allocation failures. | |
2080 | * | |
2081 | * We most definitely don't want callers attempting to | |
2082 | * allocate greater than order-1 page units with | |
2083 | * __GFP_NOFAIL. | |
2084 | */ | |
2085 | WARN_ON_ONCE(order > 1); | |
2086 | } | |
2087 | spin_lock_irqsave(&zone->lock, flags); | |
2088 | page = __rmqueue(zone, order, migratetype); | |
2089 | spin_unlock(&zone->lock); | |
2090 | if (!page) | |
2091 | goto failed; | |
2092 | __mod_zone_freepage_state(zone, -(1 << order), | |
2093 | get_freepage_migratetype(page)); | |
2094 | } | |
2095 | ||
2096 | __mod_zone_page_state(zone, NR_ALLOC_BATCH, -(1 << order)); | |
2097 | if (atomic_long_read(&zone->vm_stat[NR_ALLOC_BATCH]) <= 0 && | |
2098 | !test_bit(ZONE_FAIR_DEPLETED, &zone->flags)) | |
2099 | set_bit(ZONE_FAIR_DEPLETED, &zone->flags); | |
2100 | ||
2101 | __count_zone_vm_events(PGALLOC, zone, 1 << order); | |
2102 | zone_statistics(preferred_zone, zone, gfp_flags); | |
2103 | local_irq_restore(flags); | |
2104 | ||
2105 | VM_BUG_ON_PAGE(bad_range(zone, page), page); | |
2106 | return page; | |
2107 | ||
2108 | failed: | |
2109 | local_irq_restore(flags); | |
2110 | return NULL; | |
2111 | } | |
2112 | ||
2113 | #ifdef CONFIG_FAIL_PAGE_ALLOC | |
2114 | ||
2115 | static struct { | |
2116 | struct fault_attr attr; | |
2117 | ||
2118 | u32 ignore_gfp_highmem; | |
2119 | u32 ignore_gfp_wait; | |
2120 | u32 min_order; | |
2121 | } fail_page_alloc = { | |
2122 | .attr = FAULT_ATTR_INITIALIZER, | |
2123 | .ignore_gfp_wait = 1, | |
2124 | .ignore_gfp_highmem = 1, | |
2125 | .min_order = 1, | |
2126 | }; | |
2127 | ||
2128 | static int __init setup_fail_page_alloc(char *str) | |
2129 | { | |
2130 | return setup_fault_attr(&fail_page_alloc.attr, str); | |
2131 | } | |
2132 | __setup("fail_page_alloc=", setup_fail_page_alloc); | |
2133 | ||
2134 | static bool should_fail_alloc_page(gfp_t gfp_mask, unsigned int order) | |
2135 | { | |
2136 | if (order < fail_page_alloc.min_order) | |
2137 | return false; | |
2138 | if (gfp_mask & __GFP_NOFAIL) | |
2139 | return false; | |
2140 | if (fail_page_alloc.ignore_gfp_highmem && (gfp_mask & __GFP_HIGHMEM)) | |
2141 | return false; | |
2142 | if (fail_page_alloc.ignore_gfp_wait && (gfp_mask & __GFP_WAIT)) | |
2143 | return false; | |
2144 | ||
2145 | return should_fail(&fail_page_alloc.attr, 1 << order); | |
2146 | } | |
2147 | ||
2148 | #ifdef CONFIG_FAULT_INJECTION_DEBUG_FS | |
2149 | ||
2150 | static int __init fail_page_alloc_debugfs(void) | |
2151 | { | |
2152 | umode_t mode = S_IFREG | S_IRUSR | S_IWUSR; | |
2153 | struct dentry *dir; | |
2154 | ||
2155 | dir = fault_create_debugfs_attr("fail_page_alloc", NULL, | |
2156 | &fail_page_alloc.attr); | |
2157 | if (IS_ERR(dir)) | |
2158 | return PTR_ERR(dir); | |
2159 | ||
2160 | if (!debugfs_create_bool("ignore-gfp-wait", mode, dir, | |
2161 | &fail_page_alloc.ignore_gfp_wait)) | |
2162 | goto fail; | |
2163 | if (!debugfs_create_bool("ignore-gfp-highmem", mode, dir, | |
2164 | &fail_page_alloc.ignore_gfp_highmem)) | |
2165 | goto fail; | |
2166 | if (!debugfs_create_u32("min-order", mode, dir, | |
2167 | &fail_page_alloc.min_order)) | |
2168 | goto fail; | |
2169 | ||
2170 | return 0; | |
2171 | fail: | |
2172 | debugfs_remove_recursive(dir); | |
2173 | ||
2174 | return -ENOMEM; | |
2175 | } | |
2176 | ||
2177 | late_initcall(fail_page_alloc_debugfs); | |
2178 | ||
2179 | #endif /* CONFIG_FAULT_INJECTION_DEBUG_FS */ | |
2180 | ||
2181 | #else /* CONFIG_FAIL_PAGE_ALLOC */ | |
2182 | ||
2183 | static inline bool should_fail_alloc_page(gfp_t gfp_mask, unsigned int order) | |
2184 | { | |
2185 | return false; | |
2186 | } | |
2187 | ||
2188 | #endif /* CONFIG_FAIL_PAGE_ALLOC */ | |
2189 | ||
2190 | /* | |
2191 | * Return true if free pages are above 'mark'. This takes into account the order | |
2192 | * of the allocation. | |
2193 | */ | |
2194 | static bool __zone_watermark_ok(struct zone *z, unsigned int order, | |
2195 | unsigned long mark, int classzone_idx, int alloc_flags, | |
2196 | long free_pages) | |
2197 | { | |
2198 | /* free_pages may go negative - that's OK */ | |
2199 | long min = mark; | |
2200 | int o; | |
2201 | long free_cma = 0; | |
2202 | ||
2203 | free_pages -= (1 << order) - 1; | |
2204 | if (alloc_flags & ALLOC_HIGH) | |
2205 | min -= min / 2; | |
2206 | if (alloc_flags & ALLOC_HARDER) | |
2207 | min -= min / 4; | |
2208 | #ifdef CONFIG_CMA | |
2209 | /* If allocation can't use CMA areas don't use free CMA pages */ | |
2210 | if (!(alloc_flags & ALLOC_CMA)) | |
2211 | free_cma = zone_page_state(z, NR_FREE_CMA_PAGES); | |
2212 | #endif | |
2213 | ||
2214 | if (free_pages - free_cma <= min + z->lowmem_reserve[classzone_idx]) | |
2215 | return false; | |
2216 | for (o = 0; o < order; o++) { | |
2217 | /* At the next order, this order's pages become unavailable */ | |
2218 | free_pages -= z->free_area[o].nr_free << o; | |
2219 | ||
2220 | /* Require fewer higher order pages to be free */ | |
2221 | min >>= 1; | |
2222 | ||
2223 | if (free_pages <= min) | |
2224 | return false; | |
2225 | } | |
2226 | return true; | |
2227 | } | |
2228 | ||
2229 | bool zone_watermark_ok(struct zone *z, unsigned int order, unsigned long mark, | |
2230 | int classzone_idx, int alloc_flags) | |
2231 | { | |
2232 | return __zone_watermark_ok(z, order, mark, classzone_idx, alloc_flags, | |
2233 | zone_page_state(z, NR_FREE_PAGES)); | |
2234 | } | |
2235 | ||
2236 | bool zone_watermark_ok_safe(struct zone *z, unsigned int order, | |
2237 | unsigned long mark, int classzone_idx, int alloc_flags) | |
2238 | { | |
2239 | long free_pages = zone_page_state(z, NR_FREE_PAGES); | |
2240 | ||
2241 | if (z->percpu_drift_mark && free_pages < z->percpu_drift_mark) | |
2242 | free_pages = zone_page_state_snapshot(z, NR_FREE_PAGES); | |
2243 | ||
2244 | return __zone_watermark_ok(z, order, mark, classzone_idx, alloc_flags, | |
2245 | free_pages); | |
2246 | } | |
2247 | ||
2248 | #ifdef CONFIG_NUMA | |
2249 | /* | |
2250 | * zlc_setup - Setup for "zonelist cache". Uses cached zone data to | |
2251 | * skip over zones that are not allowed by the cpuset, or that have | |
2252 | * been recently (in last second) found to be nearly full. See further | |
2253 | * comments in mmzone.h. Reduces cache footprint of zonelist scans | |
2254 | * that have to skip over a lot of full or unallowed zones. | |
2255 | * | |
2256 | * If the zonelist cache is present in the passed zonelist, then | |
2257 | * returns a pointer to the allowed node mask (either the current | |
2258 | * tasks mems_allowed, or node_states[N_MEMORY].) | |
2259 | * | |
2260 | * If the zonelist cache is not available for this zonelist, does | |
2261 | * nothing and returns NULL. | |
2262 | * | |
2263 | * If the fullzones BITMAP in the zonelist cache is stale (more than | |
2264 | * a second since last zap'd) then we zap it out (clear its bits.) | |
2265 | * | |
2266 | * We hold off even calling zlc_setup, until after we've checked the | |
2267 | * first zone in the zonelist, on the theory that most allocations will | |
2268 | * be satisfied from that first zone, so best to examine that zone as | |
2269 | * quickly as we can. | |
2270 | */ | |
2271 | static nodemask_t *zlc_setup(struct zonelist *zonelist, int alloc_flags) | |
2272 | { | |
2273 | struct zonelist_cache *zlc; /* cached zonelist speedup info */ | |
2274 | nodemask_t *allowednodes; /* zonelist_cache approximation */ | |
2275 | ||
2276 | zlc = zonelist->zlcache_ptr; | |
2277 | if (!zlc) | |
2278 | return NULL; | |
2279 | ||
2280 | if (time_after(jiffies, zlc->last_full_zap + HZ)) { | |
2281 | bitmap_zero(zlc->fullzones, MAX_ZONES_PER_ZONELIST); | |
2282 | zlc->last_full_zap = jiffies; | |
2283 | } | |
2284 | ||
2285 | allowednodes = !in_interrupt() && (alloc_flags & ALLOC_CPUSET) ? | |
2286 | &cpuset_current_mems_allowed : | |
2287 | &node_states[N_MEMORY]; | |
2288 | return allowednodes; | |
2289 | } | |
2290 | ||
2291 | /* | |
2292 | * Given 'z' scanning a zonelist, run a couple of quick checks to see | |
2293 | * if it is worth looking at further for free memory: | |
2294 | * 1) Check that the zone isn't thought to be full (doesn't have its | |
2295 | * bit set in the zonelist_cache fullzones BITMAP). | |
2296 | * 2) Check that the zones node (obtained from the zonelist_cache | |
2297 | * z_to_n[] mapping) is allowed in the passed in allowednodes mask. | |
2298 | * Return true (non-zero) if zone is worth looking at further, or | |
2299 | * else return false (zero) if it is not. | |
2300 | * | |
2301 | * This check -ignores- the distinction between various watermarks, | |
2302 | * such as GFP_HIGH, GFP_ATOMIC, PF_MEMALLOC, ... If a zone is | |
2303 | * found to be full for any variation of these watermarks, it will | |
2304 | * be considered full for up to one second by all requests, unless | |
2305 | * we are so low on memory on all allowed nodes that we are forced | |
2306 | * into the second scan of the zonelist. | |
2307 | * | |
2308 | * In the second scan we ignore this zonelist cache and exactly | |
2309 | * apply the watermarks to all zones, even it is slower to do so. | |
2310 | * We are low on memory in the second scan, and should leave no stone | |
2311 | * unturned looking for a free page. | |
2312 | */ | |
2313 | static int zlc_zone_worth_trying(struct zonelist *zonelist, struct zoneref *z, | |
2314 | nodemask_t *allowednodes) | |
2315 | { | |
2316 | struct zonelist_cache *zlc; /* cached zonelist speedup info */ | |
2317 | int i; /* index of *z in zonelist zones */ | |
2318 | int n; /* node that zone *z is on */ | |
2319 | ||
2320 | zlc = zonelist->zlcache_ptr; | |
2321 | if (!zlc) | |
2322 | return 1; | |
2323 | ||
2324 | i = z - zonelist->_zonerefs; | |
2325 | n = zlc->z_to_n[i]; | |
2326 | ||
2327 | /* This zone is worth trying if it is allowed but not full */ | |
2328 | return node_isset(n, *allowednodes) && !test_bit(i, zlc->fullzones); | |
2329 | } | |
2330 | ||
2331 | /* | |
2332 | * Given 'z' scanning a zonelist, set the corresponding bit in | |
2333 | * zlc->fullzones, so that subsequent attempts to allocate a page | |
2334 | * from that zone don't waste time re-examining it. | |
2335 | */ | |
2336 | static void zlc_mark_zone_full(struct zonelist *zonelist, struct zoneref *z) | |
2337 | { | |
2338 | struct zonelist_cache *zlc; /* cached zonelist speedup info */ | |
2339 | int i; /* index of *z in zonelist zones */ | |
2340 | ||
2341 | zlc = zonelist->zlcache_ptr; | |
2342 | if (!zlc) | |
2343 | return; | |
2344 | ||
2345 | i = z - zonelist->_zonerefs; | |
2346 | ||
2347 | set_bit(i, zlc->fullzones); | |
2348 | } | |
2349 | ||
2350 | /* | |
2351 | * clear all zones full, called after direct reclaim makes progress so that | |
2352 | * a zone that was recently full is not skipped over for up to a second | |
2353 | */ | |
2354 | static void zlc_clear_zones_full(struct zonelist *zonelist) | |
2355 | { | |
2356 | struct zonelist_cache *zlc; /* cached zonelist speedup info */ | |
2357 | ||
2358 | zlc = zonelist->zlcache_ptr; | |
2359 | if (!zlc) | |
2360 | return; | |
2361 | ||
2362 | bitmap_zero(zlc->fullzones, MAX_ZONES_PER_ZONELIST); | |
2363 | } | |
2364 | ||
2365 | static bool zone_local(struct zone *local_zone, struct zone *zone) | |
2366 | { | |
2367 | return local_zone->node == zone->node; | |
2368 | } | |
2369 | ||
2370 | static bool zone_allows_reclaim(struct zone *local_zone, struct zone *zone) | |
2371 | { | |
2372 | return node_distance(zone_to_nid(local_zone), zone_to_nid(zone)) < | |
2373 | RECLAIM_DISTANCE; | |
2374 | } | |
2375 | ||
2376 | #else /* CONFIG_NUMA */ | |
2377 | ||
2378 | static nodemask_t *zlc_setup(struct zonelist *zonelist, int alloc_flags) | |
2379 | { | |
2380 | return NULL; | |
2381 | } | |
2382 | ||
2383 | static int zlc_zone_worth_trying(struct zonelist *zonelist, struct zoneref *z, | |
2384 | nodemask_t *allowednodes) | |
2385 | { | |
2386 | return 1; | |
2387 | } | |
2388 | ||
2389 | static void zlc_mark_zone_full(struct zonelist *zonelist, struct zoneref *z) | |
2390 | { | |
2391 | } | |
2392 | ||
2393 | static void zlc_clear_zones_full(struct zonelist *zonelist) | |
2394 | { | |
2395 | } | |
2396 | ||
2397 | static bool zone_local(struct zone *local_zone, struct zone *zone) | |
2398 | { | |
2399 | return true; | |
2400 | } | |
2401 | ||
2402 | static bool zone_allows_reclaim(struct zone *local_zone, struct zone *zone) | |
2403 | { | |
2404 | return true; | |
2405 | } | |
2406 | ||
2407 | #endif /* CONFIG_NUMA */ | |
2408 | ||
2409 | static void reset_alloc_batches(struct zone *preferred_zone) | |
2410 | { | |
2411 | struct zone *zone = preferred_zone->zone_pgdat->node_zones; | |
2412 | ||
2413 | do { | |
2414 | mod_zone_page_state(zone, NR_ALLOC_BATCH, | |
2415 | high_wmark_pages(zone) - low_wmark_pages(zone) - | |
2416 | atomic_long_read(&zone->vm_stat[NR_ALLOC_BATCH])); | |
2417 | clear_bit(ZONE_FAIR_DEPLETED, &zone->flags); | |
2418 | } while (zone++ != preferred_zone); | |
2419 | } | |
2420 | ||
2421 | /* | |
2422 | * get_page_from_freelist goes through the zonelist trying to allocate | |
2423 | * a page. | |
2424 | */ | |
2425 | static struct page * | |
2426 | get_page_from_freelist(gfp_t gfp_mask, unsigned int order, int alloc_flags, | |
2427 | const struct alloc_context *ac) | |
2428 | { | |
2429 | struct zonelist *zonelist = ac->zonelist; | |
2430 | struct zoneref *z; | |
2431 | struct page *page = NULL; | |
2432 | struct zone *zone; | |
2433 | nodemask_t *allowednodes = NULL;/* zonelist_cache approximation */ | |
2434 | int zlc_active = 0; /* set if using zonelist_cache */ | |
2435 | int did_zlc_setup = 0; /* just call zlc_setup() one time */ | |
2436 | bool consider_zone_dirty = (alloc_flags & ALLOC_WMARK_LOW) && | |
2437 | (gfp_mask & __GFP_WRITE); | |
2438 | int nr_fair_skipped = 0; | |
2439 | bool zonelist_rescan; | |
2440 | ||
2441 | zonelist_scan: | |
2442 | zonelist_rescan = false; | |
2443 | ||
2444 | /* | |
2445 | * Scan zonelist, looking for a zone with enough free. | |
2446 | * See also __cpuset_node_allowed() comment in kernel/cpuset.c. | |
2447 | */ | |
2448 | for_each_zone_zonelist_nodemask(zone, z, zonelist, ac->high_zoneidx, | |
2449 | ac->nodemask) { | |
2450 | unsigned long mark; | |
2451 | ||
2452 | if (IS_ENABLED(CONFIG_NUMA) && zlc_active && | |
2453 | !zlc_zone_worth_trying(zonelist, z, allowednodes)) | |
2454 | continue; | |
2455 | if (cpusets_enabled() && | |
2456 | (alloc_flags & ALLOC_CPUSET) && | |
2457 | !cpuset_zone_allowed(zone, gfp_mask)) | |
2458 | continue; | |
2459 | /* | |
2460 | * Distribute pages in proportion to the individual | |
2461 | * zone size to ensure fair page aging. The zone a | |
2462 | * page was allocated in should have no effect on the | |
2463 | * time the page has in memory before being reclaimed. | |
2464 | */ | |
2465 | if (alloc_flags & ALLOC_FAIR) { | |
2466 | if (!zone_local(ac->preferred_zone, zone)) | |
2467 | break; | |
2468 | if (test_bit(ZONE_FAIR_DEPLETED, &zone->flags)) { | |
2469 | nr_fair_skipped++; | |
2470 | continue; | |
2471 | } | |
2472 | } | |
2473 | /* | |
2474 | * When allocating a page cache page for writing, we | |
2475 | * want to get it from a zone that is within its dirty | |
2476 | * limit, such that no single zone holds more than its | |
2477 | * proportional share of globally allowed dirty pages. | |
2478 | * The dirty limits take into account the zone's | |
2479 | * lowmem reserves and high watermark so that kswapd | |
2480 | * should be able to balance it without having to | |
2481 | * write pages from its LRU list. | |
2482 | * | |
2483 | * This may look like it could increase pressure on | |
2484 | * lower zones by failing allocations in higher zones | |
2485 | * before they are full. But the pages that do spill | |
2486 | * over are limited as the lower zones are protected | |
2487 | * by this very same mechanism. It should not become | |
2488 | * a practical burden to them. | |
2489 | * | |
2490 | * XXX: For now, allow allocations to potentially | |
2491 | * exceed the per-zone dirty limit in the slowpath | |
2492 | * (ALLOC_WMARK_LOW unset) before going into reclaim, | |
2493 | * which is important when on a NUMA setup the allowed | |
2494 | * zones are together not big enough to reach the | |
2495 | * global limit. The proper fix for these situations | |
2496 | * will require awareness of zones in the | |
2497 | * dirty-throttling and the flusher threads. | |
2498 | */ | |
2499 | if (consider_zone_dirty && !zone_dirty_ok(zone)) | |
2500 | continue; | |
2501 | ||
2502 | mark = zone->watermark[alloc_flags & ALLOC_WMARK_MASK]; | |
2503 | if (!zone_watermark_ok(zone, order, mark, | |
2504 | ac->classzone_idx, alloc_flags)) { | |
2505 | int ret; | |
2506 | ||
2507 | /* Checked here to keep the fast path fast */ | |
2508 | BUILD_BUG_ON(ALLOC_NO_WATERMARKS < NR_WMARK); | |
2509 | if (alloc_flags & ALLOC_NO_WATERMARKS) | |
2510 | goto try_this_zone; | |
2511 | ||
2512 | if (IS_ENABLED(CONFIG_NUMA) && | |
2513 | !did_zlc_setup && nr_online_nodes > 1) { | |
2514 | /* | |
2515 | * we do zlc_setup if there are multiple nodes | |
2516 | * and before considering the first zone allowed | |
2517 | * by the cpuset. | |
2518 | */ | |
2519 | allowednodes = zlc_setup(zonelist, alloc_flags); | |
2520 | zlc_active = 1; | |
2521 | did_zlc_setup = 1; | |
2522 | } | |
2523 | ||
2524 | if (zone_reclaim_mode == 0 || | |
2525 | !zone_allows_reclaim(ac->preferred_zone, zone)) | |
2526 | goto this_zone_full; | |
2527 | ||
2528 | /* | |
2529 | * As we may have just activated ZLC, check if the first | |
2530 | * eligible zone has failed zone_reclaim recently. | |
2531 | */ | |
2532 | if (IS_ENABLED(CONFIG_NUMA) && zlc_active && | |
2533 | !zlc_zone_worth_trying(zonelist, z, allowednodes)) | |
2534 | continue; | |
2535 | ||
2536 | ret = zone_reclaim(zone, gfp_mask, order); | |
2537 | switch (ret) { | |
2538 | case ZONE_RECLAIM_NOSCAN: | |
2539 | /* did not scan */ | |
2540 | continue; | |
2541 | case ZONE_RECLAIM_FULL: | |
2542 | /* scanned but unreclaimable */ | |
2543 | continue; | |
2544 | default: | |
2545 | /* did we reclaim enough */ | |
2546 | if (zone_watermark_ok(zone, order, mark, | |
2547 | ac->classzone_idx, alloc_flags)) | |
2548 | goto try_this_zone; | |
2549 | ||
2550 | /* | |
2551 | * Failed to reclaim enough to meet watermark. | |
2552 | * Only mark the zone full if checking the min | |
2553 | * watermark or if we failed to reclaim just | |
2554 | * 1<<order pages or else the page allocator | |
2555 | * fastpath will prematurely mark zones full | |
2556 | * when the watermark is between the low and | |
2557 | * min watermarks. | |
2558 | */ | |
2559 | if (((alloc_flags & ALLOC_WMARK_MASK) == ALLOC_WMARK_MIN) || | |
2560 | ret == ZONE_RECLAIM_SOME) | |
2561 | goto this_zone_full; | |
2562 | ||
2563 | continue; | |
2564 | } | |
2565 | } | |
2566 | ||
2567 | try_this_zone: | |
2568 | page = buffered_rmqueue(ac->preferred_zone, zone, order, | |
2569 | gfp_mask, ac->migratetype); | |
2570 | if (page) { | |
2571 | if (prep_new_page(page, order, gfp_mask, alloc_flags)) | |
2572 | goto try_this_zone; | |
2573 | return page; | |
2574 | } | |
2575 | this_zone_full: | |
2576 | if (IS_ENABLED(CONFIG_NUMA) && zlc_active) | |
2577 | zlc_mark_zone_full(zonelist, z); | |
2578 | } | |
2579 | ||
2580 | /* | |
2581 | * The first pass makes sure allocations are spread fairly within the | |
2582 | * local node. However, the local node might have free pages left | |
2583 | * after the fairness batches are exhausted, and remote zones haven't | |
2584 | * even been considered yet. Try once more without fairness, and | |
2585 | * include remote zones now, before entering the slowpath and waking | |
2586 | * kswapd: prefer spilling to a remote zone over swapping locally. | |
2587 | */ | |
2588 | if (alloc_flags & ALLOC_FAIR) { | |
2589 | alloc_flags &= ~ALLOC_FAIR; | |
2590 | if (nr_fair_skipped) { | |
2591 | zonelist_rescan = true; | |
2592 | reset_alloc_batches(ac->preferred_zone); | |
2593 | } | |
2594 | if (nr_online_nodes > 1) | |
2595 | zonelist_rescan = true; | |
2596 | } | |
2597 | ||
2598 | if (unlikely(IS_ENABLED(CONFIG_NUMA) && zlc_active)) { | |
2599 | /* Disable zlc cache for second zonelist scan */ | |
2600 | zlc_active = 0; | |
2601 | zonelist_rescan = true; | |
2602 | } | |
2603 | ||
2604 | if (zonelist_rescan) | |
2605 | goto zonelist_scan; | |
2606 | ||
2607 | return NULL; | |
2608 | } | |
2609 | ||
2610 | /* | |
2611 | * Large machines with many possible nodes should not always dump per-node | |
2612 | * meminfo in irq context. | |
2613 | */ | |
2614 | static inline bool should_suppress_show_mem(void) | |
2615 | { | |
2616 | bool ret = false; | |
2617 | ||
2618 | #if NODES_SHIFT > 8 | |
2619 | ret = in_interrupt(); | |
2620 | #endif | |
2621 | return ret; | |
2622 | } | |
2623 | ||
2624 | static DEFINE_RATELIMIT_STATE(nopage_rs, | |
2625 | DEFAULT_RATELIMIT_INTERVAL, | |
2626 | DEFAULT_RATELIMIT_BURST); | |
2627 | ||
2628 | void warn_alloc_failed(gfp_t gfp_mask, int order, const char *fmt, ...) | |
2629 | { | |
2630 | unsigned int filter = SHOW_MEM_FILTER_NODES; | |
2631 | ||
2632 | if ((gfp_mask & __GFP_NOWARN) || !__ratelimit(&nopage_rs) || | |
2633 | debug_guardpage_minorder() > 0) | |
2634 | return; | |
2635 | ||
2636 | /* | |
2637 | * This documents exceptions given to allocations in certain | |
2638 | * contexts that are allowed to allocate outside current's set | |
2639 | * of allowed nodes. | |
2640 | */ | |
2641 | if (!(gfp_mask & __GFP_NOMEMALLOC)) | |
2642 | if (test_thread_flag(TIF_MEMDIE) || | |
2643 | (current->flags & (PF_MEMALLOC | PF_EXITING))) | |
2644 | filter &= ~SHOW_MEM_FILTER_NODES; | |
2645 | if (in_interrupt() || !(gfp_mask & __GFP_WAIT)) | |
2646 | filter &= ~SHOW_MEM_FILTER_NODES; | |
2647 | ||
2648 | if (fmt) { | |
2649 | struct va_format vaf; | |
2650 | va_list args; | |
2651 | ||
2652 | va_start(args, fmt); | |
2653 | ||
2654 | vaf.fmt = fmt; | |
2655 | vaf.va = &args; | |
2656 | ||
2657 | pr_warn("%pV", &vaf); | |
2658 | ||
2659 | va_end(args); | |
2660 | } | |
2661 | ||
2662 | pr_warn("%s: page allocation failure: order:%d, mode:0x%x\n", | |
2663 | current->comm, order, gfp_mask); | |
2664 | ||
2665 | dump_stack(); | |
2666 | if (!should_suppress_show_mem()) | |
2667 | show_mem(filter); | |
2668 | } | |
2669 | ||
2670 | static inline struct page * | |
2671 | __alloc_pages_may_oom(gfp_t gfp_mask, unsigned int order, | |
2672 | const struct alloc_context *ac, unsigned long *did_some_progress) | |
2673 | { | |
2674 | struct page *page; | |
2675 | ||
2676 | *did_some_progress = 0; | |
2677 | ||
2678 | /* | |
2679 | * Acquire the oom lock. If that fails, somebody else is | |
2680 | * making progress for us. | |
2681 | */ | |
2682 | if (!mutex_trylock(&oom_lock)) { | |
2683 | *did_some_progress = 1; | |
2684 | schedule_timeout_uninterruptible(1); | |
2685 | return NULL; | |
2686 | } | |
2687 | ||
2688 | /* | |
2689 | * Go through the zonelist yet one more time, keep very high watermark | |
2690 | * here, this is only to catch a parallel oom killing, we must fail if | |
2691 | * we're still under heavy pressure. | |
2692 | */ | |
2693 | page = get_page_from_freelist(gfp_mask | __GFP_HARDWALL, order, | |
2694 | ALLOC_WMARK_HIGH|ALLOC_CPUSET, ac); | |
2695 | if (page) | |
2696 | goto out; | |
2697 | ||
