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1 | /* | |
2 | * linux/mm/page_alloc.c | |
3 | * | |
4 | * Manages the free list, the system allocates free pages here. | |
5 | * Note that kmalloc() lives in slab.c | |
6 | * | |
7 | * Copyright (C) 1991, 1992, 1993, 1994 Linus Torvalds | |
8 | * Swap reorganised 29.12.95, Stephen Tweedie | |
9 | * Support of BIGMEM added by Gerhard Wichert, Siemens AG, July 1999 | |
10 | * Reshaped it to be a zoned allocator, Ingo Molnar, Red Hat, 1999 | |
11 | * Discontiguous memory support, Kanoj Sarcar, SGI, Nov 1999 | |
12 | * Zone balancing, Kanoj Sarcar, SGI, Jan 2000 | |
13 | * Per cpu hot/cold page lists, bulk allocation, Martin J. Bligh, Sept 2002 | |
14 | * (lots of bits borrowed from Ingo Molnar & Andrew Morton) | |
15 | */ | |
16 | ||
17 | #include <linux/stddef.h> | |
18 | #include <linux/mm.h> | |
19 | #include <linux/swap.h> | |
20 | #include <linux/interrupt.h> | |
21 | #include <linux/pagemap.h> | |
22 | #include <linux/bootmem.h> | |
23 | #include <linux/compiler.h> | |
24 | #include <linux/kernel.h> | |
25 | #include <linux/module.h> | |
26 | #include <linux/suspend.h> | |
27 | #include <linux/pagevec.h> | |
28 | #include <linux/blkdev.h> | |
29 | #include <linux/slab.h> | |
30 | #include <linux/notifier.h> | |
31 | #include <linux/topology.h> | |
32 | #include <linux/sysctl.h> | |
33 | #include <linux/cpu.h> | |
34 | #include <linux/cpuset.h> | |
35 | #include <linux/memory_hotplug.h> | |
36 | #include <linux/nodemask.h> | |
37 | #include <linux/vmalloc.h> | |
38 | #include <linux/mempolicy.h> | |
39 | #include <linux/stop_machine.h> | |
40 | ||
41 | #include <asm/tlbflush.h> | |
42 | #include <asm/div64.h> | |
43 | #include "internal.h" | |
44 | ||
45 | /* | |
46 | * MCD - HACK: Find somewhere to initialize this EARLY, or make this | |
47 | * initializer cleaner | |
48 | */ | |
49 | nodemask_t node_online_map __read_mostly = { { [0] = 1UL } }; | |
50 | EXPORT_SYMBOL(node_online_map); | |
51 | nodemask_t node_possible_map __read_mostly = NODE_MASK_ALL; | |
52 | EXPORT_SYMBOL(node_possible_map); | |
53 | unsigned long totalram_pages __read_mostly; | |
54 | unsigned long totalreserve_pages __read_mostly; | |
55 | long nr_swap_pages; | |
56 | int percpu_pagelist_fraction; | |
57 | ||
58 | static void __free_pages_ok(struct page *page, unsigned int order); | |
59 | ||
60 | /* | |
61 | * results with 256, 32 in the lowmem_reserve sysctl: | |
62 | * 1G machine -> (16M dma, 800M-16M normal, 1G-800M high) | |
63 | * 1G machine -> (16M dma, 784M normal, 224M high) | |
64 | * NORMAL allocation will leave 784M/256 of ram reserved in the ZONE_DMA | |
65 | * HIGHMEM allocation will leave 224M/32 of ram reserved in ZONE_NORMAL | |
66 | * HIGHMEM allocation will (224M+784M)/256 of ram reserved in ZONE_DMA | |
67 | * | |
68 | * TBD: should special case ZONE_DMA32 machines here - in those we normally | |
69 | * don't need any ZONE_NORMAL reservation | |
70 | */ | |
71 | int sysctl_lowmem_reserve_ratio[MAX_NR_ZONES-1] = { | |
72 | 256, | |
73 | #ifdef CONFIG_ZONE_DMA32 | |
74 | 256, | |
75 | #endif | |
76 | #ifdef CONFIG_HIGHMEM | |
77 | 32 | |
78 | #endif | |
79 | }; | |
80 | ||
81 | EXPORT_SYMBOL(totalram_pages); | |
82 | ||
83 | /* | |
84 | * Used by page_zone() to look up the address of the struct zone whose | |
85 | * id is encoded in the upper bits of page->flags | |
86 | */ | |
87 | struct zone *zone_table[1 << ZONETABLE_SHIFT] __read_mostly; | |
88 | EXPORT_SYMBOL(zone_table); | |
89 | ||
90 | static char *zone_names[MAX_NR_ZONES] = { | |
91 | "DMA", | |
92 | #ifdef CONFIG_ZONE_DMA32 | |
93 | "DMA32", | |
94 | #endif | |
95 | "Normal", | |
96 | #ifdef CONFIG_HIGHMEM | |
97 | "HighMem" | |
98 | #endif | |
99 | }; | |
100 | ||
101 | int min_free_kbytes = 1024; | |
102 | ||
103 | unsigned long __meminitdata nr_kernel_pages; | |
104 | unsigned long __meminitdata nr_all_pages; | |
105 | ||
106 | #ifdef CONFIG_DEBUG_VM | |
107 | static int page_outside_zone_boundaries(struct zone *zone, struct page *page) | |
108 | { | |
109 | int ret = 0; | |
110 | unsigned seq; | |
111 | unsigned long pfn = page_to_pfn(page); | |
112 | ||
113 | do { | |
114 | seq = zone_span_seqbegin(zone); | |
115 | if (pfn >= zone->zone_start_pfn + zone->spanned_pages) | |
116 | ret = 1; | |
117 | else if (pfn < zone->zone_start_pfn) | |
118 | ret = 1; | |
119 | } while (zone_span_seqretry(zone, seq)); | |
120 | ||
121 | return ret; | |
122 | } | |
123 | ||
124 | static int page_is_consistent(struct zone *zone, struct page *page) | |
125 | { | |
126 | #ifdef CONFIG_HOLES_IN_ZONE | |
127 | if (!pfn_valid(page_to_pfn(page))) | |
128 | return 0; | |
129 | #endif | |
130 | if (zone != page_zone(page)) | |
131 | return 0; | |
132 | ||
133 | return 1; | |
134 | } | |
135 | /* | |
136 | * Temporary debugging check for pages not lying within a given zone. | |
137 | */ | |
138 | static int bad_range(struct zone *zone, struct page *page) | |
139 | { | |
140 | if (page_outside_zone_boundaries(zone, page)) | |
141 | return 1; | |
142 | if (!page_is_consistent(zone, page)) | |
143 | return 1; | |
144 | ||
145 | return 0; | |
146 | } | |
147 | #else | |
148 | static inline int bad_range(struct zone *zone, struct page *page) | |
149 | { | |
150 | return 0; | |
151 | } | |
152 | #endif | |
153 | ||
154 | static void bad_page(struct page *page) | |
155 | { | |
156 | printk(KERN_EMERG "Bad page state in process '%s'\n" | |
157 | KERN_EMERG "page:%p flags:0x%0*lx mapping:%p mapcount:%d count:%d\n" | |
158 | KERN_EMERG "Trying to fix it up, but a reboot is needed\n" | |
159 | KERN_EMERG "Backtrace:\n", | |
160 | current->comm, page, (int)(2*sizeof(unsigned long)), | |
161 | (unsigned long)page->flags, page->mapping, | |
162 | page_mapcount(page), page_count(page)); | |
163 | dump_stack(); | |
164 | page->flags &= ~(1 << PG_lru | | |
165 | 1 << PG_private | | |
166 | 1 << PG_locked | | |
167 | 1 << PG_active | | |
168 | 1 << PG_dirty | | |
169 | 1 << PG_reclaim | | |
170 | 1 << PG_slab | | |
171 | 1 << PG_swapcache | | |
172 | 1 << PG_writeback | | |
173 | 1 << PG_buddy ); | |
174 | set_page_count(page, 0); | |
175 | reset_page_mapcount(page); | |
176 | page->mapping = NULL; | |
177 | add_taint(TAINT_BAD_PAGE); | |
178 | } | |
179 | ||
180 | /* | |
181 | * Higher-order pages are called "compound pages". They are structured thusly: | |
182 | * | |
183 | * The first PAGE_SIZE page is called the "head page". | |
184 | * | |
185 | * The remaining PAGE_SIZE pages are called "tail pages". | |
186 | * | |
187 | * All pages have PG_compound set. All pages have their ->private pointing at | |
188 | * the head page (even the head page has this). | |
189 | * | |
190 | * The first tail page's ->lru.next holds the address of the compound page's | |
191 | * put_page() function. Its ->lru.prev holds the order of allocation. | |
192 | * This usage means that zero-order pages may not be compound. | |
193 | */ | |
194 | ||
195 | static void free_compound_page(struct page *page) | |
196 | { | |
197 | __free_pages_ok(page, (unsigned long)page[1].lru.prev); | |
198 | } | |
199 | ||
200 | static void prep_compound_page(struct page *page, unsigned long order) | |
201 | { | |
202 | int i; | |
203 | int nr_pages = 1 << order; | |
204 | ||
205 | page[1].lru.next = (void *)free_compound_page; /* set dtor */ | |
206 | page[1].lru.prev = (void *)order; | |
207 | for (i = 0; i < nr_pages; i++) { | |
208 | struct page *p = page + i; | |
209 | ||
210 | __SetPageCompound(p); | |
211 | set_page_private(p, (unsigned long)page); | |
212 | } | |
213 | } | |
214 | ||
215 | static void destroy_compound_page(struct page *page, unsigned long order) | |
216 | { | |
217 | int i; | |
218 | int nr_pages = 1 << order; | |
219 | ||
220 | if (unlikely((unsigned long)page[1].lru.prev != order)) | |
221 | bad_page(page); | |
222 | ||
223 | for (i = 0; i < nr_pages; i++) { | |
224 | struct page *p = page + i; | |
225 | ||
226 | if (unlikely(!PageCompound(p) | | |
227 | (page_private(p) != (unsigned long)page))) | |
228 | bad_page(page); | |
229 | __ClearPageCompound(p); | |
230 | } | |
231 | } | |
232 | ||
233 | static inline void prep_zero_page(struct page *page, int order, gfp_t gfp_flags) | |
234 | { | |
235 | int i; | |
236 | ||
237 | VM_BUG_ON((gfp_flags & (__GFP_WAIT | __GFP_HIGHMEM)) == __GFP_HIGHMEM); | |
238 | /* | |
239 | * clear_highpage() will use KM_USER0, so it's a bug to use __GFP_ZERO | |
240 | * and __GFP_HIGHMEM from hard or soft interrupt context. | |
241 | */ | |
242 | VM_BUG_ON((gfp_flags & __GFP_HIGHMEM) && in_interrupt()); | |
243 | for (i = 0; i < (1 << order); i++) | |
244 | clear_highpage(page + i); | |
245 | } | |
246 | ||
247 | /* | |
248 | * function for dealing with page's order in buddy system. | |
249 | * zone->lock is already acquired when we use these. | |
250 | * So, we don't need atomic page->flags operations here. | |
251 | */ | |
252 | static inline unsigned long page_order(struct page *page) | |
253 | { | |
254 | return page_private(page); | |
255 | } | |
256 | ||
257 | static inline void set_page_order(struct page *page, int order) | |
258 | { | |
259 | set_page_private(page, order); | |
260 | __SetPageBuddy(page); | |
261 | } | |
262 | ||
263 | static inline void rmv_page_order(struct page *page) | |
264 | { | |
265 | __ClearPageBuddy(page); | |
266 | set_page_private(page, 0); | |
267 | } | |
268 | ||
269 | /* | |
270 | * Locate the struct page for both the matching buddy in our | |
271 | * pair (buddy1) and the combined O(n+1) page they form (page). | |
272 | * | |
273 | * 1) Any buddy B1 will have an order O twin B2 which satisfies | |
274 | * the following equation: | |
275 | * B2 = B1 ^ (1 << O) | |
276 | * For example, if the starting buddy (buddy2) is #8 its order | |
277 | * 1 buddy is #10: | |
278 | * B2 = 8 ^ (1 << 1) = 8 ^ 2 = 10 | |
279 | * | |
280 | * 2) Any buddy B will have an order O+1 parent P which | |
281 | * satisfies the following equation: | |
282 | * P = B & ~(1 << O) | |
283 | * | |
284 | * Assumption: *_mem_map is contiguous at least up to MAX_ORDER | |
285 | */ | |
286 | static inline struct page * | |
287 | __page_find_buddy(struct page *page, unsigned long page_idx, unsigned int order) | |
288 | { | |
289 | unsigned long buddy_idx = page_idx ^ (1 << order); | |
290 | ||
291 | return page + (buddy_idx - page_idx); | |
292 | } | |
293 | ||
294 | static inline unsigned long | |
295 | __find_combined_index(unsigned long page_idx, unsigned int order) | |
296 | { | |
297 | return (page_idx & ~(1 << order)); | |
298 | } | |
299 | ||
300 | /* | |
301 | * This function checks whether a page is free && is the buddy | |
302 | * we can do coalesce a page and its buddy if | |
303 | * (a) the buddy is not in a hole && | |
