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1da177e4 LT |
1 | /* |
2 | * linux/mm/swap.c | |
3 | * | |
4 | * Copyright (C) 1991, 1992, 1993, 1994 Linus Torvalds | |
5 | */ | |
6 | ||
7 | /* | |
183ff22b | 8 | * This file contains the default values for the operation of the |
1da177e4 LT |
9 | * Linux VM subsystem. Fine-tuning documentation can be found in |
10 | * Documentation/sysctl/vm.txt. | |
11 | * Started 18.12.91 | |
12 | * Swap aging added 23.2.95, Stephen Tweedie. | |
13 | * Buffermem limits added 12.3.98, Rik van Riel. | |
14 | */ | |
15 | ||
16 | #include <linux/mm.h> | |
17 | #include <linux/sched.h> | |
18 | #include <linux/kernel_stat.h> | |
19 | #include <linux/swap.h> | |
20 | #include <linux/mman.h> | |
21 | #include <linux/pagemap.h> | |
22 | #include <linux/pagevec.h> | |
23 | #include <linux/init.h> | |
24 | #include <linux/module.h> | |
25 | #include <linux/mm_inline.h> | |
26 | #include <linux/buffer_head.h> /* for try_to_release_page() */ | |
1da177e4 LT |
27 | #include <linux/percpu_counter.h> |
28 | #include <linux/percpu.h> | |
29 | #include <linux/cpu.h> | |
30 | #include <linux/notifier.h> | |
e0bf68dd | 31 | #include <linux/backing-dev.h> |
66e1707b | 32 | #include <linux/memcontrol.h> |
1da177e4 LT |
33 | |
34 | /* How many pages do we try to swap or page in/out together? */ | |
35 | int page_cluster; | |
36 | ||
f04e9ebb | 37 | static DEFINE_PER_CPU(struct pagevec[NR_LRU_LISTS], lru_add_pvecs); |
f84f9504 | 38 | static DEFINE_PER_CPU(struct pagevec, lru_rotate_pvecs); |
902aaed0 | 39 | |
b221385b AB |
40 | /* |
41 | * This path almost never happens for VM activity - pages are normally | |
42 | * freed via pagevecs. But it gets used by networking. | |
43 | */ | |
920c7a5d | 44 | static void __page_cache_release(struct page *page) |
b221385b AB |
45 | { |
46 | if (PageLRU(page)) { | |
47 | unsigned long flags; | |
48 | struct zone *zone = page_zone(page); | |
49 | ||
50 | spin_lock_irqsave(&zone->lru_lock, flags); | |
51 | VM_BUG_ON(!PageLRU(page)); | |
52 | __ClearPageLRU(page); | |
53 | del_page_from_lru(zone, page); | |
54 | spin_unlock_irqrestore(&zone->lru_lock, flags); | |
55 | } | |
56 | free_hot_page(page); | |
57 | } | |
58 | ||
8519fb30 | 59 | static void put_compound_page(struct page *page) |
1da177e4 | 60 | { |
d85f3385 | 61 | page = compound_head(page); |
8519fb30 | 62 | if (put_page_testzero(page)) { |
33f2ef89 | 63 | compound_page_dtor *dtor; |
1da177e4 | 64 | |
33f2ef89 | 65 | dtor = get_compound_page_dtor(page); |
8519fb30 | 66 | (*dtor)(page); |
1da177e4 | 67 | } |
8519fb30 NP |
68 | } |
69 | ||
70 | void put_page(struct page *page) | |
71 | { | |
72 | if (unlikely(PageCompound(page))) | |
73 | put_compound_page(page); | |
74 | else if (put_page_testzero(page)) | |
1da177e4 LT |
75 | __page_cache_release(page); |
76 | } | |
77 | EXPORT_SYMBOL(put_page); | |
1da177e4 | 78 | |
1d7ea732 | 79 | /** |
7682486b RD |
80 | * put_pages_list() - release a list of pages |
81 | * @pages: list of pages threaded on page->lru | |
1d7ea732 AZ |
82 | * |
83 | * Release a list of pages which are strung together on page.lru. Currently | |