2698 | if (!(gfp_mask & __GFP_NOFAIL)) { | |
2699 | /* Coredumps can quickly deplete all memory reserves */ | |
2700 | if (current->flags & PF_DUMPCORE) | |
2701 | goto out; | |
2702 | /* The OOM killer will not help higher order allocs */ | |
2703 | if (order > PAGE_ALLOC_COSTLY_ORDER) | |
2704 | goto out; | |
2705 | /* The OOM killer does not needlessly kill tasks for lowmem */ | |
2706 | if (ac->high_zoneidx < ZONE_NORMAL) | |
2707 | goto out; | |
2708 | /* The OOM killer does not compensate for IO-less reclaim */ | |
2709 | if (!(gfp_mask & __GFP_FS)) { | |
2710 | /* | |
2711 | * XXX: Page reclaim didn't yield anything, | |
2712 | * and the OOM killer can't be invoked, but | |
2713 | * keep looping as per tradition. | |
2714 | */ | |
2715 | *did_some_progress = 1; | |
2716 | goto out; | |
2717 | } | |
2718 | if (pm_suspended_storage()) | |
2719 | goto out; | |
2720 | /* The OOM killer may not free memory on a specific node */ | |
2721 | if (gfp_mask & __GFP_THISNODE) | |
2722 | goto out; | |
2723 | } | |
2724 | /* Exhausted what can be done so it's blamo time */ | |
2725 | if (out_of_memory(ac->zonelist, gfp_mask, order, ac->nodemask, false) | |
2726 | || WARN_ON_ONCE(gfp_mask & __GFP_NOFAIL)) | |
2727 | *did_some_progress = 1; | |
2728 | out: | |
2729 | mutex_unlock(&oom_lock); | |
2730 | return page; | |
2731 | } | |
2732 | ||
2733 | #ifdef CONFIG_COMPACTION | |
2734 | /* Try memory compaction for high-order allocations before reclaim */ | |
2735 | static struct page * | |
2736 | __alloc_pages_direct_compact(gfp_t gfp_mask, unsigned int order, | |
2737 | int alloc_flags, const struct alloc_context *ac, | |
2738 | enum migrate_mode mode, int *contended_compaction, | |
2739 | bool *deferred_compaction) | |
2740 | { | |
2741 | unsigned long compact_result; | |
2742 | struct page *page; | |
2743 | ||
2744 | if (!order) | |
2745 | return NULL; | |
2746 | ||
2747 | current->flags |= PF_MEMALLOC; | |
2748 | compact_result = try_to_compact_pages(gfp_mask, order, alloc_flags, ac, | |
2749 | mode, contended_compaction); | |
2750 | current->flags &= ~PF_MEMALLOC; | |
2751 | ||
2752 | switch (compact_result) { | |
2753 | case COMPACT_DEFERRED: | |
2754 | *deferred_compaction = true; | |
2755 | /* fall-through */ | |
2756 | case COMPACT_SKIPPED: | |
2757 | return NULL; | |
2758 | default: | |
2759 | break; | |
2760 | } | |
2761 | ||
2762 | /* | |
2763 | * At least in one zone compaction wasn't deferred or skipped, so let's | |
2764 | * count a compaction stall | |
2765 | */ | |
2766 | count_vm_event(COMPACTSTALL); | |
2767 | ||
2768 | page = get_page_from_freelist(gfp_mask, order, | |
2769 | alloc_flags & ~ALLOC_NO_WATERMARKS, ac); | |
2770 | ||
2771 | if (page) { | |
2772 | struct zone *zone = page_zone(page); | |
2773 | ||
2774 | zone->compact_blockskip_flush = false; | |
2775 | compaction_defer_reset(zone, order, true); | |
2776 | count_vm_event(COMPACTSUCCESS); | |
2777 | return page; | |
2778 | } | |
2779 | ||
2780 | /* | |
2781 | * It's bad if compaction run occurs and fails. The most likely reason | |
2782 | * is that pages exist, but not enough to satisfy watermarks. | |
2783 | */ | |
2784 | count_vm_event(COMPACTFAIL); | |
2785 | ||
2786 | cond_resched(); | |
2787 | ||
2788 | return NULL; | |
2789 | } | |
2790 | #else | |
2791 | static inline struct page * | |
2792 | __alloc_pages_direct_compact(gfp_t gfp_mask, unsigned int order, | |
2793 | int alloc_flags, const struct alloc_context *ac, | |
2794 | enum migrate_mode mode, int *contended_compaction, | |
2795 | bool *deferred_compaction) | |
2796 | { | |
2797 | return NULL; | |
2798 | } | |
2799 | #endif /* CONFIG_COMPACTION */ | |
2800 | ||
2801 | /* Perform direct synchronous page reclaim */ | |
2802 | static int | |
2803 | __perform_reclaim(gfp_t gfp_mask, unsigned int order, | |
2804 | const struct alloc_context *ac) | |
2805 | { | |
2806 | struct reclaim_state reclaim_state; | |
2807 | int progress; | |
2808 | ||
2809 | cond_resched(); | |
2810 | ||
2811 | /* We now go into synchronous reclaim */ | |
2812 | cpuset_memory_pressure_bump(); | |
2813 | current->flags |= PF_MEMALLOC; | |
2814 | lockdep_set_current_reclaim_state(gfp_mask); | |
2815 | reclaim_state.reclaimed_slab = 0; | |
2816 | current->reclaim_state = &reclaim_state; | |
2817 | ||
2818 | progress = try_to_free_pages(ac->zonelist, order, gfp_mask, | |
2819 | ac->nodemask); | |
2820 | ||
2821 | current->reclaim_state = NULL; | |
2822 | lockdep_clear_current_reclaim_state(); | |
2823 | current->flags &= ~PF_MEMALLOC; | |
2824 | ||
2825 | cond_resched(); | |
2826 | ||
2827 | return progress; | |
2828 | } | |
2829 | ||
2830 | /* The really slow allocator path where we enter direct reclaim */ | |
2831 | static inline struct page * | |
2832 | __alloc_pages_direct_reclaim(gfp_t gfp_mask, unsigned int order, | |
2833 | int alloc_flags, const struct alloc_context *ac, | |
2834 | unsigned long *did_some_progress) | |
2835 | { | |
2836 | struct page *page = NULL; | |
2837 | bool drained = false; | |
2838 | ||
2839 | *did_some_progress = __perform_reclaim(gfp_mask, order, ac); | |
2840 | if (unlikely(!(*did_some_progress))) | |
2841 | return NULL; | |
2842 | ||
2843 | /* After successful reclaim, reconsider all zones for allocation */ | |
2844 | if (IS_ENABLED(CONFIG_NUMA)) | |
2845 | zlc_clear_zones_full(ac->zonelist); | |
2846 | ||
2847 | retry: | |
2848 | page = get_page_from_freelist(gfp_mask, order, | |
2849 | alloc_flags & ~ALLOC_NO_WATERMARKS, ac); | |
2850 | ||
2851 | /* | |
2852 | * If an allocation failed after direct reclaim, it could be because | |
2853 | * pages are pinned on the per-cpu lists. Drain them and try again | |
2854 | */ | |
2855 | if (!page && !drained) { | |
2856 | drain_all_pages(NULL); | |
2857 | drained = true; | |
2858 | goto retry; | |
2859 | } | |
2860 | ||
2861 | return page; | |
2862 | } | |
2863 | ||
2864 | /* | |
2865 | * This is called in the allocator slow-path if the allocation request is of | |
2866 | * sufficient urgency to ignore watermarks and take other desperate measures | |
2867 | */ | |
2868 | static inline struct page * | |
2869 | __alloc_pages_high_priority(gfp_t gfp_mask, unsigned int order, | |
2870 | const struct alloc_context *ac) | |
2871 | { | |
2872 | struct page *page; | |
2873 | ||
2874 | do { | |
2875 | page = get_page_from_freelist(gfp_mask, order, | |
2876 | ALLOC_NO_WATERMARKS, ac); | |
2877 | ||
2878 | if (!page && gfp_mask & __GFP_NOFAIL) | |
2879 | wait_iff_congested(ac->preferred_zone, BLK_RW_ASYNC, | |
2880 | HZ/50); | |
2881 | } while (!page && (gfp_mask & __GFP_NOFAIL)); | |
2882 | ||
2883 | return page; | |
2884 | } | |
2885 | ||
2886 | static void wake_all_kswapds(unsigned int order, const struct alloc_context *ac) | |
2887 | { | |
2888 | struct zoneref *z; | |
2889 | struct zone *zone; | |
2890 | ||
2891 | for_each_zone_zonelist_nodemask(zone, z, ac->zonelist, | |
2892 | ac->high_zoneidx, ac->nodemask) | |
2893 | wakeup_kswapd(zone, order, zone_idx(ac->preferred_zone)); | |
2894 | } | |
2895 | ||
2896 | static inline int | |
2897 | gfp_to_alloc_flags(gfp_t gfp_mask) | |
2898 | { | |
2899 | int alloc_flags = ALLOC_WMARK_MIN | ALLOC_CPUSET; | |
2900 | const bool atomic = !(gfp_mask & (__GFP_WAIT | __GFP_NO_KSWAPD)); | |
2901 | ||
2902 | /* __GFP_HIGH is assumed to be the same as ALLOC_HIGH to save a branch. */ | |
2903 | BUILD_BUG_ON(__GFP_HIGH != (__force gfp_t) ALLOC_HIGH); | |
2904 | ||
2905 | /* | |
2906 | * The caller may dip into page reserves a bit more if the caller | |
2907 | * cannot run direct reclaim, or if the caller has realtime scheduling | |
2908 | * policy or is asking for __GFP_HIGH memory. GFP_ATOMIC requests will | |
2909 | * set both ALLOC_HARDER (atomic == true) and ALLOC_HIGH (__GFP_HIGH). | |
2910 | */ | |
2911 | alloc_flags |= (__force int) (gfp_mask & __GFP_HIGH); | |
2912 | ||
2913 | if (atomic) { | |
2914 | /* | |
2915 | * Not worth trying to allocate harder for __GFP_NOMEMALLOC even | |
2916 | * if it can't schedule. | |
2917 | */ | |
2918 | if (!(gfp_mask & __GFP_NOMEMALLOC)) | |
2919 | alloc_flags |= ALLOC_HARDER; | |
2920 | /* | |
2921 | * Ignore cpuset mems for GFP_ATOMIC rather than fail, see the | |
2922 | * comment for __cpuset_node_allowed(). | |
2923 | */ | |
2924 | alloc_flags &= ~ALLOC_CPUSET; | |
2925 | } else if (unlikely(rt_task(current)) && !in_interrupt()) | |
2926 | alloc_flags |= ALLOC_HARDER; | |
2927 | ||
2928 | if (likely(!(gfp_mask & __GFP_NOMEMALLOC))) { | |
2929 | if (gfp_mask & __GFP_MEMALLOC) | |
2930 | alloc_flags |= ALLOC_NO_WATERMARKS; | |
2931 | else if (in_serving_softirq() && (current->flags & PF_MEMALLOC)) | |
2932 | alloc_flags |= ALLOC_NO_WATERMARKS; | |
2933 | else if (!in_interrupt() && | |
2934 | ((current->flags & PF_MEMALLOC) || | |
2935 | unlikely(test_thread_flag(TIF_MEMDIE)))) | |
2936 | alloc_flags |= ALLOC_NO_WATERMARKS; | |
2937 | } | |
2938 | #ifdef CONFIG_CMA | |
2939 | if (gfpflags_to_migratetype(gfp_mask) == MIGRATE_MOVABLE) | |
2940 | alloc_flags |= ALLOC_CMA; | |
2941 | #endif | |
2942 | return alloc_flags; | |
2943 | } | |
2944 | ||
2945 | bool gfp_pfmemalloc_allowed(gfp_t gfp_mask) | |
2946 | { | |
2947 | return !!(gfp_to_alloc_flags(gfp_mask) & ALLOC_NO_WATERMARKS); | |
2948 | } | |
2949 | ||
2950 | static inline struct page * | |
2951 | __alloc_pages_slowpath(gfp_t gfp_mask, unsigned int order, | |
2952 | struct alloc_context *ac) | |
2953 | { | |
2954 | const gfp_t wait = gfp_mask & __GFP_WAIT; | |
2955 | struct page *page = NULL; | |
2956 | int alloc_flags; | |
2957 | unsigned long pages_reclaimed = 0; | |
2958 | unsigned long did_some_progress; | |
2959 | enum migrate_mode migration_mode = MIGRATE_ASYNC; | |
2960 | bool deferred_compaction = false; | |
2961 | int contended_compaction = COMPACT_CONTENDED_NONE; | |
2962 | ||
2963 | /* | |
2964 | * In the slowpath, we sanity check order to avoid ever trying to | |
2965 | * reclaim >= MAX_ORDER areas which will never succeed. Callers may | |
2966 | * be using allocators in order of preference for an area that is | |
2967 | * too large. | |
2968 | */ | |
2969 | if (order >= MAX_ORDER) { | |
2970 | WARN_ON_ONCE(!(gfp_mask & __GFP_NOWARN)); | |
2971 | return NULL; | |
2972 | } | |
2973 | ||
2974 | /* | |
2975 | * If this allocation cannot block and it is for a specific node, then | |
2976 | * fail early. There's no need to wakeup kswapd or retry for a | |
2977 | * speculative node-specific allocation. | |
2978 | */ | |
2979 | if (IS_ENABLED(CONFIG_NUMA) && (gfp_mask & __GFP_THISNODE) && !wait) | |
2980 | goto nopage; | |
2981 | ||
2982 | retry: | |
2983 | if (!(gfp_mask & __GFP_NO_KSWAPD)) | |
2984 | wake_all_kswapds(order, ac); | |
2985 | ||
2986 | /* | |
2987 | * OK, we're below the kswapd watermark and have kicked background | |
2988 | * reclaim. Now things get more complex, so set up alloc_flags according | |
2989 | * to how we want to proceed. | |
2990 | */ | |
2991 | alloc_flags = gfp_to_alloc_flags(gfp_mask); | |
2992 | ||
2993 | /* | |
2994 | * Find the true preferred zone if the allocation is unconstrained by | |
2995 | * cpusets. | |
2996 | */ | |
2997 | if (!(alloc_flags & ALLOC_CPUSET) && !ac->nodemask) { | |
2998 | struct zoneref *preferred_zoneref; | |
2999 | preferred_zoneref = first_zones_zonelist(ac->zonelist, | |
3000 | ac->high_zoneidx, NULL, &ac->preferred_zone); | |
3001 | ac->classzone_idx = zonelist_zone_idx(preferred_zoneref); | |
3002 | } | |
3003 | ||
3004 | /* This is the last chance, in general, before the goto nopage. */ | |
3005 | page = get_page_from_freelist(gfp_mask, order, | |
3006 | alloc_flags & ~ALLOC_NO_WATERMARKS, ac); | |
3007 | if (page) | |
3008 | goto got_pg; | |
3009 | ||
3010 | /* Allocate without watermarks if the context allows */ | |
3011 | if (alloc_flags & ALLOC_NO_WATERMARKS) { | |
3012 | /* | |
3013 | * Ignore mempolicies if ALLOC_NO_WATERMARKS on the grounds | |
3014 | * the allocation is high priority and these type of | |
3015 | * allocations are system rather than user orientated | |
3016 | */ | |
3017 | ac->zonelist = node_zonelist(numa_node_id(), gfp_mask); | |
3018 | ||
3019 | page = __alloc_pages_high_priority(gfp_mask, order, ac); | |
3020 | ||
3021 | if (page) { | |
3022 | goto got_pg; | |
3023 | } | |
3024 | } | |
3025 | ||
3026 | /* Atomic allocations - we can't balance anything */ | |
3027 | if (!wait) { | |
3028 | /* | |
3029 | * All existing users of the deprecated __GFP_NOFAIL are | |
3030 | * blockable, so warn of any new users that actually allow this | |
3031 | * type of allocation to fail. | |
3032 | */ | |
3033 | WARN_ON_ONCE(gfp_mask & __GFP_NOFAIL); | |
3034 | goto nopage; | |
3035 | } | |
3036 | ||
3037 | /* Avoid recursion of direct reclaim */ | |
3038 | if (current->flags & PF_MEMALLOC) | |
3039 | goto nopage; | |
3040 | ||
3041 | /* Avoid allocations with no watermarks from looping endlessly */ | |
3042 | if (test_thread_flag(TIF_MEMDIE) && !(gfp_mask & __GFP_NOFAIL)) | |
3043 | goto nopage; | |
3044 | ||
3045 | /* | |
3046 | * Try direct compaction. The first pass is asynchronous. Subsequent | |
3047 | * attempts after direct reclaim are synchronous | |
3048 | */ | |
3049 | page = __alloc_pages_direct_compact(gfp_mask, order, alloc_flags, ac, | |
3050 | migration_mode, | |
3051 | &contended_compaction, | |
3052 | &deferred_compaction); | |
3053 | if (page) | |
3054 | goto got_pg; | |
3055 | ||
3056 | /* Checks for THP-specific high-order allocations */ | |
3057 | if ((gfp_mask & GFP_TRANSHUGE) == GFP_TRANSHUGE) { | |
3058 | /* | |
3059 | * If compaction is deferred for high-order allocations, it is | |
3060 | * because sync compaction recently failed. If this is the case | |
3061 | * and the caller requested a THP allocation, we do not want | |
3062 | * to heavily disrupt the system, so we fail the allocation | |
3063 | * instead of entering direct reclaim. | |
3064 | */ | |
3065 | if (deferred_compaction) | |
3066 | goto nopage; | |
3067 | ||
3068 | /* | |
3069 | * In all zones where compaction was attempted (and not | |
3070 | * deferred or skipped), lock contention has been detected. | |
3071 | * For THP allocation we do not want to disrupt the others | |
3072 | * so we fallback to base pages instead. | |
3073 | */ | |
3074 | if (contended_compaction == COMPACT_CONTENDED_LOCK) | |
3075 | goto nopage; | |
3076 | ||
3077 | /* | |
3078 | * If compaction was aborted due to need_resched(), we do not | |
3079 | * want to further increase allocation latency, unless it is | |
3080 | * khugepaged trying to collapse. | |
3081 | */ | |
3082 | if (contended_compaction == COMPACT_CONTENDED_SCHED | |
3083 | && !(current->flags & PF_KTHREAD)) | |
3084 | goto nopage; | |
3085 | } | |
3086 | ||
3087 | /* | |
3088 | * It can become very expensive to allocate transparent hugepages at | |
3089 | * fault, so use asynchronous memory compaction for THP unless it is | |
3090 | * khugepaged trying to collapse. | |
3091 | */ | |
3092 | if ((gfp_mask & GFP_TRANSHUGE) != GFP_TRANSHUGE || | |
3093 | (current->flags & PF_KTHREAD)) | |
3094 | migration_mode = MIGRATE_SYNC_LIGHT; | |
3095 | ||
3096 | /* Try direct reclaim and then allocating */ | |
3097 | page = __alloc_pages_direct_reclaim(gfp_mask, order, alloc_flags, ac, | |
3098 | &did_some_progress); | |
3099 | if (page) | |
3100 | goto got_pg; | |
3101 | ||
3102 | /* Do not loop if specifically requested */ | |
3103 | if (gfp_mask & __GFP_NORETRY) | |
3104 | goto noretry; | |
3105 | ||
3106 | /* Keep reclaiming pages as long as there is reasonable progress */ | |
3107 | pages_reclaimed += did_some_progress; | |
3108 | if ((did_some_progress && order <= PAGE_ALLOC_COSTLY_ORDER) || | |
3109 | ((gfp_mask & __GFP_REPEAT) && pages_reclaimed < (1 << order))) { | |
3110 | /* Wait for some write requests to complete then retry */ | |
3111 | wait_iff_congested(ac->preferred_zone, BLK_RW_ASYNC, HZ/50); | |
3112 | goto retry; | |
3113 | } | |
3114 | ||
3115 | /* Reclaim has failed us, start killing things */ | |
3116 | page = __alloc_pages_may_oom(gfp_mask, order, ac, &did_some_progress); | |
3117 | if (page) | |
3118 | goto got_pg; | |
3119 | ||
3120 | /* Retry as long as the OOM killer is making progress */ | |
3121 | if (did_some_progress) | |
3122 | goto retry; | |
3123 | ||
3124 | noretry: | |
3125 | /* | |
3126 | * High-order allocations do not necessarily loop after | |
3127 | * direct reclaim and reclaim/compaction depends on compaction | |
3128 | * being called after reclaim so call directly if necessary | |
3129 | */ | |
3130 | page = __alloc_pages_direct_compact(gfp_mask, order, alloc_flags, | |
3131 | ac, migration_mode, | |
3132 | &contended_compaction, | |
3133 | &deferred_compaction); | |
3134 | if (page) | |
3135 | goto got_pg; | |
3136 | nopage: | |
3137 | warn_alloc_failed(gfp_mask, order, NULL); | |
3138 | got_pg: | |
3139 | return page; | |
3140 | } | |
3141 | ||
3142 | /* | |
3143 | * This is the 'heart' of the zoned buddy allocator. | |
3144 | */ | |
3145 | struct page * | |
3146 | __alloc_pages_nodemask(gfp_t gfp_mask, unsigned int order, | |
3147 | struct zonelist *zonelist, nodemask_t *nodemask) | |
3148 | { | |
3149 | struct zoneref *preferred_zoneref; | |
3150 | struct page *page = NULL; | |
3151 | unsigned int cpuset_mems_cookie; | |
3152 | int alloc_flags = ALLOC_WMARK_LOW|ALLOC_CPUSET|ALLOC_FAIR; | |
3153 | gfp_t alloc_mask; /* The gfp_t that was actually used for allocation */ | |
3154 | struct alloc_context ac = { | |
3155 | .high_zoneidx = gfp_zone(gfp_mask), | |
3156 | .nodemask = nodemask, | |
3157 | .migratetype = gfpflags_to_migratetype(gfp_mask), | |
3158 | }; | |
3159 | ||
3160 | gfp_mask &= gfp_allowed_mask; | |
3161 | ||
3162 | lockdep_trace_alloc(gfp_mask); | |
3163 | ||
3164 | might_sleep_if(gfp_mask & __GFP_WAIT); | |
3165 | ||
3166 | if (should_fail_alloc_page(gfp_mask, order)) | |
3167 | return NULL; | |
3168 | ||
3169 | /* | |
3170 | * Check the zones suitable for the gfp_mask contain at least one | |
3171 | * valid zone. It's possible to have an empty zonelist as a result | |
3172 | * of __GFP_THISNODE and a memoryless node | |
3173 | */ | |
3174 | if (unlikely(!zonelist->_zonerefs->zone)) | |
3175 | return NULL; | |
3176 | ||
3177 | if (IS_ENABLED(CONFIG_CMA) && ac.migratetype == MIGRATE_MOVABLE) | |
3178 | alloc_flags |= ALLOC_CMA; | |
3179 | ||
3180 | retry_cpuset: | |
3181 | cpuset_mems_cookie = read_mems_allowed_begin(); | |
3182 | ||
3183 | /* We set it here, as __alloc_pages_slowpath might have changed it */ | |
3184 | ac.zonelist = zonelist; | |
3185 | /* The preferred zone is used for statistics later */ | |
3186 | preferred_zoneref = first_zones_zonelist(ac.zonelist, ac.high_zoneidx, | |
3187 | ac.nodemask ? : &cpuset_current_mems_allowed, | |
3188 | &ac.preferred_zone); | |
3189 | if (!ac.preferred_zone) | |
3190 | goto out; | |
3191 | ac.classzone_idx = zonelist_zone_idx(preferred_zoneref); | |
3192 | ||
3193 | /* First allocation attempt */ | |
3194 | alloc_mask = gfp_mask|__GFP_HARDWALL; | |
3195 | page = get_page_from_freelist(alloc_mask, order, alloc_flags, &ac); | |
3196 | if (unlikely(!page)) { | |
3197 | /* | |
3198 | * Runtime PM, block IO and its error handling path | |
3199 | * can deadlock because I/O on the device might not | |
3200 | * complete. | |
3201 | */ | |
3202 | alloc_mask = memalloc_noio_flags(gfp_mask); | |
3203 | ||
3204 | page = __alloc_pages_slowpath(alloc_mask, order, &ac); | |
3205 | } | |
3206 | ||
3207 | if (kmemcheck_enabled && page) | |
3208 | kmemcheck_pagealloc_alloc(page, order, gfp_mask); | |
3209 | ||
3210 | trace_mm_page_alloc(page, order, alloc_mask, ac.migratetype); | |
3211 | ||
3212 | out: | |
3213 | /* | |
3214 | * When updating a task's mems_allowed, it is possible to race with | |
3215 | * parallel threads in such a way that an allocation can fail while | |
3216 | * the mask is being updated. If a page allocation is about to fail, | |
3217 | * check if the cpuset changed during allocation and if so, retry. | |
3218 | */ | |
3219 | if (unlikely(!page && read_mems_allowed_retry(cpuset_mems_cookie))) | |
3220 | goto retry_cpuset; | |
3221 | ||
3222 | return page; | |
3223 | } | |
3224 | EXPORT_SYMBOL(__alloc_pages_nodemask); | |
3225 | ||
3226 | /* | |
3227 | * Common helper functions. | |
3228 | */ | |
3229 | unsigned long __get_free_pages(gfp_t gfp_mask, unsigned int order) | |
3230 | { | |
3231 | struct page *page; | |
3232 | ||
3233 | /* | |
3234 | * __get_free_pages() returns a 32-bit address, which cannot represent | |
3235 | * a highmem page | |
3236 | */ | |
3237 | VM_BUG_ON((gfp_mask & __GFP_HIGHMEM) != 0); | |
3238 | ||
3239 | page = alloc_pages(gfp_mask, order); | |
3240 | if (!page) | |
3241 | return 0; | |
3242 | return (unsigned long) page_address(page); | |
3243 | } | |
3244 | EXPORT_SYMBOL(__get_free_pages); | |
3245 | ||
3246 | unsigned long get_zeroed_page(gfp_t gfp_mask) | |
3247 | { | |
3248 | return __get_free_pages(gfp_mask | __GFP_ZERO, 0); | |
3249 | } | |
3250 | EXPORT_SYMBOL(get_zeroed_page); | |
3251 | ||
3252 | void __free_pages(struct page *page, unsigned int order) | |
3253 | { | |
3254 | if (put_page_testzero(page)) { | |
3255 | if (order == 0) | |
3256 | free_hot_cold_page(page, false); | |
3257 | else | |
3258 | __free_pages_ok(page, order); | |
3259 | } | |
3260 | } | |
3261 | ||
3262 | EXPORT_SYMBOL(__free_pages); | |
3263 | ||
3264 | void free_pages(unsigned long addr, unsigned int order) | |
3265 | { | |
3266 | if (addr != 0) { | |
3267 | VM_BUG_ON(!virt_addr_valid((void *)addr)); | |
3268 | __free_pages(virt_to_page((void *)addr), order); | |
3269 | } | |
3270 | } | |
3271 | ||
3272 | EXPORT_SYMBOL(free_pages); | |
3273 | ||
3274 | /* | |
3275 | * Page Fragment: | |
3276 | * An arbitrary-length arbitrary-offset area of memory which resides | |
3277 | * within a 0 or higher order page. Multiple fragments within that page | |
3278 | * are individually refcounted, in the page's reference counter. | |
3279 | * | |
3280 | * The page_frag functions below provide a simple allocation framework for | |
3281 | * page fragments. This is used by the network stack and network device | |
3282 | * drivers to provide a backing region of memory for use as either an | |
3283 | * sk_buff->head, or to be used in the "frags" portion of skb_shared_info. | |
3284 | */ | |
3285 | static struct page *__page_frag_refill(struct page_frag_cache *nc, | |
3286 | gfp_t gfp_mask) | |
3287 | { | |
3288 | struct page *page = NULL; | |
3289 | gfp_t gfp = gfp_mask; | |
3290 | ||
3291 | #if (PAGE_SIZE < PAGE_FRAG_CACHE_MAX_SIZE) | |
3292 | gfp_mask |= __GFP_COMP | __GFP_NOWARN | __GFP_NORETRY | | |
3293 | __GFP_NOMEMALLOC; | |
3294 | page = alloc_pages_node(NUMA_NO_NODE, gfp_mask, | |
3295 | PAGE_FRAG_CACHE_MAX_ORDER); | |
3296 | nc->size = page ? PAGE_FRAG_CACHE_MAX_SIZE : PAGE_SIZE; | |
3297 | #endif | |
3298 | if (unlikely(!page)) | |
3299 | page = alloc_pages_node(NUMA_NO_NODE, gfp, 0); | |
3300 | ||
3301 | nc->va = page ? page_address(page) : NULL; | |
3302 | ||
3303 | return page; | |
3304 | } | |
3305 | ||
3306 | void *__alloc_page_frag(struct page_frag_cache *nc, | |
3307 | unsigned int fragsz, gfp_t gfp_mask) | |
3308 | { | |
3309 | unsigned int size = PAGE_SIZE; | |
3310 | struct page *page; | |
3311 | int offset; | |
3312 | ||
3313 | if (unlikely(!nc->va)) { | |
3314 | refill: | |
3315 | page = __page_frag_refill(nc, gfp_mask); | |