304 | * (b) the buddy is in the buddy system && | |
305 | * (c) a page and its buddy have the same order && | |
306 | * (d) a page and its buddy are in the same zone. | |
307 | * | |
308 | * For recording whether a page is in the buddy system, we use PG_buddy. | |
309 | * Setting, clearing, and testing PG_buddy is serialized by zone->lock. | |
310 | * | |
311 | * For recording page's order, we use page_private(page). | |
312 | */ | |
313 | static inline int page_is_buddy(struct page *page, struct page *buddy, | |
314 | int order) | |
315 | { | |
316 | #ifdef CONFIG_HOLES_IN_ZONE | |
317 | if (!pfn_valid(page_to_pfn(buddy))) | |
318 | return 0; | |
319 | #endif | |
320 | ||
321 | if (page_zone_id(page) != page_zone_id(buddy)) | |
322 | return 0; | |
323 | ||
324 | if (PageBuddy(buddy) && page_order(buddy) == order) { | |
325 | BUG_ON(page_count(buddy) != 0); | |
326 | return 1; | |
327 | } | |
328 | return 0; | |
329 | } | |
330 | ||
331 | /* | |
332 | * Freeing function for a buddy system allocator. | |
333 | * | |
334 | * The concept of a buddy system is to maintain direct-mapped table | |
335 | * (containing bit values) for memory blocks of various "orders". | |
336 | * The bottom level table contains the map for the smallest allocatable | |
337 | * units of memory (here, pages), and each level above it describes | |
338 | * pairs of units from the levels below, hence, "buddies". | |
339 | * At a high level, all that happens here is marking the table entry | |
340 | * at the bottom level available, and propagating the changes upward | |
341 | * as necessary, plus some accounting needed to play nicely with other | |
342 | * parts of the VM system. | |
343 | * At each level, we keep a list of pages, which are heads of continuous | |
344 | * free pages of length of (1 << order) and marked with PG_buddy. Page's | |
345 | * order is recorded in page_private(page) field. | |
346 | * So when we are allocating or freeing one, we can derive the state of the | |
347 | * other. That is, if we allocate a small block, and both were | |
348 | * free, the remainder of the region must be split into blocks. | |
349 | * If a block is freed, and its buddy is also free, then this | |
350 | * triggers coalescing into a block of larger size. | |
351 | * | |
352 | * -- wli | |
353 | */ | |
354 | ||
355 | static inline void __free_one_page(struct page *page, | |
356 | struct zone *zone, unsigned int order) | |
357 | { | |
358 | unsigned long page_idx; | |
359 | int order_size = 1 << order; | |
360 | ||
361 | if (unlikely(PageCompound(page))) | |
362 | destroy_compound_page(page, order); | |
363 | ||
364 | page_idx = page_to_pfn(page) & ((1 << MAX_ORDER) - 1); | |
365 | ||
366 | VM_BUG_ON(page_idx & (order_size - 1)); | |
367 | VM_BUG_ON(bad_range(zone, page)); | |
368 | ||
369 | zone->free_pages += order_size; | |
370 | while (order < MAX_ORDER-1) { | |
371 | unsigned long combined_idx; | |
372 | struct free_area *area; | |
373 | struct page *buddy; | |
374 | ||
375 | buddy = __page_find_buddy(page, page_idx, order); | |
376 | if (!page_is_buddy(page, buddy, order)) | |
377 | break; /* Move the buddy up one level. */ | |
378 | ||
379 | list_del(&buddy->lru); | |
380 | area = zone->free_area + order; | |
381 | area->nr_free--; | |
382 | rmv_page_order(buddy); | |
383 | combined_idx = __find_combined_index(page_idx, order); | |
384 | page = page + (combined_idx - page_idx); | |
385 | page_idx = combined_idx; | |
386 | order++; | |
387 | } | |
388 | set_page_order(page, order); | |
389 | list_add(&page->lru, &zone->free_area[order].free_list); | |
390 | zone->free_area[order].nr_free++; | |
391 | } | |
392 | ||
393 | static inline int free_pages_check(struct page *page) | |
394 | { | |
395 | if (unlikely(page_mapcount(page) | | |
396 | (page->mapping != NULL) | | |
397 | (page_count(page) != 0) | | |
398 | (page->flags & ( | |
399 | 1 << PG_lru | | |
400 | 1 << PG_private | | |
401 | 1 << PG_locked | | |
402 | 1 << PG_active | | |
403 | 1 << PG_reclaim | | |
404 | 1 << PG_slab | | |
405 | 1 << PG_swapcache | | |
406 | 1 << PG_writeback | | |
407 | 1 << PG_reserved | | |
408 | 1 << PG_buddy )))) | |
409 | bad_page(page); | |
410 | if (PageDirty(page)) | |
411 | __ClearPageDirty(page); | |
412 | /* | |
413 | * For now, we report if PG_reserved was found set, but do not | |
414 | * clear it, and do not free the page. But we shall soon need | |
415 | * to do more, for when the ZERO_PAGE count wraps negative. | |
416 | */ | |
417 | return PageReserved(page); | |
418 | } | |
419 | ||
420 | /* | |
421 | * Frees a list of pages. | |
422 | * Assumes all pages on list are in same zone, and of same order. | |
423 | * count is the number of pages to free. | |
424 | * | |
425 | * If the zone was previously in an "all pages pinned" state then look to | |
426 | * see if this freeing clears that state. | |
427 | * | |
428 | * And clear the zone's pages_scanned counter, to hold off the "all pages are | |
429 | * pinned" detection logic. | |
430 | */ | |
431 | static void free_pages_bulk(struct zone *zone, int count, | |
432 | struct list_head *list, int order) | |
433 | { | |
434 | spin_lock(&zone->lock); | |
435 | zone->all_unreclaimable = 0; | |
436 | zone->pages_scanned = 0; | |
437 | while (count--) { | |
438 | struct page *page; | |
439 | ||
440 | VM_BUG_ON(list_empty(list)); | |
441 | page = list_entry(list->prev, struct page, lru); | |
442 | /* have to delete it as __free_one_page list manipulates */ | |
443 | list_del(&page->lru); | |
444 | __free_one_page(page, zone, order); | |
445 | } | |
446 | spin_unlock(&zone->lock); | |
447 | } | |
448 | ||
449 | static void free_one_page(struct zone *zone, struct page *page, int order) | |
450 | { | |
451 | LIST_HEAD(list); | |
452 | list_add(&page->lru, &list); | |
453 | free_pages_bulk(zone, 1, &list, order); | |
454 | } | |
455 | ||
456 | static void __free_pages_ok(struct page *page, unsigned int order) | |
457 | { | |
458 | unsigned long flags; | |
459 | int i; | |
460 | int reserved = 0; | |
461 | ||
462 | arch_free_page(page, order); | |
463 | if (!PageHighMem(page)) | |
464 | debug_check_no_locks_freed(page_address(page), | |
465 | PAGE_SIZE<<order); | |
466 | ||
467 | for (i = 0 ; i < (1 << order) ; ++i) | |
468 | reserved += free_pages_check(page + i); | |
469 | if (reserved) | |
470 | return; | |
471 | ||
472 | kernel_map_pages(page, 1 << order, 0); | |
473 | local_irq_save(flags); | |
474 | __count_vm_events(PGFREE, 1 << order); | |
475 | free_one_page(page_zone(page), page, order); | |
476 | local_irq_restore(flags); | |
477 | } | |
478 | ||
479 | /* | |
480 | * permit the bootmem allocator to evade page validation on high-order frees | |
481 | */ | |
482 | void fastcall __init __free_pages_bootmem(struct page *page, unsigned int order) | |
483 | { | |
484 | if (order == 0) { | |
485 | __ClearPageReserved(page); | |
486 | set_page_count(page, 0); | |
487 | set_page_refcounted(page); | |
488 | __free_page(page); | |
489 | } else { | |
490 | int loop; | |
491 | ||
492 | prefetchw(page); | |
493 | for (loop = 0; loop < BITS_PER_LONG; loop++) { | |
494 | struct page *p = &page[loop]; | |
495 | ||
496 | if (loop + 1 < BITS_PER_LONG) | |
497 | prefetchw(p + 1); | |
498 | __ClearPageReserved(p); | |
499 | set_page_count(p, 0); | |
500 | } | |
501 | ||
502 | set_page_refcounted(page); | |
503 | __free_pages(page, order); | |
504 | } | |
505 | } | |
506 | ||
507 | ||
508 | /* | |
509 | * The order of subdivision here is critical for the IO subsystem. | |
510 | * Please do not alter this order without good reasons and regression | |
511 | * testing. Specifically, as large blocks of memory are subdivided, | |
512 | * the order in which smaller blocks are delivered depends on the order | |
513 | * they're subdivided in this function. This is the primary factor | |
514 | * influencing the order in which pages are delivered to the IO | |
515 | * subsystem according to empirical testing, and this is also justified | |
516 | * by considering the behavior of a buddy system containing a single | |
517 | * large block of memory acted on by a series of small allocations. | |
518 | * This behavior is a critical factor in sglist merging's success. | |
519 | * | |
520 | * -- wli | |
521 | */ | |
522 | static inline void expand(struct zone *zone, struct page *page, | |
523 | int low, int high, struct free_area *area) | |
524 | { | |
525 | unsigned long size = 1 << high; | |
526 | ||
527 | while (high > low) { | |
528 | area--; | |
529 | high--; | |
530 | size >>= 1; | |
531 | VM_BUG_ON(bad_range(zone, &page[size])); | |
532 | list_add(&page[size].lru, &area->free_list); | |
533 | area->nr_free++; | |
534 | set_page_order(&page[size], high); | |
535 | } | |
536 | } | |
537 | ||
538 | /* | |
539 | * This page is about to be returned from the page allocator | |
540 | */ | |
541 | static int prep_new_page(struct page *page, int order, gfp_t gfp_flags) | |
542 | { | |
543 | if (unlikely(page_mapcount(page) | | |
544 | (page->mapping != NULL) | | |
545 | (page_count(page) != 0) | | |
546 | (page->flags & ( | |
547 | 1 << PG_lru | | |
548 | 1 << PG_private | | |
549 | 1 << PG_locked | | |
550 | 1 << PG_active | | |
551 | 1 << PG_dirty | | |
552 | 1 << PG_reclaim | | |
553 | 1 << PG_slab | | |
554 | 1 << PG_swapcache | | |
555 | 1 << PG_writeback | | |
556 | 1 << PG_reserved | | |
557 | 1 << PG_buddy )))) | |
558 | bad_page(page); | |
559 | ||
560 | /* | |
561 | * For now, we report if PG_reserved was found set, but do not | |
562 | * clear it, and do not allocate the page: as a safety net. | |
563 | */ | |
564 | if (PageReserved(page)) | |
565 | return 1; | |
566 | ||
567 | page->flags &= ~(1 << PG_uptodate | 1 << PG_error | | |
568 | 1 << PG_referenced | 1 << PG_arch_1 | | |
569 | 1 << PG_checked | 1 << PG_mappedtodisk); | |
570 | set_page_private(page, 0); | |
571 | set_page_refcounted(page); | |
572 | kernel_map_pages(page, 1 << order, 1); | |
573 | ||
574 | if (gfp_flags & __GFP_ZERO) | |
575 | prep_zero_page(page, order, gfp_flags); | |
576 | ||
577 | if (order && (gfp_flags & __GFP_COMP)) | |
578 | prep_compound_page(page, order); | |
579 | ||
580 | return 0; | |
581 | } | |
582 | ||
583 | /* | |
584 | * Do the hard work of removing an element from the buddy allocator. | |
585 | * Call me with the zone->lock already held. | |
586 | */ | |
587 | static struct page *__rmqueue(struct zone *zone, unsigned int order) | |
588 | { | |
589 | struct free_area * area; | |
590 | unsigned int current_order; | |
591 | struct page *page; | |
592 | ||
593 | for (current_order = order; current_order < MAX_ORDER; ++current_order) { | |
594 | area = zone->free_area + current_order; | |
595 | if (list_empty(&area->free_list)) | |
596 | continue; | |
597 | ||