84 | * used by read_cache_pages() and related error recovery code. | |
1d7ea732 AZ |
85 | */ |
86 | void put_pages_list(struct list_head *pages) | |
87 | { | |
88 | while (!list_empty(pages)) { | |
89 | struct page *victim; | |
90 | ||
91 | victim = list_entry(pages->prev, struct page, lru); | |
92 | list_del(&victim->lru); | |
93 | page_cache_release(victim); | |
94 | } | |
95 | } | |
96 | EXPORT_SYMBOL(put_pages_list); | |
97 | ||
902aaed0 HH |
98 | /* |
99 | * pagevec_move_tail() must be called with IRQ disabled. | |
100 | * Otherwise this may cause nasty races. | |
101 | */ | |
102 | static void pagevec_move_tail(struct pagevec *pvec) | |
103 | { | |
104 | int i; | |
105 | int pgmoved = 0; | |
106 | struct zone *zone = NULL; | |
107 | ||
108 | for (i = 0; i < pagevec_count(pvec); i++) { | |
109 | struct page *page = pvec->pages[i]; | |
110 | struct zone *pagezone = page_zone(page); | |
111 | ||
112 | if (pagezone != zone) { | |
113 | if (zone) | |
114 | spin_unlock(&zone->lru_lock); | |
115 | zone = pagezone; | |
116 | spin_lock(&zone->lru_lock); | |
117 | } | |
894bc310 | 118 | if (PageLRU(page) && !PageActive(page) && !PageUnevictable(page)) { |
4f98a2fe RR |
119 | int lru = page_is_file_cache(page); |
120 | list_move_tail(&page->lru, &zone->lru[lru].list); | |
902aaed0 HH |
121 | pgmoved++; |
122 | } | |
123 | } | |
124 | if (zone) | |
125 | spin_unlock(&zone->lru_lock); | |
126 | __count_vm_events(PGROTATED, pgmoved); | |
127 | release_pages(pvec->pages, pvec->nr, pvec->cold); | |
128 | pagevec_reinit(pvec); | |
129 | } | |
130 | ||
1da177e4 LT |
131 | /* |
132 | * Writeback is about to end against a page which has been marked for immediate | |
133 | * reclaim. If it still appears to be reclaimable, move it to the tail of the | |
902aaed0 | 134 | * inactive list. |
1da177e4 | 135 | */ |
ac6aadb2 | 136 | void rotate_reclaimable_page(struct page *page) |
1da177e4 | 137 | { |
ac6aadb2 | 138 | if (!PageLocked(page) && !PageDirty(page) && !PageActive(page) && |
894bc310 | 139 | !PageUnevictable(page) && PageLRU(page)) { |
ac6aadb2 MS |
140 | struct pagevec *pvec; |
141 | unsigned long flags; | |
142 | ||
143 | page_cache_get(page); | |
144 | local_irq_save(flags); | |
145 | pvec = &__get_cpu_var(lru_rotate_pvecs); | |
146 | if (!pagevec_add(pvec, page)) | |
147 | pagevec_move_tail(pvec); | |
148 | local_irq_restore(flags); | |
149 | } | |
1da177e4 LT |
150 | } |
151 | ||
152 | /* | |
153 | * FIXME: speed this up? | |
154 | */ | |
920c7a5d | 155 | void activate_page(struct page *page) |
1da177e4 LT |
156 | { |
157 | struct zone *zone = page_zone(page); | |
158 | ||
159 | spin_lock_irq(&zone->lru_lock); | |
894bc310 | 160 | if (PageLRU(page) && !PageActive(page) && !PageUnevictable(page)) { |
4f98a2fe RR |
161 | int file = page_is_file_cache(page); |
162 | int lru = LRU_BASE + file; | |
163 | del_page_from_lru_list(zone, page, lru); | |
164 | ||
1da177e4 | 165 | SetPageActive(page); |
4f98a2fe RR |
166 | lru += LRU_ACTIVE; |
167 | add_page_to_lru_list(zone, page, lru); | |
f8891e5e | 168 | __count_vm_event(PGACTIVATE); |