3316 | if (!page) | |
3317 | return NULL; | |
3318 | ||
3319 | #if (PAGE_SIZE < PAGE_FRAG_CACHE_MAX_SIZE) | |
3320 | /* if size can vary use size else just use PAGE_SIZE */ | |
3321 | size = nc->size; | |
3322 | #endif | |
3323 | /* Even if we own the page, we do not use atomic_set(). | |
3324 | * This would break get_page_unless_zero() users. | |
3325 | */ | |
3326 | atomic_add(size - 1, &page->_count); | |
3327 | ||
3328 | /* reset page count bias and offset to start of new frag */ | |
3329 | nc->pfmemalloc = page->pfmemalloc; | |
3330 | nc->pagecnt_bias = size; | |
3331 | nc->offset = size; | |
3332 | } | |
3333 | ||
3334 | offset = nc->offset - fragsz; | |
3335 | if (unlikely(offset < 0)) { | |
3336 | page = virt_to_page(nc->va); | |
3337 | ||
3338 | if (!atomic_sub_and_test(nc->pagecnt_bias, &page->_count)) | |
3339 | goto refill; | |
3340 | ||
3341 | #if (PAGE_SIZE < PAGE_FRAG_CACHE_MAX_SIZE) | |
3342 | /* if size can vary use size else just use PAGE_SIZE */ | |
3343 | size = nc->size; | |
3344 | #endif | |
3345 | /* OK, page count is 0, we can safely set it */ | |
3346 | atomic_set(&page->_count, size); | |
3347 | ||
3348 | /* reset page count bias and offset to start of new frag */ | |
3349 | nc->pagecnt_bias = size; | |
3350 | offset = size - fragsz; | |
3351 | } | |
3352 | ||
3353 | nc->pagecnt_bias--; | |
3354 | nc->offset = offset; | |
3355 | ||
3356 | return nc->va + offset; | |
3357 | } | |
3358 | EXPORT_SYMBOL(__alloc_page_frag); | |
3359 | ||
3360 | /* | |
3361 | * Frees a page fragment allocated out of either a compound or order 0 page. | |
3362 | */ | |
3363 | void __free_page_frag(void *addr) | |
3364 | { | |
3365 | struct page *page = virt_to_head_page(addr); | |
3366 | ||
3367 | if (unlikely(put_page_testzero(page))) | |
3368 | __free_pages_ok(page, compound_order(page)); | |
3369 | } | |
3370 | EXPORT_SYMBOL(__free_page_frag); | |
3371 | ||
3372 | /* | |
3373 | * alloc_kmem_pages charges newly allocated pages to the kmem resource counter | |
3374 | * of the current memory cgroup. | |
3375 | * | |
3376 | * It should be used when the caller would like to use kmalloc, but since the | |
3377 | * allocation is large, it has to fall back to the page allocator. | |
3378 | */ | |
3379 | struct page *alloc_kmem_pages(gfp_t gfp_mask, unsigned int order) | |
3380 | { | |
3381 | struct page *page; | |
3382 | struct mem_cgroup *memcg = NULL; | |
3383 | ||
3384 | if (!memcg_kmem_newpage_charge(gfp_mask, &memcg, order)) | |
3385 | return NULL; | |
3386 | page = alloc_pages(gfp_mask, order); | |
3387 | memcg_kmem_commit_charge(page, memcg, order); | |
3388 | return page; | |
3389 | } | |
3390 | ||
3391 | struct page *alloc_kmem_pages_node(int nid, gfp_t gfp_mask, unsigned int order) | |
3392 | { | |
3393 | struct page *page; | |
3394 | struct mem_cgroup *memcg = NULL; | |
3395 | ||
3396 | if (!memcg_kmem_newpage_charge(gfp_mask, &memcg, order)) | |
3397 | return NULL; | |
3398 | page = alloc_pages_node(nid, gfp_mask, order); | |
3399 | memcg_kmem_commit_charge(page, memcg, order); | |
3400 | return page; | |
3401 | } | |
3402 | ||
3403 | /* | |
3404 | * __free_kmem_pages and free_kmem_pages will free pages allocated with | |
3405 | * alloc_kmem_pages. | |
3406 | */ | |
3407 | void __free_kmem_pages(struct page *page, unsigned int order) | |
3408 | { | |
3409 | memcg_kmem_uncharge_pages(page, order); | |
3410 | __free_pages(page, order); | |
3411 | } | |
3412 | ||
3413 | void free_kmem_pages(unsigned long addr, unsigned int order) | |
3414 | { | |
3415 | if (addr != 0) { | |
3416 | VM_BUG_ON(!virt_addr_valid((void *)addr)); | |
3417 | __free_kmem_pages(virt_to_page((void *)addr), order); | |
3418 | } | |
3419 | } | |
3420 | ||
3421 | static void *make_alloc_exact(unsigned long addr, unsigned order, size_t size) | |
3422 | { | |
3423 | if (addr) { | |
3424 | unsigned long alloc_end = addr + (PAGE_SIZE << order); | |
3425 | unsigned long used = addr + PAGE_ALIGN(size); | |
3426 | ||
3427 | split_page(virt_to_page((void *)addr), order); | |
3428 | while (used < alloc_end) { | |
3429 | free_page(used); | |
3430 | used += PAGE_SIZE; | |
3431 | } | |
3432 | } | |
3433 | return (void *)addr; | |
3434 | } | |
3435 | ||
3436 | /** | |
3437 | * alloc_pages_exact - allocate an exact number physically-contiguous pages. | |
3438 | * @size: the number of bytes to allocate | |
3439 | * @gfp_mask: GFP flags for the allocation | |
3440 | * | |
3441 | * This function is similar to alloc_pages(), except that it allocates the | |
3442 | * minimum number of pages to satisfy the request. alloc_pages() can only | |
3443 | * allocate memory in power-of-two pages. | |
3444 | * | |
3445 | * This function is also limited by MAX_ORDER. | |
3446 | * | |
3447 | * Memory allocated by this function must be released by free_pages_exact(). | |
3448 | */ | |
3449 | void *alloc_pages_exact(size_t size, gfp_t gfp_mask) | |
3450 | { | |
3451 | unsigned int order = get_order(size); | |
3452 | unsigned long addr; | |
3453 | ||
3454 | addr = __get_free_pages(gfp_mask, order); | |
3455 | return make_alloc_exact(addr, order, size); | |
3456 | } | |
3457 | EXPORT_SYMBOL(alloc_pages_exact); | |
3458 | ||
3459 | /** | |
3460 | * alloc_pages_exact_nid - allocate an exact number of physically-contiguous | |
3461 | * pages on a node. | |
3462 | * @nid: the preferred node ID where memory should be allocated | |
3463 | * @size: the number of bytes to allocate | |
3464 | * @gfp_mask: GFP flags for the allocation | |
3465 | * | |
3466 | * Like alloc_pages_exact(), but try to allocate on node nid first before falling | |
3467 | * back. | |
3468 | * Note this is not alloc_pages_exact_node() which allocates on a specific node, | |
3469 | * but is not exact. | |
3470 | */ | |
3471 | void * __meminit alloc_pages_exact_nid(int nid, size_t size, gfp_t gfp_mask) | |
3472 | { | |
3473 | unsigned order = get_order(size); | |
3474 | struct page *p = alloc_pages_node(nid, gfp_mask, order); | |
3475 | if (!p) | |
3476 | return NULL; | |
3477 | return make_alloc_exact((unsigned long)page_address(p), order, size); | |
3478 | } | |
3479 | ||
3480 | /** | |
3481 | * free_pages_exact - release memory allocated via alloc_pages_exact() | |
3482 | * @virt: the value returned by alloc_pages_exact. | |
3483 | * @size: size of allocation, same value as passed to alloc_pages_exact(). | |
3484 | * | |
3485 | * Release the memory allocated by a previous call to alloc_pages_exact. | |
3486 | */ | |
3487 | void free_pages_exact(void *virt, size_t size) | |
3488 | { | |
3489 | unsigned long addr = (unsigned long)virt; | |
3490 | unsigned long end = addr + PAGE_ALIGN(size); | |
3491 | ||
3492 | while (addr < end) { | |
3493 | free_page(addr); | |
3494 | addr += PAGE_SIZE; | |
3495 | } | |
3496 | } | |
3497 | EXPORT_SYMBOL(free_pages_exact); | |
3498 | ||
3499 | /** | |
3500 | * nr_free_zone_pages - count number of pages beyond high watermark | |
3501 | * @offset: The zone index of the highest zone | |
3502 | * | |
3503 | * nr_free_zone_pages() counts the number of counts pages which are beyond the | |
3504 | * high watermark within all zones at or below a given zone index. For each | |
3505 | * zone, the number of pages is calculated as: | |
3506 | * managed_pages - high_pages | |
3507 | */ | |
3508 | static unsigned long nr_free_zone_pages(int offset) | |
3509 | { | |
3510 | struct zoneref *z; | |
3511 | struct zone *zone; | |
3512 | ||
3513 | /* Just pick one node, since fallback list is circular */ | |
3514 | unsigned long sum = 0; | |
3515 | ||
3516 | struct zonelist *zonelist = node_zonelist(numa_node_id(), GFP_KERNEL); | |
3517 | ||
3518 | for_each_zone_zonelist(zone, z, zonelist, offset) { | |
3519 | unsigned long size = zone->managed_pages; | |
3520 | unsigned long high = high_wmark_pages(zone); | |
3521 | if (size > high) | |
3522 | sum += size - high; | |
3523 | } | |
3524 | ||
3525 | return sum; | |
3526 | } | |
3527 | ||
3528 | /** | |
3529 | * nr_free_buffer_pages - count number of pages beyond high watermark | |
3530 | * | |
3531 | * nr_free_buffer_pages() counts the number of pages which are beyond the high | |
3532 | * watermark within ZONE_DMA and ZONE_NORMAL. | |
3533 | */ | |
3534 | unsigned long nr_free_buffer_pages(void) | |
3535 | { | |
3536 | return nr_free_zone_pages(gfp_zone(GFP_USER)); | |
3537 | } | |
3538 | EXPORT_SYMBOL_GPL(nr_free_buffer_pages); | |
3539 | ||
3540 | /** | |
3541 | * nr_free_pagecache_pages - count number of pages beyond high watermark | |
3542 | * | |
3543 | * nr_free_pagecache_pages() counts the number of pages which are beyond the | |
3544 | * high watermark within all zones. | |
3545 | */ | |
3546 | unsigned long nr_free_pagecache_pages(void) | |
3547 | { | |
3548 | return nr_free_zone_pages(gfp_zone(GFP_HIGHUSER_MOVABLE)); | |
3549 | } | |
3550 | ||
3551 | static inline void show_node(struct zone *zone) | |
3552 | { | |
3553 | if (IS_ENABLED(CONFIG_NUMA)) | |
3554 | printk("Node %d ", zone_to_nid(zone)); | |
3555 | } | |
3556 | ||
3557 | void si_meminfo(struct sysinfo *val) | |
3558 | { | |
3559 | val->totalram = totalram_pages; | |
3560 | val->sharedram = global_page_state(NR_SHMEM); | |
3561 | val->freeram = global_page_state(NR_FREE_PAGES); | |
3562 | val->bufferram = nr_blockdev_pages(); | |
3563 | val->totalhigh = totalhigh_pages; | |
3564 | val->freehigh = nr_free_highpages(); | |
3565 | val->mem_unit = PAGE_SIZE; | |
3566 | } | |
3567 | ||
3568 | EXPORT_SYMBOL(si_meminfo); | |
3569 | ||
3570 | #ifdef CONFIG_NUMA | |
3571 | void si_meminfo_node(struct sysinfo *val, int nid) | |
3572 | { | |
3573 | int zone_type; /* needs to be signed */ | |
3574 | unsigned long managed_pages = 0; | |
3575 | pg_data_t *pgdat = NODE_DATA(nid); | |
3576 | ||
3577 | for (zone_type = 0; zone_type < MAX_NR_ZONES; zone_type++) | |
3578 | managed_pages += pgdat->node_zones[zone_type].managed_pages; | |
3579 | val->totalram = managed_pages; | |
3580 | val->sharedram = node_page_state(nid, NR_SHMEM); | |
3581 | val->freeram = node_page_state(nid, NR_FREE_PAGES); | |
3582 | #ifdef CONFIG_HIGHMEM | |
3583 | val->totalhigh = pgdat->node_zones[ZONE_HIGHMEM].managed_pages; | |
3584 | val->freehigh = zone_page_state(&pgdat->node_zones[ZONE_HIGHMEM], | |
3585 | NR_FREE_PAGES); | |
3586 | #else | |
3587 | val->totalhigh = 0; | |
3588 | val->freehigh = 0; | |
3589 | #endif | |
3590 | val->mem_unit = PAGE_SIZE; | |
3591 | } | |
3592 | #endif | |
3593 | ||
3594 | /* | |
3595 | * Determine whether the node should be displayed or not, depending on whether | |
3596 | * SHOW_MEM_FILTER_NODES was passed to show_free_areas(). | |
3597 | */ | |
3598 | bool skip_free_areas_node(unsigned int flags, int nid) | |
3599 | { | |
3600 | bool ret = false; | |
3601 | unsigned int cpuset_mems_cookie; | |
3602 | ||
3603 | if (!(flags & SHOW_MEM_FILTER_NODES)) | |
3604 | goto out; | |
3605 | ||
3606 | do { | |
3607 | cpuset_mems_cookie = read_mems_allowed_begin(); | |
3608 | ret = !node_isset(nid, cpuset_current_mems_allowed); | |
3609 | } while (read_mems_allowed_retry(cpuset_mems_cookie)); | |
3610 | out: | |
3611 | return ret; | |
3612 | } | |
3613 | ||
3614 | #define K(x) ((x) << (PAGE_SHIFT-10)) | |
3615 | ||
3616 | static void show_migration_types(unsigned char type) | |
3617 | { | |
3618 | static const char types[MIGRATE_TYPES] = { | |
3619 | [MIGRATE_UNMOVABLE] = 'U', | |
3620 | [MIGRATE_RECLAIMABLE] = 'E', | |
3621 | [MIGRATE_MOVABLE] = 'M', | |
3622 | [MIGRATE_RESERVE] = 'R', | |
3623 | #ifdef CONFIG_CMA | |
3624 | [MIGRATE_CMA] = 'C', | |
3625 | #endif | |
3626 | #ifdef CONFIG_MEMORY_ISOLATION | |
3627 | [MIGRATE_ISOLATE] = 'I', | |
3628 | #endif | |
3629 | }; | |
3630 | char tmp[MIGRATE_TYPES + 1]; | |
3631 | char *p = tmp; | |
3632 | int i; | |
3633 | ||
3634 | for (i = 0; i < MIGRATE_TYPES; i++) { | |
3635 | if (type & (1 << i)) | |
3636 | *p++ = types[i]; | |
3637 | } | |
3638 | ||
3639 | *p = '\0'; | |
3640 | printk("(%s) ", tmp); | |
3641 | } | |
3642 | ||
3643 | /* | |
3644 | * Show free area list (used inside shift_scroll-lock stuff) | |
3645 | * We also calculate the percentage fragmentation. We do this by counting the | |
3646 | * memory on each free list with the exception of the first item on the list. | |
3647 | * | |
3648 | * Bits in @filter: | |
3649 | * SHOW_MEM_FILTER_NODES: suppress nodes that are not allowed by current's | |
3650 | * cpuset. | |
3651 | */ | |
3652 | void show_free_areas(unsigned int filter) | |
3653 | { | |
3654 | unsigned long free_pcp = 0; | |
3655 | int cpu; | |
3656 | struct zone *zone; | |
3657 | ||
3658 | for_each_populated_zone(zone) { | |
3659 | if (skip_free_areas_node(filter, zone_to_nid(zone))) | |
3660 | continue; | |
3661 | ||
3662 | for_each_online_cpu(cpu) | |
3663 | free_pcp += per_cpu_ptr(zone->pageset, cpu)->pcp.count; | |
3664 | } | |
3665 | ||
3666 | printk("active_anon:%lu inactive_anon:%lu isolated_anon:%lu\n" | |
3667 | " active_file:%lu inactive_file:%lu isolated_file:%lu\n" | |
3668 | " unevictable:%lu dirty:%lu writeback:%lu unstable:%lu\n" | |
3669 | " slab_reclaimable:%lu slab_unreclaimable:%lu\n" | |
3670 | " mapped:%lu shmem:%lu pagetables:%lu bounce:%lu\n" | |
3671 | " free:%lu free_pcp:%lu free_cma:%lu\n", | |
3672 | global_page_state(NR_ACTIVE_ANON), | |
3673 | global_page_state(NR_INACTIVE_ANON), | |
3674 | global_page_state(NR_ISOLATED_ANON), | |
3675 | global_page_state(NR_ACTIVE_FILE), | |
3676 | global_page_state(NR_INACTIVE_FILE), | |
3677 | global_page_state(NR_ISOLATED_FILE), | |
3678 | global_page_state(NR_UNEVICTABLE), | |
3679 | global_page_state(NR_FILE_DIRTY), | |
3680 | global_page_state(NR_WRITEBACK), | |
3681 | global_page_state(NR_UNSTABLE_NFS), | |
3682 | global_page_state(NR_SLAB_RECLAIMABLE), | |
3683 | global_page_state(NR_SLAB_UNRECLAIMABLE), | |
3684 | global_page_state(NR_FILE_MAPPED), | |
3685 | global_page_state(NR_SHMEM), | |
3686 | global_page_state(NR_PAGETABLE), | |
3687 | global_page_state(NR_BOUNCE), | |
3688 | global_page_state(NR_FREE_PAGES), | |
3689 | free_pcp, | |
3690 | global_page_state(NR_FREE_CMA_PAGES)); | |
3691 | ||
3692 | for_each_populated_zone(zone) { | |
3693 | int i; | |
3694 | ||
3695 | if (skip_free_areas_node(filter, zone_to_nid(zone))) | |
3696 | continue; | |
3697 | ||
3698 | free_pcp = 0; | |
3699 | for_each_online_cpu(cpu) | |
3700 | free_pcp += per_cpu_ptr(zone->pageset, cpu)->pcp.count; | |
3701 | ||
3702 | show_node(zone); | |
3703 | printk("%s" | |
3704 | " free:%lukB" | |
3705 | " min:%lukB" | |
3706 | " low:%lukB" | |
3707 | " high:%lukB" | |
3708 | " active_anon:%lukB" | |
3709 | " inactive_anon:%lukB" | |
3710 | " active_file:%lukB" | |
3711 | " inactive_file:%lukB" | |
3712 | " unevictable:%lukB" | |
3713 | " isolated(anon):%lukB" | |
3714 | " isolated(file):%lukB" | |
3715 | " present:%lukB" | |
3716 | " managed:%lukB" | |
3717 | " mlocked:%lukB" | |
3718 | " dirty:%lukB" | |
3719 | " writeback:%lukB" | |
3720 | " mapped:%lukB" | |
3721 | " shmem:%lukB" | |
3722 | " slab_reclaimable:%lukB" | |
3723 | " slab_unreclaimable:%lukB" | |
3724 | " kernel_stack:%lukB" | |
3725 | " pagetables:%lukB" | |
3726 | " unstable:%lukB" | |
3727 | " bounce:%lukB" | |
3728 | " free_pcp:%lukB" | |
3729 | " local_pcp:%ukB" | |
3730 | " free_cma:%lukB" | |
3731 | " writeback_tmp:%lukB" | |
3732 | " pages_scanned:%lu" | |
3733 | " all_unreclaimable? %s" | |
3734 | "\n", | |
3735 | zone->name, | |
3736 | K(zone_page_state(zone, NR_FREE_PAGES)), | |
3737 | K(min_wmark_pages(zone)), | |
3738 | K(low_wmark_pages(zone)), | |
3739 | K(high_wmark_pages(zone)), | |
3740 | K(zone_page_state(zone, NR_ACTIVE_ANON)), | |
3741 | K(zone_page_state(zone, NR_INACTIVE_ANON)), | |
3742 | K(zone_page_state(zone, NR_ACTIVE_FILE)), | |
3743 | K(zone_page_state(zone, NR_INACTIVE_FILE)), | |
3744 | K(zone_page_state(zone, NR_UNEVICTABLE)), | |
3745 | K(zone_page_state(zone, NR_ISOLATED_ANON)), | |
3746 | K(zone_page_state(zone, NR_ISOLATED_FILE)), | |
3747 | K(zone->present_pages), | |
3748 | K(zone->managed_pages), | |
3749 | K(zone_page_state(zone, NR_MLOCK)), | |
3750 | K(zone_page_state(zone, NR_FILE_DIRTY)), | |
3751 | K(zone_page_state(zone, NR_WRITEBACK)), | |
3752 | K(zone_page_state(zone, NR_FILE_MAPPED)), | |
3753 | K(zone_page_state(zone, NR_SHMEM)), | |
3754 | K(zone_page_state(zone, NR_SLAB_RECLAIMABLE)), | |
3755 | K(zone_page_state(zone, NR_SLAB_UNRECLAIMABLE)), | |
3756 | zone_page_state(zone, NR_KERNEL_STACK) * | |
3757 | THREAD_SIZE / 1024, | |
3758 | K(zone_page_state(zone, NR_PAGETABLE)), | |
3759 | K(zone_page_state(zone, NR_UNSTABLE_NFS)), | |
3760 | K(zone_page_state(zone, NR_BOUNCE)), | |
3761 | K(free_pcp), | |
3762 | K(this_cpu_read(zone->pageset->pcp.count)), | |
3763 | K(zone_page_state(zone, NR_FREE_CMA_PAGES)), | |
3764 | K(zone_page_state(zone, NR_WRITEBACK_TEMP)), | |
3765 | K(zone_page_state(zone, NR_PAGES_SCANNED)), | |
3766 | (!zone_reclaimable(zone) ? "yes" : "no") | |
3767 | ); | |
3768 | printk("lowmem_reserve[]:"); | |
3769 | for (i = 0; i < MAX_NR_ZONES; i++) | |
3770 | printk(" %ld", zone->lowmem_reserve[i]); | |
3771 | printk("\n"); | |
3772 | } | |
3773 | ||
3774 | for_each_populated_zone(zone) { | |
3775 | unsigned long nr[MAX_ORDER], flags, order, total = 0; | |
3776 | unsigned char types[MAX_ORDER]; | |
3777 | ||
3778 | if (skip_free_areas_node(filter, zone_to_nid(zone))) | |
3779 | continue; | |
3780 | show_node(zone); | |
3781 | printk("%s: ", zone->name); | |
3782 | ||
3783 | spin_lock_irqsave(&zone->lock, flags); | |
3784 | for (order = 0; order < MAX_ORDER; order++) { | |
3785 | struct free_area *area = &zone->free_area[order]; | |
3786 | int type; | |
3787 | ||
3788 | nr[order] = area->nr_free; | |
3789 | total += nr[order] << order; | |
3790 | ||
3791 | types[order] = 0; | |
3792 | for (type = 0; type < MIGRATE_TYPES; type++) { | |
3793 | if (!list_empty(&area->free_list[type])) | |
3794 | types[order] |= 1 << type; | |
3795 | } | |
3796 | } | |
3797 | spin_unlock_irqrestore(&zone->lock, flags); | |
3798 | for (order = 0; order < MAX_ORDER; order++) { | |
3799 | printk("%lu*%lukB ", nr[order], K(1UL) << order); | |
3800 | if (nr[order]) | |
3801 | show_migration_types(types[order]); | |
3802 | } | |
3803 | printk("= %lukB\n", K(total)); | |
3804 | } | |
3805 | ||
3806 | hugetlb_show_meminfo(); | |
3807 | ||
3808 | printk("%ld total pagecache pages\n", global_page_state(NR_FILE_PAGES)); | |
3809 | ||
3810 | show_swap_cache_info(); | |
3811 | } | |
3812 | ||
3813 | static void zoneref_set_zone(struct zone *zone, struct zoneref *zoneref) | |
3814 | { | |
3815 | zoneref->zone = zone; | |
3816 | zoneref->zone_idx = zone_idx(zone); | |
3817 | } | |
3818 | ||
3819 | /* | |
3820 | * Builds allocation fallback zone lists. | |
3821 | * | |
3822 | * Add all populated zones of a node to the zonelist. | |
3823 | */ | |
3824 | static int build_zonelists_node(pg_data_t *pgdat, struct zonelist *zonelist, | |
3825 | int nr_zones) | |
3826 | { | |
3827 | struct zone *zone; | |
3828 | enum zone_type zone_type = MAX_NR_ZONES; | |
3829 | ||
3830 | do { | |
3831 | zone_type--; | |
3832 | zone = pgdat->node_zones + zone_type; | |
3833 | if (populated_zone(zone)) { | |
3834 | zoneref_set_zone(zone, | |
3835 | &zonelist->_zonerefs[nr_zones++]); | |
3836 | check_highest_zone(zone_type); | |
3837 | } | |
3838 | } while (zone_type); | |
3839 | ||
3840 | return nr_zones; | |
3841 | } | |
3842 | ||
3843 | ||
3844 | /* | |
3845 | * zonelist_order: | |
3846 | * 0 = automatic detection of better ordering. | |
3847 | * 1 = order by ([node] distance, -zonetype) | |
3848 | * 2 = order by (-zonetype, [node] distance) | |
3849 | * | |
3850 | * If not NUMA, ZONELIST_ORDER_ZONE and ZONELIST_ORDER_NODE will create | |
3851 | * the same zonelist. So only NUMA can configure this param. | |
3852 | */ | |
3853 | #define ZONELIST_ORDER_DEFAULT 0 | |
3854 | #define ZONELIST_ORDER_NODE 1 | |
3855 | #define ZONELIST_ORDER_ZONE 2 | |
3856 | ||
3857 | /* zonelist order in the kernel. | |
3858 | * set_zonelist_order() will set this to NODE or ZONE. | |
3859 | */ | |
3860 | static int current_zonelist_order = ZONELIST_ORDER_DEFAULT; | |
3861 | static char zonelist_order_name[3][8] = {"Default", "Node", "Zone"}; | |
3862 | ||
3863 | ||
3864 | #ifdef CONFIG_NUMA | |
3865 | /* The value user specified ....changed by config */ | |
3866 | static int user_zonelist_order = ZONELIST_ORDER_DEFAULT; | |
3867 | /* string for sysctl */ | |
3868 | #define NUMA_ZONELIST_ORDER_LEN 16 | |
3869 | char numa_zonelist_order[16] = "default"; | |
3870 | ||
3871 | /* | |
3872 | * interface for configure zonelist ordering. | |
3873 | * command line option "numa_zonelist_order" | |
3874 | * = "[dD]efault - default, automatic configuration. | |
3875 | * = "[nN]ode - order by node locality, then by zone within node | |
3876 | * = "[zZ]one - order by zone, then by locality within zone | |
3877 | */ | |
3878 | ||
3879 | static int __parse_numa_zonelist_order(char *s) | |
3880 | { | |
3881 | if (*s == 'd' || *s == 'D') { | |
3882 | user_zonelist_order = ZONELIST_ORDER_DEFAULT; | |
3883 | } else if (*s == 'n' || *s == 'N') { | |
3884 | user_zonelist_order = ZONELIST_ORDER_NODE; | |
3885 | } else if (*s == 'z' || *s == 'Z') { | |
3886 | user_zonelist_order = ZONELIST_ORDER_ZONE; | |
3887 | } else { | |
3888 | printk(KERN_WARNING | |
3889 | "Ignoring invalid numa_zonelist_order value: " | |
3890 | "%s\n", s); | |
3891 | return -EINVAL; | |
3892 | } | |
3893 | return 0; | |
3894 | } | |
3895 | ||
3896 | static __init int setup_numa_zonelist_order(char *s) | |
3897 | { | |
3898 | int ret; | |
3899 | ||
3900 | if (!s) | |
3901 | return 0; | |
3902 | ||
3903 | ret = __parse_numa_zonelist_order(s); | |
3904 | if (ret == 0) | |
3905 | strlcpy(numa_zonelist_order, s, NUMA_ZONELIST_ORDER_LEN); | |
3906 | ||
3907 | return ret; | |
3908 | } | |
3909 | early_param("numa_zonelist_order", setup_numa_zonelist_order); | |
3910 | ||
3911 | /* | |
3912 | * sysctl handler for numa_zonelist_order | |
3913 | */ | |
3914 | int numa_zonelist_order_handler(struct ctl_table *table, int write, | |
3915 | void __user *buffer, size_t *length, | |
3916 | loff_t *ppos) | |
3917 | { | |
3918 | char saved_string[NUMA_ZONELIST_ORDER_LEN]; | |
3919 | int ret; | |
3920 | static DEFINE_MUTEX(zl_order_mutex); | |
3921 | ||
3922 | mutex_lock(&zl_order_mutex); | |
3923 | if (write) { | |
3924 | if (strlen((char *)table->data) >= NUMA_ZONELIST_ORDER_LEN) { | |
3925 | ret = -EINVAL; | |
3926 | goto out; | |
3927 | } | |
3928 | strcpy(saved_string, (char *)table->data); | |
3929 | } | |
3930 | ret = proc_dostring(table, write, buffer, length, ppos); | |
3931 | if (ret) | |
3932 | goto out; | |
3933 | if (write) { | |
3934 | int oldval = user_zonelist_order; | |
3935 | ||
3936 | ret = __parse_numa_zonelist_order((char *)table->data); | |
3937 | if (ret) { | |
3938 | /* | |
3939 | * bogus value. restore saved string | |
3940 | */ | |
3941 | strncpy((char *)table->data, saved_string, | |
3942 | NUMA_ZONELIST_ORDER_LEN); | |
3943 | user_zonelist_order = oldval; | |
3944 | } else if (oldval != user_zonelist_order) { | |
3945 | mutex_lock(&zonelists_mutex); | |
3946 | build_all_zonelists(NULL, NULL); | |
3947 | mutex_unlock(&zonelists_mutex); | |
3948 | } | |
3949 | } | |
3950 | out: | |
3951 | mutex_unlock(&zl_order_mutex); | |
3952 | return ret; | |
3953 | } | |
