Commit | Line | Data |
---|---|---|
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); |
902aaed0 | 42 | |
b221385b AB |
43 | /* |
44 | * This path almost never happens for VM activity - pages are normally | |
45 | * freed via pagevecs. But it gets used by networking. | |
46 | */ | |
920c7a5d | 47 | static void __page_cache_release(struct page *page) |
b221385b AB |
48 | { |
49 | if (PageLRU(page)) { | |
50 | unsigned long flags; | |
51 | struct zone *zone = page_zone(page); | |
52 | ||
53 | spin_lock_irqsave(&zone->lru_lock, flags); | |
54 | VM_BUG_ON(!PageLRU(page)); | |
55 | __ClearPageLRU(page); | |
56 | del_page_from_lru(zone, page); | |
57 | spin_unlock_irqrestore(&zone->lru_lock, flags); | |
58 | } | |
91807063 AA |
59 | } |
60 | ||
61 | static void __put_single_page(struct page *page) | |
62 | { | |
63 | __page_cache_release(page); | |
fc91668e | 64 | free_hot_cold_page(page, 0); |
b221385b AB |
65 | } |
66 | ||
91807063 | 67 | static void __put_compound_page(struct page *page) |
1da177e4 | 68 | { |
91807063 | 69 | compound_page_dtor *dtor; |
1da177e4 | 70 | |
91807063 AA |
71 | __page_cache_release(page); |
72 | dtor = get_compound_page_dtor(page); | |
73 | (*dtor)(page); | |
74 | } | |
75 | ||
76 | static void put_compound_page(struct page *page) | |
77 | { | |
78 | if (unlikely(PageTail(page))) { | |
79 | /* __split_huge_page_refcount can run under us */ | |
80 | struct page *page_head = page->first_page; | |
81 | smp_rmb(); | |
82 | /* | |
83 | * If PageTail is still set after smp_rmb() we can be sure | |
84 | * that the page->first_page we read wasn't a dangling pointer. | |
85 | * See __split_huge_page_refcount() smp_wmb(). | |
86 | */ | |
87 | if (likely(PageTail(page) && get_page_unless_zero(page_head))) { | |
88 | unsigned long flags; | |
89 | /* | |
90 | * Verify that our page_head wasn't converted | |
91 | * to a a regular page before we got a | |
92 | * reference on it. | |
93 | */ | |
94 | if (unlikely(!PageHead(page_head))) { | |
95 | /* PageHead is cleared after PageTail */ | |
96 | smp_rmb(); | |
97 | VM_BUG_ON(PageTail(page)); | |
98 | goto out_put_head; | |
99 | } | |
100 | /* | |
101 | * Only run compound_lock on a valid PageHead, | |
102 | * after having it pinned with | |
103 | * get_page_unless_zero() above. | |
104 | */ | |
105 | smp_mb(); | |
106 | /* page_head wasn't a dangling pointer */ | |
107 | flags = compound_lock_irqsave(page_head); | |
108 | if (unlikely(!PageTail(page))) { | |
109 | /* __split_huge_page_refcount run before us */ | |
110 | compound_unlock_irqrestore(page_head, flags); | |
111 | VM_BUG_ON(PageHead(page_head)); | |
112 | out_put_head: | |
113 | if (put_page_testzero(page_head)) | |
114 | __put_single_page(page_head); | |
115 | out_put_single: | |
116 | if (put_page_testzero(page)) | |
117 | __put_single_page(page); | |
118 | return; | |
119 | } | |
120 | VM_BUG_ON(page_head != page->first_page); | |
121 | /* | |
122 | * We can release the refcount taken by | |
123 | * get_page_unless_zero now that | |
124 | * split_huge_page_refcount is blocked on the | |
125 | * compound_lock. | |
126 | */ | |
127 | if (put_page_testzero(page_head)) | |
128 | VM_BUG_ON(1); | |
129 | /* __split_huge_page_refcount will wait now */ | |
130 | VM_BUG_ON(atomic_read(&page->_count) <= 0); | |
131 | atomic_dec(&page->_count); | |