598 | page = list_entry(area->free_list.next, struct page, lru); | |
599 | list_del(&page->lru); | |
600 | rmv_page_order(page); | |
601 | area->nr_free--; | |
602 | zone->free_pages -= 1UL << order; | |
603 | expand(zone, page, order, current_order, area); | |
604 | return page; | |
605 | } | |
606 | ||
607 | return NULL; | |
608 | } | |
609 | ||
610 | /* | |
611 | * Obtain a specified number of elements from the buddy allocator, all under | |
612 | * a single hold of the lock, for efficiency. Add them to the supplied list. | |
613 | * Returns the number of new pages which were placed at *list. | |
614 | */ | |
615 | static int rmqueue_bulk(struct zone *zone, unsigned int order, | |
616 | unsigned long count, struct list_head *list) | |
617 | { | |
618 | int i; | |
619 | ||
620 | spin_lock(&zone->lock); | |
621 | for (i = 0; i < count; ++i) { | |
622 | struct page *page = __rmqueue(zone, order); | |
623 | if (unlikely(page == NULL)) | |
624 | break; | |
625 | list_add_tail(&page->lru, list); | |
626 | } | |
627 | spin_unlock(&zone->lock); | |
628 | return i; | |
629 | } | |
630 | ||
631 | #ifdef CONFIG_NUMA | |
632 | /* | |
633 | * Called from the slab reaper to drain pagesets on a particular node that | |
634 | * belong to the currently executing processor. | |
635 | * Note that this function must be called with the thread pinned to | |
636 | * a single processor. | |
637 | */ | |
638 | void drain_node_pages(int nodeid) | |
639 | { | |
640 | int i; | |
641 | enum zone_type z; | |
642 | unsigned long flags; | |
643 | ||
644 | for (z = 0; z < MAX_NR_ZONES; z++) { | |
645 | struct zone *zone = NODE_DATA(nodeid)->node_zones + z; | |
646 | struct per_cpu_pageset *pset; | |
647 | ||
648 | pset = zone_pcp(zone, smp_processor_id()); | |
649 | for (i = 0; i < ARRAY_SIZE(pset->pcp); i++) { | |
650 | struct per_cpu_pages *pcp; | |
651 | ||
652 | pcp = &pset->pcp[i]; | |
653 | if (pcp->count) { | |
654 | local_irq_save(flags); | |
655 | free_pages_bulk(zone, pcp->count, &pcp->list, 0); | |
656 | pcp->count = 0; | |
657 | local_irq_restore(flags); | |
658 | } | |
659 | } | |
660 | } | |
661 | } | |
662 | #endif | |
663 | ||
664 | #if defined(CONFIG_PM) || defined(CONFIG_HOTPLUG_CPU) | |
665 | static void __drain_pages(unsigned int cpu) | |
666 | { | |
667 | unsigned long flags; | |
668 | struct zone *zone; | |
669 | int i; | |
670 | ||
671 | for_each_zone(zone) { | |
672 | struct per_cpu_pageset *pset; | |
673 | ||
674 | pset = zone_pcp(zone, cpu); | |
675 | for (i = 0; i < ARRAY_SIZE(pset->pcp); i++) { | |
676 | struct per_cpu_pages *pcp; | |
677 | ||
678 | pcp = &pset->pcp[i]; | |
679 | local_irq_save(flags); | |
680 | free_pages_bulk(zone, pcp->count, &pcp->list, 0); | |
681 | pcp->count = 0; | |
682 | local_irq_restore(flags); | |
683 | } | |
684 | } | |
685 | } | |
686 | #endif /* CONFIG_PM || CONFIG_HOTPLUG_CPU */ | |
687 | ||
688 | #ifdef CONFIG_PM | |
689 | ||
690 | void mark_free_pages(struct zone *zone) | |
691 | { | |
692 | unsigned long zone_pfn, flags; | |
693 | int order; | |
694 | struct list_head *curr; | |
695 | ||
696 | if (!zone->spanned_pages) | |
697 | return; | |
698 | ||
699 | spin_lock_irqsave(&zone->lock, flags); | |
700 | for (zone_pfn = 0; zone_pfn < zone->spanned_pages; ++zone_pfn) | |
701 | ClearPageNosaveFree(pfn_to_page(zone_pfn + zone->zone_start_pfn)); | |
702 | ||
703 | for (order = MAX_ORDER - 1; order >= 0; --order) | |
704 | list_for_each(curr, &zone->free_area[order].free_list) { | |
705 | unsigned long start_pfn, i; | |
706 | ||
707 | start_pfn = page_to_pfn(list_entry(curr, struct page, lru)); | |
708 | ||
709 | for (i=0; i < (1<<order); i++) | |
710 | SetPageNosaveFree(pfn_to_page(start_pfn+i)); | |
711 | } | |
712 | spin_unlock_irqrestore(&zone->lock, flags); | |
713 | } | |
714 | ||
715 | /* | |
716 | * Spill all of this CPU's per-cpu pages back into the buddy allocator. | |
717 | */ | |
718 | void drain_local_pages(void) | |
719 | { | |
720 | unsigned long flags; | |
721 | ||
722 | local_irq_save(flags); | |
723 | __drain_pages(smp_processor_id()); | |
724 | local_irq_restore(flags); | |
725 | } | |
726 | #endif /* CONFIG_PM */ | |
727 | ||
728 | /* | |
729 | * Free a 0-order page | |
730 | */ | |
731 | static void fastcall free_hot_cold_page(struct page *page, int cold) | |
732 | { | |
733 | struct zone *zone = page_zone(page); | |
734 | struct per_cpu_pages *pcp; | |
735 | unsigned long flags; | |
736 | ||
737 | arch_free_page(page, 0); | |
738 | ||
739 | if (PageAnon(page)) | |
740 | page->mapping = NULL; | |
741 | if (free_pages_check(page)) | |
742 | return; | |
743 | ||
744 | kernel_map_pages(page, 1, 0); | |
745 | ||
746 | pcp = &zone_pcp(zone, get_cpu())->pcp[cold]; | |
747 | local_irq_save(flags); | |
748 | __count_vm_event(PGFREE); | |
749 | list_add(&page->lru, &pcp->list); | |
750 | pcp->count++; | |
751 | if (pcp->count >= pcp->high) { | |
752 | free_pages_bulk(zone, pcp->batch, &pcp->list, 0); | |
753 | pcp->count -= pcp->batch; | |
754 | } | |
755 | local_irq_restore(flags); | |
756 | put_cpu(); | |
757 | } | |
758 | ||
759 | void fastcall free_hot_page(struct page *page) | |
760 | { | |
761 | free_hot_cold_page(page, 0); | |
762 | } | |
763 | ||
764 | void fastcall free_cold_page(struct page *page) | |
765 | { | |
766 | free_hot_cold_page(page, 1); | |
767 | } | |
768 | ||
769 | /* | |
770 | * split_page takes a non-compound higher-order page, and splits it into | |
771 | * n (1<<order) sub-pages: page[0..n] | |
772 | * Each sub-page must be freed individually. | |
773 | * | |
774 | * Note: this is probably too low level an operation for use in drivers. | |
775 | * Please consult with lkml before using this in your driver. | |
776 | */ | |
777 | void split_page(struct page *page, unsigned int order) | |
778 | { | |
779 | int i; | |
780 | ||
781 | VM_BUG_ON(PageCompound(page)); | |
782 | VM_BUG_ON(!page_count(page)); | |
783 | for (i = 1; i < (1 << order); i++) | |
784 | set_page_refcounted(page + i); | |
785 | } | |
786 | ||
787 | /* | |
788 | * Really, prep_compound_page() should be called from __rmqueue_bulk(). But | |
789 | * we cheat by calling it from here, in the order > 0 path. Saves a branch | |
790 | * or two. | |
791 | */ | |
792 | static struct page *buffered_rmqueue(struct zonelist *zonelist, | |
793 | struct zone *zone, int order, gfp_t gfp_flags) | |
794 | { | |
795 | unsigned long flags; | |
796 | struct page *page; | |
797 | int cold = !!(gfp_flags & __GFP_COLD); | |
798 | int cpu; | |
799 | ||
800 | again: | |
801 | cpu = get_cpu(); | |
802 | if (likely(order == 0)) { | |
803 | struct per_cpu_pages *pcp; | |
804 | ||
805 | pcp = &zone_pcp(zone, cpu)->pcp[cold]; | |
806 | local_irq_save(flags); | |
807 | if (!pcp->count) { | |
808 | pcp->count += rmqueue_bulk(zone, 0, | |
809 | pcp->batch, &pcp->list); | |
810 | if (unlikely(!pcp->count)) | |
811 | goto failed; | |
812 | } | |
813 | page = list_entry(pcp->list.next, struct page, lru); | |
814 | list_del(&page->lru); | |
815 | pcp->count--; | |
816 | } else { | |
817 | spin_lock_irqsave(&zone->lock, flags); | |
818 | page = __rmqueue(zone, order); | |
819 | spin_unlock(&zone->lock); | |
820 | if (!page) | |
821 | goto failed; | |
822 | } | |
823 | ||
824 | __count_zone_vm_events(PGALLOC, zone, 1 << order); | |
825 | zone_statistics(zonelist, zone); | |
826 | local_irq_restore(flags); | |
827 | put_cpu(); | |
828 | ||
829 | VM_BUG_ON(bad_range(zone, page)); | |
830 | if (prep_new_page(page, order, gfp_flags)) | |
831 | goto again; | |
832 | return page; | |
833 | ||
834 | failed: | |
835 | local_irq_restore(flags); | |
836 | put_cpu(); | |
837 | return NULL; | |
838 | } | |
839 | ||
840 | #define ALLOC_NO_WATERMARKS 0x01 /* don't check watermarks at all */ | |
841 | #define ALLOC_WMARK_MIN 0x02 /* use pages_min watermark */ | |
842 | #define ALLOC_WMARK_LOW 0x04 /* use pages_low watermark */ | |
843 | #define ALLOC_WMARK_HIGH 0x08 /* use pages_high watermark */ | |
844 | #define ALLOC_HARDER 0x10 /* try to alloc harder */ | |
845 | #define ALLOC_HIGH 0x20 /* __GFP_HIGH set */ | |
846 | #define ALLOC_CPUSET 0x40 /* check for correct cpuset */ | |
847 | ||
848 | /* | |
849 | * Return 1 if free pages are above 'mark'. This takes into account the order | |
850 | * of the allocation. | |
851 | */ | |
852 | int zone_watermark_ok(struct zone *z, int order, unsigned long mark, | |
853 | int classzone_idx, int alloc_flags) | |
854 | { | |
855 | /* free_pages my go negative - that's OK */ | |
856 | long min = mark, free_pages = z->free_pages - (1 << order) + 1; | |
857 | int o; | |
858 | ||
859 | if (alloc_flags & ALLOC_HIGH) | |
860 | min -= min / 2; | |
861 | if (alloc_flags & ALLOC_HARDER) | |
862 | min -= min / 4; | |
863 | ||
864 | if (free_pages <= min + z->lowmem_reserve[classzone_idx]) | |
865 | return 0; | |
866 | for (o = 0; o < order; o++) { | |
867 | /* At the next order, this order's pages become unavailable */ | |
868 | free_pages -= z->free_area[o].nr_free << o; | |
869 | ||
870 | /* Require fewer higher order pages to be free */ | |
871 | min >>= 1; | |
872 | ||
873 | if (free_pages <= min) | |
874 | return 0; | |
875 | } | |
876 | return 1; | |
877 | } | |
878 | ||
879 | /* | |
880 | * get_page_from_freeliest goes through the zonelist trying to allocate | |
881 | * a page. | |
882 | */ | |
883 | static struct page * | |
884 | get_page_from_freelist(gfp_t gfp_mask, unsigned int order, | |
885 | struct zonelist *zonelist, int alloc_flags) | |
886 | { | |
887 | struct zone **z = zonelist->zones; | |
888 | struct page *page = NULL; | |
889 | int classzone_idx = zone_idx(*z); | |
890 | ||
891 | /* | |
892 | * Go through the zonelist once, looking for a zone with enough free. | |
893 | * See also cpuset_zone_allowed() comment in kernel/cpuset.c. | |
894 | */ | |
895 | do { | |
896 | if ((alloc_flags & ALLOC_CPUSET) && | |
897 | !cpuset_zone_allowed(*z, gfp_mask)) | |
898 | continue; | |
899 | ||
900 | if (!(alloc_flags & ALLOC_NO_WATERMARKS)) { | |
901 | unsigned long mark; | |
902 | if (alloc_flags & ALLOC_WMARK_MIN) | |
903 | mark = (*z)->pages_min; | |
904 | else if (alloc_flags & ALLOC_WMARK_LOW) | |
905 | mark = (*z)->pages_low; | |
906 | else | |
907 | mark = (*z)->pages_high; | |
908 | if (!zone_watermark_ok(*z, order, mark, | |
909 | classzone_idx, alloc_flags)) | |
910 | if (!zone_reclaim_mode || | |
911 | !zone_reclaim(*z, gfp_mask, order)) | |
912 | continue; | |
913 | } | |
914 | ||
915 | page = buffered_rmqueue(zonelist, *z, order, gfp_mask); | |
916 | if (page) { | |
917 | break; | |
918 | } | |
919 | } while (*(++z) != NULL); | |
920 | return page; | |
921 | } | |
922 | ||
923 | /* | |
924 | * This is the 'heart' of the zoned buddy allocator. | |
925 | */ | |
926 | struct page * fastcall | |