894bc310 | 169 | mem_cgroup_move_lists(page, lru); |
4f98a2fe RR |
170 | |
171 | zone->recent_rotated[!!file]++; | |
172 | zone->recent_scanned[!!file]++; | |
1da177e4 LT |
173 | } |
174 | spin_unlock_irq(&zone->lru_lock); | |
175 | } | |
176 | ||
177 | /* | |
178 | * Mark a page as having seen activity. | |
179 | * | |
180 | * inactive,unreferenced -> inactive,referenced | |
181 | * inactive,referenced -> active,unreferenced | |
182 | * active,unreferenced -> active,referenced | |
183 | */ | |
920c7a5d | 184 | void mark_page_accessed(struct page *page) |
1da177e4 | 185 | { |
894bc310 LS |
186 | if (!PageActive(page) && !PageUnevictable(page) && |
187 | PageReferenced(page) && PageLRU(page)) { | |
1da177e4 LT |
188 | activate_page(page); |
189 | ClearPageReferenced(page); | |
190 | } else if (!PageReferenced(page)) { | |
191 | SetPageReferenced(page); | |
192 | } | |
193 | } | |
194 | ||
195 | EXPORT_SYMBOL(mark_page_accessed); | |
196 | ||
f04e9ebb | 197 | void __lru_cache_add(struct page *page, enum lru_list lru) |
1da177e4 | 198 | { |
f04e9ebb | 199 | struct pagevec *pvec = &get_cpu_var(lru_add_pvecs)[lru]; |
1da177e4 LT |
200 | |
201 | page_cache_get(page); | |
202 | if (!pagevec_add(pvec, page)) | |
f04e9ebb | 203 | ____pagevec_lru_add(pvec, lru); |
1da177e4 LT |
204 | put_cpu_var(lru_add_pvecs); |
205 | } | |
206 | ||
f04e9ebb KM |
207 | /** |
208 | * lru_cache_add_lru - add a page to a page list | |
209 | * @page: the page to be added to the LRU. | |
210 | * @lru: the LRU list to which the page is added. | |
211 | */ | |
212 | void lru_cache_add_lru(struct page *page, enum lru_list lru) | |
1da177e4 | 213 | { |
f04e9ebb | 214 | if (PageActive(page)) { |
894bc310 | 215 | VM_BUG_ON(PageUnevictable(page)); |
f04e9ebb | 216 | ClearPageActive(page); |
894bc310 LS |
217 | } else if (PageUnevictable(page)) { |
218 | VM_BUG_ON(PageActive(page)); | |
219 | ClearPageUnevictable(page); | |
f04e9ebb | 220 | } |
1da177e4 | 221 | |
894bc310 | 222 | VM_BUG_ON(PageLRU(page) || PageActive(page) || PageUnevictable(page)); |
f04e9ebb | 223 | __lru_cache_add(page, lru); |
1da177e4 LT |
224 | } |
225 | ||
894bc310 LS |
226 | /** |
227 | * add_page_to_unevictable_list - add a page to the unevictable list | |
228 | * @page: the page to be added to the unevictable list | |
229 | * | |
230 | * Add page directly to its zone's unevictable list. To avoid races with | |
231 | * tasks that might be making the page evictable, through eg. munlock, | |
232 | * munmap or exit, while it's not on the lru, we want to add the page | |
233 | * while it's locked or otherwise "invisible" to other tasks. This is | |
234 | * difficult to do when using the pagevec cache, so bypass that. | |
235 | */ | |
236 | void add_page_to_unevictable_list(struct page *page) | |
237 | { | |
238 | struct zone *zone = page_zone(page); | |
239 | ||
240 | spin_lock_irq(&zone->lru_lock); | |
241 | SetPageUnevictable(page); | |
242 | SetPageLRU(page); | |
243 | add_page_to_lru_list(zone, page, LRU_UNEVICTABLE); | |
244 | spin_unlock_irq(&zone->lru_lock); | |
245 | } | |
246 | ||
902aaed0 HH |
247 | /* |
