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Commit | Line | Data |
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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> | |
b95f1b31 | 24 | #include <linux/export.h> |
1da177e4 LT |
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> |
5a0e3ad6 | 33 | #include <linux/gfp.h> |
1da177e4 | 34 | |
64d6519d LS |
35 | #include "internal.h" |
36 | ||
1da177e4 LT |
37 | /* How many pages do we try to swap or page in/out together? */ |
38 | int page_cluster; | |
39 | ||
f04e9ebb | 40 | static DEFINE_PER_CPU(struct pagevec[NR_LRU_LISTS], lru_add_pvecs); |
f84f9504 | 41 | static DEFINE_PER_CPU(struct pagevec, lru_rotate_pvecs); |
31560180 | 42 | static DEFINE_PER_CPU(struct pagevec, lru_deactivate_pvecs); |
902aaed0 | 43 | |
b221385b AB |
44 | /* |
45 | * This path almost never happens for VM activity - pages are normally | |
46 | * freed via pagevecs. But it gets used by networking. | |
47 | */ | |
920c7a5d | 48 | static void __page_cache_release(struct page *page) |
b221385b AB |
49 | { |
50 | if (PageLRU(page)) { | |
51 | unsigned long flags; | |
52 | struct zone *zone = page_zone(page); | |
53 | ||
54 | spin_lock_irqsave(&zone->lru_lock, flags); | |
55 | VM_BUG_ON(!PageLRU(page)); | |
56 | __ClearPageLRU(page); | |
57 | del_page_from_lru(zone, page); | |
58 | spin_unlock_irqrestore(&zone->lru_lock, flags); | |
59 | } | |
91807063 AA |
60 | } |
61 | ||
62 | static void __put_single_page(struct page *page) | |
63 | { | |
64 | __page_cache_release(page); | |
fc91668e | 65 | free_hot_cold_page(page, 0); |
b221385b AB |
66 | } |
67 | ||
91807063 | 68 | static void __put_compound_page(struct page *page) |
1da177e4 | 69 | { |
91807063 | 70 | compound_page_dtor *dtor; |
1da177e4 | 71 | |
91807063 AA |
72 | __page_cache_release(page); |
73 | dtor = get_compound_page_dtor(page); | |
74 | (*dtor)(page); | |
75 | } | |
76 | ||
77 | static void put_compound_page(struct page *page) | |
78 | { | |
79 | if (unlikely(PageTail(page))) { | |
80 | /* __split_huge_page_refcount can run under us */ | |
70b50f94 AA |
81 | struct page *page_head = compound_trans_head(page); |
82 | ||
83 | if (likely(page != page_head && | |
84 | get_page_unless_zero(page_head))) { | |
91807063 AA |
85 | unsigned long flags; |
86 | /* | |
70b50f94 AA |
87 | * page_head wasn't a dangling pointer but it |
88 | * may not be a head page anymore by the time | |
89 | * we obtain the lock. That is ok as long as it | |
90 | * can't be freed from under us. | |
91807063 | 91 | */ |
91807063 AA |
92 | flags = compound_lock_irqsave(page_head); |
93 | if (unlikely(!PageTail(page))) { | |
94 | /* __split_huge_page_refcount run before us */ | |
95 | compound_unlock_irqrestore(page_head, flags); | |
96 | VM_BUG_ON(PageHead(page_head)); | |
91807063 AA |
97 | if (put_page_testzero(page_head)) |
98 | __put_single_page(page_head); | |
99 | out_put_single: | |
100 | if (put_page_testzero(page)) | |
101 | __put_single_page(page); | |
102 | return; | |
103 | } | |
104 | VM_BUG_ON(page_head != page->first_page); | |
105 | /* | |
106 | * We can release the refcount taken by | |
70b50f94 AA |
107 | * get_page_unless_zero() now that |
108 | * __split_huge_page_refcount() is blocked on | |
109 | * the compound_lock. | |
91807063 AA |
110 | */ |
111 | if (put_page_testzero(page_head)) | |
112 | VM_BUG_ON(1); | |
113 | /* __split_huge_page_refcount will wait now */ | |
70b50f94 AA |
114 | VM_BUG_ON(page_mapcount(page) <= 0); |
115 | atomic_dec(&page->_mapcount); | |
91807063 | 116 | VM_BUG_ON(atomic_read(&page_head->_count) <= 0); |
70b50f94 | 117 | VM_BUG_ON(atomic_read(&page->_count) != 0); |