927 | __alloc_pages(gfp_t gfp_mask, unsigned int order, | |
928 | struct zonelist *zonelist) | |
929 | { | |
930 | const gfp_t wait = gfp_mask & __GFP_WAIT; | |
931 | struct zone **z; | |
932 | struct page *page; | |
933 | struct reclaim_state reclaim_state; | |
934 | struct task_struct *p = current; | |
935 | int do_retry; | |
936 | int alloc_flags; | |
937 | int did_some_progress; | |
938 | ||
939 | might_sleep_if(wait); | |
940 | ||
941 | restart: | |
942 | z = zonelist->zones; /* the list of zones suitable for gfp_mask */ | |
943 | ||
944 | if (unlikely(*z == NULL)) { | |
945 | /* Should this ever happen?? */ | |
946 | return NULL; | |
947 | } | |
948 | ||
949 | page = get_page_from_freelist(gfp_mask|__GFP_HARDWALL, order, | |
950 | zonelist, ALLOC_WMARK_LOW|ALLOC_CPUSET); | |
951 | if (page) | |
952 | goto got_pg; | |
953 | ||
954 | do { | |
955 | wakeup_kswapd(*z, order); | |
956 | } while (*(++z)); | |
957 | ||
958 | /* | |
959 | * OK, we're below the kswapd watermark and have kicked background | |
960 | * reclaim. Now things get more complex, so set up alloc_flags according | |
961 | * to how we want to proceed. | |
962 | * | |
963 | * The caller may dip into page reserves a bit more if the caller | |
964 | * cannot run direct reclaim, or if the caller has realtime scheduling | |
965 | * policy or is asking for __GFP_HIGH memory. GFP_ATOMIC requests will | |
966 | * set both ALLOC_HARDER (!wait) and ALLOC_HIGH (__GFP_HIGH). | |
967 | */ | |
968 | alloc_flags = ALLOC_WMARK_MIN; | |
969 | if ((unlikely(rt_task(p)) && !in_interrupt()) || !wait) | |
970 | alloc_flags |= ALLOC_HARDER; | |
971 | if (gfp_mask & __GFP_HIGH) | |
972 | alloc_flags |= ALLOC_HIGH; | |
973 | if (wait) | |
974 | alloc_flags |= ALLOC_CPUSET; | |
975 | ||
976 | /* | |
977 | * Go through the zonelist again. Let __GFP_HIGH and allocations | |
978 | * coming from realtime tasks go deeper into reserves. | |
979 | * | |
980 | * This is the last chance, in general, before the goto nopage. | |
981 | * Ignore cpuset if GFP_ATOMIC (!wait) rather than fail alloc. | |
982 | * See also cpuset_zone_allowed() comment in kernel/cpuset.c. | |
983 | */ | |
984 | page = get_page_from_freelist(gfp_mask, order, zonelist, alloc_flags); | |
985 | if (page) | |
986 | goto got_pg; | |
987 | ||
988 | /* This allocation should allow future memory freeing. */ | |
989 | ||
990 | if (((p->flags & PF_MEMALLOC) || unlikely(test_thread_flag(TIF_MEMDIE))) | |
991 | && !in_interrupt()) { | |
992 | if (!(gfp_mask & __GFP_NOMEMALLOC)) { | |
993 | nofail_alloc: | |
994 | /* go through the zonelist yet again, ignoring mins */ | |
995 | page = get_page_from_freelist(gfp_mask, order, | |
996 | zonelist, ALLOC_NO_WATERMARKS); | |
997 | if (page) | |
998 | goto got_pg; | |
999 | if (gfp_mask & __GFP_NOFAIL) { | |
1000 | blk_congestion_wait(WRITE, HZ/50); | |
1001 | goto nofail_alloc; | |
1002 | } | |
1003 | } | |
1004 | goto nopage; | |
1005 | } | |
1006 | ||
1007 | /* Atomic allocations - we can't balance anything */ | |
1008 | if (!wait) | |
1009 | goto nopage; | |
1010 | ||
1011 | rebalance: | |
1012 | cond_resched(); | |
1013 | ||
1014 | /* We now go into synchronous reclaim */ | |
1015 | cpuset_memory_pressure_bump(); | |
1016 | p->flags |= PF_MEMALLOC; | |
1017 | reclaim_state.reclaimed_slab = 0; | |
1018 | p->reclaim_state = &reclaim_state; | |
1019 | ||
1020 | did_some_progress = try_to_free_pages(zonelist->zones, gfp_mask); | |
1021 | ||
1022 | p->reclaim_state = NULL; | |
1023 | p->flags &= ~PF_MEMALLOC; | |
1024 | ||
1025 | cond_resched(); | |
1026 | ||
1027 | if (likely(did_some_progress)) { | |
1028 | page = get_page_from_freelist(gfp_mask, order, | |
1029 | zonelist, alloc_flags); | |
1030 | if (page) | |
1031 | goto got_pg; | |
1032 | } else if ((gfp_mask & __GFP_FS) && !(gfp_mask & __GFP_NORETRY)) { | |
1033 | /* | |
1034 | * Go through the zonelist yet one more time, keep | |
1035 | * very high watermark here, this is only to catch | |
1036 | * a parallel oom killing, we must fail if we're still | |
1037 | * under heavy pressure. | |
1038 | */ | |
1039 | page = get_page_from_freelist(gfp_mask|__GFP_HARDWALL, order, | |
1040 | zonelist, ALLOC_WMARK_HIGH|ALLOC_CPUSET); | |
1041 | if (page) | |
1042 | goto got_pg; | |
1043 | ||
1044 | out_of_memory(zonelist, gfp_mask, order); | |
1045 | goto restart; | |
1046 | } | |
1047 | ||
1048 | /* | |
1049 | * Don't let big-order allocations loop unless the caller explicitly | |
1050 | * requests that. Wait for some write requests to complete then retry. | |
1051 | * | |
1052 | * In this implementation, __GFP_REPEAT means __GFP_NOFAIL for order | |
1053 | * <= 3, but that may not be true in other implementations. | |
1054 | */ | |
1055 | do_retry = 0; | |
1056 | if (!(gfp_mask & __GFP_NORETRY)) { | |
1057 | if ((order <= 3) || (gfp_mask & __GFP_REPEAT)) | |
1058 | do_retry = 1; | |
1059 | if (gfp_mask & __GFP_NOFAIL) | |
1060 | do_retry = 1; | |
1061 | } | |
1062 | if (do_retry) { | |
1063 | blk_congestion_wait(WRITE, HZ/50); | |
1064 | goto rebalance; | |
1065 | } | |
1066 | ||
1067 | nopage: | |
1068 | if (!(gfp_mask & __GFP_NOWARN) && printk_ratelimit()) { | |
1069 | printk(KERN_WARNING "%s: page allocation failure." | |
1070 | " order:%d, mode:0x%x\n", | |
1071 | p->comm, order, gfp_mask); | |
1072 | dump_stack(); | |
1073 | show_mem(); | |
1074 | } | |
1075 | got_pg: | |
1076 | return page; | |
1077 | } | |
1078 | ||
1079 | EXPORT_SYMBOL(__alloc_pages); | |
1080 | ||
1081 | /* | |
1082 | * Common helper functions. | |
1083 | */ | |
1084 | fastcall unsigned long __get_free_pages(gfp_t gfp_mask, unsigned int order) | |
1085 | { | |
1086 | struct page * page; | |
1087 | page = alloc_pages(gfp_mask, order); | |
1088 | if (!page) | |
1089 | return 0; | |
1090 | return (unsigned long) page_address(page); | |
1091 | } | |
1092 | ||
1093 | EXPORT_SYMBOL(__get_free_pages); | |
1094 | ||
1095 | fastcall unsigned long get_zeroed_page(gfp_t gfp_mask) | |
1096 | { | |
1097 | struct page * page; | |
1098 | ||
1099 | /* | |
1100 | * get_zeroed_page() returns a 32-bit address, which cannot represent | |
1101 | * a highmem page | |
1102 | */ | |
1103 | VM_BUG_ON((gfp_mask & __GFP_HIGHMEM) != 0); | |
1104 | ||
1105 | page = alloc_pages(gfp_mask | __GFP_ZERO, 0); | |
1106 | if (page) | |
1107 | return (unsigned long) page_address(page); | |
1108 | return 0; | |
1109 | } | |
1110 | ||
1111 | EXPORT_SYMBOL(get_zeroed_page); | |
1112 | ||
1113 | void __pagevec_free(struct pagevec *pvec) | |
1114 | { | |
1115 | int i = pagevec_count(pvec); | |
1116 | ||
1117 | while (--i >= 0) | |
1118 | free_hot_cold_page(pvec->pages[i], pvec->cold); | |
1119 | } | |
1120 | ||
1121 | fastcall void __free_pages(struct page *page, unsigned int order) | |
1122 | { | |
1123 | if (put_page_testzero(page)) { | |
1124 | if (order == 0) | |
1125 | free_hot_page(page); | |
1126 | else | |
1127 | __free_pages_ok(page, order); | |
1128 | } | |
1129 | } | |
1130 | ||
1131 | EXPORT_SYMBOL(__free_pages); | |
1132 | ||
1133 | fastcall void free_pages(unsigned long addr, unsigned int order) | |
1134 | { | |
1135 | if (addr != 0) { | |
1136 | VM_BUG_ON(!virt_addr_valid((void *)addr)); | |
1137 | __free_pages(virt_to_page((void *)addr), order); | |
1138 | } | |
1139 | } | |
1140 | ||
1141 | EXPORT_SYMBOL(free_pages); | |
1142 | ||
1143 | /* | |
1144 | * Total amount of free (allocatable) RAM: | |
1145 | */ | |
1146 | unsigned int nr_free_pages(void) | |
1147 | { | |
1148 | unsigned int sum = 0; | |
1149 | struct zone *zone; | |
1150 | ||
1151 | for_each_zone(zone) | |
1152 | sum += zone->free_pages; | |
1153 | ||
1154 | return sum; | |
1155 | } | |
1156 | ||
1157 | EXPORT_SYMBOL(nr_free_pages); | |
1158 | ||
1159 | #ifdef CONFIG_NUMA | |
1160 | unsigned int nr_free_pages_pgdat(pg_data_t *pgdat) | |
1161 | { | |
1162 | unsigned int sum = 0; | |
1163 | enum zone_type i; | |
1164 | ||
1165 | for (i = 0; i < MAX_NR_ZONES; i++) | |
1166 | sum += pgdat->node_zones[i].free_pages; | |
1167 | ||
1168 | return sum; | |
1169 | } | |
1170 | #endif | |
1171 | ||
1172 | static unsigned int nr_free_zone_pages(int offset) | |
1173 | { | |
1174 | /* Just pick one node, since fallback list is circular */ | |
1175 | pg_data_t *pgdat = NODE_DATA(numa_node_id()); | |
1176 | unsigned int sum = 0; | |
1177 | ||
1178 | struct zonelist *zonelist = pgdat->node_zonelists + offset; | |
1179 | struct zone **zonep = zonelist->zones; | |
1180 | struct zone *zone; | |
1181 | ||
1182 | for (zone = *zonep++; zone; zone = *zonep++) { | |
1183 | unsigned long size = zone->present_pages; | |
1184 | unsigned long high = zone->pages_high; | |
1185 | if (size > high) | |
1186 | sum += size - high; | |
1187 | } | |
1188 | ||
1189 | return sum; | |
1190 | } | |
1191 | ||
1192 | /* | |
1193 | * Amount of free RAM allocatable within ZONE_DMA and ZONE_NORMAL | |
1194 | */ | |
1195 | unsigned int nr_free_buffer_pages(void) | |
1196 | { | |
1197 | return nr_free_zone_pages(gfp_zone(GFP_USER)); | |
1198 | } | |
1199 | ||
1200 | /* | |
1201 | * Amount of free RAM allocatable within all zones | |
1202 | */ | |
1203 | unsigned int nr_free_pagecache_pages(void) | |
1204 | { | |
1205 | return nr_free_zone_pages(gfp_zone(GFP_HIGHUSER)); | |
1206 | } | |
1207 | #ifdef CONFIG_NUMA | |
1208 | static void show_node(struct zone *zone) | |
1209 | { | |
1210 | printk("Node %d ", zone->zone_pgdat->node_id); | |
1211 | } | |
1212 | #else | |
1213 | #define show_node(zone) do { } while (0) | |
1214 | #endif | |
1215 | ||
1216 | void si_meminfo(struct sysinfo *val) | |
1217 | { | |
1218 | val->totalram = totalram_pages; | |
1219 | val->sharedram = 0; | |
1220 | val->freeram = nr_free_pages(); | |
1221 | val->bufferram = nr_blockdev_pages(); | |
1222 | val->totalhigh = totalhigh_pages; | |
1223 | val->freehigh = nr_free_highpages(); | |
1224 | val->mem_unit = PAGE_SIZE; | |
1225 | } | |
1226 | ||
1227 | EXPORT_SYMBOL(si_meminfo); | |
1228 | ||
1229 | #ifdef CONFIG_NUMA | |
1230 | void si_meminfo_node(struct sysinfo *val, int nid) | |
1231 | { | |
1232 | pg_data_t *pgdat = NODE_DATA(nid); | |
1233 | ||
1234 | val->totalram = pgdat->node_present_pages; | |
1235 | val->freeram = nr_free_pages_pgdat(pgdat); | |
1236 | #ifdef CONFIG_HIGHMEM | |
1237 | val->totalhigh = pgdat->node_zones[ZONE_HIGHMEM].present_pages; | |
1238 | val->freehigh = pgdat->node_zones[ZONE_HIGHMEM].free_pages; | |
1239 | #else | |
1240 | val->totalhigh = 0; | |
1241 | val->freehigh = 0; | |
1242 | #endif | |
1243 | val->mem_unit = PAGE_SIZE; | |
1244 | } | |
1245 | #endif | |
1246 | ||
1247 | #define K(x) ((x) << (PAGE_SHIFT-10)) | |
1248 | ||
1249 | /* | |
1250 | * Show free area list (used inside shift_scroll-lock stuff) | |
1251 | * We also calculate the percentage fragmentation. We do this by counting the | |