132 | VM_BUG_ON(atomic_read(&page_head->_count) <= 0); | |
133 | compound_unlock_irqrestore(page_head, flags); | |
a95a82e9 AA |
134 | if (put_page_testzero(page_head)) { |
135 | if (PageHead(page_head)) | |
136 | __put_compound_page(page_head); | |
137 | else | |
138 | __put_single_page(page_head); | |
139 | } | |
91807063 AA |
140 | } else { |
141 | /* page_head is a dangling pointer */ | |
142 | VM_BUG_ON(PageTail(page)); | |
143 | goto out_put_single; | |
144 | } | |
145 | } else if (put_page_testzero(page)) { | |
146 | if (PageHead(page)) | |
147 | __put_compound_page(page); | |
148 | else | |
149 | __put_single_page(page); | |
1da177e4 | 150 | } |
8519fb30 NP |
151 | } |
152 | ||
153 | void put_page(struct page *page) | |
154 | { | |
155 | if (unlikely(PageCompound(page))) | |
156 | put_compound_page(page); | |
157 | else if (put_page_testzero(page)) | |
91807063 | 158 | __put_single_page(page); |
1da177e4 LT |
159 | } |
160 | EXPORT_SYMBOL(put_page); | |
1da177e4 | 161 | |
1d7ea732 | 162 | /** |
7682486b RD |
163 | * put_pages_list() - release a list of pages |
164 | * @pages: list of pages threaded on page->lru | |
1d7ea732 AZ |
165 | * |
166 | * Release a list of pages which are strung together on page.lru. Currently | |
167 | * used by read_cache_pages() and related error recovery code. | |
1d7ea732 AZ |
168 | */ |
169 | void put_pages_list(struct list_head *pages) | |
170 | { | |
171 | while (!list_empty(pages)) { | |
172 | struct page *victim; | |
173 | ||
174 | victim = list_entry(pages->prev, struct page, lru); | |
175 | list_del(&victim->lru); | |
176 | page_cache_release(victim); | |
177 | } | |
178 | } | |
179 | EXPORT_SYMBOL(put_pages_list); | |
180 | ||
83896fb5 LT |
181 | /* |
182 | * pagevec_move_tail() must be called with IRQ disabled. | |
183 | * Otherwise this may cause nasty races. | |
184 | */ | |
185 | static void pagevec_move_tail(struct pagevec *pvec) | |
902aaed0 HH |
186 | { |
187 | int i; | |
83896fb5 | 188 | int pgmoved = 0; |
902aaed0 HH |
189 | struct zone *zone = NULL; |
190 | ||
191 | for (i = 0; i < pagevec_count(pvec); i++) { | |
192 | struct page *page = pvec->pages[i]; | |
193 | struct zone *pagezone = page_zone(page); | |
194 | ||
195 | if (pagezone != zone) { | |
196 | if (zone) | |
83896fb5 | 197 | spin_unlock(&zone->lru_lock); |
902aaed0 | 198 | zone = pagezone; |
83896fb5 LT |
199 | spin_lock(&zone->lru_lock); |
200 | } | |
201 | if (PageLRU(page) && !PageActive(page) && !PageUnevictable(page)) { | |
202 | int lru = page_lru_base_type(page); | |
203 | list_move_tail(&page->lru, &zone->lru[lru].list); | |
204 | pgmoved++; | |
902aaed0 HH |
205 | } |
206 | } | |
207 | if (zone) | |
83896fb5 | 208 | spin_unlock(&zone->lru_lock); |
d8505dee | 209 | __count_vm_events(PGROTATED, pgmoved); |
83896fb5 LT |
210 | release_pages(pvec->pages, pvec->nr, pvec->cold); |
211 | pagevec_reinit(pvec); | |
d8505dee SL |
212 | } |
213 | ||
1da177e4 LT |
214 | /* |
215 | * Writeback is about to end against a page which has been marked for immediate | |
216 | * reclaim. If it still appears to be reclaimable, move it to the tail of the | |
902aaed0 | 217 | * inactive list. |
1da177e4 | 218 | */ |
83896fb5 | 219 | void rotate_reclaimable_page(struct page *page) |
1da177e4 | 220 | { |
ac6aadb2 | 221 | if (!PageLocked(page) && !PageDirty(page) && !PageActive(page) && |