91807063 | 118 | compound_unlock_irqrestore(page_head, flags); |
a95a82e9 AA |
119 | if (put_page_testzero(page_head)) { |
120 | if (PageHead(page_head)) | |
121 | __put_compound_page(page_head); | |
122 | else | |
123 | __put_single_page(page_head); | |
124 | } | |
91807063 AA |
125 | } else { |
126 | /* page_head is a dangling pointer */ | |
127 | VM_BUG_ON(PageTail(page)); | |
128 | goto out_put_single; | |
129 | } | |
130 | } else if (put_page_testzero(page)) { | |
131 | if (PageHead(page)) | |
132 | __put_compound_page(page); | |
133 | else | |
134 | __put_single_page(page); | |
1da177e4 | 135 | } |
8519fb30 NP |
136 | } |
137 | ||
138 | void put_page(struct page *page) | |
139 | { | |
140 | if (unlikely(PageCompound(page))) | |
141 | put_compound_page(page); | |
142 | else if (put_page_testzero(page)) | |
91807063 | 143 | __put_single_page(page); |
1da177e4 LT |
144 | } |
145 | EXPORT_SYMBOL(put_page); | |
1da177e4 | 146 | |
70b50f94 AA |
147 | /* |
148 | * This function is exported but must not be called by anything other | |
149 | * than get_page(). It implements the slow path of get_page(). | |
150 | */ | |
151 | bool __get_page_tail(struct page *page) | |
152 | { | |
153 | /* | |
154 | * This takes care of get_page() if run on a tail page | |
155 | * returned by one of the get_user_pages/follow_page variants. | |
156 | * get_user_pages/follow_page itself doesn't need the compound | |
157 | * lock because it runs __get_page_tail_foll() under the | |
158 | * proper PT lock that already serializes against | |
159 | * split_huge_page(). | |
160 | */ | |
161 | unsigned long flags; | |
162 | bool got = false; | |
163 | struct page *page_head = compound_trans_head(page); | |
164 | ||
165 | if (likely(page != page_head && get_page_unless_zero(page_head))) { | |
166 | /* | |
167 | * page_head wasn't a dangling pointer but it | |
168 | * may not be a head page anymore by the time | |
169 | * we obtain the lock. That is ok as long as it | |
170 | * can't be freed from under us. | |
171 | */ | |
172 | flags = compound_lock_irqsave(page_head); | |
173 | /* here __split_huge_page_refcount won't run anymore */ | |
174 | if (likely(PageTail(page))) { | |
175 | __get_page_tail_foll(page, false); | |
176 | got = true; | |
177 | } | |
178 | compound_unlock_irqrestore(page_head, flags); | |
179 | if (unlikely(!got)) | |
180 | put_page(page_head); | |
181 | } | |
182 | return got; | |
183 | } | |
184 | EXPORT_SYMBOL(__get_page_tail); | |
185 | ||
1d7ea732 | 186 | /** |
7682486b RD |
187 | * put_pages_list() - release a list of pages |
188 | * @pages: list of pages threaded on page->lru | |
1d7ea732 AZ |
189 | * |
190 | * Release a list of pages which are strung together on page.lru. Currently | |
191 | * used by read_cache_pages() and related error recovery code. | |
1d7ea732 AZ |
192 | */ |
193 | void put_pages_list(struct list_head *pages) | |
194 | { | |
195 | while (!list_empty(pages)) { | |
196 | struct page *victim; | |
197 | ||
198 | victim = list_entry(pages->prev, struct page, lru); | |
199 | list_del(&victim->lru); | |
200 | page_cache_release(victim); | |
201 | } | |
202 | } | |
203 | EXPORT_SYMBOL(put_pages_list); | |
204 | ||
3dd7ae8e SL |
205 | static void pagevec_lru_move_fn(struct pagevec *pvec, |
206 | void (*move_fn)(struct page *page, void *arg), | |
207 | void *arg) | |
902aaed0 HH |
208 | { |
209 | int i; | |
902aaed0 | 210 | struct zone *zone = NULL; |
3dd7ae8e | 211 | unsigned long flags = 0; |
902aaed0 HH |
212 | |
213 | for (i = 0; i < pagevec_count(pvec); i++) { | |
214 | struct page *page = pvec->pages[i]; | |
215 | struct zone *pagezone = page_zone(page); | |
216 | ||
217 | if (pagezone != zone) { | |