1252 | * memory on each free list with the exception of the first item on the list. | |
1253 | */ | |
1254 | void show_free_areas(void) | |
1255 | { | |
1256 | int cpu, temperature; | |
1257 | unsigned long active; | |
1258 | unsigned long inactive; | |
1259 | unsigned long free; | |
1260 | struct zone *zone; | |
1261 | ||
1262 | for_each_zone(zone) { | |
1263 | show_node(zone); | |
1264 | printk("%s per-cpu:", zone->name); | |
1265 | ||
1266 | if (!populated_zone(zone)) { | |
1267 | printk(" empty\n"); | |
1268 | continue; | |
1269 | } else | |
1270 | printk("\n"); | |
1271 | ||
1272 | for_each_online_cpu(cpu) { | |
1273 | struct per_cpu_pageset *pageset; | |
1274 | ||
1275 | pageset = zone_pcp(zone, cpu); | |
1276 | ||
1277 | for (temperature = 0; temperature < 2; temperature++) | |
1278 | printk("cpu %d %s: high %d, batch %d used:%d\n", | |
1279 | cpu, | |
1280 | temperature ? "cold" : "hot", | |
1281 | pageset->pcp[temperature].high, | |
1282 | pageset->pcp[temperature].batch, | |
1283 | pageset->pcp[temperature].count); | |
1284 | } | |
1285 | } | |
1286 | ||
1287 | get_zone_counts(&active, &inactive, &free); | |
1288 | ||
1289 | printk("Active:%lu inactive:%lu dirty:%lu writeback:%lu " | |
1290 | "unstable:%lu free:%u slab:%lu mapped:%lu pagetables:%lu\n", | |
1291 | active, | |
1292 | inactive, | |
1293 | global_page_state(NR_FILE_DIRTY), | |
1294 | global_page_state(NR_WRITEBACK), | |
1295 | global_page_state(NR_UNSTABLE_NFS), | |
1296 | nr_free_pages(), | |
1297 | global_page_state(NR_SLAB), | |
1298 | global_page_state(NR_FILE_MAPPED), | |
1299 | global_page_state(NR_PAGETABLE)); | |
1300 | ||
1301 | for_each_zone(zone) { | |
1302 | int i; | |
1303 | ||
1304 | show_node(zone); | |
1305 | printk("%s" | |
1306 | " free:%lukB" | |
1307 | " min:%lukB" | |
1308 | " low:%lukB" | |
1309 | " high:%lukB" | |
1310 | " active:%lukB" | |
1311 | " inactive:%lukB" | |
1312 | " present:%lukB" | |
1313 | " pages_scanned:%lu" | |
1314 | " all_unreclaimable? %s" | |
1315 | "\n", | |
1316 | zone->name, | |
1317 | K(zone->free_pages), | |
1318 | K(zone->pages_min), | |
1319 | K(zone->pages_low), | |
1320 | K(zone->pages_high), | |
1321 | K(zone->nr_active), | |
1322 | K(zone->nr_inactive), | |
1323 | K(zone->present_pages), | |
1324 | zone->pages_scanned, | |
1325 | (zone->all_unreclaimable ? "yes" : "no") | |
1326 | ); | |
1327 | printk("lowmem_reserve[]:"); | |
1328 | for (i = 0; i < MAX_NR_ZONES; i++) | |
1329 | printk(" %lu", zone->lowmem_reserve[i]); | |
1330 | printk("\n"); | |
1331 | } | |
1332 | ||
1333 | for_each_zone(zone) { | |
1334 | unsigned long nr[MAX_ORDER], flags, order, total = 0; | |
1335 | ||
1336 | show_node(zone); | |
1337 | printk("%s: ", zone->name); | |
1338 | if (!populated_zone(zone)) { | |
1339 | printk("empty\n"); | |
1340 | continue; | |
1341 | } | |
1342 | ||
1343 | spin_lock_irqsave(&zone->lock, flags); | |
1344 | for (order = 0; order < MAX_ORDER; order++) { | |
1345 | nr[order] = zone->free_area[order].nr_free; | |
1346 | total += nr[order] << order; | |
1347 | } | |
1348 | spin_unlock_irqrestore(&zone->lock, flags); | |
1349 | for (order = 0; order < MAX_ORDER; order++) | |
1350 | printk("%lu*%lukB ", nr[order], K(1UL) << order); | |
1351 | printk("= %lukB\n", K(total)); | |
1352 | } | |
1353 | ||
1354 | show_swap_cache_info(); | |
1355 | } | |
1356 | ||
1357 | /* | |
1358 | * Builds allocation fallback zone lists. | |
1359 | * | |
1360 | * Add all populated zones of a node to the zonelist. | |
1361 | */ | |
1362 | static int __meminit build_zonelists_node(pg_data_t *pgdat, | |
1363 | struct zonelist *zonelist, int nr_zones, enum zone_type zone_type) | |
1364 | { | |
1365 | struct zone *zone; | |
1366 | ||
1367 | BUG_ON(zone_type >= MAX_NR_ZONES); | |
1368 | zone_type++; | |
1369 | ||
1370 | do { | |
1371 | zone_type--; | |
1372 | zone = pgdat->node_zones + zone_type; | |
1373 | if (populated_zone(zone)) { | |
1374 | zonelist->zones[nr_zones++] = zone; | |
1375 | check_highest_zone(zone_type); | |
1376 | } | |
1377 | ||
1378 | } while (zone_type); | |
1379 | return nr_zones; | |
1380 | } | |
1381 | ||
1382 | #ifdef CONFIG_NUMA | |
1383 | #define MAX_NODE_LOAD (num_online_nodes()) | |
1384 | static int __meminitdata node_load[MAX_NUMNODES]; | |
1385 | /** | |
1386 | * find_next_best_node - find the next node that should appear in a given node's fallback list | |
1387 | * @node: node whose fallback list we're appending | |
1388 | * @used_node_mask: nodemask_t of already used nodes | |
1389 | * | |
1390 | * We use a number of factors to determine which is the next node that should | |
1391 | * appear on a given node's fallback list. The node should not have appeared | |
1392 | * already in @node's fallback list, and it should be the next closest node | |
1393 | * according to the distance array (which contains arbitrary distance values | |
1394 | * from each node to each node in the system), and should also prefer nodes | |
1395 | * with no CPUs, since presumably they'll have very little allocation pressure | |
1396 | * on them otherwise. | |
1397 | * It returns -1 if no node is found. | |
1398 | */ | |
1399 | static int __meminit find_next_best_node(int node, nodemask_t *used_node_mask) | |
1400 | { | |
1401 | int n, val; | |
1402 | int min_val = INT_MAX; | |
1403 | int best_node = -1; | |
1404 | ||
1405 | /* Use the local node if we haven't already */ | |
1406 | if (!node_isset(node, *used_node_mask)) { | |
1407 | node_set(node, *used_node_mask); | |
1408 | return node; | |
1409 | } | |
1410 | ||
1411 | for_each_online_node(n) { | |
1412 | cpumask_t tmp; | |
1413 | ||
1414 | /* Don't want a node to appear more than once */ | |
1415 | if (node_isset(n, *used_node_mask)) | |
1416 | continue; | |
1417 | ||
1418 | /* Use the distance array to find the distance */ | |
1419 | val = node_distance(node, n); | |
1420 | ||
1421 | /* Penalize nodes under us ("prefer the next node") */ | |
1422 | val += (n < node); | |
1423 | ||
1424 | /* Give preference to headless and unused nodes */ | |
1425 | tmp = node_to_cpumask(n); | |
1426 | if (!cpus_empty(tmp)) | |
1427 | val += PENALTY_FOR_NODE_WITH_CPUS; | |
1428 | ||
1429 | /* Slight preference for less loaded node */ | |
1430 | val *= (MAX_NODE_LOAD*MAX_NUMNODES); | |
1431 | val += node_load[n]; | |
1432 | ||
1433 | if (val < min_val) { | |
1434 | min_val = val; | |
1435 | best_node = n; | |
1436 | } | |
1437 | } | |
1438 | ||
1439 | if (best_node >= 0) | |
1440 | node_set(best_node, *used_node_mask); | |
1441 | ||
1442 | return best_node; | |
1443 | } | |
1444 | ||
1445 | static void __meminit build_zonelists(pg_data_t *pgdat) | |
1446 | { | |
1447 | int j, node, local_node; | |
1448 | enum zone_type i; | |
1449 | int prev_node, load; | |
1450 | struct zonelist *zonelist; | |
1451 | nodemask_t used_mask; | |
1452 | ||
1453 | /* initialize zonelists */ | |
1454 | for (i = 0; i < MAX_NR_ZONES; i++) { | |
1455 | zonelist = pgdat->node_zonelists + i; | |
1456 | zonelist->zones[0] = NULL; | |
1457 | } | |
1458 | ||
1459 | /* NUMA-aware ordering of nodes */ | |
1460 | local_node = pgdat->node_id; | |
1461 | load = num_online_nodes(); | |
1462 | prev_node = local_node; | |
1463 | nodes_clear(used_mask); | |
1464 | while ((node = find_next_best_node(local_node, &used_mask)) >= 0) { | |
1465 | int distance = node_distance(local_node, node); | |
1466 | ||
1467 | /* | |
1468 | * If another node is sufficiently far away then it is better | |
1469 | * to reclaim pages in a zone before going off node. | |
1470 | */ | |
1471 | if (distance > RECLAIM_DISTANCE) | |
1472 | zone_reclaim_mode = 1; | |
1473 | ||
1474 | /* | |
1475 | * We don't want to pressure a particular node. | |
1476 | * So adding penalty to the first node in same | |
1477 | * distance group to make it round-robin. | |
1478 | */ | |
1479 | ||
1480 | if (distance != node_distance(local_node, prev_node)) | |
1481 | node_load[node] += load; | |
1482 | prev_node = node; | |
1483 | load--; | |
1484 | for (i = 0; i < MAX_NR_ZONES; i++) { | |
1485 | zonelist = pgdat->node_zonelists + i; | |
1486 | for (j = 0; zonelist->zones[j] != NULL; j++); | |
1487 | ||
1488 | j = build_zonelists_node(NODE_DATA(node), zonelist, j, i); | |
1489 | zonelist->zones[j] = NULL; | |
1490 | } | |
1491 | } | |
1492 | } | |
1493 | ||
1494 | #else /* CONFIG_NUMA */ | |
1495 | ||
1496 | static void __meminit build_zonelists(pg_data_t *pgdat) | |
1497 | { | |
1498 | int node, local_node; | |
1499 | enum zone_type i,j; | |
1500 | ||
1501 | local_node = pgdat->node_id; | |
1502 | for (i = 0; i < MAX_NR_ZONES; i++) { | |
1503 | struct zonelist *zonelist; | |
1504 | ||
1505 | zonelist = pgdat->node_zonelists + i; | |
1506 | ||
1507 | j = build_zonelists_node(pgdat, zonelist, 0, i); | |
1508 | /* | |
1509 | * Now we build the zonelist so that it contains the zones | |
1510 | * of all the other nodes. | |
1511 | * We don't want to pressure a particular node, so when | |
1512 | * building the zones for node N, we make sure that the | |
1513 | * zones coming right after the local ones are those from | |
1514 | * node N+1 (modulo N) | |
1515 | */ | |
1516 | for (node = local_node + 1; node < MAX_NUMNODES; node++) { | |
1517 | if (!node_online(node)) | |
1518 | continue; | |
1519 | j = build_zonelists_node(NODE_DATA(node), zonelist, j, i); | |
1520 | } | |
1521 | for (node = 0; node < local_node; node++) { | |
1522 | if (!node_online(node)) | |
1523 | continue; | |
1524 | j = build_zonelists_node(NODE_DATA(node), zonelist, j, i); | |
1525 | } | |
1526 | ||
1527 | zonelist->zones[j] = NULL; | |
1528 | } | |
1529 | } | |
1530 | ||
1531 | #endif /* CONFIG_NUMA */ | |
1532 | ||
1533 | /* return values int ....just for stop_machine_run() */ | |
1534 | static int __meminit __build_all_zonelists(void *dummy) | |
1535 | { | |
1536 | int nid; | |
1537 | for_each_online_node(nid) | |
1538 | build_zonelists(NODE_DATA(nid)); | |
1539 | return 0; | |
1540 | } | |
1541 | ||
1542 | void __meminit build_all_zonelists(void) | |
1543 | { | |
1544 | if (system_state == SYSTEM_BOOTING) { | |
1545 | __build_all_zonelists(0); | |
1546 | cpuset_init_current_mems_allowed(); | |
1547 | } else { | |
1548 | /* we have to stop all cpus to guaranntee there is no user | |
1549 | of zonelist */ | |
1550 | stop_machine_run(__build_all_zonelists, NULL, NR_CPUS); | |
1551 | /* cpuset refresh routine should be here */ | |
1552 | } | |
1553 | vm_total_pages = nr_free_pagecache_pages(); | |
1554 | printk("Built %i zonelists. Total pages: %ld\n", | |
1555 | num_online_nodes(), vm_total_pages); | |
1556 | } | |
1557 | ||
1558 | /* | |
1559 | * Helper functions to size the waitqueue hash table. | |
1560 | * Essentially these want to choose hash table sizes sufficiently | |