3954 | ||
3955 | ||
3956 | #define MAX_NODE_LOAD (nr_online_nodes) | |
3957 | static int node_load[MAX_NUMNODES]; | |
3958 | ||
3959 | /** | |
3960 | * find_next_best_node - find the next node that should appear in a given node's fallback list | |
3961 | * @node: node whose fallback list we're appending | |
3962 | * @used_node_mask: nodemask_t of already used nodes | |
3963 | * | |
3964 | * We use a number of factors to determine which is the next node that should | |
3965 | * appear on a given node's fallback list. The node should not have appeared | |
3966 | * already in @node's fallback list, and it should be the next closest node | |
3967 | * according to the distance array (which contains arbitrary distance values | |
3968 | * from each node to each node in the system), and should also prefer nodes | |
3969 | * with no CPUs, since presumably they'll have very little allocation pressure | |
3970 | * on them otherwise. | |
3971 | * It returns -1 if no node is found. | |
3972 | */ | |
3973 | static int find_next_best_node(int node, nodemask_t *used_node_mask) | |
3974 | { | |
3975 | int n, val; | |
3976 | int min_val = INT_MAX; | |
3977 | int best_node = NUMA_NO_NODE; | |
3978 | const struct cpumask *tmp = cpumask_of_node(0); | |
3979 | ||
3980 | /* Use the local node if we haven't already */ | |
3981 | if (!node_isset(node, *used_node_mask)) { | |
3982 | node_set(node, *used_node_mask); | |
3983 | return node; | |
3984 | } | |
3985 | ||
3986 | for_each_node_state(n, N_MEMORY) { | |
3987 | ||
3988 | /* Don't want a node to appear more than once */ | |
3989 | if (node_isset(n, *used_node_mask)) | |
3990 | continue; | |
3991 | ||
3992 | /* Use the distance array to find the distance */ | |
3993 | val = node_distance(node, n); | |
3994 | ||
3995 | /* Penalize nodes under us ("prefer the next node") */ | |
3996 | val += (n < node); | |
3997 | ||
3998 | /* Give preference to headless and unused nodes */ | |
3999 | tmp = cpumask_of_node(n); | |
4000 | if (!cpumask_empty(tmp)) | |
4001 | val += PENALTY_FOR_NODE_WITH_CPUS; | |
4002 | ||
4003 | /* Slight preference for less loaded node */ | |
4004 | val *= (MAX_NODE_LOAD*MAX_NUMNODES); | |
4005 | val += node_load[n]; | |
4006 | ||
4007 | if (val < min_val) { | |
4008 | min_val = val; | |
4009 | best_node = n; | |
4010 | } | |
4011 | } | |
4012 | ||
4013 | if (best_node >= 0) | |
4014 | node_set(best_node, *used_node_mask); | |
4015 | ||
4016 | return best_node; | |
4017 | } | |
4018 | ||
4019 | ||
4020 | /* | |
4021 | * Build zonelists ordered by node and zones within node. | |
4022 | * This results in maximum locality--normal zone overflows into local | |
4023 | * DMA zone, if any--but risks exhausting DMA zone. | |
4024 | */ | |
4025 | static void build_zonelists_in_node_order(pg_data_t *pgdat, int node) | |
4026 | { | |
4027 | int j; | |
4028 | struct zonelist *zonelist; | |
4029 | ||
4030 | zonelist = &pgdat->node_zonelists[0]; | |
4031 | for (j = 0; zonelist->_zonerefs[j].zone != NULL; j++) | |
4032 | ; | |
4033 | j = build_zonelists_node(NODE_DATA(node), zonelist, j); | |
4034 | zonelist->_zonerefs[j].zone = NULL; | |
4035 | zonelist->_zonerefs[j].zone_idx = 0; | |
4036 | } | |
4037 | ||
4038 | /* | |
4039 | * Build gfp_thisnode zonelists | |
4040 | */ | |
4041 | static void build_thisnode_zonelists(pg_data_t *pgdat) | |
4042 | { | |
4043 | int j; | |
4044 | struct zonelist *zonelist; | |
4045 | ||
4046 | zonelist = &pgdat->node_zonelists[1]; | |
4047 | j = build_zonelists_node(pgdat, zonelist, 0); | |
4048 | zonelist->_zonerefs[j].zone = NULL; | |
4049 | zonelist->_zonerefs[j].zone_idx = 0; | |
4050 | } | |
4051 | ||
4052 | /* | |
4053 | * Build zonelists ordered by zone and nodes within zones. | |
4054 | * This results in conserving DMA zone[s] until all Normal memory is | |
4055 | * exhausted, but results in overflowing to remote node while memory | |
4056 | * may still exist in local DMA zone. | |
4057 | */ | |
4058 | static int node_order[MAX_NUMNODES]; | |
4059 | ||
4060 | static void build_zonelists_in_zone_order(pg_data_t *pgdat, int nr_nodes) | |
4061 | { | |
4062 | int pos, j, node; | |
4063 | int zone_type; /* needs to be signed */ | |
4064 | struct zone *z; | |
4065 | struct zonelist *zonelist; | |
4066 | ||
4067 | zonelist = &pgdat->node_zonelists[0]; | |
4068 | pos = 0; | |
4069 | for (zone_type = MAX_NR_ZONES - 1; zone_type >= 0; zone_type--) { | |
4070 | for (j = 0; j < nr_nodes; j++) { | |
4071 | node = node_order[j]; | |
4072 | z = &NODE_DATA(node)->node_zones[zone_type]; | |
4073 | if (populated_zone(z)) { | |
4074 | zoneref_set_zone(z, | |
4075 | &zonelist->_zonerefs[pos++]); | |
4076 | check_highest_zone(zone_type); | |
4077 | } | |
4078 | } | |
4079 | } | |
4080 | zonelist->_zonerefs[pos].zone = NULL; | |
4081 | zonelist->_zonerefs[pos].zone_idx = 0; | |
4082 | } | |
4083 | ||
4084 | #if defined(CONFIG_64BIT) | |
4085 | /* | |
4086 | * Devices that require DMA32/DMA are relatively rare and do not justify a | |
4087 | * penalty to every machine in case the specialised case applies. Default | |
4088 | * to Node-ordering on 64-bit NUMA machines | |
4089 | */ | |
4090 | static int default_zonelist_order(void) | |
4091 | { | |
4092 | return ZONELIST_ORDER_NODE; | |
4093 | } | |
4094 | #else | |
4095 | /* | |
4096 | * On 32-bit, the Normal zone needs to be preserved for allocations accessible | |
4097 | * by the kernel. If processes running on node 0 deplete the low memory zone | |
4098 | * then reclaim will occur more frequency increasing stalls and potentially | |
4099 | * be easier to OOM if a large percentage of the zone is under writeback or | |
4100 | * dirty. The problem is significantly worse if CONFIG_HIGHPTE is not set. | |
4101 | * Hence, default to zone ordering on 32-bit. | |
4102 | */ | |
4103 | static int default_zonelist_order(void) | |
4104 | { | |
4105 | return ZONELIST_ORDER_ZONE; | |
4106 | } | |
4107 | #endif /* CONFIG_64BIT */ | |
4108 | ||
4109 | static void set_zonelist_order(void) | |
4110 | { | |
4111 | if (user_zonelist_order == ZONELIST_ORDER_DEFAULT) | |
4112 | current_zonelist_order = default_zonelist_order(); | |
4113 | else | |
4114 | current_zonelist_order = user_zonelist_order; | |
4115 | } | |
4116 | ||
4117 | static void build_zonelists(pg_data_t *pgdat) | |
4118 | { | |
4119 | int j, node, load; | |
4120 | enum zone_type i; | |
4121 | nodemask_t used_mask; | |
4122 | int local_node, prev_node; | |
4123 | struct zonelist *zonelist; | |
4124 | int order = current_zonelist_order; | |
4125 | ||
4126 | /* initialize zonelists */ | |
4127 | for (i = 0; i < MAX_ZONELISTS; i++) { | |
4128 | zonelist = pgdat->node_zonelists + i; | |
4129 | zonelist->_zonerefs[0].zone = NULL; | |
4130 | zonelist->_zonerefs[0].zone_idx = 0; | |
4131 | } | |
4132 | ||
4133 | /* NUMA-aware ordering of nodes */ | |
4134 | local_node = pgdat->node_id; | |
4135 | load = nr_online_nodes; | |
4136 | prev_node = local_node; | |
4137 | nodes_clear(used_mask); | |
4138 | ||
4139 | memset(node_order, 0, sizeof(node_order)); | |
4140 | j = 0; | |
4141 | ||
4142 | while ((node = find_next_best_node(local_node, &used_mask)) >= 0) { | |
4143 | /* | |
4144 | * We don't want to pressure a particular node. | |
4145 | * So adding penalty to the first node in same | |
4146 | * distance group to make it round-robin. | |
4147 | */ | |
4148 | if (node_distance(local_node, node) != | |
4149 | node_distance(local_node, prev_node)) | |
4150 | node_load[node] = load; | |
4151 | ||
4152 | prev_node = node; | |
4153 | load--; | |
4154 | if (order == ZONELIST_ORDER_NODE) | |
4155 | build_zonelists_in_node_order(pgdat, node); | |
4156 | else | |
4157 | node_order[j++] = node; /* remember order */ | |
4158 | } | |
4159 | ||
4160 | if (order == ZONELIST_ORDER_ZONE) { | |
4161 | /* calculate node order -- i.e., DMA last! */ | |
4162 | build_zonelists_in_zone_order(pgdat, j); | |
4163 | } | |
4164 | ||
4165 | build_thisnode_zonelists(pgdat); | |
4166 | } | |
4167 | ||
4168 | /* Construct the zonelist performance cache - see further mmzone.h */ | |
4169 | static void build_zonelist_cache(pg_data_t *pgdat) | |
4170 | { | |
4171 | struct zonelist *zonelist; | |
4172 | struct zonelist_cache *zlc; | |
4173 | struct zoneref *z; | |
4174 | ||
4175 | zonelist = &pgdat->node_zonelists[0]; | |
4176 | zonelist->zlcache_ptr = zlc = &zonelist->zlcache; | |
4177 | bitmap_zero(zlc->fullzones, MAX_ZONES_PER_ZONELIST); | |
4178 | for (z = zonelist->_zonerefs; z->zone; z++) | |
4179 | zlc->z_to_n[z - zonelist->_zonerefs] = zonelist_node_idx(z); | |
4180 | } | |
4181 | ||
4182 | #ifdef CONFIG_HAVE_MEMORYLESS_NODES | |
4183 | /* | |
4184 | * Return node id of node used for "local" allocations. | |
4185 | * I.e., first node id of first zone in arg node's generic zonelist. | |
4186 | * Used for initializing percpu 'numa_mem', which is used primarily | |
4187 | * for kernel allocations, so use GFP_KERNEL flags to locate zonelist. | |
4188 | */ | |
4189 | int local_memory_node(int node) | |
4190 | { | |
4191 | struct zone *zone; | |
4192 | ||
4193 | (void)first_zones_zonelist(node_zonelist(node, GFP_KERNEL), | |
4194 | gfp_zone(GFP_KERNEL), | |
4195 | NULL, | |
4196 | &zone); | |
4197 | return zone->node; | |
4198 | } | |
4199 | #endif | |
4200 | ||
4201 | #else /* CONFIG_NUMA */ | |
4202 | ||
4203 | static void set_zonelist_order(void) | |
4204 | { | |
4205 | current_zonelist_order = ZONELIST_ORDER_ZONE; | |
4206 | } | |
4207 | ||
4208 | static void build_zonelists(pg_data_t *pgdat) | |
4209 | { | |
4210 | int node, local_node; | |
4211 | enum zone_type j; | |
4212 | struct zonelist *zonelist; | |
4213 | ||
4214 | local_node = pgdat->node_id; | |
4215 | ||
4216 | zonelist = &pgdat->node_zonelists[0]; | |
4217 | j = build_zonelists_node(pgdat, zonelist, 0); | |
4218 | ||
4219 | /* | |
4220 | * Now we build the zonelist so that it contains the zones | |
4221 | * of all the other nodes. | |
4222 | * We don't want to pressure a particular node, so when | |
4223 | * building the zones for node N, we make sure that the | |
4224 | * zones coming right after the local ones are those from | |
4225 | * node N+1 (modulo N) | |
4226 | */ | |
4227 | for (node = local_node + 1; node < MAX_NUMNODES; node++) { | |
4228 | if (!node_online(node)) | |
4229 | continue; | |
4230 | j = build_zonelists_node(NODE_DATA(node), zonelist, j); | |
4231 | } | |
4232 | for (node = 0; node < local_node; node++) { | |
4233 | if (!node_online(node)) | |
4234 | continue; | |
4235 | j = build_zonelists_node(NODE_DATA(node), zonelist, j); | |
4236 | } | |
4237 | ||
4238 | zonelist->_zonerefs[j].zone = NULL; | |
4239 | zonelist->_zonerefs[j].zone_idx = 0; | |
4240 | } | |
4241 | ||
4242 | /* non-NUMA variant of zonelist performance cache - just NULL zlcache_ptr */ | |
4243 | static void build_zonelist_cache(pg_data_t *pgdat) | |
4244 | { | |
4245 | pgdat->node_zonelists[0].zlcache_ptr = NULL; | |
4246 | } | |
4247 | ||
4248 | #endif /* CONFIG_NUMA */ | |
4249 | ||
4250 | /* | |
4251 | * Boot pageset table. One per cpu which is going to be used for all | |
4252 | * zones and all nodes. The parameters will be set in such a way | |
4253 | * that an item put on a list will immediately be handed over to | |
4254 | * the buddy list. This is safe since pageset manipulation is done | |
4255 | * with interrupts disabled. | |
4256 | * | |
4257 | * The boot_pagesets must be kept even after bootup is complete for | |
4258 | * unused processors and/or zones. They do play a role for bootstrapping | |
4259 | * hotplugged processors. | |
4260 | * | |
4261 | * zoneinfo_show() and maybe other functions do | |
4262 | * not check if the processor is online before following the pageset pointer. | |
4263 | * Other parts of the kernel may not check if the zone is available. | |
4264 | */ | |
4265 | static void setup_pageset(struct per_cpu_pageset *p, unsigned long batch); | |
4266 | static DEFINE_PER_CPU(struct per_cpu_pageset, boot_pageset); | |
4267 | static void setup_zone_pageset(struct zone *zone); | |
4268 | ||
4269 | /* | |
4270 | * Global mutex to protect against size modification of zonelists | |
4271 | * as well as to serialize pageset setup for the new populated zone. | |
4272 | */ | |
4273 | DEFINE_MUTEX(zonelists_mutex); | |
4274 | ||
4275 | /* return values int ....just for stop_machine() */ | |
4276 | static int __build_all_zonelists(void *data) | |
4277 | { | |
4278 | int nid; | |
4279 | int cpu; | |
4280 | pg_data_t *self = data; | |
4281 | ||
4282 | #ifdef CONFIG_NUMA | |
4283 | memset(node_load, 0, sizeof(node_load)); | |
4284 | #endif | |
4285 | ||
4286 | if (self && !node_online(self->node_id)) { | |
4287 | build_zonelists(self); | |
4288 | build_zonelist_cache(self); | |
4289 | } | |
4290 | ||
4291 | for_each_online_node(nid) { | |
4292 | pg_data_t *pgdat = NODE_DATA(nid); | |
4293 | ||
4294 | build_zonelists(pgdat); | |
4295 | build_zonelist_cache(pgdat); | |
4296 | } | |
4297 | ||
4298 | /* | |
4299 | * Initialize the boot_pagesets that are going to be used | |
4300 | * for bootstrapping processors. The real pagesets for | |
4301 | * each zone will be allocated later when the per cpu | |
4302 | * allocator is available. | |
4303 | * | |
4304 | * boot_pagesets are used also for bootstrapping offline | |
4305 | * cpus if the system is already booted because the pagesets | |
4306 | * are needed to initialize allocators on a specific cpu too. | |
4307 | * F.e. the percpu allocator needs the page allocator which | |
4308 | * needs the percpu allocator in order to allocate its pagesets | |
4309 | * (a chicken-egg dilemma). | |
4310 | */ | |
4311 | for_each_possible_cpu(cpu) { | |
4312 | setup_pageset(&per_cpu(boot_pageset, cpu), 0); | |
4313 | ||
4314 | #ifdef CONFIG_HAVE_MEMORYLESS_NODES | |
4315 | /* | |
4316 | * We now know the "local memory node" for each node-- | |
4317 | * i.e., the node of the first zone in the generic zonelist. | |
4318 | * Set up numa_mem percpu variable for on-line cpus. During | |
4319 | * boot, only the boot cpu should be on-line; we'll init the | |
4320 | * secondary cpus' numa_mem as they come on-line. During | |
4321 | * node/memory hotplug, we'll fixup all on-line cpus. | |
4322 | */ | |
4323 | if (cpu_online(cpu)) | |
4324 | set_cpu_numa_mem(cpu, local_memory_node(cpu_to_node(cpu))); | |
4325 | #endif | |
4326 | } | |
4327 | ||
4328 | return 0; | |
4329 | } | |
4330 | ||
4331 | static noinline void __init | |
4332 | build_all_zonelists_init(void) | |
4333 | { | |
4334 | __build_all_zonelists(NULL); | |
4335 | mminit_verify_zonelist(); | |
4336 | cpuset_init_current_mems_allowed(); | |
4337 | } | |
4338 | ||
4339 | /* | |
4340 | * Called with zonelists_mutex held always | |
4341 | * unless system_state == SYSTEM_BOOTING. | |
4342 | * | |
4343 | * __ref due to (1) call of __meminit annotated setup_zone_pageset | |
4344 | * [we're only called with non-NULL zone through __meminit paths] and | |
4345 | * (2) call of __init annotated helper build_all_zonelists_init | |
4346 | * [protected by SYSTEM_BOOTING]. | |
4347 | */ | |
4348 | void __ref build_all_zonelists(pg_data_t *pgdat, struct zone *zone) | |
4349 | { | |
4350 | set_zonelist_order(); | |
4351 | ||
4352 | if (system_state == SYSTEM_BOOTING) { | |
4353 | build_all_zonelists_init(); | |
4354 | } else { | |
4355 | #ifdef CONFIG_MEMORY_HOTPLUG | |
4356 | if (zone) | |
4357 | setup_zone_pageset(zone); | |
4358 | #endif | |
4359 | /* we have to stop all cpus to guarantee there is no user | |
4360 | of zonelist */ | |
4361 | stop_machine(__build_all_zonelists, pgdat, NULL); | |
4362 | /* cpuset refresh routine should be here */ | |
4363 | } | |
4364 | vm_total_pages = nr_free_pagecache_pages(); | |
4365 | /* | |
4366 | * Disable grouping by mobility if the number of pages in the | |
4367 | * system is too low to allow the mechanism to work. It would be | |
4368 | * more accurate, but expensive to check per-zone. This check is | |
4369 | * made on memory-hotadd so a system can start with mobility | |
4370 | * disabled and enable it later | |
4371 | */ | |
4372 | if (vm_total_pages < (pageblock_nr_pages * MIGRATE_TYPES)) | |
4373 | page_group_by_mobility_disabled = 1; | |
4374 | else | |
4375 | page_group_by_mobility_disabled = 0; | |
4376 | ||
4377 | pr_info("Built %i zonelists in %s order, mobility grouping %s. " | |
4378 | "Total pages: %ld\n", | |
4379 | nr_online_nodes, | |
4380 | zonelist_order_name[current_zonelist_order], | |
4381 | page_group_by_mobility_disabled ? "off" : "on", | |
4382 | vm_total_pages); | |
4383 | #ifdef CONFIG_NUMA | |
4384 | pr_info("Policy zone: %s\n", zone_names[policy_zone]); | |
4385 | #endif | |
4386 | } | |
4387 | ||
4388 | /* | |
4389 | * Helper functions to size the waitqueue hash table. | |
4390 | * Essentially these want to choose hash table sizes sufficiently | |
4391 | * large so that collisions trying to wait on pages are rare. | |
4392 | * But in fact, the number of active page waitqueues on typical | |
4393 | * systems is ridiculously low, less than 200. So this is even | |
4394 | * conservative, even though it seems large. | |
4395 | * | |
4396 | * The constant PAGES_PER_WAITQUEUE specifies the ratio of pages to | |
4397 | * waitqueues, i.e. the size of the waitq table given the number of pages. | |
4398 | */ | |
4399 | #define PAGES_PER_WAITQUEUE 256 | |
4400 | ||
4401 | #ifndef CONFIG_MEMORY_HOTPLUG | |
4402 | static inline unsigned long wait_table_hash_nr_entries(unsigned long pages) | |
4403 | { | |
4404 | unsigned long size = 1; | |
4405 | ||
4406 | pages /= PAGES_PER_WAITQUEUE; | |
4407 | ||
4408 | while (size < pages) | |
4409 | size <<= 1; | |
4410 | ||
4411 | /* | |
4412 | * Once we have dozens or even hundreds of threads sleeping | |
4413 | * on IO we've got bigger problems than wait queue collision. | |
4414 | * Limit the size of the wait table to a reasonable size. | |
4415 | */ | |
4416 | size = min(size, 4096UL); | |
4417 | ||
4418 | return max(size, 4UL); | |
4419 | } | |
4420 | #else | |
4421 | /* | |
4422 | * A zone's size might be changed by hot-add, so it is not possible to determine | |
4423 | * a suitable size for its wait_table. So we use the maximum size now. | |
4424 | * | |
4425 | * The max wait table size = 4096 x sizeof(wait_queue_head_t). ie: | |
4426 | * | |
4427 | * i386 (preemption config) : 4096 x 16 = 64Kbyte. | |
4428 | * ia64, x86-64 (no preemption): 4096 x 20 = 80Kbyte. | |
4429 | * ia64, x86-64 (preemption) : 4096 x 24 = 96Kbyte. | |
4430 | * | |
4431 | * The maximum entries are prepared when a zone's memory is (512K + 256) pages | |
4432 | * or more by the traditional way. (See above). It equals: | |
4433 | * | |
4434 | * i386, x86-64, powerpc(4K page size) : = ( 2G + 1M)byte. | |
4435 | * ia64(16K page size) : = ( 8G + 4M)byte. | |
4436 | * powerpc (64K page size) : = (32G +16M)byte. | |
4437 | */ | |
4438 | static inline unsigned long wait_table_hash_nr_entries(unsigned long pages) | |
4439 | { | |
4440 | return 4096UL; | |
4441 | } | |
4442 | #endif | |
4443 | ||
4444 | /* | |
4445 | * This is an integer logarithm so that shifts can be used later | |
4446 | * to extract the more random high bits from the multiplicative | |
4447 | * hash function before the remainder is taken. | |
4448 | */ | |
4449 | static inline unsigned long wait_table_bits(unsigned long size) | |
4450 | { | |
4451 | return ffz(~size); | |
4452 | } | |
4453 | ||
4454 | /* | |
4455 | * Check if a pageblock contains reserved pages | |
4456 | */ | |
4457 | static int pageblock_is_reserved(unsigned long start_pfn, unsigned long end_pfn) | |
4458 | { | |
4459 | unsigned long pfn; | |
4460 | ||
4461 | for (pfn = start_pfn; pfn < end_pfn; pfn++) { | |
4462 | if (!pfn_valid_within(pfn) || PageReserved(pfn_to_page(pfn))) | |
4463 | return 1; | |
4464 | } | |
4465 | return 0; | |
4466 | } | |
4467 | ||
4468 | /* | |
4469 | * Mark a number of pageblocks as MIGRATE_RESERVE. The number | |
4470 | * of blocks reserved is based on min_wmark_pages(zone). The memory within | |
4471 | * the reserve will tend to store contiguous free pages. Setting min_free_kbytes | |
4472 | * higher will lead to a bigger reserve which will get freed as contiguous | |
4473 | * blocks as reclaim kicks in | |
4474 | */ | |
4475 | static void setup_zone_migrate_reserve(struct zone *zone) | |
4476 | { | |
4477 | unsigned long start_pfn, pfn, end_pfn, block_end_pfn; | |
4478 | struct page *page; | |
4479 | unsigned long block_migratetype; | |
4480 | int reserve; | |
4481 | int old_reserve; | |
4482 | ||
4483 | /* | |
4484 | * Get the start pfn, end pfn and the number of blocks to reserve | |
4485 | * We have to be careful to be aligned to pageblock_nr_pages to | |
4486 | * make sure that we always check pfn_valid for the first page in | |
4487 | * the block. | |
4488 | */ | |
4489 | start_pfn = zone->zone_start_pfn; | |
4490 | end_pfn = zone_end_pfn(zone); | |
4491 | start_pfn = roundup(start_pfn, pageblock_nr_pages); | |
4492 | reserve = roundup(min_wmark_pages(zone), pageblock_nr_pages) >> | |
4493 | pageblock_order; | |
4494 | ||
4495 | /* | |
4496 | * Reserve blocks are generally in place to help high-order atomic | |
4497 | * allocations that are short-lived. A min_free_kbytes value that | |
4498 | * would result in more than 2 reserve blocks for atomic allocations | |
4499 | * is assumed to be in place to help anti-fragmentation for the | |
4500 | * future allocation of hugepages at runtime. | |
4501 | */ | |
4502 | reserve = min(2, reserve); | |
4503 | old_reserve = zone->nr_migrate_reserve_block; | |
4504 | ||
4505 | /* When memory hot-add, we almost always need to do nothing */ | |
4506 | if (reserve == old_reserve) | |
4507 | return; | |
4508 | zone->nr_migrate_reserve_block = reserve; | |
4509 | ||
4510 | for (pfn = start_pfn; pfn < end_pfn; pfn += pageblock_nr_pages) { | |
4511 | if (!early_page_nid_uninitialised(pfn, zone_to_nid(zone))) | |
4512 | return; | |
4513 | ||
4514 | if (!pfn_valid(pfn)) | |
4515 | continue; | |
4516 | page = pfn_to_page(pfn); | |
4517 | ||
4518 | /* Watch out for overlapping nodes */ | |
4519 | if (page_to_nid(page) != zone_to_nid(zone)) | |
4520 | continue; | |
4521 | ||
4522 | block_migratetype = get_pageblock_migratetype(page); | |
4523 | ||
4524 | /* Only test what is necessary when the reserves are not met */ | |
4525 | if (reserve > 0) { | |
4526 | /* | |
4527 | * Blocks with reserved pages will never free, skip | |
4528 | * them. | |
4529 | */ | |
4530 | block_end_pfn = min(pfn + pageblock_nr_pages, end_pfn); | |
4531 | if (pageblock_is_reserved(pfn, block_end_pfn)) | |
4532 | continue; | |
4533 | ||
4534 | /* If this block is reserved, account for it */ | |
4535 | if (block_migratetype == MIGRATE_RESERVE) { | |
4536 | reserve--; | |
4537 | continue; | |
4538 | } | |
4539 | ||
4540 | /* Suitable for reserving if this block is movable */ | |
4541 | if (block_migratetype == MIGRATE_MOVABLE) { | |
4542 | set_pageblock_migratetype(page, | |
4543 | MIGRATE_RESERVE); | |
4544 | move_freepages_block(zone, page, | |
4545 | MIGRATE_RESERVE); | |
4546 | reserve--; | |
4547 | continue; | |
4548 | } | |
4549 | } else if (!old_reserve) { | |
4550 | /* | |
4551 | * At boot time we don't need to scan the whole zone | |
4552 | * for turning off MIGRATE_RESERVE. | |
4553 | */ | |
4554 | break; | |
4555 | } | |
4556 | ||