218 | if (zone) | |
3dd7ae8e | 219 | spin_unlock_irqrestore(&zone->lru_lock, flags); |
902aaed0 | 220 | zone = pagezone; |
3dd7ae8e | 221 | spin_lock_irqsave(&zone->lru_lock, flags); |
902aaed0 | 222 | } |
3dd7ae8e SL |
223 | |
224 | (*move_fn)(page, arg); | |
902aaed0 HH |
225 | } |
226 | if (zone) | |
3dd7ae8e | 227 | spin_unlock_irqrestore(&zone->lru_lock, flags); |
83896fb5 LT |
228 | release_pages(pvec->pages, pvec->nr, pvec->cold); |
229 | pagevec_reinit(pvec); | |
d8505dee SL |
230 | } |
231 | ||
3dd7ae8e SL |
232 | static void pagevec_move_tail_fn(struct page *page, void *arg) |
233 | { | |
234 | int *pgmoved = arg; | |
3dd7ae8e SL |
235 | |
236 | if (PageLRU(page) && !PageActive(page) && !PageUnevictable(page)) { | |
237 | enum lru_list lru = page_lru_base_type(page); | |
925b7673 JW |
238 | struct lruvec *lruvec; |
239 | ||
240 | lruvec = mem_cgroup_lru_move_lists(page_zone(page), | |
241 | page, lru, lru); | |
242 | list_move_tail(&page->lru, &lruvec->lists[lru]); | |
3dd7ae8e SL |
243 | (*pgmoved)++; |
244 | } | |
245 | } | |
246 | ||
247 | /* | |
248 | * pagevec_move_tail() must be called with IRQ disabled. | |
249 | * Otherwise this may cause nasty races. | |
250 | */ | |
251 | static void pagevec_move_tail(struct pagevec *pvec) | |
252 | { | |
253 | int pgmoved = 0; | |
254 | ||
255 | pagevec_lru_move_fn(pvec, pagevec_move_tail_fn, &pgmoved); | |
256 | __count_vm_events(PGROTATED, pgmoved); | |
257 | } | |
258 | ||
1da177e4 LT |
259 | /* |
260 | * Writeback is about to end against a page which has been marked for immediate | |
261 | * reclaim. If it still appears to be reclaimable, move it to the tail of the | |
902aaed0 | 262 | * inactive list. |
1da177e4 | 263 | */ |
3dd7ae8e | 264 | void rotate_reclaimable_page(struct page *page) |
1da177e4 | 265 | { |
ac6aadb2 | 266 | if (!PageLocked(page) && !PageDirty(page) && !PageActive(page) && |
894bc310 | 267 | !PageUnevictable(page) && PageLRU(page)) { |
ac6aadb2 MS |
268 | struct pagevec *pvec; |
269 | unsigned long flags; | |
270 | ||
271 | page_cache_get(page); | |
272 | local_irq_save(flags); | |
273 | pvec = &__get_cpu_var(lru_rotate_pvecs); | |
274 | if (!pagevec_add(pvec, page)) | |
275 | pagevec_move_tail(pvec); | |
276 | local_irq_restore(flags); | |
277 | } | |
1da177e4 LT |
278 | } |
279 | ||
3e2f41f1 KM |
280 | static void update_page_reclaim_stat(struct zone *zone, struct page *page, |
281 | int file, int rotated) | |
282 | { | |
283 | struct zone_reclaim_stat *reclaim_stat = &zone->reclaim_stat; | |
284 | struct zone_reclaim_stat *memcg_reclaim_stat; | |
285 | ||
286 | memcg_reclaim_stat = mem_cgroup_get_reclaim_stat_from_page(page); | |
287 | ||
288 | reclaim_stat->recent_scanned[file]++; | |
289 | if (rotated) | |
290 | reclaim_stat->recent_rotated[file]++; | |
291 | ||
292 | if (!memcg_reclaim_stat) | |
293 | return; | |
294 | ||
295 | memcg_reclaim_stat->recent_scanned[file]++; | |
296 | if (rotated) | |
297 | memcg_reclaim_stat->recent_rotated[file]++; | |
298 | } | |
299 | ||
eb709b0d | 300 | static void __activate_page(struct page *page, void *arg) |
1da177e4 LT |
301 | { |
302 | struct zone *zone = page_zone(page); | |
744ed144 | 303 | |
744ed144 | 304 | if (PageLRU(page) && !PageActive(page) && !PageUnevictable(page)) { |
7a608572 LT |
305 | int file = page_is_file_cache(page); |
306 | int lru = page_lru_base_type(page); | |
307 | del_page_from_lru_list(zone, page, lru); | |
744ed144 | 308 | |
7a608572 LT |
309 | SetPageActive(page); |
310 | lru += LRU_ACTIVE; | |
311 | add_page_to_lru_list(zone, page, lru); | |
312 | __count_vm_event(PGACTIVATE); | |
4f98a2fe | 313 | |
7a608572 | 314 | update_page_reclaim_stat(zone, page, file, 1); |