1561 | * large so that collisions trying to wait on pages are rare. | |
1562 | * But in fact, the number of active page waitqueues on typical | |
1563 | * systems is ridiculously low, less than 200. So this is even | |
1564 | * conservative, even though it seems large. | |
1565 | * | |
1566 | * The constant PAGES_PER_WAITQUEUE specifies the ratio of pages to | |
1567 | * waitqueues, i.e. the size of the waitq table given the number of pages. | |
1568 | */ | |
1569 | #define PAGES_PER_WAITQUEUE 256 | |
1570 | ||
1571 | #ifndef CONFIG_MEMORY_HOTPLUG | |
1572 | static inline unsigned long wait_table_hash_nr_entries(unsigned long pages) | |
1573 | { | |
1574 | unsigned long size = 1; | |
1575 | ||
1576 | pages /= PAGES_PER_WAITQUEUE; | |
1577 | ||
1578 | while (size < pages) | |
1579 | size <<= 1; | |
1580 | ||
1581 | /* | |
1582 | * Once we have dozens or even hundreds of threads sleeping | |
1583 | * on IO we've got bigger problems than wait queue collision. | |
1584 | * Limit the size of the wait table to a reasonable size. | |
1585 | */ | |
1586 | size = min(size, 4096UL); | |
1587 | ||
1588 | return max(size, 4UL); | |
1589 | } | |
1590 | #else | |
1591 | /* | |
1592 | * A zone's size might be changed by hot-add, so it is not possible to determine | |
1593 | * a suitable size for its wait_table. So we use the maximum size now. | |
1594 | * | |
1595 | * The max wait table size = 4096 x sizeof(wait_queue_head_t). ie: | |
1596 | * | |
1597 | * i386 (preemption config) : 4096 x 16 = 64Kbyte. | |
1598 | * ia64, x86-64 (no preemption): 4096 x 20 = 80Kbyte. | |
1599 | * ia64, x86-64 (preemption) : 4096 x 24 = 96Kbyte. | |
1600 | * | |
1601 | * The maximum entries are prepared when a zone's memory is (512K + 256) pages | |
1602 | * or more by the traditional way. (See above). It equals: | |
1603 | * | |
1604 | * i386, x86-64, powerpc(4K page size) : = ( 2G + 1M)byte. | |
1605 | * ia64(16K page size) : = ( 8G + 4M)byte. | |
1606 | * powerpc (64K page size) : = (32G +16M)byte. | |
1607 | */ | |
1608 | static inline unsigned long wait_table_hash_nr_entries(unsigned long pages) | |
1609 | { | |
1610 | return 4096UL; | |
1611 | } | |
1612 | #endif | |
1613 | ||
1614 | /* | |
1615 | * This is an integer logarithm so that shifts can be used later | |
1616 | * to extract the more random high bits from the multiplicative | |
1617 | * hash function before the remainder is taken. | |
1618 | */ | |
1619 | static inline unsigned long wait_table_bits(unsigned long size) | |
1620 | { | |
1621 | return ffz(~size); | |
1622 | } | |
1623 | ||
1624 | #define LONG_ALIGN(x) (((x)+(sizeof(long))-1)&~((sizeof(long))-1)) | |
1625 | ||
1626 | static void __init calculate_zone_totalpages(struct pglist_data *pgdat, | |
1627 | unsigned long *zones_size, unsigned long *zholes_size) | |
1628 | { | |
1629 | unsigned long realtotalpages, totalpages = 0; | |
1630 | enum zone_type i; | |
1631 | ||
1632 | for (i = 0; i < MAX_NR_ZONES; i++) | |
1633 | totalpages += zones_size[i]; | |
1634 | pgdat->node_spanned_pages = totalpages; | |
1635 | ||
1636 | realtotalpages = totalpages; | |
1637 | if (zholes_size) | |
1638 | for (i = 0; i < MAX_NR_ZONES; i++) | |
1639 | realtotalpages -= zholes_size[i]; | |
1640 | pgdat->node_present_pages = realtotalpages; | |
1641 | printk(KERN_DEBUG "On node %d totalpages: %lu\n", pgdat->node_id, realtotalpages); | |
1642 | } | |
1643 | ||
1644 | ||
1645 | /* | |
1646 | * Initially all pages are reserved - free ones are freed | |
1647 | * up by free_all_bootmem() once the early boot process is | |
1648 | * done. Non-atomic initialization, single-pass. | |
1649 | */ | |
1650 | void __meminit memmap_init_zone(unsigned long size, int nid, unsigned long zone, | |
1651 | unsigned long start_pfn) | |
1652 | { | |
1653 | struct page *page; | |
1654 | unsigned long end_pfn = start_pfn + size; | |
1655 | unsigned long pfn; | |
1656 | ||
1657 | for (pfn = start_pfn; pfn < end_pfn; pfn++) { | |
1658 | if (!early_pfn_valid(pfn)) | |
1659 | continue; | |
1660 | page = pfn_to_page(pfn); | |
1661 | set_page_links(page, zone, nid, pfn); | |
1662 | init_page_count(page); | |
1663 | reset_page_mapcount(page); | |
1664 | SetPageReserved(page); | |
1665 | INIT_LIST_HEAD(&page->lru); | |
1666 | #ifdef WANT_PAGE_VIRTUAL | |
1667 | /* The shift won't overflow because ZONE_NORMAL is below 4G. */ | |
1668 | if (!is_highmem_idx(zone)) | |
1669 | set_page_address(page, __va(pfn << PAGE_SHIFT)); | |
1670 | #endif | |
1671 | } | |
1672 | } | |
1673 | ||
1674 | void zone_init_free_lists(struct pglist_data *pgdat, struct zone *zone, | |
1675 | unsigned long size) | |
1676 | { | |
1677 | int order; | |
1678 | for (order = 0; order < MAX_ORDER ; order++) { | |
1679 | INIT_LIST_HEAD(&zone->free_area[order].free_list); | |
1680 | zone->free_area[order].nr_free = 0; | |
1681 | } | |
1682 | } | |
1683 | ||
1684 | #define ZONETABLE_INDEX(x, zone_nr) ((x << ZONES_SHIFT) | zone_nr) | |
1685 | void zonetable_add(struct zone *zone, int nid, enum zone_type zid, | |
1686 | unsigned long pfn, unsigned long size) | |
1687 | { | |
1688 | unsigned long snum = pfn_to_section_nr(pfn); | |
1689 | unsigned long end = pfn_to_section_nr(pfn + size); | |
1690 | ||
1691 | if (FLAGS_HAS_NODE) | |
1692 | zone_table[ZONETABLE_INDEX(nid, zid)] = zone; | |
1693 | else | |
1694 | for (; snum <= end; snum++) | |
1695 | zone_table[ZONETABLE_INDEX(snum, zid)] = zone; | |
1696 | } | |
1697 | ||
1698 | #ifndef __HAVE_ARCH_MEMMAP_INIT | |
1699 | #define memmap_init(size, nid, zone, start_pfn) \ | |
1700 | memmap_init_zone((size), (nid), (zone), (start_pfn)) | |
1701 | #endif | |
1702 | ||
1703 | static int __cpuinit zone_batchsize(struct zone *zone) | |
1704 | { | |
1705 | int batch; | |
1706 | ||
1707 | /* | |
1708 | * The per-cpu-pages pools are set to around 1000th of the | |
1709 | * size of the zone. But no more than 1/2 of a meg. | |
1710 | * | |
1711 | * OK, so we don't know how big the cache is. So guess. | |
1712 | */ | |
1713 | batch = zone->present_pages / 1024; | |
1714 | if (batch * PAGE_SIZE > 512 * 1024) | |
1715 | batch = (512 * 1024) / PAGE_SIZE; | |
1716 | batch /= 4; /* We effectively *= 4 below */ | |
1717 | if (batch < 1) | |
1718 | batch = 1; | |
1719 | ||
1720 | /* | |
1721 | * Clamp the batch to a 2^n - 1 value. Having a power | |
1722 | * of 2 value was found to be more likely to have | |
1723 | * suboptimal cache aliasing properties in some cases. | |
1724 | * | |
1725 | * For example if 2 tasks are alternately allocating | |
1726 | * batches of pages, one task can end up with a lot | |
1727 | * of pages of one half of the possible page colors | |
1728 | * and the other with pages of the other colors. | |
1729 | */ | |
1730 | batch = (1 << (fls(batch + batch/2)-1)) - 1; | |
1731 | ||
1732 | return batch; | |
1733 | } | |
1734 | ||
1735 | inline void setup_pageset(struct per_cpu_pageset *p, unsigned long batch) | |
1736 | { | |
1737 | struct per_cpu_pages *pcp; | |
1738 | ||
1739 | memset(p, 0, sizeof(*p)); | |
1740 | ||
1741 | pcp = &p->pcp[0]; /* hot */ | |
1742 | pcp->count = 0; | |
1743 | pcp->high = 6 * batch; | |
1744 | pcp->batch = max(1UL, 1 * batch); | |
1745 | INIT_LIST_HEAD(&pcp->list); | |
1746 | ||
1747 | pcp = &p->pcp[1]; /* cold*/ | |
1748 | pcp->count = 0; | |
1749 | pcp->high = 2 * batch; | |
1750 | pcp->batch = max(1UL, batch/2); | |
1751 | INIT_LIST_HEAD(&pcp->list); | |
1752 | } | |
1753 | ||
1754 | /* | |
1755 | * setup_pagelist_highmark() sets the high water mark for hot per_cpu_pagelist | |
1756 | * to the value high for the pageset p. | |
1757 | */ | |
1758 | ||
1759 | static void setup_pagelist_highmark(struct per_cpu_pageset *p, | |
1760 | unsigned long high) | |
1761 | { | |
1762 | struct per_cpu_pages *pcp; | |
1763 | ||
1764 | pcp = &p->pcp[0]; /* hot list */ | |
1765 | pcp->high = high; | |
1766 | pcp->batch = max(1UL, high/4); | |
1767 | if ((high/4) > (PAGE_SHIFT * 8)) | |
1768 | pcp->batch = PAGE_SHIFT * 8; | |
1769 | } | |
1770 | ||
1771 | ||
1772 | #ifdef CONFIG_NUMA | |
1773 | /* | |
1774 | * Boot pageset table. One per cpu which is going to be used for all | |
1775 | * zones and all nodes. The parameters will be set in such a way | |
1776 | * that an item put on a list will immediately be handed over to | |
1777 | * the buddy list. This is safe since pageset manipulation is done | |
1778 | * with interrupts disabled. | |
1779 | * | |
1780 | * Some NUMA counter updates may also be caught by the boot pagesets. | |
1781 | * | |
1782 | * The boot_pagesets must be kept even after bootup is complete for | |
1783 | * unused processors and/or zones. They do play a role for bootstrapping | |
1784 | * hotplugged processors. | |
1785 | * | |
1786 | * zoneinfo_show() and maybe other functions do | |
1787 | * not check if the processor is online before following the pageset pointer. | |
1788 | * Other parts of the kernel may not check if the zone is available. | |
1789 | */ | |
1790 | static struct per_cpu_pageset boot_pageset[NR_CPUS]; | |
1791 | ||
1792 | /* | |
1793 | * Dynamically allocate memory for the | |
1794 | * per cpu pageset array in struct zone. | |
1795 | */ | |
1796 | static int __cpuinit process_zones(int cpu) | |
1797 | { | |
1798 | struct zone *zone, *dzone; | |
1799 | ||
1800 | for_each_zone(zone) { | |
1801 | ||
1802 | zone_pcp(zone, cpu) = kmalloc_node(sizeof(struct per_cpu_pageset), | |
1803 | GFP_KERNEL, cpu_to_node(cpu)); | |
1804 | if (!zone_pcp(zone, cpu)) | |
1805 | goto bad; | |
1806 | ||
1807 | setup_pageset(zone_pcp(zone, cpu), zone_batchsize(zone)); | |
1808 | ||
1809 | if (percpu_pagelist_fraction) | |
1810 | setup_pagelist_highmark(zone_pcp(zone, cpu), | |
1811 | (zone->present_pages / percpu_pagelist_fraction)); | |
1812 | } | |
1813 | ||
1814 | return 0; | |
1815 | bad: | |
1816 | for_each_zone(dzone) { | |
1817 | if (dzone == zone) | |
1818 | break; | |
1819 | kfree(zone_pcp(dzone, cpu)); | |
1820 | zone_pcp(dzone, cpu) = NULL; | |
1821 | } | |
1822 | return -ENOMEM; | |
1823 | } | |
1824 | ||
1825 | static inline void free_zone_pagesets(int cpu) | |
1826 | { | |
1827 | struct zone *zone; | |
1828 | ||
1829 | for_each_zone(zone) { | |
1830 | struct per_cpu_pageset *pset = zone_pcp(zone, cpu); | |
1831 | ||
1832 | /* Free per_cpu_pageset if it is slab allocated */ | |
1833 | if (pset != &boot_pageset[cpu]) | |
1834 | kfree(pset); | |
1835 | zone_pcp(zone, cpu) = NULL; | |
1836 | } | |
1837 | } | |
1838 | ||
1839 | static int __cpuinit pageset_cpuup_callback(struct notifier_block *nfb, | |
1840 | unsigned long action, | |
1841 | void *hcpu) | |
1842 | { | |
1843 | int cpu = (long)hcpu; | |
1844 | int ret = NOTIFY_OK; | |
1845 | ||
1846 | switch (action) { | |
1847 | case CPU_UP_PREPARE: | |
1848 | if (process_zones(cpu)) | |
1849 | ret = NOTIFY_BAD; | |