894bc310 | 222 | !PageUnevictable(page) && PageLRU(page)) { |
ac6aadb2 MS |
223 | struct pagevec *pvec; |
224 | unsigned long flags; | |
225 | ||
226 | page_cache_get(page); | |
227 | local_irq_save(flags); | |
228 | pvec = &__get_cpu_var(lru_rotate_pvecs); | |
229 | if (!pagevec_add(pvec, page)) | |
230 | pagevec_move_tail(pvec); | |
231 | local_irq_restore(flags); | |
232 | } | |
1da177e4 LT |
233 | } |
234 | ||
3e2f41f1 KM |
235 | static void update_page_reclaim_stat(struct zone *zone, struct page *page, |
236 | int file, int rotated) | |
237 | { | |
238 | struct zone_reclaim_stat *reclaim_stat = &zone->reclaim_stat; | |
239 | struct zone_reclaim_stat *memcg_reclaim_stat; | |
240 | ||
241 | memcg_reclaim_stat = mem_cgroup_get_reclaim_stat_from_page(page); | |
242 | ||
243 | reclaim_stat->recent_scanned[file]++; | |
244 | if (rotated) | |
245 | reclaim_stat->recent_rotated[file]++; | |
246 | ||
247 | if (!memcg_reclaim_stat) | |
248 | return; | |
249 | ||
250 | memcg_reclaim_stat->recent_scanned[file]++; | |
251 | if (rotated) | |
252 | memcg_reclaim_stat->recent_rotated[file]++; | |
253 | } | |
254 | ||
1da177e4 | 255 | /* |
7a608572 | 256 | * FIXME: speed this up? |
1da177e4 | 257 | */ |
7a608572 | 258 | void activate_page(struct page *page) |
1da177e4 LT |
259 | { |
260 | struct zone *zone = page_zone(page); | |
744ed144 | 261 | |
7a608572 | 262 | spin_lock_irq(&zone->lru_lock); |
744ed144 | 263 | if (PageLRU(page) && !PageActive(page) && !PageUnevictable(page)) { |
7a608572 LT |
264 | int file = page_is_file_cache(page); |
265 | int lru = page_lru_base_type(page); | |
266 | del_page_from_lru_list(zone, page, lru); | |
744ed144 | 267 | |
7a608572 LT |
268 | SetPageActive(page); |
269 | lru += LRU_ACTIVE; | |
270 | add_page_to_lru_list(zone, page, lru); | |
271 | __count_vm_event(PGACTIVATE); | |
4f98a2fe | 272 | |
7a608572 | 273 | update_page_reclaim_stat(zone, page, file, 1); |
1da177e4 LT |
274 | } |
275 | spin_unlock_irq(&zone->lru_lock); | |
276 | } | |
277 | ||
278 | /* | |
279 | * Mark a page as having seen activity. | |
280 | * | |
281 | * inactive,unreferenced -> inactive,referenced | |
282 | * inactive,referenced -> active,unreferenced | |
283 | * active,unreferenced -> active,referenced | |
284 | */ | |
920c7a5d | 285 | void mark_page_accessed(struct page *page) |
1da177e4 | 286 | { |
894bc310 LS |
287 | if (!PageActive(page) && !PageUnevictable(page) && |
288 | PageReferenced(page) && PageLRU(page)) { | |
1da177e4 LT |
289 | activate_page(page); |
290 | ClearPageReferenced(page); | |
291 | } else if (!PageReferenced(page)) { | |
292 | SetPageReferenced(page); | |
293 | } | |
294 | } | |
295 | ||
296 | EXPORT_SYMBOL(mark_page_accessed); | |
297 | ||
f04e9ebb | 298 | void __lru_cache_add(struct page *page, enum lru_list lru) |
1da177e4 | 299 | { |
f04e9ebb | 300 | struct pagevec *pvec = &get_cpu_var(lru_add_pvecs)[lru]; |
1da177e4 LT |
301 | |
302 | page_cache_get(page); | |
303 | if (!pagevec_add(pvec, page)) | |
f04e9ebb | 304 | ____pagevec_lru_add(pvec, lru); |
1da177e4 LT |
305 | put_cpu_var(lru_add_pvecs); |
306 | } | |
47846b06 | 307 | EXPORT_SYMBOL(__lru_cache_add); |
1da177e4 | 308 | |
f04e9ebb KM |
309 | /** |
310 | * lru_cache_add_lru - add a page to a page list | |
311 | * @page: the page to be added to the LRU. | |