1da177e4 | 315 | } |
eb709b0d SL |
316 | } |
317 | ||
318 | #ifdef CONFIG_SMP | |
319 | static DEFINE_PER_CPU(struct pagevec, activate_page_pvecs); | |
320 | ||
321 | static void activate_page_drain(int cpu) | |
322 | { | |
323 | struct pagevec *pvec = &per_cpu(activate_page_pvecs, cpu); | |
324 | ||
325 | if (pagevec_count(pvec)) | |
326 | pagevec_lru_move_fn(pvec, __activate_page, NULL); | |
327 | } | |
328 | ||
329 | void activate_page(struct page *page) | |
330 | { | |
331 | if (PageLRU(page) && !PageActive(page) && !PageUnevictable(page)) { | |
332 | struct pagevec *pvec = &get_cpu_var(activate_page_pvecs); | |
333 | ||
334 | page_cache_get(page); | |
335 | if (!pagevec_add(pvec, page)) | |
336 | pagevec_lru_move_fn(pvec, __activate_page, NULL); | |
337 | put_cpu_var(activate_page_pvecs); | |
338 | } | |
339 | } | |
340 | ||
341 | #else | |
342 | static inline void activate_page_drain(int cpu) | |
343 | { | |
344 | } | |
345 | ||
346 | void activate_page(struct page *page) | |
347 | { | |
348 | struct zone *zone = page_zone(page); | |
349 | ||
350 | spin_lock_irq(&zone->lru_lock); | |
351 | __activate_page(page, NULL); | |
1da177e4 LT |
352 | spin_unlock_irq(&zone->lru_lock); |
353 | } | |
eb709b0d | 354 | #endif |
1da177e4 LT |
355 | |
356 | /* | |
357 | * Mark a page as having seen activity. | |
358 | * | |
359 | * inactive,unreferenced -> inactive,referenced | |
360 | * inactive,referenced -> active,unreferenced | |
361 | * active,unreferenced -> active,referenced | |
362 | */ | |
920c7a5d | 363 | void mark_page_accessed(struct page *page) |
1da177e4 | 364 | { |
894bc310 LS |
365 | if (!PageActive(page) && !PageUnevictable(page) && |
366 | PageReferenced(page) && PageLRU(page)) { | |
1da177e4 LT |
367 | activate_page(page); |
368 | ClearPageReferenced(page); | |
369 | } else if (!PageReferenced(page)) { | |
370 | SetPageReferenced(page); | |
371 | } | |
372 | } | |
373 | ||
374 | EXPORT_SYMBOL(mark_page_accessed); | |
375 | ||
f04e9ebb | 376 | void __lru_cache_add(struct page *page, enum lru_list lru) |
1da177e4 | 377 | { |
f04e9ebb | 378 | struct pagevec *pvec = &get_cpu_var(lru_add_pvecs)[lru]; |
1da177e4 LT |
379 | |
380 | page_cache_get(page); | |
381 | if (!pagevec_add(pvec, page)) | |
f04e9ebb | 382 | ____pagevec_lru_add(pvec, lru); |
1da177e4 LT |
383 | put_cpu_var(lru_add_pvecs); |
384 | } | |
47846b06 | 385 | EXPORT_SYMBOL(__lru_cache_add); |
1da177e4 | 386 | |
f04e9ebb KM |
387 | /** |
388 | * lru_cache_add_lru - add a page to a page list | |
389 | * @page: the page to be added to the LRU. | |
390 | * @lru: the LRU list to which the page is added. | |
391 | */ | |
392 | void lru_cache_add_lru(struct page *page, enum lru_list lru) | |
1da177e4 | 393 | { |
f04e9ebb | 394 | if (PageActive(page)) { |
894bc310 | 395 | VM_BUG_ON(PageUnevictable(page)); |
f04e9ebb | 396 | ClearPageActive(page); |
894bc310 LS |
397 | } else if (PageUnevictable(page)) { |
398 | VM_BUG_ON(PageActive(page)); | |
399 | ClearPageUnevictable(page); | |
f04e9ebb | 400 | } |
1da177e4 | 401 | |
894bc310 | 402 | VM_BUG_ON(PageLRU(page) || PageActive(page) || PageUnevictable(page)); |
f04e9ebb | 403 | __lru_cache_add(page, lru); |
1da177e4 LT |
404 | } |
405 | ||
894bc310 LS |
406 | /** |
407 | * add_page_to_unevictable_list - add a page to the unevictable list | |
408 | * @page: the page to be added to the unevictable list | |
409 | * | |
410 | * Add page directly to its zone's unevictable list. To avoid races with | |
411 | * tasks that might be making the page evictable, through eg. munlock, | |
412 | * munmap or exit, while it's not on the lru, we want to add the page | |