4557 | /* | |
4558 | * If the reserve is met and this is a previous reserved block, | |
4559 | * take it back | |
4560 | */ | |
4561 | if (block_migratetype == MIGRATE_RESERVE) { | |
4562 | set_pageblock_migratetype(page, MIGRATE_MOVABLE); | |
4563 | move_freepages_block(zone, page, MIGRATE_MOVABLE); | |
4564 | } | |
4565 | } | |
4566 | } | |
4567 | ||
4568 | /* | |
4569 | * Initially all pages are reserved - free ones are freed | |
4570 | * up by free_all_bootmem() once the early boot process is | |
4571 | * done. Non-atomic initialization, single-pass. | |
4572 | */ | |
4573 | void __meminit memmap_init_zone(unsigned long size, int nid, unsigned long zone, | |
4574 | unsigned long start_pfn, enum memmap_context context) | |
4575 | { | |
4576 | pg_data_t *pgdat = NODE_DATA(nid); | |
4577 | unsigned long end_pfn = start_pfn + size; | |
4578 | unsigned long pfn; | |
4579 | struct zone *z; | |
4580 | unsigned long nr_initialised = 0; | |
4581 | ||
4582 | if (highest_memmap_pfn < end_pfn - 1) | |
4583 | highest_memmap_pfn = end_pfn - 1; | |
4584 | ||
4585 | z = &pgdat->node_zones[zone]; | |
4586 | for (pfn = start_pfn; pfn < end_pfn; pfn++) { | |
4587 | /* | |
4588 | * There can be holes in boot-time mem_map[]s | |
4589 | * handed to this function. They do not | |
4590 | * exist on hotplugged memory. | |
4591 | */ | |
4592 | if (context == MEMMAP_EARLY) { | |
4593 | if (!early_pfn_valid(pfn)) | |
4594 | continue; | |
4595 | if (!early_pfn_in_nid(pfn, nid)) | |
4596 | continue; | |
4597 | if (!update_defer_init(pgdat, pfn, end_pfn, | |
4598 | &nr_initialised)) | |
4599 | break; | |
4600 | } | |
4601 | ||
4602 | /* | |
4603 | * Mark the block movable so that blocks are reserved for | |
4604 | * movable at startup. This will force kernel allocations | |
4605 | * to reserve their blocks rather than leaking throughout | |
4606 | * the address space during boot when many long-lived | |
4607 | * kernel allocations are made. Later some blocks near | |
4608 | * the start are marked MIGRATE_RESERVE by | |
4609 | * setup_zone_migrate_reserve() | |
4610 | * | |
4611 | * bitmap is created for zone's valid pfn range. but memmap | |
4612 | * can be created for invalid pages (for alignment) | |
4613 | * check here not to call set_pageblock_migratetype() against | |
4614 | * pfn out of zone. | |
4615 | */ | |
4616 | if (!(pfn & (pageblock_nr_pages - 1))) { | |
4617 | struct page *page = pfn_to_page(pfn); | |
4618 | ||
4619 | __init_single_page(page, pfn, zone, nid); | |
4620 | set_pageblock_migratetype(page, MIGRATE_MOVABLE); | |
4621 | } else { | |
4622 | __init_single_pfn(pfn, zone, nid); | |
4623 | } | |
4624 | } | |
4625 | } | |
4626 | ||
4627 | static void __meminit zone_init_free_lists(struct zone *zone) | |
4628 | { | |
4629 | unsigned int order, t; | |
4630 | for_each_migratetype_order(order, t) { | |
4631 | INIT_LIST_HEAD(&zone->free_area[order].free_list[t]); | |
4632 | zone->free_area[order].nr_free = 0; | |
4633 | } | |
4634 | } | |
4635 | ||
4636 | #ifndef __HAVE_ARCH_MEMMAP_INIT | |
4637 | #define memmap_init(size, nid, zone, start_pfn) \ | |
4638 | memmap_init_zone((size), (nid), (zone), (start_pfn), MEMMAP_EARLY) | |
4639 | #endif | |
4640 | ||
4641 | static int zone_batchsize(struct zone *zone) | |
4642 | { | |
4643 | #ifdef CONFIG_MMU | |
4644 | int batch; | |
4645 | ||
4646 | /* | |
4647 | * The per-cpu-pages pools are set to around 1000th of the | |
4648 | * size of the zone. But no more than 1/2 of a meg. | |
4649 | * | |
4650 | * OK, so we don't know how big the cache is. So guess. | |
4651 | */ | |
4652 | batch = zone->managed_pages / 1024; | |
4653 | if (batch * PAGE_SIZE > 512 * 1024) | |
4654 | batch = (512 * 1024) / PAGE_SIZE; | |
4655 | batch /= 4; /* We effectively *= 4 below */ | |
4656 | if (batch < 1) | |
4657 | batch = 1; | |
4658 | ||
4659 | /* | |
4660 | * Clamp the batch to a 2^n - 1 value. Having a power | |
4661 | * of 2 value was found to be more likely to have | |
4662 | * suboptimal cache aliasing properties in some cases. | |
4663 | * | |
4664 | * For example if 2 tasks are alternately allocating | |
4665 | * batches of pages, one task can end up with a lot | |
4666 | * of pages of one half of the possible page colors | |
4667 | * and the other with pages of the other colors. | |
4668 | */ | |
4669 | batch = rounddown_pow_of_two(batch + batch/2) - 1; | |
4670 | ||
4671 | return batch; | |
4672 | ||
4673 | #else | |
4674 | /* The deferral and batching of frees should be suppressed under NOMMU | |
4675 | * conditions. | |
4676 | * | |
4677 | * The problem is that NOMMU needs to be able to allocate large chunks | |
4678 | * of contiguous memory as there's no hardware page translation to | |
4679 | * assemble apparent contiguous memory from discontiguous pages. | |
4680 | * | |
4681 | * Queueing large contiguous runs of pages for batching, however, | |
4682 | * causes the pages to actually be freed in smaller chunks. As there | |
4683 | * can be a significant delay between the individual batches being | |
4684 | * recycled, this leads to the once large chunks of space being | |
4685 | * fragmented and becoming unavailable for high-order allocations. | |
4686 | */ | |
4687 | return 0; | |
4688 | #endif | |
4689 | } | |
4690 | ||
4691 | /* | |
4692 | * pcp->high and pcp->batch values are related and dependent on one another: | |
4693 | * ->batch must never be higher then ->high. | |
4694 | * The following function updates them in a safe manner without read side | |
4695 | * locking. | |
4696 | * | |
4697 | * Any new users of pcp->batch and pcp->high should ensure they can cope with | |
4698 | * those fields changing asynchronously (acording the the above rule). | |
4699 | * | |
4700 | * mutex_is_locked(&pcp_batch_high_lock) required when calling this function | |
4701 | * outside of boot time (or some other assurance that no concurrent updaters | |
4702 | * exist). | |
4703 | */ | |
4704 | static void pageset_update(struct per_cpu_pages *pcp, unsigned long high, | |
4705 | unsigned long batch) | |
4706 | { | |
4707 | /* start with a fail safe value for batch */ | |
4708 | pcp->batch = 1; | |
4709 | smp_wmb(); | |
4710 | ||
4711 | /* Update high, then batch, in order */ | |
4712 | pcp->high = high; | |
4713 | smp_wmb(); | |
4714 | ||
4715 | pcp->batch = batch; | |
4716 | } | |
4717 | ||
4718 | /* a companion to pageset_set_high() */ | |
4719 | static void pageset_set_batch(struct per_cpu_pageset *p, unsigned long batch) | |
4720 | { | |
4721 | pageset_update(&p->pcp, 6 * batch, max(1UL, 1 * batch)); | |
4722 | } | |
4723 | ||
4724 | static void pageset_init(struct per_cpu_pageset *p) | |
4725 | { | |
4726 | struct per_cpu_pages *pcp; | |
4727 | int migratetype; | |
4728 | ||
4729 | memset(p, 0, sizeof(*p)); | |
4730 | ||
4731 | pcp = &p->pcp; | |
4732 | pcp->count = 0; | |
4733 | for (migratetype = 0; migratetype < MIGRATE_PCPTYPES; migratetype++) | |
4734 | INIT_LIST_HEAD(&pcp->lists[migratetype]); | |
4735 | } | |
4736 | ||
4737 | static void setup_pageset(struct per_cpu_pageset *p, unsigned long batch) | |
4738 | { | |
4739 | pageset_init(p); | |
4740 | pageset_set_batch(p, batch); | |
4741 | } | |
4742 | ||
4743 | /* | |
4744 | * pageset_set_high() sets the high water mark for hot per_cpu_pagelist | |
4745 | * to the value high for the pageset p. | |
4746 | */ | |
4747 | static void pageset_set_high(struct per_cpu_pageset *p, | |
4748 | unsigned long high) | |
4749 | { | |
4750 | unsigned long batch = max(1UL, high / 4); | |
4751 | if ((high / 4) > (PAGE_SHIFT * 8)) | |
4752 | batch = PAGE_SHIFT * 8; | |
4753 | ||
4754 | pageset_update(&p->pcp, high, batch); | |
4755 | } | |
4756 | ||
4757 | static void pageset_set_high_and_batch(struct zone *zone, | |
4758 | struct per_cpu_pageset *pcp) | |
4759 | { | |
4760 | if (percpu_pagelist_fraction) | |
4761 | pageset_set_high(pcp, | |
4762 | (zone->managed_pages / | |
4763 | percpu_pagelist_fraction)); | |
4764 | else | |
4765 | pageset_set_batch(pcp, zone_batchsize(zone)); | |
4766 | } | |
4767 | ||
4768 | static void __meminit zone_pageset_init(struct zone *zone, int cpu) | |
4769 | { | |
4770 | struct per_cpu_pageset *pcp = per_cpu_ptr(zone->pageset, cpu); | |
4771 | ||
4772 | pageset_init(pcp); | |
4773 | pageset_set_high_and_batch(zone, pcp); | |
4774 | } | |
4775 | ||
4776 | static void __meminit setup_zone_pageset(struct zone *zone) | |
4777 | { | |
4778 | int cpu; | |
4779 | zone->pageset = alloc_percpu(struct per_cpu_pageset); | |
4780 | for_each_possible_cpu(cpu) | |
4781 | zone_pageset_init(zone, cpu); | |
4782 | } | |
4783 | ||
4784 | /* | |
4785 | * Allocate per cpu pagesets and initialize them. | |
4786 | * Before this call only boot pagesets were available. | |
4787 | */ | |
4788 | void __init setup_per_cpu_pageset(void) | |
4789 | { | |
4790 | struct zone *zone; | |
4791 | ||
4792 | for_each_populated_zone(zone) | |
4793 | setup_zone_pageset(zone); | |
4794 | } | |
4795 | ||
4796 | static noinline __init_refok | |
4797 | int zone_wait_table_init(struct zone *zone, unsigned long zone_size_pages) | |
4798 | { | |
4799 | int i; | |
4800 | size_t alloc_size; | |
4801 | ||
4802 | /* | |
4803 | * The per-page waitqueue mechanism uses hashed waitqueues | |
4804 | * per zone. | |
4805 | */ | |
4806 | zone->wait_table_hash_nr_entries = | |
4807 | wait_table_hash_nr_entries(zone_size_pages); | |
4808 | zone->wait_table_bits = | |
4809 | wait_table_bits(zone->wait_table_hash_nr_entries); | |
4810 | alloc_size = zone->wait_table_hash_nr_entries | |
4811 | * sizeof(wait_queue_head_t); | |
4812 | ||
4813 | if (!slab_is_available()) { | |
4814 | zone->wait_table = (wait_queue_head_t *) | |
4815 | memblock_virt_alloc_node_nopanic( | |
4816 | alloc_size, zone->zone_pgdat->node_id); | |
4817 | } else { | |
4818 | /* | |
4819 | * This case means that a zone whose size was 0 gets new memory | |
4820 | * via memory hot-add. | |
4821 | * But it may be the case that a new node was hot-added. In | |
4822 | * this case vmalloc() will not be able to use this new node's | |
4823 | * memory - this wait_table must be initialized to use this new | |
4824 | * node itself as well. | |
4825 | * To use this new node's memory, further consideration will be | |
4826 | * necessary. | |
4827 | */ | |
4828 | zone->wait_table = vmalloc(alloc_size); | |
4829 | } | |
4830 | if (!zone->wait_table) | |
4831 | return -ENOMEM; | |
4832 | ||
4833 | for (i = 0; i < zone->wait_table_hash_nr_entries; ++i) | |
4834 | init_waitqueue_head(zone->wait_table + i); | |
4835 | ||
4836 | return 0; | |
4837 | } | |
4838 | ||
4839 | static __meminit void zone_pcp_init(struct zone *zone) | |
4840 | { | |
4841 | /* | |
4842 | * per cpu subsystem is not up at this point. The following code | |
4843 | * relies on the ability of the linker to provide the | |
4844 | * offset of a (static) per cpu variable into the per cpu area. | |
4845 | */ | |
4846 | zone->pageset = &boot_pageset; | |
4847 | ||
4848 | if (populated_zone(zone)) | |
4849 | printk(KERN_DEBUG " %s zone: %lu pages, LIFO batch:%u\n", | |
4850 | zone->name, zone->present_pages, | |
4851 | zone_batchsize(zone)); | |
4852 | } | |
4853 | ||
4854 | int __meminit init_currently_empty_zone(struct zone *zone, | |
4855 | unsigned long zone_start_pfn, | |
4856 | unsigned long size, | |
4857 | enum memmap_context context) | |
4858 | { | |
4859 | struct pglist_data *pgdat = zone->zone_pgdat; | |
4860 | int ret; | |
4861 | ret = zone_wait_table_init(zone, size); | |
4862 | if (ret) | |
4863 | return ret; | |
4864 | pgdat->nr_zones = zone_idx(zone) + 1; | |
4865 | ||
4866 | zone->zone_start_pfn = zone_start_pfn; | |
4867 | ||
4868 | mminit_dprintk(MMINIT_TRACE, "memmap_init", | |
4869 | "Initialising map node %d zone %lu pfns %lu -> %lu\n", | |
4870 | pgdat->node_id, | |
4871 | (unsigned long)zone_idx(zone), | |
4872 | zone_start_pfn, (zone_start_pfn + size)); | |
4873 | ||
4874 | zone_init_free_lists(zone); | |
4875 | ||
4876 | return 0; | |
4877 | } | |
4878 | ||
4879 | #ifdef CONFIG_HAVE_MEMBLOCK_NODE_MAP | |
4880 | #ifndef CONFIG_HAVE_ARCH_EARLY_PFN_TO_NID | |
4881 | ||
4882 | /* | |
4883 | * Required by SPARSEMEM. Given a PFN, return what node the PFN is on. | |
4884 | */ | |
4885 | int __meminit __early_pfn_to_nid(unsigned long pfn, | |
4886 | struct mminit_pfnnid_cache *state) | |
4887 | { | |
4888 | unsigned long start_pfn, end_pfn; | |
4889 | int nid; | |
4890 | ||
4891 | if (state->last_start <= pfn && pfn < state->last_end) | |
4892 | return state->last_nid; | |
4893 | ||
4894 | nid = memblock_search_pfn_nid(pfn, &start_pfn, &end_pfn); | |
4895 | if (nid != -1) { | |
4896 | state->last_start = start_pfn; | |
4897 | state->last_end = end_pfn; | |
4898 | state->last_nid = nid; | |
4899 | } | |
4900 | ||
4901 | return nid; | |
4902 | } | |
4903 | #endif /* CONFIG_HAVE_ARCH_EARLY_PFN_TO_NID */ | |
4904 | ||
4905 | /** | |
4906 | * free_bootmem_with_active_regions - Call memblock_free_early_nid for each active range | |
4907 | * @nid: The node to free memory on. If MAX_NUMNODES, all nodes are freed. | |
4908 | * @max_low_pfn: The highest PFN that will be passed to memblock_free_early_nid | |
4909 | * | |
4910 | * If an architecture guarantees that all ranges registered contain no holes | |
4911 | * and may be freed, this this function may be used instead of calling | |
4912 | * memblock_free_early_nid() manually. | |
4913 | */ | |
4914 | void __init free_bootmem_with_active_regions(int nid, unsigned long max_low_pfn) | |
4915 | { | |
4916 | unsigned long start_pfn, end_pfn; | |
4917 | int i, this_nid; | |
4918 | ||
4919 | for_each_mem_pfn_range(i, nid, &start_pfn, &end_pfn, &this_nid) { | |
4920 | start_pfn = min(start_pfn, max_low_pfn); | |
4921 | end_pfn = min(end_pfn, max_low_pfn); | |
4922 | ||
4923 | if (start_pfn < end_pfn) | |
4924 | memblock_free_early_nid(PFN_PHYS(start_pfn), | |
4925 | (end_pfn - start_pfn) << PAGE_SHIFT, | |
4926 | this_nid); | |
4927 | } | |
4928 | } | |
4929 | ||
4930 | /** | |
4931 | * sparse_memory_present_with_active_regions - Call memory_present for each active range | |
4932 | * @nid: The node to call memory_present for. If MAX_NUMNODES, all nodes will be used. | |
4933 | * | |
4934 | * If an architecture guarantees that all ranges registered contain no holes and may | |
4935 | * be freed, this function may be used instead of calling memory_present() manually. | |
4936 | */ | |
4937 | void __init sparse_memory_present_with_active_regions(int nid) | |
4938 | { | |
4939 | unsigned long start_pfn, end_pfn; | |
4940 | int i, this_nid; | |
4941 | ||
4942 | for_each_mem_pfn_range(i, nid, &start_pfn, &end_pfn, &this_nid) | |
4943 | memory_present(this_nid, start_pfn, end_pfn); | |
4944 | } | |
4945 | ||
4946 | /** | |
4947 | * get_pfn_range_for_nid - Return the start and end page frames for a node | |
4948 | * @nid: The nid to return the range for. If MAX_NUMNODES, the min and max PFN are returned. | |
4949 | * @start_pfn: Passed by reference. On return, it will have the node start_pfn. | |
4950 | * @end_pfn: Passed by reference. On return, it will have the node end_pfn. | |
4951 | * | |
4952 | * It returns the start and end page frame of a node based on information | |
4953 | * provided by memblock_set_node(). If called for a node | |
4954 | * with no available memory, a warning is printed and the start and end | |
4955 | * PFNs will be 0. | |
4956 | */ | |
4957 | void __meminit get_pfn_range_for_nid(unsigned int nid, | |
4958 | unsigned long *start_pfn, unsigned long *end_pfn) | |
4959 | { | |
4960 | unsigned long this_start_pfn, this_end_pfn; | |
4961 | int i; | |
4962 | ||
4963 | *start_pfn = -1UL; | |
4964 | *end_pfn = 0; | |
4965 | ||
4966 | for_each_mem_pfn_range(i, nid, &this_start_pfn, &this_end_pfn, NULL) { | |
4967 | *start_pfn = min(*start_pfn, this_start_pfn); | |
4968 | *end_pfn = max(*end_pfn, this_end_pfn); | |
4969 | } | |
4970 | ||
4971 | if (*start_pfn == -1UL) | |
4972 | *start_pfn = 0; | |
4973 | } | |
4974 | ||
4975 | /* | |
4976 | * This finds a zone that can be used for ZONE_MOVABLE pages. The | |
4977 | * assumption is made that zones within a node are ordered in monotonic | |
4978 | * increasing memory addresses so that the "highest" populated zone is used | |
4979 | */ | |
4980 | static void __init find_usable_zone_for_movable(void) | |
4981 | { | |
4982 | int zone_index; | |
4983 | for (zone_index = MAX_NR_ZONES - 1; zone_index >= 0; zone_index--) { | |
4984 | if (zone_index == ZONE_MOVABLE) | |
4985 | continue; | |
4986 | ||
4987 | if (arch_zone_highest_possible_pfn[zone_index] > | |
4988 | arch_zone_lowest_possible_pfn[zone_index]) | |
4989 | break; | |
4990 | } | |
4991 | ||
4992 | VM_BUG_ON(zone_index == -1); | |
4993 | movable_zone = zone_index; | |
4994 | } | |
4995 | ||
4996 | /* | |
4997 | * The zone ranges provided by the architecture do not include ZONE_MOVABLE | |
4998 | * because it is sized independent of architecture. Unlike the other zones, | |
4999 | * the starting point for ZONE_MOVABLE is not fixed. It may be different | |
5000 | * in each node depending on the size of each node and how evenly kernelcore | |
5001 | * is distributed. This helper function adjusts the zone ranges | |
5002 | * provided by the architecture for a given node by using the end of the | |
5003 | * highest usable zone for ZONE_MOVABLE. This preserves the assumption that | |
5004 | * zones within a node are in order of monotonic increases memory addresses | |
5005 | */ | |
5006 | static void __meminit adjust_zone_range_for_zone_movable(int nid, | |
5007 | unsigned long zone_type, | |
5008 | unsigned long node_start_pfn, | |
5009 | unsigned long node_end_pfn, | |
5010 | unsigned long *zone_start_pfn, | |
5011 | unsigned long *zone_end_pfn) | |
5012 | { | |
5013 | /* Only adjust if ZONE_MOVABLE is on this node */ | |
5014 | if (zone_movable_pfn[nid]) { | |
5015 | /* Size ZONE_MOVABLE */ | |
5016 | if (zone_type == ZONE_MOVABLE) { | |
5017 | *zone_start_pfn = zone_movable_pfn[nid]; | |
5018 | *zone_end_pfn = min(node_end_pfn, | |
5019 | arch_zone_highest_possible_pfn[movable_zone]); | |
5020 | ||
5021 | /* Adjust for ZONE_MOVABLE starting within this range */ | |
5022 | } else if (*zone_start_pfn < zone_movable_pfn[nid] && | |
5023 | *zone_end_pfn > zone_movable_pfn[nid]) { | |
5024 | *zone_end_pfn = zone_movable_pfn[nid]; | |
5025 | ||
5026 | /* Check if this whole range is within ZONE_MOVABLE */ | |
5027 | } else if (*zone_start_pfn >= zone_movable_pfn[nid]) | |
5028 | *zone_start_pfn = *zone_end_pfn; | |
5029 | } | |
5030 | } | |
5031 | ||
5032 | /* | |
5033 | * Return the number of pages a zone spans in a node, including holes | |
5034 | * present_pages = zone_spanned_pages_in_node() - zone_absent_pages_in_node() | |
5035 | */ | |
5036 | static unsigned long __meminit zone_spanned_pages_in_node(int nid, | |
5037 | unsigned long zone_type, | |
5038 | unsigned long node_start_pfn, | |
5039 | unsigned long node_end_pfn, | |
5040 | unsigned long *ignored) | |
5041 | { | |
5042 | unsigned long zone_start_pfn, zone_end_pfn; | |
5043 | ||
5044 | /* Get the start and end of the zone */ | |
5045 | zone_start_pfn = arch_zone_lowest_possible_pfn[zone_type]; | |
5046 | zone_end_pfn = arch_zone_highest_possible_pfn[zone_type]; | |
5047 | adjust_zone_range_for_zone_movable(nid, zone_type, | |
5048 | node_start_pfn, node_end_pfn, | |
5049 | &zone_start_pfn, &zone_end_pfn); | |
5050 | ||
5051 | /* Check that this node has pages within the zone's required range */ | |
5052 | if (zone_end_pfn < node_start_pfn || zone_start_pfn > node_end_pfn) | |
5053 | return 0; | |
5054 | ||
5055 | /* Move the zone boundaries inside the node if necessary */ | |
5056 | zone_end_pfn = min(zone_end_pfn, node_end_pfn); | |
5057 | zone_start_pfn = max(zone_start_pfn, node_start_pfn); | |
5058 | ||
5059 | /* Return the spanned pages */ | |
5060 | return zone_end_pfn - zone_start_pfn; | |
5061 | } | |
5062 | ||
5063 | /* | |
5064 | * Return the number of holes in a range on a node. If nid is MAX_NUMNODES, | |
5065 | * then all holes in the requested range will be accounted for. | |
5066 | */ | |
5067 | unsigned long __meminit __absent_pages_in_range(int nid, | |
5068 | unsigned long range_start_pfn, | |
5069 | unsigned long range_end_pfn) | |
5070 | { | |
5071 | unsigned long nr_absent = range_end_pfn - range_start_pfn; | |
5072 | unsigned long start_pfn, end_pfn; | |
5073 | int i; | |
5074 | ||
5075 | for_each_mem_pfn_range(i, nid, &start_pfn, &end_pfn, NULL) { | |
5076 | start_pfn = clamp(start_pfn, range_start_pfn, range_end_pfn); | |
5077 | end_pfn = clamp(end_pfn, range_start_pfn, range_end_pfn); | |
5078 | nr_absent -= end_pfn - start_pfn; | |
5079 | } | |
5080 | return nr_absent; | |
5081 | } | |
5082 | ||
5083 | /** | |
5084 | * absent_pages_in_range - Return number of page frames in holes within a range | |
5085 | * @start_pfn: The start PFN to start searching for holes | |
5086 | * @end_pfn: The end PFN to stop searching for holes | |
5087 | * | |
5088 | * It returns the number of pages frames in memory holes within a range. | |
5089 | */ | |
5090 | unsigned long __init absent_pages_in_range(unsigned long start_pfn, | |
5091 | unsigned long end_pfn) | |
5092 | { | |
5093 | return __absent_pages_in_range(MAX_NUMNODES, start_pfn, end_pfn); | |
5094 | } | |
5095 | ||
5096 | /* Return the number of page frames in holes in a zone on a node */ | |
5097 | static unsigned long __meminit zone_absent_pages_in_node(int nid, | |
5098 | unsigned long zone_type, | |
5099 | unsigned long node_start_pfn, | |
5100 | unsigned long node_end_pfn, | |
5101 | unsigned long *ignored) | |
5102 | { | |
5103 | unsigned long zone_low = arch_zone_lowest_possible_pfn[zone_type]; | |
5104 | unsigned long zone_high = arch_zone_highest_possible_pfn[zone_type]; | |
5105 | unsigned long zone_start_pfn, zone_end_pfn; | |
5106 | ||
5107 | zone_start_pfn = clamp(node_start_pfn, zone_low, zone_high); | |
5108 | zone_end_pfn = clamp(node_end_pfn, zone_low, zone_high); | |
5109 | ||
5110 | adjust_zone_range_for_zone_movable(nid, zone_type, | |
5111 | node_start_pfn, node_end_pfn, | |
5112 | &zone_start_pfn, &zone_end_pfn); | |
5113 | return __absent_pages_in_range(nid, zone_start_pfn, zone_end_pfn); | |
5114 | } | |
5115 | ||
5116 | #else /* CONFIG_HAVE_MEMBLOCK_NODE_MAP */ | |
5117 | static inline unsigned long __meminit zone_spanned_pages_in_node(int nid, | |
5118 | unsigned long zone_type, | |
5119 | unsigned long node_start_pfn, | |
5120 | unsigned long node_end_pfn, | |
5121 | unsigned long *zones_size) | |
5122 | { | |
5123 | return zones_size[zone_type]; | |
5124 | } | |
5125 | ||
5126 | static inline unsigned long __meminit zone_absent_pages_in_node(int nid, | |
5127 | unsigned long zone_type, | |
5128 | unsigned long node_start_pfn, | |
5129 | unsigned long node_end_pfn, | |
5130 | unsigned long *zholes_size) | |
5131 | { | |
5132 | if (!zholes_size) | |
5133 | return 0; | |
5134 | ||
5135 | return zholes_size[zone_type]; | |
5136 | } | |
5137 | ||
5138 | #endif /* CONFIG_HAVE_MEMBLOCK_NODE_MAP */ | |
5139 | ||
5140 | static void __meminit calculate_node_totalpages(struct pglist_data *pgdat, | |
5141 | unsigned long node_start_pfn, | |
5142 | unsigned long node_end_pfn, | |
5143 | unsigned long *zones_size, | |
5144 | unsigned long *zholes_size) | |
5145 | { | |