312 | * @lru: the LRU list to which the page is added. | |
313 | */ | |
314 | void lru_cache_add_lru(struct page *page, enum lru_list lru) | |
1da177e4 | 315 | { |
f04e9ebb | 316 | if (PageActive(page)) { |
894bc310 | 317 | VM_BUG_ON(PageUnevictable(page)); |
f04e9ebb | 318 | ClearPageActive(page); |
894bc310 LS |
319 | } else if (PageUnevictable(page)) { |
320 | VM_BUG_ON(PageActive(page)); | |
321 | ClearPageUnevictable(page); | |
f04e9ebb | 322 | } |
1da177e4 | 323 | |
894bc310 | 324 | VM_BUG_ON(PageLRU(page) || PageActive(page) || PageUnevictable(page)); |
f04e9ebb | 325 | __lru_cache_add(page, lru); |
1da177e4 LT |
326 | } |
327 | ||
894bc310 LS |
328 | /** |
329 | * add_page_to_unevictable_list - add a page to the unevictable list | |
330 | * @page: the page to be added to the unevictable list | |
331 | * | |
332 | * Add page directly to its zone's unevictable list. To avoid races with | |
333 | * tasks that might be making the page evictable, through eg. munlock, | |
334 | * munmap or exit, while it's not on the lru, we want to add the page | |
335 | * while it's locked or otherwise "invisible" to other tasks. This is | |
336 | * difficult to do when using the pagevec cache, so bypass that. | |
337 | */ | |
338 | void add_page_to_unevictable_list(struct page *page) | |
339 | { | |
340 | struct zone *zone = page_zone(page); | |
341 | ||
342 | spin_lock_irq(&zone->lru_lock); | |
343 | SetPageUnevictable(page); | |
344 | SetPageLRU(page); | |
345 | add_page_to_lru_list(zone, page, LRU_UNEVICTABLE); | |
346 | spin_unlock_irq(&zone->lru_lock); | |
347 | } | |
348 | ||
902aaed0 HH |
349 | /* |
350 | * Drain pages out of the cpu's pagevecs. | |
351 | * Either "cpu" is the current CPU, and preemption has already been | |
352 | * disabled; or "cpu" is being hot-unplugged, and is already dead. | |
353 | */ | |
354 | static void drain_cpu_pagevecs(int cpu) | |
1da177e4 | 355 | { |
f04e9ebb | 356 | struct pagevec *pvecs = per_cpu(lru_add_pvecs, cpu); |
902aaed0 | 357 | struct pagevec *pvec; |
f04e9ebb | 358 | int lru; |
1da177e4 | 359 | |
f04e9ebb KM |
360 | for_each_lru(lru) { |
361 | pvec = &pvecs[lru - LRU_BASE]; | |
362 | if (pagevec_count(pvec)) | |
363 | ____pagevec_lru_add(pvec, lru); | |
364 | } | |
902aaed0 HH |
365 | |
366 | pvec = &per_cpu(lru_rotate_pvecs, cpu); | |
367 | if (pagevec_count(pvec)) { | |
368 | unsigned long flags; | |
369 | ||
370 | /* No harm done if a racing interrupt already did this */ | |
371 | local_irq_save(flags); | |
372 | pagevec_move_tail(pvec); | |
373 | local_irq_restore(flags); | |
374 | } | |
80bfed90 AM |
375 | } |
376 | ||
377 | void lru_add_drain(void) | |
378 | { | |
902aaed0 | 379 | drain_cpu_pagevecs(get_cpu()); |
80bfed90 | 380 | put_cpu(); |
1da177e4 LT |
381 | } |
382 | ||
c4028958 | 383 | static void lru_add_drain_per_cpu(struct work_struct *dummy) |
053837fc NP |
384 | { |
385 | lru_add_drain(); | |
386 | } | |
387 | ||
388 | /* | |
389 | * Returns 0 for success | |
390 | */ | |
391 | int lru_add_drain_all(void) | |
392 | { | |
c4028958 | 393 | return schedule_on_each_cpu(lru_add_drain_per_cpu); |
053837fc NP |
394 | } |
395 | ||
1da177e4 LT |
396 | /* |
397 | * Batched page_cache_release(). Decrement the reference count on all the | |
398 | * passed pages. If it fell to zero then remove the page from the LRU and | |
399 | * free it. | |