413 | * while it's locked or otherwise "invisible" to other tasks. This is | |
414 | * difficult to do when using the pagevec cache, so bypass that. | |
415 | */ | |
416 | void add_page_to_unevictable_list(struct page *page) | |
417 | { | |
418 | struct zone *zone = page_zone(page); | |
419 | ||
420 | spin_lock_irq(&zone->lru_lock); | |
421 | SetPageUnevictable(page); | |
422 | SetPageLRU(page); | |
423 | add_page_to_lru_list(zone, page, LRU_UNEVICTABLE); | |
424 | spin_unlock_irq(&zone->lru_lock); | |
425 | } | |
426 | ||
31560180 MK |
427 | /* |
428 | * If the page can not be invalidated, it is moved to the | |
429 | * inactive list to speed up its reclaim. It is moved to the | |
430 | * head of the list, rather than the tail, to give the flusher | |
431 | * threads some time to write it out, as this is much more | |
432 | * effective than the single-page writeout from reclaim. | |
278df9f4 MK |
433 | * |
434 | * If the page isn't page_mapped and dirty/writeback, the page | |
435 | * could reclaim asap using PG_reclaim. | |
436 | * | |
437 | * 1. active, mapped page -> none | |
438 | * 2. active, dirty/writeback page -> inactive, head, PG_reclaim | |
439 | * 3. inactive, mapped page -> none | |
440 | * 4. inactive, dirty/writeback page -> inactive, head, PG_reclaim | |
441 | * 5. inactive, clean -> inactive, tail | |
442 | * 6. Others -> none | |
443 | * | |
444 | * In 4, why it moves inactive's head, the VM expects the page would | |
445 | * be write it out by flusher threads as this is much more effective | |
446 | * than the single-page writeout from reclaim. | |
31560180 | 447 | */ |
3dd7ae8e | 448 | static void lru_deactivate_fn(struct page *page, void *arg) |
31560180 MK |
449 | { |
450 | int lru, file; | |
278df9f4 | 451 | bool active; |
3dd7ae8e | 452 | struct zone *zone = page_zone(page); |
31560180 | 453 | |
278df9f4 | 454 | if (!PageLRU(page)) |
31560180 MK |
455 | return; |
456 | ||
bad49d9c MK |
457 | if (PageUnevictable(page)) |
458 | return; | |
459 | ||
31560180 MK |
460 | /* Some processes are using the page */ |
461 | if (page_mapped(page)) | |
462 | return; | |
463 | ||
278df9f4 MK |
464 | active = PageActive(page); |
465 | ||
31560180 MK |
466 | file = page_is_file_cache(page); |
467 | lru = page_lru_base_type(page); | |
278df9f4 | 468 | del_page_from_lru_list(zone, page, lru + active); |
31560180 MK |
469 | ClearPageActive(page); |
470 | ClearPageReferenced(page); | |
471 | add_page_to_lru_list(zone, page, lru); | |
31560180 | 472 | |
278df9f4 MK |
473 | if (PageWriteback(page) || PageDirty(page)) { |
474 | /* | |
475 | * PG_reclaim could be raced with end_page_writeback | |
476 | * It can make readahead confusing. But race window | |
477 | * is _really_ small and it's non-critical problem. | |
478 | */ | |
479 | SetPageReclaim(page); | |
480 | } else { | |
925b7673 | 481 | struct lruvec *lruvec; |
278df9f4 MK |
482 | /* |
483 | * The page's writeback ends up during pagevec | |
484 | * We moves tha page into tail of inactive. | |
485 | */ | |
925b7673 JW |
486 | lruvec = mem_cgroup_lru_move_lists(zone, page, lru, lru); |
487 | list_move_tail(&page->lru, &lruvec->lists[lru]); | |
278df9f4 MK |
488 | __count_vm_event(PGROTATED); |
489 | } | |
490 | ||
491 | if (active) | |
492 | __count_vm_event(PGDEACTIVATE); | |
31560180 MK |
493 | update_page_reclaim_stat(zone, page, file, 0); |
494 | } | |
495 | ||
902aaed0 HH |
496 | /* |
497 | * Drain pages out of the cpu's pagevecs. | |
498 | * Either "cpu" is the current CPU, and preemption has already been | |
499 | * disabled; or "cpu" is being hot-unplugged, and is already dead. | |
500 | */ | |
501 | static void drain_cpu_pagevecs(int cpu) | |
1da177e4 | 502 | { |