5146 | unsigned long realtotalpages = 0, totalpages = 0; | |
5147 | enum zone_type i; | |
5148 | ||
5149 | for (i = 0; i < MAX_NR_ZONES; i++) { | |
5150 | struct zone *zone = pgdat->node_zones + i; | |
5151 | unsigned long size, real_size; | |
5152 | ||
5153 | size = zone_spanned_pages_in_node(pgdat->node_id, i, | |
5154 | node_start_pfn, | |
5155 | node_end_pfn, | |
5156 | zones_size); | |
5157 | real_size = size - zone_absent_pages_in_node(pgdat->node_id, i, | |
5158 | node_start_pfn, node_end_pfn, | |
5159 | zholes_size); | |
5160 | zone->spanned_pages = size; | |
5161 | zone->present_pages = real_size; | |
5162 | ||
5163 | totalpages += size; | |
5164 | realtotalpages += real_size; | |
5165 | } | |
5166 | ||
5167 | pgdat->node_spanned_pages = totalpages; | |
5168 | pgdat->node_present_pages = realtotalpages; | |
5169 | printk(KERN_DEBUG "On node %d totalpages: %lu\n", pgdat->node_id, | |
5170 | realtotalpages); | |
5171 | } | |
5172 | ||
5173 | #ifndef CONFIG_SPARSEMEM | |
5174 | /* | |
5175 | * Calculate the size of the zone->blockflags rounded to an unsigned long | |
5176 | * Start by making sure zonesize is a multiple of pageblock_order by rounding | |
5177 | * up. Then use 1 NR_PAGEBLOCK_BITS worth of bits per pageblock, finally | |
5178 | * round what is now in bits to nearest long in bits, then return it in | |
5179 | * bytes. | |
5180 | */ | |
5181 | static unsigned long __init usemap_size(unsigned long zone_start_pfn, unsigned long zonesize) | |
5182 | { | |
5183 | unsigned long usemapsize; | |
5184 | ||
5185 | zonesize += zone_start_pfn & (pageblock_nr_pages-1); | |
5186 | usemapsize = roundup(zonesize, pageblock_nr_pages); | |
5187 | usemapsize = usemapsize >> pageblock_order; | |
5188 | usemapsize *= NR_PAGEBLOCK_BITS; | |
5189 | usemapsize = roundup(usemapsize, 8 * sizeof(unsigned long)); | |
5190 | ||
5191 | return usemapsize / 8; | |
5192 | } | |
5193 | ||
5194 | static void __init setup_usemap(struct pglist_data *pgdat, | |
5195 | struct zone *zone, | |
5196 | unsigned long zone_start_pfn, | |
5197 | unsigned long zonesize) | |
5198 | { | |
5199 | unsigned long usemapsize = usemap_size(zone_start_pfn, zonesize); | |
5200 | zone->pageblock_flags = NULL; | |
5201 | if (usemapsize) | |
5202 | zone->pageblock_flags = | |
5203 | memblock_virt_alloc_node_nopanic(usemapsize, | |
5204 | pgdat->node_id); | |
5205 | } | |
5206 | #else | |
5207 | static inline void setup_usemap(struct pglist_data *pgdat, struct zone *zone, | |
5208 | unsigned long zone_start_pfn, unsigned long zonesize) {} | |
5209 | #endif /* CONFIG_SPARSEMEM */ | |
5210 | ||
5211 | #ifdef CONFIG_HUGETLB_PAGE_SIZE_VARIABLE | |
5212 | ||
5213 | /* Initialise the number of pages represented by NR_PAGEBLOCK_BITS */ | |
5214 | void __paginginit set_pageblock_order(void) | |
5215 | { | |
5216 | unsigned int order; | |
5217 | ||
5218 | /* Check that pageblock_nr_pages has not already been setup */ | |
5219 | if (pageblock_order) | |
5220 | return; | |
5221 | ||
5222 | if (HPAGE_SHIFT > PAGE_SHIFT) | |
5223 | order = HUGETLB_PAGE_ORDER; | |
5224 | else | |
5225 | order = MAX_ORDER - 1; | |
5226 | ||
5227 | /* | |
5228 | * Assume the largest contiguous order of interest is a huge page. | |
5229 | * This value may be variable depending on boot parameters on IA64 and | |
5230 | * powerpc. | |
5231 | */ | |
5232 | pageblock_order = order; | |
5233 | } | |
5234 | #else /* CONFIG_HUGETLB_PAGE_SIZE_VARIABLE */ | |
5235 | ||
5236 | /* | |
5237 | * When CONFIG_HUGETLB_PAGE_SIZE_VARIABLE is not set, set_pageblock_order() | |
5238 | * is unused as pageblock_order is set at compile-time. See | |
5239 | * include/linux/pageblock-flags.h for the values of pageblock_order based on | |
5240 | * the kernel config | |
5241 | */ | |
5242 | void __paginginit set_pageblock_order(void) | |
5243 | { | |
5244 | } | |
5245 | ||
5246 | #endif /* CONFIG_HUGETLB_PAGE_SIZE_VARIABLE */ | |
5247 | ||
5248 | static unsigned long __paginginit calc_memmap_size(unsigned long spanned_pages, | |
5249 | unsigned long present_pages) | |
5250 | { | |
5251 | unsigned long pages = spanned_pages; | |
5252 | ||
5253 | /* | |
5254 | * Provide a more accurate estimation if there are holes within | |
5255 | * the zone and SPARSEMEM is in use. If there are holes within the | |
5256 | * zone, each populated memory region may cost us one or two extra | |
5257 | * memmap pages due to alignment because memmap pages for each | |
5258 | * populated regions may not naturally algined on page boundary. | |
5259 | * So the (present_pages >> 4) heuristic is a tradeoff for that. | |
5260 | */ | |
5261 | if (spanned_pages > present_pages + (present_pages >> 4) && | |
5262 | IS_ENABLED(CONFIG_SPARSEMEM)) | |
5263 | pages = present_pages; | |
5264 | ||
5265 | return PAGE_ALIGN(pages * sizeof(struct page)) >> PAGE_SHIFT; | |
5266 | } | |
5267 | ||
5268 | /* | |
5269 | * Set up the zone data structures: | |
5270 | * - mark all pages reserved | |
5271 | * - mark all memory queues empty | |
5272 | * - clear the memory bitmaps | |
5273 | * | |
5274 | * NOTE: pgdat should get zeroed by caller. | |
5275 | */ | |
5276 | static void __paginginit free_area_init_core(struct pglist_data *pgdat, | |
5277 | unsigned long node_start_pfn, unsigned long node_end_pfn) | |
5278 | { | |
5279 | enum zone_type j; | |
5280 | int nid = pgdat->node_id; | |
5281 | unsigned long zone_start_pfn = pgdat->node_start_pfn; | |
5282 | int ret; | |
5283 | ||
5284 | pgdat_resize_init(pgdat); | |
5285 | #ifdef CONFIG_NUMA_BALANCING | |
5286 | spin_lock_init(&pgdat->numabalancing_migrate_lock); | |
5287 | pgdat->numabalancing_migrate_nr_pages = 0; | |
5288 | pgdat->numabalancing_migrate_next_window = jiffies; | |
5289 | #endif | |
5290 | init_waitqueue_head(&pgdat->kswapd_wait); | |
5291 | init_waitqueue_head(&pgdat->pfmemalloc_wait); | |
5292 | pgdat_page_ext_init(pgdat); | |
5293 | ||
5294 | for (j = 0; j < MAX_NR_ZONES; j++) { | |
5295 | struct zone *zone = pgdat->node_zones + j; | |
5296 | unsigned long size, realsize, freesize, memmap_pages; | |
5297 | ||
5298 | size = zone->spanned_pages; | |
5299 | realsize = freesize = zone->present_pages; | |
5300 | ||
5301 | /* | |
5302 | * Adjust freesize so that it accounts for how much memory | |
5303 | * is used by this zone for memmap. This affects the watermark | |
5304 | * and per-cpu initialisations | |
5305 | */ | |
5306 | memmap_pages = calc_memmap_size(size, realsize); | |
5307 | if (!is_highmem_idx(j)) { | |
5308 | if (freesize >= memmap_pages) { | |
5309 | freesize -= memmap_pages; | |
5310 | if (memmap_pages) | |
5311 | printk(KERN_DEBUG | |
5312 | " %s zone: %lu pages used for memmap\n", | |
5313 | zone_names[j], memmap_pages); | |
5314 | } else | |
5315 | printk(KERN_WARNING | |
5316 | " %s zone: %lu pages exceeds freesize %lu\n", | |
5317 | zone_names[j], memmap_pages, freesize); | |
5318 | } | |
5319 | ||
5320 | /* Account for reserved pages */ | |
5321 | if (j == 0 && freesize > dma_reserve) { | |
5322 | freesize -= dma_reserve; | |
5323 | printk(KERN_DEBUG " %s zone: %lu pages reserved\n", | |
5324 | zone_names[0], dma_reserve); | |
5325 | } | |
5326 | ||
5327 | if (!is_highmem_idx(j)) | |
5328 | nr_kernel_pages += freesize; | |
5329 | /* Charge for highmem memmap if there are enough kernel pages */ | |
5330 | else if (nr_kernel_pages > memmap_pages * 2) | |
5331 | nr_kernel_pages -= memmap_pages; | |
5332 | nr_all_pages += freesize; | |
5333 | ||
5334 | /* | |
5335 | * Set an approximate value for lowmem here, it will be adjusted | |
5336 | * when the bootmem allocator frees pages into the buddy system. | |
5337 | * And all highmem pages will be managed by the buddy system. | |
5338 | */ | |
5339 | zone->managed_pages = is_highmem_idx(j) ? realsize : freesize; | |
5340 | #ifdef CONFIG_NUMA | |
5341 | zone->node = nid; | |
5342 | zone->min_unmapped_pages = (freesize*sysctl_min_unmapped_ratio) | |
5343 | / 100; | |
5344 | zone->min_slab_pages = (freesize * sysctl_min_slab_ratio) / 100; | |
5345 | #endif | |
5346 | zone->name = zone_names[j]; | |
5347 | spin_lock_init(&zone->lock); | |
5348 | spin_lock_init(&zone->lru_lock); | |
5349 | zone_seqlock_init(zone); | |
5350 | zone->zone_pgdat = pgdat; | |
5351 | zone_pcp_init(zone); | |
5352 | ||
5353 | /* For bootup, initialized properly in watermark setup */ | |
5354 | mod_zone_page_state(zone, NR_ALLOC_BATCH, zone->managed_pages); | |
5355 | ||
5356 | lruvec_init(&zone->lruvec); | |
5357 | if (!size) | |
5358 | continue; | |
5359 | ||
5360 | set_pageblock_order(); | |
5361 | setup_usemap(pgdat, zone, zone_start_pfn, size); | |
5362 | ret = init_currently_empty_zone(zone, zone_start_pfn, | |
5363 | size, MEMMAP_EARLY); | |
5364 | BUG_ON(ret); | |
5365 | memmap_init(size, nid, j, zone_start_pfn); | |
5366 | zone_start_pfn += size; | |
5367 | } | |
5368 | } | |
5369 | ||
5370 | static void __init_refok alloc_node_mem_map(struct pglist_data *pgdat) | |
5371 | { | |
5372 | /* Skip empty nodes */ | |
5373 | if (!pgdat->node_spanned_pages) | |
5374 | return; | |
5375 | ||
5376 | #ifdef CONFIG_FLAT_NODE_MEM_MAP | |
5377 | /* ia64 gets its own node_mem_map, before this, without bootmem */ | |
5378 | if (!pgdat->node_mem_map) { | |
5379 | unsigned long size, start, end; | |
5380 | struct page *map; | |
5381 | ||
5382 | /* | |
5383 | * The zone's endpoints aren't required to be MAX_ORDER | |
5384 | * aligned but the node_mem_map endpoints must be in order | |
5385 | * for the buddy allocator to function correctly. | |
5386 | */ | |
5387 | start = pgdat->node_start_pfn & ~(MAX_ORDER_NR_PAGES - 1); | |
5388 | end = pgdat_end_pfn(pgdat); | |
5389 | end = ALIGN(end, MAX_ORDER_NR_PAGES); | |
5390 | size = (end - start) * sizeof(struct page); | |
5391 | map = alloc_remap(pgdat->node_id, size); | |
5392 | if (!map) | |
5393 | map = memblock_virt_alloc_node_nopanic(size, | |
5394 | pgdat->node_id); | |
5395 | pgdat->node_mem_map = map + (pgdat->node_start_pfn - start); | |
5396 | } | |
5397 | #ifndef CONFIG_NEED_MULTIPLE_NODES | |
5398 | /* | |
5399 | * With no DISCONTIG, the global mem_map is just set as node 0's | |
5400 | */ | |
5401 | if (pgdat == NODE_DATA(0)) { | |
5402 | mem_map = NODE_DATA(0)->node_mem_map; | |
5403 | #ifdef CONFIG_HAVE_MEMBLOCK_NODE_MAP | |
5404 | if (page_to_pfn(mem_map) != pgdat->node_start_pfn) | |
5405 | mem_map -= (pgdat->node_start_pfn - ARCH_PFN_OFFSET); | |
5406 | #endif /* CONFIG_HAVE_MEMBLOCK_NODE_MAP */ | |
5407 | } | |
5408 | #endif | |
5409 | #endif /* CONFIG_FLAT_NODE_MEM_MAP */ | |
5410 | } | |
5411 | ||
5412 | void __paginginit free_area_init_node(int nid, unsigned long *zones_size, | |
5413 | unsigned long node_start_pfn, unsigned long *zholes_size) | |
5414 | { | |
5415 | pg_data_t *pgdat = NODE_DATA(nid); | |
5416 | unsigned long start_pfn = 0; | |
5417 | unsigned long end_pfn = 0; | |
5418 | ||
5419 | /* pg_data_t should be reset to zero when it's allocated */ | |
5420 | WARN_ON(pgdat->nr_zones || pgdat->classzone_idx); | |
5421 | ||
5422 | reset_deferred_meminit(pgdat); | |
5423 | pgdat->node_id = nid; | |
5424 | pgdat->node_start_pfn = node_start_pfn; | |
5425 | #ifdef CONFIG_HAVE_MEMBLOCK_NODE_MAP | |
5426 | get_pfn_range_for_nid(nid, &start_pfn, &end_pfn); | |
5427 | pr_info("Initmem setup node %d [mem %#018Lx-%#018Lx]\n", nid, | |
5428 | (u64)start_pfn << PAGE_SHIFT, ((u64)end_pfn << PAGE_SHIFT) - 1); | |
5429 | #endif | |
5430 | calculate_node_totalpages(pgdat, start_pfn, end_pfn, | |
5431 | zones_size, zholes_size); | |
5432 | ||
5433 | alloc_node_mem_map(pgdat); | |
5434 | #ifdef CONFIG_FLAT_NODE_MEM_MAP | |
5435 | printk(KERN_DEBUG "free_area_init_node: node %d, pgdat %08lx, node_mem_map %08lx\n", | |
5436 | nid, (unsigned long)pgdat, | |
5437 | (unsigned long)pgdat->node_mem_map); | |
5438 | #endif | |
5439 | ||
5440 | free_area_init_core(pgdat, start_pfn, end_pfn); | |
5441 | } | |
5442 | ||
5443 | #ifdef CONFIG_HAVE_MEMBLOCK_NODE_MAP | |
5444 | ||
5445 | #if MAX_NUMNODES > 1 | |
5446 | /* | |
5447 | * Figure out the number of possible node ids. | |
5448 | */ | |
5449 | void __init setup_nr_node_ids(void) | |
5450 | { | |
5451 | unsigned int node; | |
5452 | unsigned int highest = 0; | |
5453 | ||
5454 | for_each_node_mask(node, node_possible_map) | |
5455 | highest = node; | |
5456 | nr_node_ids = highest + 1; | |
5457 | } | |
5458 | #endif | |
5459 | ||
5460 | /** | |
5461 | * node_map_pfn_alignment - determine the maximum internode alignment | |
5462 | * | |
5463 | * This function should be called after node map is populated and sorted. | |
5464 | * It calculates the maximum power of two alignment which can distinguish | |
5465 | * all the nodes. | |
5466 | * | |
5467 | * For example, if all nodes are 1GiB and aligned to 1GiB, the return value | |
5468 | * would indicate 1GiB alignment with (1 << (30 - PAGE_SHIFT)). If the | |
5469 | * nodes are shifted by 256MiB, 256MiB. Note that if only the last node is | |
5470 | * shifted, 1GiB is enough and this function will indicate so. | |
5471 | * | |
5472 | * This is used to test whether pfn -> nid mapping of the chosen memory | |
5473 | * model has fine enough granularity to avoid incorrect mapping for the | |
5474 | * populated node map. | |
5475 | * | |
5476 | * Returns the determined alignment in pfn's. 0 if there is no alignment | |
5477 | * requirement (single node). | |
5478 | */ | |
5479 | unsigned long __init node_map_pfn_alignment(void) | |
5480 | { | |
5481 | unsigned long accl_mask = 0, last_end = 0; | |
5482 | unsigned long start, end, mask; | |
5483 | int last_nid = -1; | |
5484 | int i, nid; | |
5485 | ||
5486 | for_each_mem_pfn_range(i, MAX_NUMNODES, &start, &end, &nid) { | |
5487 | if (!start || last_nid < 0 || last_nid == nid) { | |
5488 | last_nid = nid; | |
5489 | last_end = end; | |
5490 | continue; | |
5491 | } | |
5492 | ||
5493 | /* | |
5494 | * Start with a mask granular enough to pin-point to the | |
5495 | * start pfn and tick off bits one-by-one until it becomes | |
5496 | * too coarse to separate the current node from the last. | |
5497 | */ | |
5498 | mask = ~((1 << __ffs(start)) - 1); | |
5499 | while (mask && last_end <= (start & (mask << 1))) | |
5500 | mask <<= 1; | |
5501 | ||
5502 | /* accumulate all internode masks */ | |
5503 | accl_mask |= mask; | |
5504 | } | |
5505 | ||
5506 | /* convert mask to number of pages */ | |
5507 | return ~accl_mask + 1; | |
5508 | } | |
5509 | ||
5510 | /* Find the lowest pfn for a node */ | |
5511 | static unsigned long __init find_min_pfn_for_node(int nid) | |
5512 | { | |
5513 | unsigned long min_pfn = ULONG_MAX; | |
5514 | unsigned long start_pfn; | |
5515 | int i; | |
5516 | ||
5517 | for_each_mem_pfn_range(i, nid, &start_pfn, NULL, NULL) | |
5518 | min_pfn = min(min_pfn, start_pfn); | |
5519 | ||
5520 | if (min_pfn == ULONG_MAX) { | |
5521 | printk(KERN_WARNING | |
5522 | "Could not find start_pfn for node %d\n", nid); | |
5523 | return 0; | |
5524 | } | |
5525 | ||
5526 | return min_pfn; | |
5527 | } | |
5528 | ||
5529 | /** | |
5530 | * find_min_pfn_with_active_regions - Find the minimum PFN registered | |
5531 | * | |
5532 | * It returns the minimum PFN based on information provided via | |
5533 | * memblock_set_node(). | |
5534 | */ | |
5535 | unsigned long __init find_min_pfn_with_active_regions(void) | |
5536 | { | |
5537 | return find_min_pfn_for_node(MAX_NUMNODES); | |
5538 | } | |
5539 | ||
5540 | /* | |
5541 | * early_calculate_totalpages() | |
5542 | * Sum pages in active regions for movable zone. | |
5543 | * Populate N_MEMORY for calculating usable_nodes. | |
5544 | */ | |
5545 | static unsigned long __init early_calculate_totalpages(void) | |
5546 | { | |
5547 | unsigned long totalpages = 0; | |
5548 | unsigned long start_pfn, end_pfn; | |
5549 | int i, nid; | |
5550 | ||
5551 | for_each_mem_pfn_range(i, MAX_NUMNODES, &start_pfn, &end_pfn, &nid) { | |
5552 | unsigned long pages = end_pfn - start_pfn; | |
5553 | ||
5554 | totalpages += pages; | |
5555 | if (pages) | |
5556 | node_set_state(nid, N_MEMORY); | |
5557 | } | |
5558 | return totalpages; | |
5559 | } | |
5560 | ||
5561 | /* | |
5562 | * Find the PFN the Movable zone begins in each node. Kernel memory | |
5563 | * is spread evenly between nodes as long as the nodes have enough | |
5564 | * memory. When they don't, some nodes will have more kernelcore than | |
5565 | * others | |
5566 | */ | |
5567 | static void __init find_zone_movable_pfns_for_nodes(void) | |
5568 | { | |
5569 | int i, nid; | |
5570 | unsigned long usable_startpfn; | |
5571 | unsigned long kernelcore_node, kernelcore_remaining; | |
5572 | /* save the state before borrow the nodemask */ | |
5573 | nodemask_t saved_node_state = node_states[N_MEMORY]; | |
5574 | unsigned long totalpages = early_calculate_totalpages(); | |
5575 | int usable_nodes = nodes_weight(node_states[N_MEMORY]); | |
5576 | struct memblock_region *r; | |
5577 | ||
5578 | /* Need to find movable_zone earlier when movable_node is specified. */ | |
5579 | find_usable_zone_for_movable(); | |
5580 | ||
5581 | /* | |
5582 | * If movable_node is specified, ignore kernelcore and movablecore | |
5583 | * options. | |
5584 | */ | |
5585 | if (movable_node_is_enabled()) { | |
5586 | for_each_memblock(memory, r) { | |
5587 | if (!memblock_is_hotpluggable(r)) | |
5588 | continue; | |
5589 | ||
5590 | nid = r->nid; | |
5591 | ||
5592 | usable_startpfn = PFN_DOWN(r->base); | |
5593 | zone_movable_pfn[nid] = zone_movable_pfn[nid] ? | |
5594 | min(usable_startpfn, zone_movable_pfn[nid]) : | |
5595 | usable_startpfn; | |
5596 | } | |
5597 | ||
5598 | goto out2; | |
5599 | } | |
5600 | ||
5601 | /* | |
5602 | * If movablecore=nn[KMG] was specified, calculate what size of | |
5603 | * kernelcore that corresponds so that memory usable for | |
5604 | * any allocation type is evenly spread. If both kernelcore | |
5605 | * and movablecore are specified, then the value of kernelcore | |
5606 | * will be used for required_kernelcore if it's greater than | |
5607 | * what movablecore would have allowed. | |
5608 | */ | |
5609 | if (required_movablecore) { | |
5610 | unsigned long corepages; | |
5611 | ||
5612 | /* | |
5613 | * Round-up so that ZONE_MOVABLE is at least as large as what | |
5614 | * was requested by the user | |
5615 | */ | |
5616 | required_movablecore = | |
5617 | roundup(required_movablecore, MAX_ORDER_NR_PAGES); | |
5618 | corepages = totalpages - required_movablecore; | |
5619 | ||
5620 | required_kernelcore = max(required_kernelcore, corepages); | |
5621 | } | |
5622 | ||
5623 | /* If kernelcore was not specified, there is no ZONE_MOVABLE */ | |
5624 | if (!required_kernelcore) | |
5625 | goto out; | |
5626 | ||
5627 | /* usable_startpfn is the lowest possible pfn ZONE_MOVABLE can be at */ | |
5628 | usable_startpfn = arch_zone_lowest_possible_pfn[movable_zone]; | |
5629 | ||
5630 | restart: | |
5631 | /* Spread kernelcore memory as evenly as possible throughout nodes */ | |
5632 | kernelcore_node = required_kernelcore / usable_nodes; | |
5633 | for_each_node_state(nid, N_MEMORY) { | |
5634 | unsigned long start_pfn, end_pfn; | |
5635 | ||
5636 | /* | |
5637 | * Recalculate kernelcore_node if the division per node | |
5638 | * now exceeds what is necessary to satisfy the requested | |
5639 | * amount of memory for the kernel | |
5640 | */ | |
5641 | if (required_kernelcore < kernelcore_node) | |
5642 | kernelcore_node = required_kernelcore / usable_nodes; | |
5643 | ||
5644 | /* | |
5645 | * As the map is walked, we track how much memory is usable | |
5646 | * by the kernel using kernelcore_remaining. When it is | |
5647 | * 0, the rest of the node is usable by ZONE_MOVABLE | |
5648 | */ | |
5649 | kernelcore_remaining = kernelcore_node; | |
5650 | ||
5651 | /* Go through each range of PFNs within this node */ | |
5652 | for_each_mem_pfn_range(i, nid, &start_pfn, &end_pfn, NULL) { | |
5653 | unsigned long size_pages; | |
5654 | ||
5655 | start_pfn = max(start_pfn, zone_movable_pfn[nid]); | |
5656 | if (start_pfn >= end_pfn) | |
5657 | continue; | |
5658 | ||
5659 | /* Account for what is only usable for kernelcore */ | |
5660 | if (start_pfn < usable_startpfn) { | |
5661 | unsigned long kernel_pages; | |
5662 | kernel_pages = min(end_pfn, usable_startpfn) | |
5663 | - start_pfn; | |
5664 | ||
5665 | kernelcore_remaining -= min(kernel_pages, | |
5666 | kernelcore_remaining); | |
5667 | required_kernelcore -= min(kernel_pages, | |
5668 | required_kernelcore); | |
5669 | ||
5670 | /* Continue if range is now fully accounted */ | |
5671 | if (end_pfn <= usable_startpfn) { | |
5672 | ||
5673 | /* | |
5674 | * Push zone_movable_pfn to the end so | |
5675 | * that if we have to rebalance | |
5676 | * kernelcore across nodes, we will | |
5677 | * not double account here | |
5678 | */ | |
5679 | zone_movable_pfn[nid] = end_pfn; | |
5680 | continue; | |
5681 | } | |
5682 | start_pfn = usable_startpfn; | |
5683 | } | |
5684 | ||
5685 | /* | |
5686 | * The usable PFN range for ZONE_MOVABLE is from | |
5687 | * start_pfn->end_pfn. Calculate size_pages as the | |
5688 | * number of pages used as kernelcore | |
5689 | */ | |
5690 | size_pages = end_pfn - start_pfn; | |
5691 | if (size_pages > kernelcore_remaining) | |
5692 | size_pages = kernelcore_remaining; | |
5693 | zone_movable_pfn[nid] = start_pfn + size_pages; | |
5694 | ||
5695 | /* | |
5696 | * Some kernelcore has been met, update counts and | |
5697 | * break if the kernelcore for this node has been | |
5698 | * satisfied | |
5699 | */ | |
5700 | required_kernelcore -= min(required_kernelcore, | |
5701 | size_pages); | |
5702 | kernelcore_remaining -= size_pages; | |
5703 | if (!kernelcore_remaining) | |
5704 | break; | |
5705 | } | |
5706 | } | |
5707 | ||
5708 | /* | |
5709 | * If there is still required_kernelcore, we do another pass with one | |
5710 | * less node in the count. This will push zone_movable_pfn[nid] further | |
5711 | * along on the nodes that still have memory until kernelcore is | |
5712 | * satisfied | |
5713 | */ | |
5714 | usable_nodes--; | |
5715 | if (usable_nodes && required_kernelcore > usable_nodes) | |
5716 | goto restart; | |
5717 | ||
5718 | out2: | |
5719 | /* Align start of ZONE_MOVABLE on all nids to MAX_ORDER_NR_PAGES */ | |
5720 | for (nid = 0; nid < MAX_NUMNODES; nid++) | |
5721 | zone_movable_pfn[nid] = | |
5722 | roundup(zone_movable_pfn[nid], MAX_ORDER_NR_PAGES); | |
5723 | ||
5724 | out: | |
5725 | /* restore the node_state */ | |
5726 | node_states[N_MEMORY] = saved_node_state; | |
5727 | } | |
5728 | ||
5729 | /* Any regular or high memory on that node ? */ | |
5730 | static void check_for_memory(pg_data_t *pgdat, int nid) | |
5731 | { | |
5732 | enum zone_type zone_type; | |
5733 | ||
5734 | if (N_MEMORY == N_NORMAL_MEMORY) | |
5735 | return; | |
5736 | ||
5737 | for (zone_type = 0; zone_type <= ZONE_MOVABLE - 1; zone_type++) { | |
5738 | struct zone *zone = &pgdat->node_zones[zone_type]; | |
5739 | if (populated_zone(zone)) { | |
5740 | node_set_state(nid, N_HIGH_MEMORY); | |
5741 | if (N_NORMAL_MEMORY != N_HIGH_MEMORY && | |
5742 | zone_type <= ZONE_NORMAL) | |
5743 | node_set_state(nid, N_NORMAL_MEMORY); | |
5744 | break; | |
5745 | } | |
5746 | } | |
5747 | } | |
5748 | ||
5749 | /** | |
5750 | * free_area_init_nodes - Initialise all pg_data_t and zone data | |