248 | * Drain pages out of the cpu's pagevecs. | |
249 | * Either "cpu" is the current CPU, and preemption has already been | |
250 | * disabled; or "cpu" is being hot-unplugged, and is already dead. | |
251 | */ | |
252 | static void drain_cpu_pagevecs(int cpu) | |
1da177e4 | 253 | { |
f04e9ebb | 254 | struct pagevec *pvecs = per_cpu(lru_add_pvecs, cpu); |
902aaed0 | 255 | struct pagevec *pvec; |
f04e9ebb | 256 | int lru; |
1da177e4 | 257 | |
f04e9ebb KM |
258 | for_each_lru(lru) { |
259 | pvec = &pvecs[lru - LRU_BASE]; | |
260 | if (pagevec_count(pvec)) | |
261 | ____pagevec_lru_add(pvec, lru); | |
262 | } | |
902aaed0 HH |
263 | |
264 | pvec = &per_cpu(lru_rotate_pvecs, cpu); | |
265 | if (pagevec_count(pvec)) { | |
266 | unsigned long flags; | |
267 | ||
268 | /* No harm done if a racing interrupt already did this */ | |
269 | local_irq_save(flags); | |
270 | pagevec_move_tail(pvec); | |
271 | local_irq_restore(flags); | |
272 | } | |
80bfed90 AM |
273 | } |
274 | ||
275 | void lru_add_drain(void) | |
276 | { | |
902aaed0 | 277 | drain_cpu_pagevecs(get_cpu()); |
80bfed90 | 278 | put_cpu(); |
1da177e4 LT |
279 | } |
280 | ||
b291f000 | 281 | #if defined(CONFIG_NUMA) || defined(CONFIG_UNEVICTABLE_LRU) |
c4028958 | 282 | static void lru_add_drain_per_cpu(struct work_struct *dummy) |
053837fc NP |
283 | { |
284 | lru_add_drain(); | |
285 | } | |
286 | ||
287 | /* | |
288 | * Returns 0 for success | |
289 | */ | |
290 | int lru_add_drain_all(void) | |
291 | { | |
c4028958 | 292 | return schedule_on_each_cpu(lru_add_drain_per_cpu); |
053837fc NP |
293 | } |
294 | ||
295 | #else | |
296 | ||
297 | /* | |
298 | * Returns 0 for success | |
299 | */ | |
300 | int lru_add_drain_all(void) | |
301 | { | |
302 | lru_add_drain(); | |
303 | return 0; | |
304 | } | |
305 | #endif | |
306 | ||
1da177e4 LT |
307 | /* |
308 | * Batched page_cache_release(). Decrement the reference count on all the | |
309 | * passed pages. If it fell to zero then remove the page from the LRU and | |
310 | * free it. | |
311 | * | |
312 | * Avoid taking zone->lru_lock if possible, but if it is taken, retain it | |
313 | * for the remainder of the operation. | |
314 | * | |
ab33dc09 FLVC |
315 | * The locking in this function is against shrink_inactive_list(): we recheck |
316 | * the page count inside the lock to see whether shrink_inactive_list() | |
317 | * grabbed the page via the LRU. If it did, give up: shrink_inactive_list() | |
318 | * will free it. | |
1da177e4 LT |
319 | */ |
320 | void release_pages(struct page **pages, int nr, int cold) | |
321 | { | |
322 | int i; | |
323 | struct pagevec pages_to_free; | |
324 | struct zone *zone = NULL; | |
902aaed0 | 325 | unsigned long uninitialized_var(flags); |
1da177e4 LT |
326 | |
327 | pagevec_init(&pages_to_free, cold); | |
328 | for (i = 0; i < nr; i++) { | |
329 | struct page *page = pages[i]; | |
1da177e4 | 330 | |
8519fb30 NP |
331 | if (unlikely(PageCompound(page))) { |
332 | if (zone) { | |
902aaed0 | 333 | spin_unlock_irqrestore(&zone->lru_lock, flags); |
8519fb30 NP |
334 | zone = NULL; |
335 | } | |
336 | put_compound_page(page); | |