f04e9ebb | 503 | struct pagevec *pvecs = per_cpu(lru_add_pvecs, cpu); |
902aaed0 | 504 | struct pagevec *pvec; |
f04e9ebb | 505 | int lru; |
1da177e4 | 506 | |
f04e9ebb KM |
507 | for_each_lru(lru) { |
508 | pvec = &pvecs[lru - LRU_BASE]; | |
509 | if (pagevec_count(pvec)) | |
510 | ____pagevec_lru_add(pvec, lru); | |
511 | } | |
902aaed0 HH |
512 | |
513 | pvec = &per_cpu(lru_rotate_pvecs, cpu); | |
514 | if (pagevec_count(pvec)) { | |
515 | unsigned long flags; | |
516 | ||
517 | /* No harm done if a racing interrupt already did this */ | |
518 | local_irq_save(flags); | |
519 | pagevec_move_tail(pvec); | |
520 | local_irq_restore(flags); | |
521 | } | |
31560180 MK |
522 | |
523 | pvec = &per_cpu(lru_deactivate_pvecs, cpu); | |
524 | if (pagevec_count(pvec)) | |
3dd7ae8e | 525 | pagevec_lru_move_fn(pvec, lru_deactivate_fn, NULL); |
eb709b0d SL |
526 | |
527 | activate_page_drain(cpu); | |
31560180 MK |
528 | } |
529 | ||
530 | /** | |
531 | * deactivate_page - forcefully deactivate a page | |
532 | * @page: page to deactivate | |
533 | * | |
534 | * This function hints the VM that @page is a good reclaim candidate, | |
535 | * for example if its invalidation fails due to the page being dirty | |
536 | * or under writeback. | |
537 | */ | |
538 | void deactivate_page(struct page *page) | |
539 | { | |
821ed6bb MK |
540 | /* |
541 | * In a workload with many unevictable page such as mprotect, unevictable | |
542 | * page deactivation for accelerating reclaim is pointless. | |
543 | */ | |
544 | if (PageUnevictable(page)) | |
545 | return; | |
546 | ||
31560180 MK |
547 | if (likely(get_page_unless_zero(page))) { |
548 | struct pagevec *pvec = &get_cpu_var(lru_deactivate_pvecs); | |
549 | ||
550 | if (!pagevec_add(pvec, page)) | |
3dd7ae8e | 551 | pagevec_lru_move_fn(pvec, lru_deactivate_fn, NULL); |
31560180 MK |
552 | put_cpu_var(lru_deactivate_pvecs); |
553 | } | |
80bfed90 AM |
554 | } |
555 | ||
556 | void lru_add_drain(void) | |
557 | { | |
902aaed0 | 558 | drain_cpu_pagevecs(get_cpu()); |
80bfed90 | 559 | put_cpu(); |
1da177e4 LT |
560 | } |
561 | ||
c4028958 | 562 | static void lru_add_drain_per_cpu(struct work_struct *dummy) |
053837fc NP |
563 | { |
564 | lru_add_drain(); | |
565 | } | |
566 | ||
567 | /* | |
568 | * Returns 0 for success | |
569 | */ | |
570 | int lru_add_drain_all(void) | |
571 | { | |
c4028958 | 572 | return schedule_on_each_cpu(lru_add_drain_per_cpu); |
053837fc NP |
573 | } |
574 | ||
1da177e4 LT |
575 | /* |
576 | * Batched page_cache_release(). Decrement the reference count on all the | |
577 | * passed pages. If it fell to zero then remove the page from the LRU and | |
578 | * free it. | |
579 | * | |
580 | * Avoid taking zone->lru_lock if possible, but if it is taken, retain it | |
581 | * for the remainder of the operation. | |
582 | * | |
ab33dc09 FLVC |
583 | * The locking in this function is against shrink_inactive_list(): we recheck |
584 | * the page count inside the lock to see whether shrink_inactive_list() | |
585 | * grabbed the page via the LRU. If it did, give up: shrink_inactive_list() | |
586 | * will free it. | |
1da177e4 LT |
587 | */ |
588 | void release_pages(struct page **pages, int nr, int cold) | |
589 | { | |
590 | int i; | |
cc59850e | 591 | LIST_HEAD(pages_to_free); |
1da177e4 | 592 | struct zone *zone = NULL; |
902aaed0 | 593 | unsigned long uninitialized_var(flags); |
1da177e4 | 594 | |
1da177e4 LT |
595 | for (i = 0; i < nr; i++) { |
596 | struct page *page = pages[i]; | |
1da177e4 | 597 | |
8519fb30 NP |
598 | if (unlikely(PageCompound(page))) { |
599 | if (zone) { | |
902aaed0 | 600 | spin_unlock_irqrestore(&zone->lru_lock, flags); |