400 | * | |
401 | * Avoid taking zone->lru_lock if possible, but if it is taken, retain it | |
402 | * for the remainder of the operation. | |
403 | * | |
ab33dc09 FLVC |
404 | * The locking in this function is against shrink_inactive_list(): we recheck |
405 | * the page count inside the lock to see whether shrink_inactive_list() | |
406 | * grabbed the page via the LRU. If it did, give up: shrink_inactive_list() | |
407 | * will free it. | |
1da177e4 LT |
408 | */ |
409 | void release_pages(struct page **pages, int nr, int cold) | |
410 | { | |
411 | int i; | |
412 | struct pagevec pages_to_free; | |
413 | struct zone *zone = NULL; | |
902aaed0 | 414 | unsigned long uninitialized_var(flags); |
1da177e4 LT |
415 | |
416 | pagevec_init(&pages_to_free, cold); | |
417 | for (i = 0; i < nr; i++) { | |
418 | struct page *page = pages[i]; | |
1da177e4 | 419 | |
8519fb30 NP |
420 | if (unlikely(PageCompound(page))) { |
421 | if (zone) { | |
902aaed0 | 422 | spin_unlock_irqrestore(&zone->lru_lock, flags); |
8519fb30 NP |
423 | zone = NULL; |
424 | } | |
425 | put_compound_page(page); | |
426 | continue; | |
427 | } | |
428 | ||
b5810039 | 429 | if (!put_page_testzero(page)) |
1da177e4 LT |
430 | continue; |
431 | ||
46453a6e NP |
432 | if (PageLRU(page)) { |
433 | struct zone *pagezone = page_zone(page); | |
894bc310 | 434 | |
46453a6e NP |
435 | if (pagezone != zone) { |
436 | if (zone) | |
902aaed0 HH |
437 | spin_unlock_irqrestore(&zone->lru_lock, |
438 | flags); | |
46453a6e | 439 | zone = pagezone; |
902aaed0 | 440 | spin_lock_irqsave(&zone->lru_lock, flags); |
46453a6e | 441 | } |
725d704e | 442 | VM_BUG_ON(!PageLRU(page)); |
67453911 | 443 | __ClearPageLRU(page); |
1da177e4 | 444 | del_page_from_lru(zone, page); |
46453a6e NP |
445 | } |
446 | ||
447 | if (!pagevec_add(&pages_to_free, page)) { | |
448 | if (zone) { | |
902aaed0 | 449 | spin_unlock_irqrestore(&zone->lru_lock, flags); |
46453a6e | 450 | zone = NULL; |
1da177e4 | 451 | } |
46453a6e NP |
452 | __pagevec_free(&pages_to_free); |
453 | pagevec_reinit(&pages_to_free); | |
454 | } | |
1da177e4 LT |
455 | } |
456 | if (zone) | |
902aaed0 | 457 | spin_unlock_irqrestore(&zone->lru_lock, flags); |
1da177e4 LT |
458 | |
459 | pagevec_free(&pages_to_free); | |
460 | } | |
0be8557b | 461 | EXPORT_SYMBOL(release_pages); |
1da177e4 LT |
462 | |
463 | /* | |
464 | * The pages which we're about to release may be in the deferred lru-addition | |
465 | * queues. That would prevent them from really being freed right now. That's | |
466 | * OK from a correctness point of view but is inefficient - those pages may be | |
467 | * cache-warm and we want to give them back to the page allocator ASAP. | |
468 | * | |
469 | * So __pagevec_release() will drain those queues here. __pagevec_lru_add() | |
470 | * and __pagevec_lru_add_active() call release_pages() directly to avoid | |
471 | * mutual recursion. | |
472 | */ | |
473 | void __pagevec_release(struct pagevec *pvec) | |
474 | { | |
475 | lru_add_drain(); | |
476 | release_pages(pvec->pages, pagevec_count(pvec), pvec->cold); | |
477 | pagevec_reinit(pvec); | |
478 | } | |
479 | ||
7f285701 SF |
480 | EXPORT_SYMBOL(__pagevec_release); |
481 | ||
71e3aac0 AA |
482 | /* used by __split_huge_page_refcount() */ |
483 | void lru_add_page_tail(struct zone* zone, | |