337 | continue; | |
338 | } | |
339 | ||
b5810039 | 340 | if (!put_page_testzero(page)) |
1da177e4 LT |
341 | continue; |
342 | ||
46453a6e NP |
343 | if (PageLRU(page)) { |
344 | struct zone *pagezone = page_zone(page); | |
894bc310 | 345 | |
46453a6e NP |
346 | if (pagezone != zone) { |
347 | if (zone) | |
902aaed0 HH |
348 | spin_unlock_irqrestore(&zone->lru_lock, |
349 | flags); | |
46453a6e | 350 | zone = pagezone; |
902aaed0 | 351 | spin_lock_irqsave(&zone->lru_lock, flags); |
46453a6e | 352 | } |
725d704e | 353 | VM_BUG_ON(!PageLRU(page)); |
67453911 | 354 | __ClearPageLRU(page); |
1da177e4 | 355 | del_page_from_lru(zone, page); |
46453a6e NP |
356 | } |
357 | ||
358 | if (!pagevec_add(&pages_to_free, page)) { | |
359 | if (zone) { | |
902aaed0 | 360 | spin_unlock_irqrestore(&zone->lru_lock, flags); |
46453a6e | 361 | zone = NULL; |
1da177e4 | 362 | } |
46453a6e NP |
363 | __pagevec_free(&pages_to_free); |
364 | pagevec_reinit(&pages_to_free); | |
365 | } | |
1da177e4 LT |
366 | } |
367 | if (zone) | |
902aaed0 | 368 | spin_unlock_irqrestore(&zone->lru_lock, flags); |
1da177e4 LT |
369 | |
370 | pagevec_free(&pages_to_free); | |
371 | } | |
372 | ||
373 | /* | |
374 | * The pages which we're about to release may be in the deferred lru-addition | |
375 | * queues. That would prevent them from really being freed right now. That's | |
376 | * OK from a correctness point of view but is inefficient - those pages may be | |
377 | * cache-warm and we want to give them back to the page allocator ASAP. | |
378 | * | |
379 | * So __pagevec_release() will drain those queues here. __pagevec_lru_add() | |
380 | * and __pagevec_lru_add_active() call release_pages() directly to avoid | |
381 | * mutual recursion. | |
382 | */ | |
383 | void __pagevec_release(struct pagevec *pvec) | |
384 | { | |
385 | lru_add_drain(); | |
386 | release_pages(pvec->pages, pagevec_count(pvec), pvec->cold); | |
387 | pagevec_reinit(pvec); | |
388 | } | |
389 | ||
7f285701 SF |
390 | EXPORT_SYMBOL(__pagevec_release); |
391 | ||
1da177e4 LT |
392 | /* |
393 | * pagevec_release() for pages which are known to not be on the LRU | |
394 | * | |
395 | * This function reinitialises the caller's pagevec. | |
396 | */ | |
397 | void __pagevec_release_nonlru(struct pagevec *pvec) | |
398 | { | |
399 | int i; | |
400 | struct pagevec pages_to_free; | |
401 | ||
402 | pagevec_init(&pages_to_free, pvec->cold); | |
1da177e4 LT |
403 | for (i = 0; i < pagevec_count(pvec); i++) { |
404 | struct page *page = pvec->pages[i]; | |
405 | ||
725d704e | 406 | VM_BUG_ON(PageLRU(page)); |
1da177e4 LT |
407 | if (put_page_testzero(page)) |
408 | pagevec_add(&pages_to_free, page); | |
409 | } | |
410 | pagevec_free(&pages_to_free); | |
411 | pagevec_reinit(pvec); | |
412 | } | |
413 | ||
414 | /* | |
415 | * Add the passed pages to the LRU, then drop the caller's refcount | |
416 | * on them. Reinitialises the caller's pagevec. | |
417 | */ | |
f04e9ebb | 418 | void ____pagevec_lru_add(struct pagevec *pvec, enum lru_list lru) |
1da177e4 LT |
419 | { |
420 | int i; | |
421 | struct zone *zone = NULL; | |