5751 | * @max_zone_pfn: an array of max PFNs for each zone | |
5752 | * | |
5753 | * This will call free_area_init_node() for each active node in the system. | |
5754 | * Using the page ranges provided by memblock_set_node(), the size of each | |
5755 | * zone in each node and their holes is calculated. If the maximum PFN | |
5756 | * between two adjacent zones match, it is assumed that the zone is empty. | |
5757 | * For example, if arch_max_dma_pfn == arch_max_dma32_pfn, it is assumed | |
5758 | * that arch_max_dma32_pfn has no pages. It is also assumed that a zone | |
5759 | * starts where the previous one ended. For example, ZONE_DMA32 starts | |
5760 | * at arch_max_dma_pfn. | |
5761 | */ | |
5762 | void __init free_area_init_nodes(unsigned long *max_zone_pfn) | |
5763 | { | |
5764 | unsigned long start_pfn, end_pfn; | |
5765 | int i, nid; | |
5766 | ||
5767 | /* Record where the zone boundaries are */ | |
5768 | memset(arch_zone_lowest_possible_pfn, 0, | |
5769 | sizeof(arch_zone_lowest_possible_pfn)); | |
5770 | memset(arch_zone_highest_possible_pfn, 0, | |
5771 | sizeof(arch_zone_highest_possible_pfn)); | |
5772 | arch_zone_lowest_possible_pfn[0] = find_min_pfn_with_active_regions(); | |
5773 | arch_zone_highest_possible_pfn[0] = max_zone_pfn[0]; | |
5774 | for (i = 1; i < MAX_NR_ZONES; i++) { | |
5775 | if (i == ZONE_MOVABLE) | |
5776 | continue; | |
5777 | arch_zone_lowest_possible_pfn[i] = | |
5778 | arch_zone_highest_possible_pfn[i-1]; | |
5779 | arch_zone_highest_possible_pfn[i] = | |
5780 | max(max_zone_pfn[i], arch_zone_lowest_possible_pfn[i]); | |
5781 | } | |
5782 | arch_zone_lowest_possible_pfn[ZONE_MOVABLE] = 0; | |
5783 | arch_zone_highest_possible_pfn[ZONE_MOVABLE] = 0; | |
5784 | ||
5785 | /* Find the PFNs that ZONE_MOVABLE begins at in each node */ | |
5786 | memset(zone_movable_pfn, 0, sizeof(zone_movable_pfn)); | |
5787 | find_zone_movable_pfns_for_nodes(); | |
5788 | ||
5789 | /* Print out the zone ranges */ | |
5790 | pr_info("Zone ranges:\n"); | |
5791 | for (i = 0; i < MAX_NR_ZONES; i++) { | |
5792 | if (i == ZONE_MOVABLE) | |
5793 | continue; | |
5794 | pr_info(" %-8s ", zone_names[i]); | |
5795 | if (arch_zone_lowest_possible_pfn[i] == | |
5796 | arch_zone_highest_possible_pfn[i]) | |
5797 | pr_cont("empty\n"); | |
5798 | else | |
5799 | pr_cont("[mem %#018Lx-%#018Lx]\n", | |
5800 | (u64)arch_zone_lowest_possible_pfn[i] | |
5801 | << PAGE_SHIFT, | |
5802 | ((u64)arch_zone_highest_possible_pfn[i] | |
5803 | << PAGE_SHIFT) - 1); | |
5804 | } | |
5805 | ||
5806 | /* Print out the PFNs ZONE_MOVABLE begins at in each node */ | |
5807 | pr_info("Movable zone start for each node\n"); | |
5808 | for (i = 0; i < MAX_NUMNODES; i++) { | |
5809 | if (zone_movable_pfn[i]) | |
5810 | pr_info(" Node %d: %#018Lx\n", i, | |
5811 | (u64)zone_movable_pfn[i] << PAGE_SHIFT); | |
5812 | } | |
5813 | ||
5814 | /* Print out the early node map */ | |
5815 | pr_info("Early memory node ranges\n"); | |
5816 | for_each_mem_pfn_range(i, MAX_NUMNODES, &start_pfn, &end_pfn, &nid) | |
5817 | pr_info(" node %3d: [mem %#018Lx-%#018Lx]\n", nid, | |
5818 | (u64)start_pfn << PAGE_SHIFT, | |
5819 | ((u64)end_pfn << PAGE_SHIFT) - 1); | |
5820 | ||
5821 | /* Initialise every node */ | |
5822 | mminit_verify_pageflags_layout(); | |
5823 | setup_nr_node_ids(); | |
5824 | for_each_online_node(nid) { | |
5825 | pg_data_t *pgdat = NODE_DATA(nid); | |
5826 | free_area_init_node(nid, NULL, | |
5827 | find_min_pfn_for_node(nid), NULL); | |
5828 | ||
5829 | /* Any memory on that node */ | |
5830 | if (pgdat->node_present_pages) | |
5831 | node_set_state(nid, N_MEMORY); | |
5832 | check_for_memory(pgdat, nid); | |
5833 | } | |
5834 | } | |
5835 | ||
5836 | static int __init cmdline_parse_core(char *p, unsigned long *core) | |
5837 | { | |
5838 | unsigned long long coremem; | |
5839 | if (!p) | |
5840 | return -EINVAL; | |
5841 | ||
5842 | coremem = memparse(p, &p); | |
5843 | *core = coremem >> PAGE_SHIFT; | |
5844 | ||
5845 | /* Paranoid check that UL is enough for the coremem value */ | |
5846 | WARN_ON((coremem >> PAGE_SHIFT) > ULONG_MAX); | |
5847 | ||
5848 | return 0; | |
5849 | } | |
5850 | ||
5851 | /* | |
5852 | * kernelcore=size sets the amount of memory for use for allocations that | |
5853 | * cannot be reclaimed or migrated. | |
5854 | */ | |
5855 | static int __init cmdline_parse_kernelcore(char *p) | |
5856 | { | |
5857 | return cmdline_parse_core(p, &required_kernelcore); | |
5858 | } | |
5859 | ||
5860 | /* | |
5861 | * movablecore=size sets the amount of memory for use for allocations that | |
5862 | * can be reclaimed or migrated. | |
5863 | */ | |
5864 | static int __init cmdline_parse_movablecore(char *p) | |
5865 | { | |
5866 | return cmdline_parse_core(p, &required_movablecore); | |
5867 | } | |
5868 | ||
5869 | early_param("kernelcore", cmdline_parse_kernelcore); | |
5870 | early_param("movablecore", cmdline_parse_movablecore); | |
5871 | ||
5872 | #endif /* CONFIG_HAVE_MEMBLOCK_NODE_MAP */ | |
5873 | ||
5874 | void adjust_managed_page_count(struct page *page, long count) | |
5875 | { | |
5876 | spin_lock(&managed_page_count_lock); | |
5877 | page_zone(page)->managed_pages += count; | |
5878 | totalram_pages += count; | |
5879 | #ifdef CONFIG_HIGHMEM | |
5880 | if (PageHighMem(page)) | |
5881 | totalhigh_pages += count; | |
5882 | #endif | |
5883 | spin_unlock(&managed_page_count_lock); | |
5884 | } | |
5885 | EXPORT_SYMBOL(adjust_managed_page_count); | |
5886 | ||
5887 | unsigned long free_reserved_area(void *start, void *end, int poison, char *s) | |
5888 | { | |
5889 | void *pos; | |
5890 | unsigned long pages = 0; | |
5891 | ||
5892 | start = (void *)PAGE_ALIGN((unsigned long)start); | |
5893 | end = (void *)((unsigned long)end & PAGE_MASK); | |
5894 | for (pos = start; pos < end; pos += PAGE_SIZE, pages++) { | |
5895 | if ((unsigned int)poison <= 0xFF) | |
5896 | memset(pos, poison, PAGE_SIZE); | |
5897 | free_reserved_page(virt_to_page(pos)); | |
5898 | } | |
5899 | ||
5900 | if (pages && s) | |
5901 | pr_info("Freeing %s memory: %ldK (%p - %p)\n", | |
5902 | s, pages << (PAGE_SHIFT - 10), start, end); | |
5903 | ||
5904 | return pages; | |
5905 | } | |
5906 | EXPORT_SYMBOL(free_reserved_area); | |
5907 | ||
5908 | #ifdef CONFIG_HIGHMEM | |
5909 | void free_highmem_page(struct page *page) | |
5910 | { | |
5911 | __free_reserved_page(page); | |
5912 | totalram_pages++; | |
5913 | page_zone(page)->managed_pages++; | |
5914 | totalhigh_pages++; | |
5915 | } | |
5916 | #endif | |
5917 | ||
5918 | ||
5919 | void __init mem_init_print_info(const char *str) | |
5920 | { | |
5921 | unsigned long physpages, codesize, datasize, rosize, bss_size; | |
5922 | unsigned long init_code_size, init_data_size; | |
5923 | ||
5924 | physpages = get_num_physpages(); | |
5925 | codesize = _etext - _stext; | |
5926 | datasize = _edata - _sdata; | |
5927 | rosize = __end_rodata - __start_rodata; | |
5928 | bss_size = __bss_stop - __bss_start; | |
5929 | init_data_size = __init_end - __init_begin; | |
5930 | init_code_size = _einittext - _sinittext; | |
5931 | ||
5932 | /* | |
5933 | * Detect special cases and adjust section sizes accordingly: | |
5934 | * 1) .init.* may be embedded into .data sections | |
5935 | * 2) .init.text.* may be out of [__init_begin, __init_end], | |
5936 | * please refer to arch/tile/kernel/vmlinux.lds.S. | |
5937 | * 3) .rodata.* may be embedded into .text or .data sections. | |
5938 | */ | |
5939 | #define adj_init_size(start, end, size, pos, adj) \ | |
5940 | do { \ | |
5941 | if (start <= pos && pos < end && size > adj) \ | |
5942 | size -= adj; \ | |
5943 | } while (0) | |
5944 | ||
5945 | adj_init_size(__init_begin, __init_end, init_data_size, | |
5946 | _sinittext, init_code_size); | |
5947 | adj_init_size(_stext, _etext, codesize, _sinittext, init_code_size); | |
5948 | adj_init_size(_sdata, _edata, datasize, __init_begin, init_data_size); | |
5949 | adj_init_size(_stext, _etext, codesize, __start_rodata, rosize); | |
5950 | adj_init_size(_sdata, _edata, datasize, __start_rodata, rosize); | |
5951 | ||
5952 | #undef adj_init_size | |
5953 | ||
5954 | pr_info("Memory: %luK/%luK available " | |
5955 | "(%luK kernel code, %luK rwdata, %luK rodata, " | |
5956 | "%luK init, %luK bss, %luK reserved, %luK cma-reserved" | |
5957 | #ifdef CONFIG_HIGHMEM | |
5958 | ", %luK highmem" | |
5959 | #endif | |
5960 | "%s%s)\n", | |
5961 | nr_free_pages() << (PAGE_SHIFT-10), physpages << (PAGE_SHIFT-10), | |
5962 | codesize >> 10, datasize >> 10, rosize >> 10, | |
5963 | (init_data_size + init_code_size) >> 10, bss_size >> 10, | |
5964 | (physpages - totalram_pages - totalcma_pages) << (PAGE_SHIFT-10), | |
5965 | totalcma_pages << (PAGE_SHIFT-10), | |
5966 | #ifdef CONFIG_HIGHMEM | |
5967 | totalhigh_pages << (PAGE_SHIFT-10), | |
5968 | #endif | |
5969 | str ? ", " : "", str ? str : ""); | |
5970 | } | |
5971 | ||
5972 | /** | |
5973 | * set_dma_reserve - set the specified number of pages reserved in the first zone | |
5974 | * @new_dma_reserve: The number of pages to mark reserved | |
5975 | * | |
5976 | * The per-cpu batchsize and zone watermarks are determined by present_pages. | |
5977 | * In the DMA zone, a significant percentage may be consumed by kernel image | |
5978 | * and other unfreeable allocations which can skew the watermarks badly. This | |
5979 | * function may optionally be used to account for unfreeable pages in the | |
5980 | * first zone (e.g., ZONE_DMA). The effect will be lower watermarks and | |
5981 | * smaller per-cpu batchsize. | |
5982 | */ | |
5983 | void __init set_dma_reserve(unsigned long new_dma_reserve) | |
5984 | { | |
5985 | dma_reserve = new_dma_reserve; | |
5986 | } | |
5987 | ||
5988 | void __init free_area_init(unsigned long *zones_size) | |
5989 | { | |
5990 | free_area_init_node(0, zones_size, | |
5991 | __pa(PAGE_OFFSET) >> PAGE_SHIFT, NULL); | |
5992 | } | |
5993 | ||
5994 | static int page_alloc_cpu_notify(struct notifier_block *self, | |
5995 | unsigned long action, void *hcpu) | |
5996 | { | |
5997 | int cpu = (unsigned long)hcpu; | |
5998 | ||
5999 | if (action == CPU_DEAD || action == CPU_DEAD_FROZEN) { | |
6000 | lru_add_drain_cpu(cpu); | |
6001 | drain_pages(cpu); | |
6002 | ||
6003 | /* | |
6004 | * Spill the event counters of the dead processor | |
6005 | * into the current processors event counters. | |
6006 | * This artificially elevates the count of the current | |
6007 | * processor. | |
6008 | */ | |
6009 | vm_events_fold_cpu(cpu); | |
6010 | ||
6011 | /* | |
6012 | * Zero the differential counters of the dead processor | |
6013 | * so that the vm statistics are consistent. | |
6014 | * | |
6015 | * This is only okay since the processor is dead and cannot | |
6016 | * race with what we are doing. | |
6017 | */ | |
6018 | cpu_vm_stats_fold(cpu); | |
6019 | } | |
6020 | return NOTIFY_OK; | |
6021 | } | |
6022 | ||
6023 | void __init page_alloc_init(void) | |
6024 | { | |
6025 | hotcpu_notifier(page_alloc_cpu_notify, 0); | |
6026 | } | |
6027 | ||
6028 | /* | |
6029 | * calculate_totalreserve_pages - called when sysctl_lower_zone_reserve_ratio | |
6030 | * or min_free_kbytes changes. | |
6031 | */ | |
6032 | static void calculate_totalreserve_pages(void) | |
6033 | { | |
6034 | struct pglist_data *pgdat; | |
6035 | unsigned long reserve_pages = 0; | |
6036 | enum zone_type i, j; | |
6037 | ||
6038 | for_each_online_pgdat(pgdat) { | |
6039 | for (i = 0; i < MAX_NR_ZONES; i++) { | |
6040 | struct zone *zone = pgdat->node_zones + i; | |
6041 | long max = 0; | |
6042 | ||
6043 | /* Find valid and maximum lowmem_reserve in the zone */ | |
6044 | for (j = i; j < MAX_NR_ZONES; j++) { | |
6045 | if (zone->lowmem_reserve[j] > max) | |
6046 | max = zone->lowmem_reserve[j]; | |
6047 | } | |
6048 | ||
6049 | /* we treat the high watermark as reserved pages. */ | |
6050 | max += high_wmark_pages(zone); | |
6051 | ||
6052 | if (max > zone->managed_pages) | |
6053 | max = zone->managed_pages; | |
6054 | reserve_pages += max; | |
6055 | /* | |
6056 | * Lowmem reserves are not available to | |
6057 | * GFP_HIGHUSER page cache allocations and | |
6058 | * kswapd tries to balance zones to their high | |
6059 | * watermark. As a result, neither should be | |
6060 | * regarded as dirtyable memory, to prevent a | |
6061 | * situation where reclaim has to clean pages | |
6062 | * in order to balance the zones. | |
6063 | */ | |
6064 | zone->dirty_balance_reserve = max; | |
6065 | } | |
6066 | } | |
6067 | dirty_balance_reserve = reserve_pages; | |
6068 | totalreserve_pages = reserve_pages; | |
6069 | } | |
6070 | ||
6071 | /* | |
6072 | * setup_per_zone_lowmem_reserve - called whenever | |
6073 | * sysctl_lower_zone_reserve_ratio changes. Ensures that each zone | |
6074 | * has a correct pages reserved value, so an adequate number of | |
6075 | * pages are left in the zone after a successful __alloc_pages(). | |
6076 | */ | |
6077 | static void setup_per_zone_lowmem_reserve(void) | |
6078 | { | |
6079 | struct pglist_data *pgdat; | |
6080 | enum zone_type j, idx; | |
6081 | ||
6082 | for_each_online_pgdat(pgdat) { | |
6083 | for (j = 0; j < MAX_NR_ZONES; j++) { | |
6084 | struct zone *zone = pgdat->node_zones + j; | |
6085 | unsigned long managed_pages = zone->managed_pages; | |
6086 | ||
6087 | zone->lowmem_reserve[j] = 0; | |
6088 | ||
6089 | idx = j; | |
6090 | while (idx) { | |
6091 | struct zone *lower_zone; | |
6092 | ||
6093 | idx--; | |
6094 | ||
6095 | if (sysctl_lowmem_reserve_ratio[idx] < 1) | |
6096 | sysctl_lowmem_reserve_ratio[idx] = 1; | |
6097 | ||
6098 | lower_zone = pgdat->node_zones + idx; | |
6099 | lower_zone->lowmem_reserve[j] = managed_pages / | |
6100 | sysctl_lowmem_reserve_ratio[idx]; | |
6101 | managed_pages += lower_zone->managed_pages; | |
6102 | } | |
6103 | } | |
6104 | } | |
6105 | ||
6106 | /* update totalreserve_pages */ | |
6107 | calculate_totalreserve_pages(); | |
6108 | } | |
6109 | ||
6110 | static void __setup_per_zone_wmarks(void) | |
6111 | { | |
6112 | unsigned long pages_min = min_free_kbytes >> (PAGE_SHIFT - 10); | |
6113 | unsigned long lowmem_pages = 0; | |
6114 | struct zone *zone; | |
6115 | unsigned long flags; | |
6116 | ||
6117 | /* Calculate total number of !ZONE_HIGHMEM pages */ | |
6118 | for_each_zone(zone) { | |
6119 | if (!is_highmem(zone)) | |
6120 | lowmem_pages += zone->managed_pages; | |
6121 | } | |
6122 | ||
6123 | for_each_zone(zone) { | |
6124 | u64 tmp; | |
6125 | ||
6126 | spin_lock_irqsave(&zone->lock, flags); | |
6127 | tmp = (u64)pages_min * zone->managed_pages; | |
6128 | do_div(tmp, lowmem_pages); | |
6129 | if (is_highmem(zone)) { | |
6130 | /* | |
6131 | * __GFP_HIGH and PF_MEMALLOC allocations usually don't | |
6132 | * need highmem pages, so cap pages_min to a small | |
6133 | * value here. | |
6134 | * | |
6135 | * The WMARK_HIGH-WMARK_LOW and (WMARK_LOW-WMARK_MIN) | |
6136 | * deltas control asynch page reclaim, and so should | |
6137 | * not be capped for highmem. | |
6138 | */ | |
6139 | unsigned long min_pages; | |
6140 | ||
6141 | min_pages = zone->managed_pages / 1024; | |
6142 | min_pages = clamp(min_pages, SWAP_CLUSTER_MAX, 128UL); | |
6143 | zone->watermark[WMARK_MIN] = min_pages; | |
6144 | } else { | |
6145 | /* | |
6146 | * If it's a lowmem zone, reserve a number of pages | |
6147 | * proportionate to the zone's size. | |
6148 | */ | |
6149 | zone->watermark[WMARK_MIN] = tmp; | |
6150 | } | |
6151 | ||
6152 | zone->watermark[WMARK_LOW] = min_wmark_pages(zone) + (tmp >> 2); | |
6153 | zone->watermark[WMARK_HIGH] = min_wmark_pages(zone) + (tmp >> 1); | |
6154 | ||
6155 | __mod_zone_page_state(zone, NR_ALLOC_BATCH, | |
6156 | high_wmark_pages(zone) - low_wmark_pages(zone) - | |
6157 | atomic_long_read(&zone->vm_stat[NR_ALLOC_BATCH])); | |
6158 | ||
6159 | setup_zone_migrate_reserve(zone); | |
6160 | spin_unlock_irqrestore(&zone->lock, flags); | |
6161 | } | |
6162 | ||
6163 | /* update totalreserve_pages */ | |
6164 | calculate_totalreserve_pages(); | |
6165 | } | |
6166 | ||
6167 | /** | |
6168 | * setup_per_zone_wmarks - called when min_free_kbytes changes | |
6169 | * or when memory is hot-{added|removed} | |
6170 | * | |
6171 | * Ensures that the watermark[min,low,high] values for each zone are set | |
6172 | * correctly with respect to min_free_kbytes. | |
6173 | */ | |
6174 | void setup_per_zone_wmarks(void) | |
6175 | { | |
6176 | mutex_lock(&zonelists_mutex); | |
6177 | __setup_per_zone_wmarks(); | |
6178 | mutex_unlock(&zonelists_mutex); | |
6179 | } | |
6180 | ||
6181 | /* | |
6182 | * The inactive anon list should be small enough that the VM never has to | |
6183 | * do too much work, but large enough that each inactive page has a chance | |
6184 | * to be referenced again before it is swapped out. | |
6185 | * | |
6186 | * The inactive_anon ratio is the target ratio of ACTIVE_ANON to | |
6187 | * INACTIVE_ANON pages on this zone's LRU, maintained by the | |
6188 | * pageout code. A zone->inactive_ratio of 3 means 3:1 or 25% of | |
6189 | * the anonymous pages are kept on the inactive list. | |
6190 | * | |
6191 | * total target max | |
6192 | * memory ratio inactive anon | |
6193 | * ------------------------------------- | |
6194 | * 10MB 1 5MB | |
6195 | * 100MB 1 50MB | |
6196 | * 1GB 3 250MB | |
6197 | * 10GB 10 0.9GB | |
6198 | * 100GB 31 3GB | |
6199 | * 1TB 101 10GB | |
6200 | * 10TB 320 32GB | |
6201 | */ | |
6202 | static void __meminit calculate_zone_inactive_ratio(struct zone *zone) | |
6203 | { | |
6204 | unsigned int gb, ratio; | |
6205 | ||
6206 | /* Zone size in gigabytes */ | |
6207 | gb = zone->managed_pages >> (30 - PAGE_SHIFT); | |
6208 | if (gb) | |
6209 | ratio = int_sqrt(10 * gb); | |
6210 | else | |
6211 | ratio = 1; | |
6212 | ||
6213 | zone->inactive_ratio = ratio; | |
6214 | } | |
6215 | ||
6216 | static void __meminit setup_per_zone_inactive_ratio(void) | |
6217 | { | |
6218 | struct zone *zone; | |
6219 | ||
6220 | for_each_zone(zone) | |
6221 | calculate_zone_inactive_ratio(zone); | |
6222 | } | |
6223 | ||
6224 | /* | |
6225 | * Initialise min_free_kbytes. | |
6226 | * | |
6227 | * For small machines we want it small (128k min). For large machines | |
6228 | * we want it large (64MB max). But it is not linear, because network | |
6229 | * bandwidth does not increase linearly with machine size. We use | |
6230 | * | |
6231 | * min_free_kbytes = 4 * sqrt(lowmem_kbytes), for better accuracy: | |
6232 | * min_free_kbytes = sqrt(lowmem_kbytes * 16) | |
6233 | * | |
6234 | * which yields | |
6235 | * | |
6236 | * 16MB: 512k | |
6237 | * 32MB: 724k | |
6238 | * 64MB: 1024k | |
6239 | * 128MB: 1448k | |
6240 | * 256MB: 2048k | |
6241 | * 512MB: 2896k | |
6242 | * 1024MB: 4096k | |
6243 | * 2048MB: 5792k | |
6244 | * 4096MB: 8192k | |
6245 | * 8192MB: 11584k | |
6246 | * 16384MB: 16384k | |
6247 | */ | |
6248 | int __meminit init_per_zone_wmark_min(void) | |
6249 | { | |
6250 | unsigned long lowmem_kbytes; | |
6251 | int new_min_free_kbytes; | |
6252 | ||
6253 | lowmem_kbytes = nr_free_buffer_pages() * (PAGE_SIZE >> 10); | |
6254 | new_min_free_kbytes = int_sqrt(lowmem_kbytes * 16); | |
6255 | ||
6256 | if (new_min_free_kbytes > user_min_free_kbytes) { | |
6257 | min_free_kbytes = new_min_free_kbytes; | |
6258 | if (min_free_kbytes < 128) | |
6259 | min_free_kbytes = 128; | |
6260 | if (min_free_kbytes > 65536) | |
6261 | min_free_kbytes = 65536; | |
6262 | } else { | |
6263 | pr_warn("min_free_kbytes is not updated to %d because user defined value %d is preferred\n", | |
6264 | new_min_free_kbytes, user_min_free_kbytes); | |
6265 | } | |
6266 | setup_per_zone_wmarks(); | |
6267 | refresh_zone_stat_thresholds(); | |
6268 | setup_per_zone_lowmem_reserve(); | |
6269 | setup_per_zone_inactive_ratio(); | |
6270 | return 0; | |
6271 | } | |
6272 | module_init(init_per_zone_wmark_min) | |
6273 | ||
6274 | /* | |
6275 | * min_free_kbytes_sysctl_handler - just a wrapper around proc_dointvec() so | |
6276 | * that we can call two helper functions whenever min_free_kbytes | |
6277 | * changes. | |
6278 | */ | |
6279 | int min_free_kbytes_sysctl_handler(struct ctl_table *table, int write, | |
6280 | void __user *buffer, size_t *length, loff_t *ppos) | |
6281 | { | |
6282 | int rc; | |
6283 | ||
6284 | rc = proc_dointvec_minmax(table, write, buffer, length, ppos); | |
6285 | if (rc) | |
6286 | return rc; | |
6287 | ||
6288 | if (write) { | |
6289 | user_min_free_kbytes = min_free_kbytes; | |
6290 | setup_per_zone_wmarks(); | |
6291 | } | |
6292 | return 0; | |
6293 | } | |
6294 | ||
6295 | #ifdef CONFIG_NUMA | |
6296 | int sysctl_min_unmapped_ratio_sysctl_handler(struct ctl_table *table, int write, | |
6297 | void __user *buffer, size_t *length, loff_t *ppos) | |
6298 | { | |
6299 | struct zone *zone; | |
6300 | int rc; | |
6301 | ||
6302 | rc = proc_dointvec_minmax(table, write, buffer, length, ppos); | |
6303 | if (rc) | |
6304 | return rc; | |
6305 | ||
6306 | for_each_zone(zone) | |
6307 | zone->min_unmapped_pages = (zone->managed_pages * | |
6308 | sysctl_min_unmapped_ratio) / 100; | |
6309 | return 0; | |
6310 | } | |
6311 | ||
6312 | int sysctl_min_slab_ratio_sysctl_handler(struct ctl_table *table, int write, | |
6313 | void __user *buffer, size_t *length, loff_t *ppos) | |
6314 | { | |
6315 | struct zone *zone; | |
6316 | int rc; | |
6317 | ||
6318 | rc = proc_dointvec_minmax(table, write, buffer, length, ppos); | |
6319 | if (rc) | |
6320 | return rc; | |
6321 | ||
6322 | for_each_zone(zone) | |
6323 | zone->min_slab_pages = (zone->managed_pages * | |
6324 | sysctl_min_slab_ratio) / 100; | |
6325 | return 0; | |
6326 | } | |
6327 | #endif | |
6328 | ||
6329 | /* | |
6330 | * lowmem_reserve_ratio_sysctl_handler - just a wrapper around | |
6331 | * proc_dointvec() so that we can call setup_per_zone_lowmem_reserve() | |
6332 | * whenever sysctl_lowmem_reserve_ratio changes. | |
6333 | * | |
6334 | * The reserve ratio obviously has absolutely no relation with the | |
6335 | * minimum watermarks. The lowmem reserve ratio can only make sense | |
6336 | * if in function of the boot time zone sizes. | |
6337 | */ | |
6338 | int lowmem_reserve_ratio_sysctl_handler(struct ctl_table *table, int write, | |
6339 | void __user *buffer, size_t *length, loff_t *ppos) | |
6340 | { | |
6341 | proc_dointvec_minmax(table, write, buffer, length, ppos); | |
6342 | setup_per_zone_lowmem_reserve(); | |
6343 | return 0; | |
6344 | } | |
6345 | ||
6346 | /* | |
6347 | * percpu_pagelist_fraction - changes the pcp->high for each zone on each | |
6348 | * cpu. It is the fraction of total pages in each zone that a hot per cpu | |
6349 | * pagelist can have before it gets flushed back to buddy allocator. | |
6350 | */ | |
6351 | int percpu_pagelist_fraction_sysctl_handler(struct ctl_table *table, int write, | |
6352 | void __user *buffer, size_t *length, loff_t *ppos) | |
6353 | { | |
6354 | struct zone *zone; | |
6355 | int old_percpu_pagelist_fraction; | |
6356 | int ret; | |
6357 | ||
6358 | mutex_lock(&pcp_batch_high_lock); | |
6359 | old_percpu_pagelist_fraction = percpu_pagelist_fraction; | |
6360 | ||
6361 | ret = proc_dointvec_minmax(table, write, buffer, length, ppos); | |
6362 | if (!write || ret < 0) | |
6363 | goto out; | |
6364 | ||
6365 | /* Sanity checking to avoid pcp imbalance */ | |
6366 | if (percpu_pagelist_fraction && | |
