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