1850 | break; | |
1851 | case CPU_UP_CANCELED: | |
1852 | case CPU_DEAD: | |
1853 | free_zone_pagesets(cpu); | |
1854 | break; | |
1855 | default: | |
1856 | break; | |
1857 | } | |
1858 | return ret; | |
1859 | } | |
1860 | ||
1861 | static struct notifier_block __cpuinitdata pageset_notifier = | |
1862 | { &pageset_cpuup_callback, NULL, 0 }; | |
1863 | ||
1864 | void __init setup_per_cpu_pageset(void) | |
1865 | { | |
1866 | int err; | |
1867 | ||
1868 | /* Initialize per_cpu_pageset for cpu 0. | |
1869 | * A cpuup callback will do this for every cpu | |
1870 | * as it comes online | |
1871 | */ | |
1872 | err = process_zones(smp_processor_id()); | |
1873 | BUG_ON(err); | |
1874 | register_cpu_notifier(&pageset_notifier); | |
1875 | } | |
1876 | ||
1877 | #endif | |
1878 | ||
1879 | static __meminit | |
1880 | int zone_wait_table_init(struct zone *zone, unsigned long zone_size_pages) | |
1881 | { | |
1882 | int i; | |
1883 | struct pglist_data *pgdat = zone->zone_pgdat; | |
1884 | size_t alloc_size; | |
1885 | ||
1886 | /* | |
1887 | * The per-page waitqueue mechanism uses hashed waitqueues | |
1888 | * per zone. | |
1889 | */ | |
1890 | zone->wait_table_hash_nr_entries = | |
1891 | wait_table_hash_nr_entries(zone_size_pages); | |
1892 | zone->wait_table_bits = | |
1893 | wait_table_bits(zone->wait_table_hash_nr_entries); | |
1894 | alloc_size = zone->wait_table_hash_nr_entries | |
1895 | * sizeof(wait_queue_head_t); | |
1896 | ||
1897 | if (system_state == SYSTEM_BOOTING) { | |
1898 | zone->wait_table = (wait_queue_head_t *) | |
1899 | alloc_bootmem_node(pgdat, alloc_size); | |
1900 | } else { | |
1901 | /* | |
1902 | * This case means that a zone whose size was 0 gets new memory | |
1903 | * via memory hot-add. | |
1904 | * But it may be the case that a new node was hot-added. In | |
1905 | * this case vmalloc() will not be able to use this new node's | |
1906 | * memory - this wait_table must be initialized to use this new | |
1907 | * node itself as well. | |
1908 | * To use this new node's memory, further consideration will be | |
1909 | * necessary. | |
1910 | */ | |
1911 | zone->wait_table = (wait_queue_head_t *)vmalloc(alloc_size); | |
1912 | } | |
1913 | if (!zone->wait_table) | |
1914 | return -ENOMEM; | |
1915 | ||
1916 | for(i = 0; i < zone->wait_table_hash_nr_entries; ++i) | |
1917 | init_waitqueue_head(zone->wait_table + i); | |
1918 | ||
1919 | return 0; | |
1920 | } | |
1921 | ||
1922 | static __meminit void zone_pcp_init(struct zone *zone) | |
1923 | { | |
1924 | int cpu; | |
1925 | unsigned long batch = zone_batchsize(zone); | |
1926 | ||
1927 | for (cpu = 0; cpu < NR_CPUS; cpu++) { | |
1928 | #ifdef CONFIG_NUMA | |
1929 | /* Early boot. Slab allocator not functional yet */ | |
1930 | zone_pcp(zone, cpu) = &boot_pageset[cpu]; | |
1931 | setup_pageset(&boot_pageset[cpu],0); | |
1932 | #else | |
1933 | setup_pageset(zone_pcp(zone,cpu), batch); | |
1934 | #endif | |
1935 | } | |
1936 | if (zone->present_pages) | |
1937 | printk(KERN_DEBUG " %s zone: %lu pages, LIFO batch:%lu\n", | |
1938 | zone->name, zone->present_pages, batch); | |
1939 | } | |
1940 | ||
1941 | __meminit int init_currently_empty_zone(struct zone *zone, | |
1942 | unsigned long zone_start_pfn, | |
1943 | unsigned long size) | |
1944 | { | |
1945 | struct pglist_data *pgdat = zone->zone_pgdat; | |
1946 | int ret; | |
1947 | ret = zone_wait_table_init(zone, size); | |
1948 | if (ret) | |
1949 | return ret; | |
1950 | pgdat->nr_zones = zone_idx(zone) + 1; | |
1951 | ||
1952 | zone->zone_start_pfn = zone_start_pfn; | |
1953 | ||
1954 | memmap_init(size, pgdat->node_id, zone_idx(zone), zone_start_pfn); | |
1955 | ||
1956 | zone_init_free_lists(pgdat, zone, zone->spanned_pages); | |
1957 | ||
1958 | return 0; | |
1959 | } | |
1960 | ||
1961 | /* | |
1962 | * Set up the zone data structures: | |
1963 | * - mark all pages reserved | |
1964 | * - mark all memory queues empty | |
1965 | * - clear the memory bitmaps | |
1966 | */ | |
1967 | static void __meminit free_area_init_core(struct pglist_data *pgdat, | |
1968 | unsigned long *zones_size, unsigned long *zholes_size) | |
1969 | { | |
1970 | enum zone_type j; | |
1971 | int nid = pgdat->node_id; | |
1972 | unsigned long zone_start_pfn = pgdat->node_start_pfn; | |
1973 | int ret; | |
1974 | ||
1975 | pgdat_resize_init(pgdat); | |
1976 | pgdat->nr_zones = 0; | |
1977 | init_waitqueue_head(&pgdat->kswapd_wait); | |
1978 | pgdat->kswapd_max_order = 0; | |
1979 | ||
1980 | for (j = 0; j < MAX_NR_ZONES; j++) { | |
1981 | struct zone *zone = pgdat->node_zones + j; | |
1982 | unsigned long size, realsize; | |
1983 | ||
1984 | realsize = size = zones_size[j]; | |
1985 | if (zholes_size) | |
1986 | realsize -= zholes_size[j]; | |
1987 | ||
1988 | if (!is_highmem_idx(j)) | |
1989 | nr_kernel_pages += realsize; | |
1990 | nr_all_pages += realsize; | |
1991 | ||
1992 | zone->spanned_pages = size; | |
1993 | zone->present_pages = realsize; | |
1994 | #ifdef CONFIG_NUMA | |
1995 | zone->min_unmapped_ratio = (realsize*sysctl_min_unmapped_ratio) | |
1996 | / 100; | |
1997 | #endif | |
1998 | zone->name = zone_names[j]; | |
1999 | spin_lock_init(&zone->lock); | |
2000 | spin_lock_init(&zone->lru_lock); | |
2001 | zone_seqlock_init(zone); | |
2002 | zone->zone_pgdat = pgdat; | |
2003 | zone->free_pages = 0; | |
2004 | ||
2005 | zone->temp_priority = zone->prev_priority = DEF_PRIORITY; | |
2006 | ||
2007 | zone_pcp_init(zone); | |
2008 | INIT_LIST_HEAD(&zone->active_list); | |
2009 | INIT_LIST_HEAD(&zone->inactive_list); | |
2010 | zone->nr_scan_active = 0; | |
2011 | zone->nr_scan_inactive = 0; | |
2012 | zone->nr_active = 0; | |
2013 | zone->nr_inactive = 0; | |
2014 | zap_zone_vm_stats(zone); | |
2015 | atomic_set(&zone->reclaim_in_progress, 0); | |
2016 | if (!size) | |
2017 | continue; | |
2018 | ||
2019 | zonetable_add(zone, nid, j, zone_start_pfn, size); | |
2020 | ret = init_currently_empty_zone(zone, zone_start_pfn, size); | |
2021 | BUG_ON(ret); | |
2022 | zone_start_pfn += size; | |
2023 | } | |
2024 | } | |
2025 | ||
2026 | static void __init alloc_node_mem_map(struct pglist_data *pgdat) | |
2027 | { | |
2028 | /* Skip empty nodes */ | |
2029 | if (!pgdat->node_spanned_pages) | |
2030 | return; | |
2031 | ||
2032 | #ifdef CONFIG_FLAT_NODE_MEM_MAP | |
2033 | /* ia64 gets its own node_mem_map, before this, without bootmem */ | |
2034 | if (!pgdat->node_mem_map) { | |
2035 | unsigned long size, start, end; | |
2036 | struct page *map; | |
2037 | ||
2038 | /* | |
2039 | * The zone's endpoints aren't required to be MAX_ORDER | |
2040 | * aligned but the node_mem_map endpoints must be in order | |
2041 | * for the buddy allocator to function correctly. | |
2042 | */ | |
2043 | start = pgdat->node_start_pfn & ~(MAX_ORDER_NR_PAGES - 1); | |
2044 | end = pgdat->node_start_pfn + pgdat->node_spanned_pages; | |
2045 | end = ALIGN(end, MAX_ORDER_NR_PAGES); | |
2046 | size = (end - start) * sizeof(struct page); | |
2047 | map = alloc_remap(pgdat->node_id, size); | |
2048 | if (!map) | |
2049 | map = alloc_bootmem_node(pgdat, size); | |
2050 | pgdat->node_mem_map = map + (pgdat->node_start_pfn - start); | |
2051 | } | |
2052 | #ifdef CONFIG_FLATMEM | |
2053 | /* | |
2054 | * With no DISCONTIG, the global mem_map is just set as node 0's | |
2055 | */ | |
2056 | if (pgdat == NODE_DATA(0)) | |
2057 | mem_map = NODE_DATA(0)->node_mem_map; | |
2058 | #endif | |
2059 | #endif /* CONFIG_FLAT_NODE_MEM_MAP */ | |
2060 | } | |
2061 | ||
2062 | void __meminit free_area_init_node(int nid, struct pglist_data *pgdat, | |
2063 | unsigned long *zones_size, unsigned long node_start_pfn, | |
2064 | unsigned long *zholes_size) | |
2065 | { | |
2066 | pgdat->node_id = nid; | |
2067 | pgdat->node_start_pfn = node_start_pfn; | |
2068 | calculate_zone_totalpages(pgdat, zones_size, zholes_size); | |
2069 | ||
2070 | alloc_node_mem_map(pgdat); | |
2071 | ||
2072 | free_area_init_core(pgdat, zones_size, zholes_size); | |
2073 | } | |
2074 | ||
2075 | #ifndef CONFIG_NEED_MULTIPLE_NODES | |
2076 | static bootmem_data_t contig_bootmem_data; | |
2077 | struct pglist_data contig_page_data = { .bdata = &contig_bootmem_data }; | |
2078 | ||
2079 | EXPORT_SYMBOL(contig_page_data); | |
2080 | #endif | |
2081 | ||
2082 | void __init free_area_init(unsigned long *zones_size) | |
2083 | { | |
2084 | free_area_init_node(0, NODE_DATA(0), zones_size, | |
2085 | __pa(PAGE_OFFSET) >> PAGE_SHIFT, NULL); | |
2086 | } | |
2087 | ||
2088 | #ifdef CONFIG_HOTPLUG_CPU | |
2089 | static int page_alloc_cpu_notify(struct notifier_block *self, | |
2090 | unsigned long action, void *hcpu) | |
2091 | { | |
2092 | int cpu = (unsigned long)hcpu; | |
2093 | ||
2094 | if (action == CPU_DEAD) { | |
2095 | local_irq_disable(); | |
2096 | __drain_pages(cpu); | |
2097 | vm_events_fold_cpu(cpu); | |
2098 | local_irq_enable(); | |
2099 | refresh_cpu_vm_stats(cpu); | |
2100 | } | |
2101 | return NOTIFY_OK; | |
2102 | } | |
2103 | #endif /* CONFIG_HOTPLUG_CPU */ | |
2104 | ||
2105 | void __init page_alloc_init(void) | |
2106 | { | |
2107 | hotcpu_notifier(page_alloc_cpu_notify, 0); | |
2108 | } | |
2109 | ||
2110 | /* | |
2111 | * calculate_totalreserve_pages - called when sysctl_lower_zone_reserve_ratio | |
2112 | * or min_free_kbytes changes. | |
2113 | */ | |
2114 | static void calculate_totalreserve_pages(void) | |
2115 | { | |
2116 | struct pglist_data *pgdat; | |
2117 | unsigned long reserve_pages = 0; | |
2118 | enum zone_type i, j; | |
2119 | ||
2120 | for_each_online_pgdat(pgdat) { | |
2121 | for (i = 0; i < MAX_NR_ZONES; i++) { | |
2122 | struct zone *zone = pgdat->node_zones + i; | |
2123 | unsigned long max = 0; | |
2124 | ||
2125 | /* Find valid and maximum lowmem_reserve in the zone */ | |
2126 | for (j = i; j < MAX_NR_ZONES; j++) { | |
2127 | if (zone->lowmem_reserve[j] > max) | |
2128 | max = zone->lowmem_reserve[j]; | |
2129 | } | |
2130 | ||
2131 | /* we treat pages_high as reserved pages. */ | |
2132 | max += zone->pages_high; | |
2133 | ||
2134 | if (max > zone->present_pages) | |
2135 | max = zone->present_pages; | |
2136 | reserve_pages += max; | |
2137 | } | |
2138 | } | |
2139 | totalreserve_pages = reserve_pages; | |
2140 | } | |
2141 | ||
2142 | /* | |
2143 | * setup_per_zone_lowmem_reserve - called whenever | |
2144 | * sysctl_lower_zone_reserve_ratio changes. Ensures that each zone | |
2145 | * has a correct pages reserved value, so an adequate number of | |
2146 | * pages are left in the zone after a successful __alloc_pages(). | |
2147 | */ | |
2148 | static void setup_per_zone_lowmem_reserve(void) | |
2149 | { | |
2150 | struct pglist_data *pgdat; | |
2151 | enum zone_type j, idx; | |
2152 | ||
2153 | for_each_online_pgdat(pgdat) { | |
2154 | for (j = 0; j < MAX_NR_ZONES; j++) { | |