6367 | percpu_pagelist_fraction < MIN_PERCPU_PAGELIST_FRACTION) { | |
6368 | percpu_pagelist_fraction = old_percpu_pagelist_fraction; | |
6369 | ret = -EINVAL; | |
6370 | goto out; | |
6371 | } | |
6372 | ||
6373 | /* No change? */ | |
6374 | if (percpu_pagelist_fraction == old_percpu_pagelist_fraction) | |
6375 | goto out; | |
6376 | ||
6377 | for_each_populated_zone(zone) { | |
6378 | unsigned int cpu; | |
6379 | ||
6380 | for_each_possible_cpu(cpu) | |
6381 | pageset_set_high_and_batch(zone, | |
6382 | per_cpu_ptr(zone->pageset, cpu)); | |
6383 | } | |
6384 | out: | |
6385 | mutex_unlock(&pcp_batch_high_lock); | |
6386 | return ret; | |
6387 | } | |
6388 | ||
6389 | #ifdef CONFIG_NUMA | |
6390 | int hashdist = HASHDIST_DEFAULT; | |
6391 | ||
6392 | static int __init set_hashdist(char *str) | |
6393 | { | |
6394 | if (!str) | |
6395 | return 0; | |
6396 | hashdist = simple_strtoul(str, &str, 0); | |
6397 | return 1; | |
6398 | } | |
6399 | __setup("hashdist=", set_hashdist); | |
6400 | #endif | |
6401 | ||
6402 | /* | |
6403 | * allocate a large system hash table from bootmem | |
6404 | * - it is assumed that the hash table must contain an exact power-of-2 | |
6405 | * quantity of entries | |
6406 | * - limit is the number of hash buckets, not the total allocation size | |
6407 | */ | |
6408 | void *__init alloc_large_system_hash(const char *tablename, | |
6409 | unsigned long bucketsize, | |
6410 | unsigned long numentries, | |
6411 | int scale, | |
6412 | int flags, | |
6413 | unsigned int *_hash_shift, | |
6414 | unsigned int *_hash_mask, | |
6415 | unsigned long low_limit, | |
6416 | unsigned long high_limit) | |
6417 | { | |
6418 | unsigned long long max = high_limit; | |
6419 | unsigned long log2qty, size; | |
6420 | void *table = NULL; | |
6421 | ||
6422 | /* allow the kernel cmdline to have a say */ | |
6423 | if (!numentries) { | |
6424 | /* round applicable memory size up to nearest megabyte */ | |
6425 | numentries = nr_kernel_pages; | |
6426 | ||
6427 | /* It isn't necessary when PAGE_SIZE >= 1MB */ | |
6428 | if (PAGE_SHIFT < 20) | |
6429 | numentries = round_up(numentries, (1<<20)/PAGE_SIZE); | |
6430 | ||
6431 | /* limit to 1 bucket per 2^scale bytes of low memory */ | |
6432 | if (scale > PAGE_SHIFT) | |
6433 | numentries >>= (scale - PAGE_SHIFT); | |
6434 | else | |
6435 | numentries <<= (PAGE_SHIFT - scale); | |
6436 | ||
6437 | /* Make sure we've got at least a 0-order allocation.. */ | |
6438 | if (unlikely(flags & HASH_SMALL)) { | |
6439 | /* Makes no sense without HASH_EARLY */ | |
6440 | WARN_ON(!(flags & HASH_EARLY)); | |
6441 | if (!(numentries >> *_hash_shift)) { | |
6442 | numentries = 1UL << *_hash_shift; | |
6443 | BUG_ON(!numentries); | |
6444 | } | |
6445 | } else if (unlikely((numentries * bucketsize) < PAGE_SIZE)) | |
6446 | numentries = PAGE_SIZE / bucketsize; | |
6447 | } | |
6448 | numentries = roundup_pow_of_two(numentries); | |
6449 | ||
6450 | /* limit allocation size to 1/16 total memory by default */ | |
6451 | if (max == 0) { | |
6452 | max = ((unsigned long long)nr_all_pages << PAGE_SHIFT) >> 4; | |
6453 | do_div(max, bucketsize); | |
6454 | } | |
6455 | max = min(max, 0x80000000ULL); | |
6456 | ||
6457 | if (numentries < low_limit) | |
6458 | numentries = low_limit; | |
6459 | if (numentries > max) | |
6460 | numentries = max; | |
6461 | ||
6462 | log2qty = ilog2(numentries); | |
6463 | ||
6464 | do { | |
6465 | size = bucketsize << log2qty; | |
6466 | if (flags & HASH_EARLY) | |
6467 | table = memblock_virt_alloc_nopanic(size, 0); | |
6468 | else if (hashdist) | |
6469 | table = __vmalloc(size, GFP_ATOMIC, PAGE_KERNEL); | |
6470 | else { | |
6471 | /* | |
6472 | * If bucketsize is not a power-of-two, we may free | |
6473 | * some pages at the end of hash table which | |
6474 | * alloc_pages_exact() automatically does | |
6475 | */ | |
6476 | if (get_order(size) < MAX_ORDER) { | |
6477 | table = alloc_pages_exact(size, GFP_ATOMIC); | |
6478 | kmemleak_alloc(table, size, 1, GFP_ATOMIC); | |
6479 | } | |
6480 | } | |
6481 | } while (!table && size > PAGE_SIZE && --log2qty); | |
6482 | ||
6483 | if (!table) | |
6484 | panic("Failed to allocate %s hash table\n", tablename); | |
6485 | ||
6486 | printk(KERN_INFO "%s hash table entries: %ld (order: %d, %lu bytes)\n", | |
6487 | tablename, | |
6488 | (1UL << log2qty), | |
6489 | ilog2(size) - PAGE_SHIFT, | |
6490 | size); | |
6491 | ||
6492 | if (_hash_shift) | |
6493 | *_hash_shift = log2qty; | |
6494 | if (_hash_mask) | |
6495 | *_hash_mask = (1 << log2qty) - 1; | |
6496 | ||
6497 | return table; | |
6498 | } | |
6499 | ||
6500 | /* Return a pointer to the bitmap storing bits affecting a block of pages */ | |
6501 | static inline unsigned long *get_pageblock_bitmap(struct zone *zone, | |
6502 | unsigned long pfn) | |
6503 | { | |
6504 | #ifdef CONFIG_SPARSEMEM | |
6505 | return __pfn_to_section(pfn)->pageblock_flags; | |
6506 | #else | |
6507 | return zone->pageblock_flags; | |
6508 | #endif /* CONFIG_SPARSEMEM */ | |
6509 | } | |
6510 | ||
6511 | static inline int pfn_to_bitidx(struct zone *zone, unsigned long pfn) | |
6512 | { | |
6513 | #ifdef CONFIG_SPARSEMEM | |
6514 | pfn &= (PAGES_PER_SECTION-1); | |
6515 | return (pfn >> pageblock_order) * NR_PAGEBLOCK_BITS; | |
6516 | #else | |
6517 | pfn = pfn - round_down(zone->zone_start_pfn, pageblock_nr_pages); | |
6518 | return (pfn >> pageblock_order) * NR_PAGEBLOCK_BITS; | |
6519 | #endif /* CONFIG_SPARSEMEM */ | |
6520 | } | |
6521 | ||
6522 | /** | |
6523 | * get_pfnblock_flags_mask - Return the requested group of flags for the pageblock_nr_pages block of pages | |
6524 | * @page: The page within the block of interest | |
6525 | * @pfn: The target page frame number | |
6526 | * @end_bitidx: The last bit of interest to retrieve | |
6527 | * @mask: mask of bits that the caller is interested in | |
6528 | * | |
6529 | * Return: pageblock_bits flags | |
6530 | */ | |
6531 | unsigned long get_pfnblock_flags_mask(struct page *page, unsigned long pfn, | |
6532 | unsigned long end_bitidx, | |
6533 | unsigned long mask) | |
6534 | { | |
6535 | struct zone *zone; | |
6536 | unsigned long *bitmap; | |
6537 | unsigned long bitidx, word_bitidx; | |
6538 | unsigned long word; | |
6539 | ||
6540 | zone = page_zone(page); | |
6541 | bitmap = get_pageblock_bitmap(zone, pfn); | |
6542 | bitidx = pfn_to_bitidx(zone, pfn); | |
6543 | word_bitidx = bitidx / BITS_PER_LONG; | |
6544 | bitidx &= (BITS_PER_LONG-1); | |
6545 | ||
6546 | word = bitmap[word_bitidx]; | |
6547 | bitidx += end_bitidx; | |
6548 | return (word >> (BITS_PER_LONG - bitidx - 1)) & mask; | |
6549 | } | |
6550 | ||
6551 | /** | |
6552 | * set_pfnblock_flags_mask - Set the requested group of flags for a pageblock_nr_pages block of pages | |
6553 | * @page: The page within the block of interest | |
6554 | * @flags: The flags to set | |
6555 | * @pfn: The target page frame number | |
6556 | * @end_bitidx: The last bit of interest | |
6557 | * @mask: mask of bits that the caller is interested in | |
6558 | */ | |
6559 | void set_pfnblock_flags_mask(struct page *page, unsigned long flags, | |
6560 | unsigned long pfn, | |
6561 | unsigned long end_bitidx, | |
6562 | unsigned long mask) | |
6563 | { | |
6564 | struct zone *zone; | |
6565 | unsigned long *bitmap; | |
6566 | unsigned long bitidx, word_bitidx; | |
6567 | unsigned long old_word, word; | |
6568 | ||
6569 | BUILD_BUG_ON(NR_PAGEBLOCK_BITS != 4); | |
6570 | ||
6571 | zone = page_zone(page); | |
6572 | bitmap = get_pageblock_bitmap(zone, pfn); | |
6573 | bitidx = pfn_to_bitidx(zone, pfn); | |
6574 | word_bitidx = bitidx / BITS_PER_LONG; | |
6575 | bitidx &= (BITS_PER_LONG-1); | |
6576 | ||
6577 | VM_BUG_ON_PAGE(!zone_spans_pfn(zone, pfn), page); | |
6578 | ||
6579 | bitidx += end_bitidx; | |
6580 | mask <<= (BITS_PER_LONG - bitidx - 1); | |
6581 | flags <<= (BITS_PER_LONG - bitidx - 1); | |
6582 | ||
6583 | word = READ_ONCE(bitmap[word_bitidx]); | |
6584 | for (;;) { | |
6585 | old_word = cmpxchg(&bitmap[word_bitidx], word, (word & ~mask) | flags); | |
6586 | if (word == old_word) | |
6587 | break; | |
6588 | word = old_word; | |
6589 | } | |
6590 | } | |
6591 | ||
6592 | /* | |
6593 | * This function checks whether pageblock includes unmovable pages or not. | |
6594 | * If @count is not zero, it is okay to include less @count unmovable pages | |
6595 | * | |
6596 | * PageLRU check without isolation or lru_lock could race so that | |
6597 | * MIGRATE_MOVABLE block might include unmovable pages. It means you can't | |
6598 | * expect this function should be exact. | |
6599 | */ | |
6600 | bool has_unmovable_pages(struct zone *zone, struct page *page, int count, | |
6601 | bool skip_hwpoisoned_pages) | |
6602 | { | |
6603 | unsigned long pfn, iter, found; | |
6604 | int mt; | |
6605 | ||
6606 | /* | |
6607 | * For avoiding noise data, lru_add_drain_all() should be called | |
6608 | * If ZONE_MOVABLE, the zone never contains unmovable pages | |
6609 | */ | |
6610 | if (zone_idx(zone) == ZONE_MOVABLE) | |
6611 | return false; | |
6612 | mt = get_pageblock_migratetype(page); | |
6613 | if (mt == MIGRATE_MOVABLE || is_migrate_cma(mt)) | |
6614 | return false; | |
6615 | ||
6616 | pfn = page_to_pfn(page); | |
6617 | for (found = 0, iter = 0; iter < pageblock_nr_pages; iter++) { | |
6618 | unsigned long check = pfn + iter; | |
6619 | ||
6620 | if (!pfn_valid_within(check)) | |
6621 | continue; | |
6622 | ||
6623 | page = pfn_to_page(check); | |
6624 | ||
6625 | /* | |
6626 | * Hugepages are not in LRU lists, but they're movable. | |
6627 | * We need not scan over tail pages bacause we don't | |
6628 | * handle each tail page individually in migration. | |
6629 | */ | |
6630 | if (PageHuge(page)) { | |
6631 | iter = round_up(iter + 1, 1<<compound_order(page)) - 1; | |
6632 | continue; | |
6633 | } | |
6634 | ||
6635 | /* | |
6636 | * We can't use page_count without pin a page | |
6637 | * because another CPU can free compound page. | |
6638 | * This check already skips compound tails of THP | |
6639 | * because their page->_count is zero at all time. | |
6640 | */ | |
6641 | if (!atomic_read(&page->_count)) { | |
6642 | if (PageBuddy(page)) | |
6643 | iter += (1 << page_order(page)) - 1; | |
6644 | continue; | |
6645 | } | |
6646 | ||
6647 | /* | |
6648 | * The HWPoisoned page may be not in buddy system, and | |
6649 | * page_count() is not 0. | |
6650 | */ | |
6651 | if (skip_hwpoisoned_pages && PageHWPoison(page)) | |
6652 | continue; | |
6653 | ||
6654 | if (!PageLRU(page)) | |
6655 | found++; | |
6656 | /* | |
6657 | * If there are RECLAIMABLE pages, we need to check | |
6658 | * it. But now, memory offline itself doesn't call | |
6659 | * shrink_node_slabs() and it still to be fixed. | |
6660 | */ | |
6661 | /* | |
6662 | * If the page is not RAM, page_count()should be 0. | |
6663 | * we don't need more check. This is an _used_ not-movable page. | |
6664 | * | |
6665 | * The problematic thing here is PG_reserved pages. PG_reserved | |
6666 | * is set to both of a memory hole page and a _used_ kernel | |
6667 | * page at boot. | |
6668 | */ | |
6669 | if (found > count) | |
6670 | return true; | |
6671 | } | |
6672 | return false; | |
6673 | } | |
6674 | ||
6675 | bool is_pageblock_removable_nolock(struct page *page) | |
6676 | { | |
6677 | struct zone *zone; | |
6678 | unsigned long pfn; | |
6679 | ||
6680 | /* | |
6681 | * We have to be careful here because we are iterating over memory | |
6682 | * sections which are not zone aware so we might end up outside of | |
6683 | * the zone but still within the section. | |
6684 | * We have to take care about the node as well. If the node is offline | |
6685 | * its NODE_DATA will be NULL - see page_zone. | |
6686 | */ | |
6687 | if (!node_online(page_to_nid(page))) | |
6688 | return false; | |
6689 | ||
6690 | zone = page_zone(page); | |
6691 | pfn = page_to_pfn(page); | |
6692 | if (!zone_spans_pfn(zone, pfn)) | |
6693 | return false; | |
6694 | ||
6695 | return !has_unmovable_pages(zone, page, 0, true); | |
6696 | } | |
6697 | ||
6698 | #ifdef CONFIG_CMA | |
6699 | ||
6700 | static unsigned long pfn_max_align_down(unsigned long pfn) | |
6701 | { | |
6702 | return pfn & ~(max_t(unsigned long, MAX_ORDER_NR_PAGES, | |
6703 | pageblock_nr_pages) - 1); | |
6704 | } | |
6705 | ||
6706 | static unsigned long pfn_max_align_up(unsigned long pfn) | |
6707 | { | |
6708 | return ALIGN(pfn, max_t(unsigned long, MAX_ORDER_NR_PAGES, | |
6709 | pageblock_nr_pages)); | |
6710 | } | |
6711 | ||
6712 | /* [start, end) must belong to a single zone. */ | |
6713 | static int __alloc_contig_migrate_range(struct compact_control *cc, | |
6714 | unsigned long start, unsigned long end) | |
6715 | { | |
6716 | /* This function is based on compact_zone() from compaction.c. */ | |
6717 | unsigned long nr_reclaimed; | |
6718 | unsigned long pfn = start; | |
6719 | unsigned int tries = 0; | |
6720 | int ret = 0; | |
6721 | ||
6722 | migrate_prep(); | |
6723 | ||
6724 | while (pfn < end || !list_empty(&cc->migratepages)) { | |
6725 | if (fatal_signal_pending(current)) { | |
6726 | ret = -EINTR; | |
6727 | break; | |
6728 | } | |
6729 | ||
6730 | if (list_empty(&cc->migratepages)) { | |
6731 | cc->nr_migratepages = 0; | |
6732 | pfn = isolate_migratepages_range(cc, pfn, end); | |
6733 | if (!pfn) { | |
6734 | ret = -EINTR; | |
6735 | break; | |
6736 | } | |
6737 | tries = 0; | |
6738 | } else if (++tries == 5) { | |
6739 | ret = ret < 0 ? ret : -EBUSY; | |
6740 | break; | |
6741 | } | |
6742 | ||
6743 | nr_reclaimed = reclaim_clean_pages_from_list(cc->zone, | |
6744 | &cc->migratepages); | |
6745 | cc->nr_migratepages -= nr_reclaimed; | |
6746 | ||
6747 | ret = migrate_pages(&cc->migratepages, alloc_migrate_target, | |
6748 | NULL, 0, cc->mode, MR_CMA); | |
6749 | } | |
6750 | if (ret < 0) { | |
6751 | putback_movable_pages(&cc->migratepages); | |
6752 | return ret; | |
6753 | } | |
6754 | return 0; | |
6755 | } | |
6756 | ||
6757 | /** | |
6758 | * alloc_contig_range() -- tries to allocate given range of pages | |
6759 | * @start: start PFN to allocate | |
6760 | * @end: one-past-the-last PFN to allocate | |
6761 | * @migratetype: migratetype of the underlaying pageblocks (either | |
6762 | * #MIGRATE_MOVABLE or #MIGRATE_CMA). All pageblocks | |
6763 | * in range must have the same migratetype and it must | |
6764 | * be either of the two. | |
6765 | * | |
6766 | * The PFN range does not have to be pageblock or MAX_ORDER_NR_PAGES | |
6767 | * aligned, however it's the caller's responsibility to guarantee that | |
6768 | * we are the only thread that changes migrate type of pageblocks the | |
6769 | * pages fall in. | |
6770 | * | |
6771 | * The PFN range must belong to a single zone. | |
6772 | * | |
6773 | * Returns zero on success or negative error code. On success all | |
6774 | * pages which PFN is in [start, end) are allocated for the caller and | |
6775 | * need to be freed with free_contig_range(). | |
6776 | */ | |
6777 | int alloc_contig_range(unsigned long start, unsigned long end, | |
6778 | unsigned migratetype) | |
6779 | { | |
6780 | unsigned long outer_start, outer_end; | |
6781 | int ret = 0, order; | |
6782 | ||
6783 | struct compact_control cc = { | |
6784 | .nr_migratepages = 0, | |
6785 | .order = -1, | |
6786 | .zone = page_zone(pfn_to_page(start)), | |
6787 | .mode = MIGRATE_SYNC, | |
6788 | .ignore_skip_hint = true, | |
6789 | }; | |
6790 | INIT_LIST_HEAD(&cc.migratepages); | |
6791 | ||
6792 | /* | |
6793 | * What we do here is we mark all pageblocks in range as | |
6794 | * MIGRATE_ISOLATE. Because pageblock and max order pages may | |
6795 | * have different sizes, and due to the way page allocator | |
6796 | * work, we align the range to biggest of the two pages so | |
6797 | * that page allocator won't try to merge buddies from | |
6798 | * different pageblocks and change MIGRATE_ISOLATE to some | |
6799 | * other migration type. | |
6800 | * | |
6801 | * Once the pageblocks are marked as MIGRATE_ISOLATE, we | |
6802 | * migrate the pages from an unaligned range (ie. pages that | |
6803 | * we are interested in). This will put all the pages in | |
6804 | * range back to page allocator as MIGRATE_ISOLATE. | |
6805 | * | |
6806 | * When this is done, we take the pages in range from page | |
6807 | * allocator removing them from the buddy system. This way | |
6808 | * page allocator will never consider using them. | |
6809 | * | |
6810 | * This lets us mark the pageblocks back as | |
6811 | * MIGRATE_CMA/MIGRATE_MOVABLE so that free pages in the | |
6812 | * aligned range but not in the unaligned, original range are | |
6813 | * put back to page allocator so that buddy can use them. | |
6814 | */ | |
6815 | ||
6816 | ret = start_isolate_page_range(pfn_max_align_down(start), | |
6817 | pfn_max_align_up(end), migratetype, | |
6818 | false); | |
6819 | if (ret) | |
6820 | return ret; | |
6821 | ||
6822 | ret = __alloc_contig_migrate_range(&cc, start, end); | |
6823 | if (ret) | |
6824 | goto done; | |
6825 | ||
6826 | /* | |
6827 | * Pages from [start, end) are within a MAX_ORDER_NR_PAGES | |
6828 | * aligned blocks that are marked as MIGRATE_ISOLATE. What's | |
6829 | * more, all pages in [start, end) are free in page allocator. | |
6830 | * What we are going to do is to allocate all pages from | |
6831 | * [start, end) (that is remove them from page allocator). | |
6832 | * | |
6833 | * The only problem is that pages at the beginning and at the | |
6834 | * end of interesting range may be not aligned with pages that | |
6835 | * page allocator holds, ie. they can be part of higher order | |
6836 | * pages. Because of this, we reserve the bigger range and | |
6837 | * once this is done free the pages we are not interested in. | |
6838 | * | |
6839 | * We don't have to hold zone->lock here because the pages are | |
6840 | * isolated thus they won't get removed from buddy. | |
6841 | */ | |
6842 | ||
6843 | lru_add_drain_all(); | |
6844 | drain_all_pages(cc.zone); | |
6845 | ||
6846 | order = 0; | |
6847 | outer_start = start; | |
6848 | while (!PageBuddy(pfn_to_page(outer_start))) { | |
6849 | if (++order >= MAX_ORDER) { | |
6850 | ret = -EBUSY; | |
6851 | goto done; | |
6852 | } | |
6853 | outer_start &= ~0UL << order; | |
6854 | } | |
6855 | ||
6856 | /* Make sure the range is really isolated. */ | |
6857 | if (test_pages_isolated(outer_start, end, false)) { | |
6858 | pr_info("%s: [%lx, %lx) PFNs busy\n", | |
6859 | __func__, outer_start, end); | |
6860 | ret = -EBUSY; | |
6861 | goto done; | |
6862 | } | |
6863 | ||
6864 | /* Grab isolated pages from freelists. */ | |
6865 | outer_end = isolate_freepages_range(&cc, outer_start, end); | |
6866 | if (!outer_end) { | |
6867 | ret = -EBUSY; | |
6868 | goto done; | |
6869 | } | |
6870 | ||
6871 | /* Free head and tail (if any) */ | |
6872 | if (start != outer_start) | |
6873 | free_contig_range(outer_start, start - outer_start); | |
6874 | if (end != outer_end) | |
6875 | free_contig_range(end, outer_end - end); | |
6876 | ||
6877 | done: | |
6878 | undo_isolate_page_range(pfn_max_align_down(start), | |
6879 | pfn_max_align_up(end), migratetype); | |
6880 | return ret; | |
6881 | } | |
6882 | ||
6883 | void free_contig_range(unsigned long pfn, unsigned nr_pages) | |
6884 | { | |
6885 | unsigned int count = 0; | |
6886 | ||
6887 | for (; nr_pages--; pfn++) { | |
6888 | struct page *page = pfn_to_page(pfn); | |
6889 | ||
6890 | count += page_count(page) != 1; | |
6891 | __free_page(page); | |
6892 | } | |
6893 | WARN(count != 0, "%d pages are still in use!\n", count); | |
6894 | } | |
6895 | #endif | |
6896 | ||
6897 | #ifdef CONFIG_MEMORY_HOTPLUG | |
6898 | /* | |
6899 | * The zone indicated has a new number of managed_pages; batch sizes and percpu | |
6900 | * page high values need to be recalulated. | |
6901 | */ | |
6902 | void __meminit zone_pcp_update(struct zone *zone) | |
6903 | { | |
6904 | unsigned cpu; | |
6905 | mutex_lock(&pcp_batch_high_lock); | |
6906 | for_each_possible_cpu(cpu) | |
6907 | pageset_set_high_and_batch(zone, | |
6908 | per_cpu_ptr(zone->pageset, cpu)); | |
6909 | mutex_unlock(&pcp_batch_high_lock); | |
6910 | } | |
6911 | #endif | |
6912 | ||
6913 | void zone_pcp_reset(struct zone *zone) | |
6914 | { | |
6915 | unsigned long flags; | |
6916 | int cpu; | |
6917 | struct per_cpu_pageset *pset; | |
6918 | ||
6919 | /* avoid races with drain_pages() */ | |
6920 | local_irq_save(flags); | |
6921 | if (zone->pageset != &boot_pageset) { | |
6922 | for_each_online_cpu(cpu) { | |
6923 | pset = per_cpu_ptr(zone->pageset, cpu); | |
6924 | drain_zonestat(zone, pset); | |
6925 | } | |
6926 | free_percpu(zone->pageset); | |
6927 | zone->pageset = &boot_pageset; | |
6928 | } | |
6929 | local_irq_restore(flags); | |
6930 | } | |
6931 | ||
6932 | #ifdef CONFIG_MEMORY_HOTREMOVE | |
6933 | /* | |
6934 | * All pages in the range must be isolated before calling this. | |
6935 | */ | |
6936 | void | |
6937 | __offline_isolated_pages(unsigned long start_pfn, unsigned long end_pfn) | |
6938 | { | |
6939 | struct page *page; | |
6940 | struct zone *zone; | |
6941 | unsigned int order, i; | |
6942 | unsigned long pfn; | |
6943 | unsigned long flags; | |
6944 | /* find the first valid pfn */ | |
6945 | for (pfn = start_pfn; pfn < end_pfn; pfn++) | |
6946 | if (pfn_valid(pfn)) | |
6947 | break; | |
6948 | if (pfn == end_pfn) | |
6949 | return; | |
6950 | zone = page_zone(pfn_to_page(pfn)); | |
6951 | spin_lock_irqsave(&zone->lock, flags); | |
6952 | pfn = start_pfn; | |
6953 | while (pfn < end_pfn) { | |
6954 | if (!pfn_valid(pfn)) { | |
6955 | pfn++; | |
6956 | continue; | |
6957 | } | |
6958 | page = pfn_to_page(pfn); | |
6959 | /* | |
6960 | * The HWPoisoned page may be not in buddy system, and | |
6961 | * page_count() is not 0. | |
6962 | */ | |
6963 | if (unlikely(!PageBuddy(page) && PageHWPoison(page))) { | |
6964 | pfn++; | |
6965 | SetPageReserved(page); | |
6966 | continue; | |
6967 | } | |
6968 | ||
6969 | BUG_ON(page_count(page)); | |
6970 | BUG_ON(!PageBuddy(page)); | |
6971 | order = page_order(page); | |
6972 | #ifdef CONFIG_DEBUG_VM | |
6973 | printk(KERN_INFO "remove from free list %lx %d %lx\n", | |
6974 | pfn, 1 << order, end_pfn); | |
6975 | #endif | |
6976 | list_del(&page->lru); | |
6977 | rmv_page_order(page); | |
6978 | zone->free_area[order].nr_free--; | |
6979 | for (i = 0; i < (1 << order); i++) | |
6980 | SetPageReserved((page+i)); | |
6981 | pfn += (1 << order); | |
6982 | } | |
6983 | spin_unlock_irqrestore(&zone->lock, flags); | |
6984 | } | |
6985 | #endif | |
6986 | ||
6987 | #ifdef CONFIG_MEMORY_FAILURE | |
6988 | bool is_free_buddy_page(struct page *page) | |
6989 | { | |
6990 | struct zone *zone = page_zone(page); | |
6991 | unsigned long pfn = page_to_pfn(page); | |
6992 | unsigned long flags; | |
6993 | unsigned int order; | |
6994 | ||
6995 | spin_lock_irqsave(&zone->lock, flags); | |
6996 | for (order = 0; order < MAX_ORDER; order++) { | |
6997 | struct page *page_head = page - (pfn & ((1 << order) - 1)); | |
6998 | ||
6999 | if (PageBuddy(page_head) && page_order(page_head) >= order) | |
7000 | break; | |
7001 | } | |
7002 | spin_unlock_irqrestore(&zone->lock, flags); | |
7003 | ||
7004 | return order < MAX_ORDER; | |
7005 | } | |
7006 | #endif |