894bc310 | 422 | VM_BUG_ON(is_unevictable_lru(lru)); |
1da177e4 LT |
423 | |
424 | for (i = 0; i < pagevec_count(pvec); i++) { | |
425 | struct page *page = pvec->pages[i]; | |
426 | struct zone *pagezone = page_zone(page); | |
427 | ||
428 | if (pagezone != zone) { | |
429 | if (zone) | |
430 | spin_unlock_irq(&zone->lru_lock); | |
431 | zone = pagezone; | |
432 | spin_lock_irq(&zone->lru_lock); | |
433 | } | |
894bc310 LS |
434 | VM_BUG_ON(PageActive(page)); |
435 | VM_BUG_ON(PageUnevictable(page)); | |
725d704e | 436 | VM_BUG_ON(PageLRU(page)); |
8d438f96 | 437 | SetPageLRU(page); |
f04e9ebb KM |
438 | if (is_active_lru(lru)) |
439 | SetPageActive(page); | |
440 | add_page_to_lru_list(zone, page, lru); | |
1da177e4 LT |
441 | } |
442 | if (zone) | |
443 | spin_unlock_irq(&zone->lru_lock); | |
444 | release_pages(pvec->pages, pvec->nr, pvec->cold); | |
445 | pagevec_reinit(pvec); | |
446 | } | |
447 | ||
f04e9ebb | 448 | EXPORT_SYMBOL(____pagevec_lru_add); |
1da177e4 LT |
449 | |
450 | /* | |
451 | * Try to drop buffers from the pages in a pagevec | |
452 | */ | |
453 | void pagevec_strip(struct pagevec *pvec) | |
454 | { | |
455 | int i; | |
456 | ||
457 | for (i = 0; i < pagevec_count(pvec); i++) { | |
458 | struct page *page = pvec->pages[i]; | |
459 | ||
529ae9aa | 460 | if (PagePrivate(page) && trylock_page(page)) { |
5b40dc78 CL |
461 | if (PagePrivate(page)) |
462 | try_to_release_page(page, 0); | |
1da177e4 LT |
463 | unlock_page(page); |
464 | } | |
465 | } | |
466 | } | |
467 | ||
68a22394 RR |
468 | /** |
469 | * pagevec_swap_free - try to free swap space from the pages in a pagevec | |
470 | * @pvec: pagevec with swapcache pages to free the swap space of | |
471 | * | |
472 | * The caller needs to hold an extra reference to each page and | |
473 | * not hold the page lock on the pages. This function uses a | |
474 | * trylock on the page lock so it may not always free the swap | |
475 | * space associated with a page. | |
476 | */ | |
477 | void pagevec_swap_free(struct pagevec *pvec) | |
478 | { | |
479 | int i; | |
480 | ||
481 | for (i = 0; i < pagevec_count(pvec); i++) { | |
482 | struct page *page = pvec->pages[i]; | |
483 | ||
484 | if (PageSwapCache(page) && trylock_page(page)) { | |
485 | if (PageSwapCache(page)) | |
486 | remove_exclusive_swap_page_ref(page); | |
487 | unlock_page(page); | |
488 | } | |
489 | } | |
490 | } | |
491 | ||
1da177e4 LT |
492 | /** |
493 | * pagevec_lookup - gang pagecache lookup | |
494 | * @pvec: Where the resulting pages are placed | |
495 | * @mapping: The address_space to search | |
496 | * @start: The starting page index | |
497 | * @nr_pages: The maximum number of pages | |
498 | * | |
499 | * pagevec_lookup() will search for and return a group of up to @nr_pages pages | |
500 | * in the mapping. The pages are placed in @pvec. pagevec_lookup() takes a | |
501 | * reference against the pages in @pvec. | |
502 | * | |
503 | * The search returns a group of mapping-contiguous pages with ascending | |
504 | * indexes. There may be holes in the indices due to not-present pages. | |
505 | * | |