8519fb30 NP |
601 | zone = NULL; |
602 | } | |
603 | put_compound_page(page); | |
604 | continue; | |
605 | } | |
606 | ||
b5810039 | 607 | if (!put_page_testzero(page)) |
1da177e4 LT |
608 | continue; |
609 | ||
46453a6e NP |
610 | if (PageLRU(page)) { |
611 | struct zone *pagezone = page_zone(page); | |
894bc310 | 612 | |
46453a6e NP |
613 | if (pagezone != zone) { |
614 | if (zone) | |
902aaed0 HH |
615 | spin_unlock_irqrestore(&zone->lru_lock, |
616 | flags); | |
46453a6e | 617 | zone = pagezone; |
902aaed0 | 618 | spin_lock_irqsave(&zone->lru_lock, flags); |
46453a6e | 619 | } |
725d704e | 620 | VM_BUG_ON(!PageLRU(page)); |
67453911 | 621 | __ClearPageLRU(page); |
1da177e4 | 622 | del_page_from_lru(zone, page); |
46453a6e NP |
623 | } |
624 | ||
cc59850e | 625 | list_add(&page->lru, &pages_to_free); |
1da177e4 LT |
626 | } |
627 | if (zone) | |
902aaed0 | 628 | spin_unlock_irqrestore(&zone->lru_lock, flags); |
1da177e4 | 629 | |
cc59850e | 630 | free_hot_cold_page_list(&pages_to_free, cold); |
1da177e4 | 631 | } |
0be8557b | 632 | EXPORT_SYMBOL(release_pages); |
1da177e4 LT |
633 | |
634 | /* | |
635 | * The pages which we're about to release may be in the deferred lru-addition | |
636 | * queues. That would prevent them from really being freed right now. That's | |
637 | * OK from a correctness point of view but is inefficient - those pages may be | |
638 | * cache-warm and we want to give them back to the page allocator ASAP. | |
639 | * | |
640 | * So __pagevec_release() will drain those queues here. __pagevec_lru_add() | |
641 | * and __pagevec_lru_add_active() call release_pages() directly to avoid | |
642 | * mutual recursion. | |
643 | */ | |
644 | void __pagevec_release(struct pagevec *pvec) | |
645 | { | |
646 | lru_add_drain(); | |
647 | release_pages(pvec->pages, pagevec_count(pvec), pvec->cold); | |
648 | pagevec_reinit(pvec); | |
649 | } | |
650 | ||
7f285701 SF |
651 | EXPORT_SYMBOL(__pagevec_release); |
652 | ||
71e3aac0 AA |
653 | /* used by __split_huge_page_refcount() */ |
654 | void lru_add_page_tail(struct zone* zone, | |
655 | struct page *page, struct page *page_tail) | |
656 | { | |
657 | int active; | |
658 | enum lru_list lru; | |
659 | const int file = 0; | |
71e3aac0 AA |
660 | |
661 | VM_BUG_ON(!PageHead(page)); | |
662 | VM_BUG_ON(PageCompound(page_tail)); | |
663 | VM_BUG_ON(PageLRU(page_tail)); | |
664 | VM_BUG_ON(!spin_is_locked(&zone->lru_lock)); | |
665 | ||
666 | SetPageLRU(page_tail); | |
667 | ||
668 | if (page_evictable(page_tail, NULL)) { | |
925b7673 JW |
669 | struct lruvec *lruvec; |
670 | ||
71e3aac0 AA |
671 | if (PageActive(page)) { |
672 | SetPageActive(page_tail); | |
673 | active = 1; | |
674 | lru = LRU_ACTIVE_ANON; | |
675 | } else { | |
676 | active = 0; | |
677 | lru = LRU_INACTIVE_ANON; | |
678 | } | |
679 | update_page_reclaim_stat(zone, page_tail, file, active); | |
925b7673 | 680 | lruvec = mem_cgroup_lru_add_list(zone, page_tail, lru); |
71e3aac0 | 681 | if (likely(PageLRU(page))) |
925b7673 | 682 | list_add(&page_tail->lru, page->lru.prev); |
71e3aac0 | 683 | else |
45676885 | 684 | list_add(&page_tail->lru, lruvec->lists[lru].prev); |
925b7673 JW |
685 | __mod_zone_page_state(zone, NR_LRU_BASE + lru, |
686 | hpage_nr_pages(page_tail)); | |
71e3aac0 AA |
687 | } else { |
688 | SetPageUnevictable(page_tail); | |
689 | add_page_to_lru_list(zone, page_tail, LRU_UNEVICTABLE); | |
690 | } | |
691 | } | |
692 | ||
3dd7ae8e SL |
693 | static void ____pagevec_lru_add_fn(struct page *page, void *arg) |
694 | { | |
695 | enum lru_list lru = (enum lru_list)arg; | |
696 | struct zone *zone = page_zone(page); | |
697 | int file = is_file_lru(lru); | |