2155 | struct zone *zone = pgdat->node_zones + j; | |
2156 | unsigned long present_pages = zone->present_pages; | |
2157 | ||
2158 | zone->lowmem_reserve[j] = 0; | |
2159 | ||
2160 | idx = j; | |
2161 | while (idx) { | |
2162 | struct zone *lower_zone; | |
2163 | ||
2164 | idx--; | |
2165 | ||
2166 | if (sysctl_lowmem_reserve_ratio[idx] < 1) | |
2167 | sysctl_lowmem_reserve_ratio[idx] = 1; | |
2168 | ||
2169 | lower_zone = pgdat->node_zones + idx; | |
2170 | lower_zone->lowmem_reserve[j] = present_pages / | |
2171 | sysctl_lowmem_reserve_ratio[idx]; | |
2172 | present_pages += lower_zone->present_pages; | |
2173 | } | |
2174 | } | |
2175 | } | |
2176 | ||
2177 | /* update totalreserve_pages */ | |
2178 | calculate_totalreserve_pages(); | |
2179 | } | |
2180 | ||
2181 | /* | |
2182 | * setup_per_zone_pages_min - called when min_free_kbytes changes. Ensures | |
2183 | * that the pages_{min,low,high} values for each zone are set correctly | |
2184 | * with respect to min_free_kbytes. | |
2185 | */ | |
2186 | void setup_per_zone_pages_min(void) | |
2187 | { | |
2188 | unsigned long pages_min = min_free_kbytes >> (PAGE_SHIFT - 10); | |
2189 | unsigned long lowmem_pages = 0; | |
2190 | struct zone *zone; | |
2191 | unsigned long flags; | |
2192 | ||
2193 | /* Calculate total number of !ZONE_HIGHMEM pages */ | |
2194 | for_each_zone(zone) { | |
2195 | if (!is_highmem(zone)) | |
2196 | lowmem_pages += zone->present_pages; | |
2197 | } | |
2198 | ||
2199 | for_each_zone(zone) { | |
2200 | u64 tmp; | |
2201 | ||
2202 | spin_lock_irqsave(&zone->lru_lock, flags); | |
2203 | tmp = (u64)pages_min * zone->present_pages; | |
2204 | do_div(tmp, lowmem_pages); | |
2205 | if (is_highmem(zone)) { | |
2206 | /* | |
2207 | * __GFP_HIGH and PF_MEMALLOC allocations usually don't | |
2208 | * need highmem pages, so cap pages_min to a small | |
2209 | * value here. | |
2210 | * | |
2211 | * The (pages_high-pages_low) and (pages_low-pages_min) | |
2212 | * deltas controls asynch page reclaim, and so should | |
2213 | * not be capped for highmem. | |
2214 | */ | |
2215 | int min_pages; | |
2216 | ||
2217 | min_pages = zone->present_pages / 1024; | |
2218 | if (min_pages < SWAP_CLUSTER_MAX) | |
2219 | min_pages = SWAP_CLUSTER_MAX; | |
2220 | if (min_pages > 128) | |
2221 | min_pages = 128; | |
2222 | zone->pages_min = min_pages; | |
2223 | } else { | |
2224 | /* | |
2225 | * If it's a lowmem zone, reserve a number of pages | |
2226 | * proportionate to the zone's size. | |
2227 | */ | |
2228 | zone->pages_min = tmp; | |
2229 | } | |
2230 | ||
2231 | zone->pages_low = zone->pages_min + (tmp >> 2); | |
2232 | zone->pages_high = zone->pages_min + (tmp >> 1); | |
2233 | spin_unlock_irqrestore(&zone->lru_lock, flags); | |
2234 | } | |
2235 | ||
2236 | /* update totalreserve_pages */ | |
2237 | calculate_totalreserve_pages(); | |
2238 | } | |
2239 | ||
2240 | /* | |
2241 | * Initialise min_free_kbytes. | |
2242 | * | |
2243 | * For small machines we want it small (128k min). For large machines | |
2244 | * we want it large (64MB max). But it is not linear, because network | |
2245 | * bandwidth does not increase linearly with machine size. We use | |
2246 | * | |
2247 | * min_free_kbytes = 4 * sqrt(lowmem_kbytes), for better accuracy: | |
2248 | * min_free_kbytes = sqrt(lowmem_kbytes * 16) | |
2249 | * | |
2250 | * which yields | |
2251 | * | |
2252 | * 16MB: 512k | |
2253 | * 32MB: 724k | |
2254 | * 64MB: 1024k | |
2255 | * 128MB: 1448k | |
2256 | * 256MB: 2048k | |
2257 | * 512MB: 2896k | |
2258 | * 1024MB: 4096k | |
2259 | * 2048MB: 5792k | |
2260 | * 4096MB: 8192k | |
2261 | * 8192MB: 11584k | |
2262 | * 16384MB: 16384k | |
2263 | */ | |
2264 | static int __init init_per_zone_pages_min(void) | |
2265 | { | |
2266 | unsigned long lowmem_kbytes; | |
2267 | ||
2268 | lowmem_kbytes = nr_free_buffer_pages() * (PAGE_SIZE >> 10); | |
2269 | ||
2270 | min_free_kbytes = int_sqrt(lowmem_kbytes * 16); | |
2271 | if (min_free_kbytes < 128) | |
2272 | min_free_kbytes = 128; | |
2273 | if (min_free_kbytes > 65536) | |
2274 | min_free_kbytes = 65536; | |
2275 | setup_per_zone_pages_min(); | |
2276 | setup_per_zone_lowmem_reserve(); | |
2277 | return 0; | |
2278 | } | |
2279 | module_init(init_per_zone_pages_min) | |
2280 | ||
2281 | /* | |
2282 | * min_free_kbytes_sysctl_handler - just a wrapper around proc_dointvec() so | |
2283 | * that we can call two helper functions whenever min_free_kbytes | |
2284 | * changes. | |
2285 | */ | |
2286 | int min_free_kbytes_sysctl_handler(ctl_table *table, int write, | |
2287 | struct file *file, void __user *buffer, size_t *length, loff_t *ppos) | |
2288 | { | |
2289 | proc_dointvec(table, write, file, buffer, length, ppos); | |
2290 | setup_per_zone_pages_min(); | |
2291 | return 0; | |
2292 | } | |
2293 | ||
2294 | #ifdef CONFIG_NUMA | |
2295 | int sysctl_min_unmapped_ratio_sysctl_handler(ctl_table *table, int write, | |
2296 | struct file *file, void __user *buffer, size_t *length, loff_t *ppos) | |
2297 | { | |
2298 | struct zone *zone; | |
2299 | int rc; | |
2300 | ||
2301 | rc = proc_dointvec_minmax(table, write, file, buffer, length, ppos); | |
2302 | if (rc) | |
2303 | return rc; | |
2304 | ||
2305 | for_each_zone(zone) | |
2306 | zone->min_unmapped_ratio = (zone->present_pages * | |
2307 | sysctl_min_unmapped_ratio) / 100; | |
2308 | return 0; | |
2309 | } | |
2310 | #endif | |
2311 | ||
2312 | /* | |
2313 | * lowmem_reserve_ratio_sysctl_handler - just a wrapper around | |
2314 | * proc_dointvec() so that we can call setup_per_zone_lowmem_reserve() | |
2315 | * whenever sysctl_lowmem_reserve_ratio changes. | |
2316 | * | |
2317 | * The reserve ratio obviously has absolutely no relation with the | |
2318 | * pages_min watermarks. The lowmem reserve ratio can only make sense | |
2319 | * if in function of the boot time zone sizes. | |
2320 | */ | |
2321 | int lowmem_reserve_ratio_sysctl_handler(ctl_table *table, int write, | |
2322 | struct file *file, void __user *buffer, size_t *length, loff_t *ppos) | |
2323 | { | |
2324 | proc_dointvec_minmax(table, write, file, buffer, length, ppos); | |
2325 | setup_per_zone_lowmem_reserve(); | |
2326 | return 0; | |
2327 | } | |
2328 | ||
2329 | /* | |
2330 | * percpu_pagelist_fraction - changes the pcp->high for each zone on each | |
2331 | * cpu. It is the fraction of total pages in each zone that a hot per cpu pagelist | |
2332 | * can have before it gets flushed back to buddy allocator. | |
2333 | */ | |
2334 | ||
2335 | int percpu_pagelist_fraction_sysctl_handler(ctl_table *table, int write, | |
2336 | struct file *file, void __user *buffer, size_t *length, loff_t *ppos) | |
2337 | { | |
2338 | struct zone *zone; | |
2339 | unsigned int cpu; | |
2340 | int ret; | |
2341 | ||
2342 | ret = proc_dointvec_minmax(table, write, file, buffer, length, ppos); | |
2343 | if (!write || (ret == -EINVAL)) | |
2344 | return ret; | |
2345 | for_each_zone(zone) { | |
2346 | for_each_online_cpu(cpu) { | |
2347 | unsigned long high; | |
2348 | high = zone->present_pages / percpu_pagelist_fraction; | |
2349 | setup_pagelist_highmark(zone_pcp(zone, cpu), high); | |
2350 | } | |
2351 | } | |
2352 | return 0; | |
2353 | } | |
2354 | ||
2355 | int hashdist = HASHDIST_DEFAULT; | |
2356 | ||
2357 | #ifdef CONFIG_NUMA | |
2358 | static int __init set_hashdist(char *str) | |
2359 | { | |
2360 | if (!str) | |
2361 | return 0; | |
2362 | hashdist = simple_strtoul(str, &str, 0); | |
2363 | return 1; | |
2364 | } | |
2365 | __setup("hashdist=", set_hashdist); | |
2366 | #endif | |
2367 | ||
2368 | /* | |
2369 | * allocate a large system hash table from bootmem | |
2370 | * - it is assumed that the hash table must contain an exact power-of-2 | |
2371 | * quantity of entries | |
2372 | * - limit is the number of hash buckets, not the total allocation size | |
2373 | */ | |
2374 | void *__init alloc_large_system_hash(const char *tablename, | |
2375 | unsigned long bucketsize, | |
2376 | unsigned long numentries, | |
2377 | int scale, | |
2378 | int flags, | |
2379 | unsigned int *_hash_shift, | |
2380 | unsigned int *_hash_mask, | |
2381 | unsigned long limit) | |
2382 | { | |
2383 | unsigned long long max = limit; | |
2384 | unsigned long log2qty, size; | |
2385 | void *table = NULL; | |
2386 | ||
2387 | /* allow the kernel cmdline to have a say */ | |
2388 | if (!numentries) { | |
2389 | /* round applicable memory size up to nearest megabyte */ | |
2390 | numentries = (flags & HASH_HIGHMEM) ? nr_all_pages : nr_kernel_pages; | |
2391 | numentries += (1UL << (20 - PAGE_SHIFT)) - 1; | |
2392 | numentries >>= 20 - PAGE_SHIFT; | |
2393 | numentries <<= 20 - PAGE_SHIFT; | |
2394 | ||
2395 | /* limit to 1 bucket per 2^scale bytes of low memory */ | |
2396 | if (scale > PAGE_SHIFT) | |
2397 | numentries >>= (scale - PAGE_SHIFT); | |
2398 | else | |
2399 | numentries <<= (PAGE_SHIFT - scale); | |
2400 | } | |
2401 | numentries = roundup_pow_of_two(numentries); | |
2402 | ||
2403 | /* limit allocation size to 1/16 total memory by default */ | |
2404 | if (max == 0) { | |
2405 | max = ((unsigned long long)nr_all_pages << PAGE_SHIFT) >> 4; | |
2406 | do_div(max, bucketsize); | |
2407 | } | |
2408 | ||
2409 | if (numentries > max) | |
2410 | numentries = max; | |
2411 | ||
2412 | log2qty = long_log2(numentries); | |
2413 | ||
2414 | do { | |
2415 | size = bucketsize << log2qty; | |
2416 | if (flags & HASH_EARLY) | |
2417 | table = alloc_bootmem(size); | |
2418 | else if (hashdist) | |
2419 | table = __vmalloc(size, GFP_ATOMIC, PAGE_KERNEL); | |
2420 | else { | |
2421 | unsigned long order; | |
2422 | for (order = 0; ((1UL << order) << PAGE_SHIFT) < size; order++) | |
2423 | ; | |
2424 | table = (void*) __get_free_pages(GFP_ATOMIC, order); | |
2425 | } | |
2426 | } while (!table && size > PAGE_SIZE && --log2qty); | |
2427 | ||
2428 | if (!table) | |
2429 | panic("Failed to allocate %s hash table\n", tablename); | |
2430 | ||
2431 | printk("%s hash table entries: %d (order: %d, %lu bytes)\n", | |
2432 | tablename, | |
2433 | (1U << log2qty), | |
2434 | long_log2(size) - PAGE_SHIFT, | |
2435 | size); | |
2436 | ||
2437 | if (_hash_shift) | |
2438 | *_hash_shift = log2qty; | |
2439 | if (_hash_mask) | |
2440 | *_hash_mask = (1 << log2qty) - 1; | |
2441 | ||
2442 | return table; | |
2443 | } | |
2444 | ||
2445 | #ifdef CONFIG_OUT_OF_LINE_PFN_TO_PAGE | |
2446 | struct page *pfn_to_page(unsigned long pfn) | |
2447 | { | |
2448 | return __pfn_to_page(pfn); | |
2449 | } | |
2450 | unsigned long page_to_pfn(struct page *page) | |
2451 | { | |
2452 | return __page_to_pfn(page); | |
2453 | } | |
2454 | EXPORT_SYMBOL(pfn_to_page); | |
2455 | EXPORT_SYMBOL(page_to_pfn); | |
2456 | #endif /* CONFIG_OUT_OF_LINE_PFN_TO_PAGE */ |