506 | * pagevec_lookup() returns the number of pages which were found. | |
507 | */ | |
508 | unsigned pagevec_lookup(struct pagevec *pvec, struct address_space *mapping, | |
509 | pgoff_t start, unsigned nr_pages) | |
510 | { | |
511 | pvec->nr = find_get_pages(mapping, start, nr_pages, pvec->pages); | |
512 | return pagevec_count(pvec); | |
513 | } | |
514 | ||
78539fdf CH |
515 | EXPORT_SYMBOL(pagevec_lookup); |
516 | ||
1da177e4 LT |
517 | unsigned pagevec_lookup_tag(struct pagevec *pvec, struct address_space *mapping, |
518 | pgoff_t *index, int tag, unsigned nr_pages) | |
519 | { | |
520 | pvec->nr = find_get_pages_tag(mapping, index, tag, | |
521 | nr_pages, pvec->pages); | |
522 | return pagevec_count(pvec); | |
523 | } | |
524 | ||
7f285701 | 525 | EXPORT_SYMBOL(pagevec_lookup_tag); |
1da177e4 LT |
526 | |
527 | #ifdef CONFIG_SMP | |
528 | /* | |
529 | * We tolerate a little inaccuracy to avoid ping-ponging the counter between | |
530 | * CPUs | |
531 | */ | |
532 | #define ACCT_THRESHOLD max(16, NR_CPUS * 2) | |
533 | ||
f84f9504 | 534 | static DEFINE_PER_CPU(long, committed_space); |
1da177e4 LT |
535 | |
536 | void vm_acct_memory(long pages) | |
537 | { | |
538 | long *local; | |
539 | ||
540 | preempt_disable(); | |
541 | local = &__get_cpu_var(committed_space); | |
542 | *local += pages; | |
543 | if (*local > ACCT_THRESHOLD || *local < -ACCT_THRESHOLD) { | |
80119ef5 | 544 | atomic_long_add(*local, &vm_committed_space); |
1da177e4 LT |
545 | *local = 0; |
546 | } | |
547 | preempt_enable(); | |
548 | } | |
1da177e4 LT |
549 | |
550 | #ifdef CONFIG_HOTPLUG_CPU | |
1da177e4 LT |
551 | |
552 | /* Drop the CPU's cached committed space back into the central pool. */ | |
553 | static int cpu_swap_callback(struct notifier_block *nfb, | |
554 | unsigned long action, | |
555 | void *hcpu) | |
556 | { | |
557 | long *committed; | |
558 | ||
559 | committed = &per_cpu(committed_space, (long)hcpu); | |
8bb78442 | 560 | if (action == CPU_DEAD || action == CPU_DEAD_FROZEN) { |
80119ef5 | 561 | atomic_long_add(*committed, &vm_committed_space); |
1da177e4 | 562 | *committed = 0; |
902aaed0 | 563 | drain_cpu_pagevecs((long)hcpu); |
1da177e4 LT |
564 | } |
565 | return NOTIFY_OK; | |
566 | } | |
567 | #endif /* CONFIG_HOTPLUG_CPU */ | |
568 | #endif /* CONFIG_SMP */ | |
569 | ||
1da177e4 LT |
570 | /* |
571 | * Perform any setup for the swap system | |
572 | */ | |
573 | void __init swap_setup(void) | |
574 | { | |
575 | unsigned long megs = num_physpages >> (20 - PAGE_SHIFT); | |
576 | ||
e0bf68dd PZ |
577 | #ifdef CONFIG_SWAP |
578 | bdi_init(swapper_space.backing_dev_info); | |
579 | #endif | |
580 | ||
1da177e4 LT |
581 | /* Use a smaller cluster for small-memory machines */ |
582 | if (megs < 16) | |
583 | page_cluster = 2; | |
584 | else | |
585 | page_cluster = 3; | |
586 | /* | |
587 | * Right now other parts of the system means that we | |
588 | * _really_ don't want to cluster much more | |
589 | */ | |
02316067 | 590 | #ifdef CONFIG_HOTPLUG_CPU |
1da177e4 | 591 | hotcpu_notifier(cpu_swap_callback, 0); |
02316067 | 592 | #endif |
1da177e4 | 593 | } |