698 | int active = is_active_lru(lru); | |
699 | ||
700 | VM_BUG_ON(PageActive(page)); | |
701 | VM_BUG_ON(PageUnevictable(page)); | |
702 | VM_BUG_ON(PageLRU(page)); | |
703 | ||
704 | SetPageLRU(page); | |
705 | if (active) | |
706 | SetPageActive(page); | |
707 | update_page_reclaim_stat(zone, page, file, active); | |
708 | add_page_to_lru_list(zone, page, lru); | |
709 | } | |
710 | ||
1da177e4 LT |
711 | /* |
712 | * Add the passed pages to the LRU, then drop the caller's refcount | |
713 | * on them. Reinitialises the caller's pagevec. | |
714 | */ | |
f04e9ebb | 715 | void ____pagevec_lru_add(struct pagevec *pvec, enum lru_list lru) |
1da177e4 | 716 | { |
894bc310 | 717 | VM_BUG_ON(is_unevictable_lru(lru)); |
1da177e4 | 718 | |
3dd7ae8e | 719 | pagevec_lru_move_fn(pvec, ____pagevec_lru_add_fn, (void *)lru); |
1da177e4 LT |
720 | } |
721 | ||
f04e9ebb | 722 | EXPORT_SYMBOL(____pagevec_lru_add); |
1da177e4 LT |
723 | |
724 | /* | |
725 | * Try to drop buffers from the pages in a pagevec | |
726 | */ | |
727 | void pagevec_strip(struct pagevec *pvec) | |
728 | { | |
729 | int i; | |
730 | ||
731 | for (i = 0; i < pagevec_count(pvec); i++) { | |
732 | struct page *page = pvec->pages[i]; | |
733 | ||
266cf658 DH |
734 | if (page_has_private(page) && trylock_page(page)) { |
735 | if (page_has_private(page)) | |
5b40dc78 | 736 | try_to_release_page(page, 0); |
1da177e4 LT |
737 | unlock_page(page); |
738 | } | |
739 | } | |
740 | } | |
741 | ||
742 | /** | |
743 | * pagevec_lookup - gang pagecache lookup | |
744 | * @pvec: Where the resulting pages are placed | |
745 | * @mapping: The address_space to search | |
746 | * @start: The starting page index | |
747 | * @nr_pages: The maximum number of pages | |
748 | * | |
749 | * pagevec_lookup() will search for and return a group of up to @nr_pages pages | |
750 | * in the mapping. The pages are placed in @pvec. pagevec_lookup() takes a | |
751 | * reference against the pages in @pvec. | |
752 | * | |
753 | * The search returns a group of mapping-contiguous pages with ascending | |
754 | * indexes. There may be holes in the indices due to not-present pages. | |
755 | * | |
756 | * pagevec_lookup() returns the number of pages which were found. | |
757 | */ | |
758 | unsigned pagevec_lookup(struct pagevec *pvec, struct address_space *mapping, | |
759 | pgoff_t start, unsigned nr_pages) | |
760 | { | |
761 | pvec->nr = find_get_pages(mapping, start, nr_pages, pvec->pages); | |
762 | return pagevec_count(pvec); | |
763 | } | |
764 | ||
78539fdf CH |
765 | EXPORT_SYMBOL(pagevec_lookup); |
766 | ||
1da177e4 LT |
767 | unsigned pagevec_lookup_tag(struct pagevec *pvec, struct address_space *mapping, |
768 | pgoff_t *index, int tag, unsigned nr_pages) | |
769 | { | |
770 | pvec->nr = find_get_pages_tag(mapping, index, tag, | |
771 | nr_pages, pvec->pages); | |
772 | return pagevec_count(pvec); | |
773 | } | |
774 | ||
7f285701 | 775 | EXPORT_SYMBOL(pagevec_lookup_tag); |
1da177e4 | 776 | |
1da177e4 LT |
777 | /* |
778 | * Perform any setup for the swap system | |
779 | */ | |
780 | void __init swap_setup(void) | |
781 | { | |
4481374c | 782 | unsigned long megs = totalram_pages >> (20 - PAGE_SHIFT); |
1da177e4 | 783 | |
e0bf68dd PZ |
784 | #ifdef CONFIG_SWAP |
785 | bdi_init(swapper_space.backing_dev_info); | |
786 | #endif | |
787 | ||
1da177e4 LT |
788 | /* Use a smaller cluster for small-memory machines */ |
789 | if (megs < 16) | |
790 | page_cluster = 2; | |
791 | else | |
792 | page_cluster = 3; | |
793 | /* | |
794 | * Right now other parts of the system means that we | |
795 | * _really_ don't want to cluster much more | |
796 | */ | |
1da177e4 | 797 | } |