484 | struct page *page, struct page *page_tail) | |
485 | { | |
486 | int active; | |
487 | enum lru_list lru; | |
488 | const int file = 0; | |
489 | struct list_head *head; | |
490 | ||
491 | VM_BUG_ON(!PageHead(page)); | |
492 | VM_BUG_ON(PageCompound(page_tail)); | |
493 | VM_BUG_ON(PageLRU(page_tail)); | |
494 | VM_BUG_ON(!spin_is_locked(&zone->lru_lock)); | |
495 | ||
496 | SetPageLRU(page_tail); | |
497 | ||
498 | if (page_evictable(page_tail, NULL)) { | |
499 | if (PageActive(page)) { | |
500 | SetPageActive(page_tail); | |
501 | active = 1; | |
502 | lru = LRU_ACTIVE_ANON; | |
503 | } else { | |
504 | active = 0; | |
505 | lru = LRU_INACTIVE_ANON; | |
506 | } | |
507 | update_page_reclaim_stat(zone, page_tail, file, active); | |
508 | if (likely(PageLRU(page))) | |
509 | head = page->lru.prev; | |
510 | else | |
511 | head = &zone->lru[lru].list; | |
512 | __add_page_to_lru_list(zone, page_tail, lru, head); | |
513 | } else { | |
514 | SetPageUnevictable(page_tail); | |
515 | add_page_to_lru_list(zone, page_tail, LRU_UNEVICTABLE); | |
516 | } | |
517 | } | |
518 | ||
1da177e4 LT |
519 | /* |
520 | * Add the passed pages to the LRU, then drop the caller's refcount | |
521 | * on them. Reinitialises the caller's pagevec. | |
522 | */ | |
f04e9ebb | 523 | void ____pagevec_lru_add(struct pagevec *pvec, enum lru_list lru) |
1da177e4 | 524 | { |
83896fb5 LT |
525 | int i; |
526 | struct zone *zone = NULL; | |
527 | ||
894bc310 | 528 | VM_BUG_ON(is_unevictable_lru(lru)); |
1da177e4 | 529 | |
83896fb5 LT |
530 | for (i = 0; i < pagevec_count(pvec); i++) { |
531 | struct page *page = pvec->pages[i]; | |
532 | struct zone *pagezone = page_zone(page); | |
533 | int file; | |
534 | int active; | |
535 | ||
536 | if (pagezone != zone) { | |
537 | if (zone) | |
538 | spin_unlock_irq(&zone->lru_lock); | |
539 | zone = pagezone; | |
540 | spin_lock_irq(&zone->lru_lock); | |
541 | } | |
542 | VM_BUG_ON(PageActive(page)); | |
543 | VM_BUG_ON(PageUnevictable(page)); | |
544 | VM_BUG_ON(PageLRU(page)); | |
545 | SetPageLRU(page); | |
546 | active = is_active_lru(lru); | |
547 | file = is_file_lru(lru); | |
548 | if (active) | |
549 | SetPageActive(page); | |
550 | update_page_reclaim_stat(zone, page, file, active); | |
551 | add_page_to_lru_list(zone, page, lru); | |
552 | } | |
553 | if (zone) | |
554 | spin_unlock_irq(&zone->lru_lock); | |
555 | release_pages(pvec->pages, pvec->nr, pvec->cold); | |
556 | pagevec_reinit(pvec); | |
1da177e4 LT |
557 | } |
558 | ||
f04e9ebb | 559 | EXPORT_SYMBOL(____pagevec_lru_add); |
1da177e4 LT |
560 | |
561 | /* | |
562 | * Try to drop buffers from the pages in a pagevec | |
563 | */ | |
564 | void pagevec_strip(struct pagevec *pvec) | |
565 | { | |
566 | int i; | |
567 | ||
568 | for (i = 0; i < pagevec_count(pvec); i++) { | |
569 | struct page *page = pvec->pages[i]; | |
570 | ||
266cf658 DH |
571 | if (page_has_private(page) && trylock_page(page)) { |
572 | if (page_has_private(page)) | |
5b40dc78 | 573 | try_to_release_page(page, 0); |
1da177e4 LT |
574 | unlock_page(page); |
575 | } | |
576 | } | |
577 | } | |
578 | ||
579 | /** | |
580 | * pagevec_lookup - gang pagecache lookup | |
581 | * @pvec: Where the resulting pages are placed | |
582 | * @mapping: The address_space to search | |
583 | * @start: The starting page index | |
584 | * @nr_pages: The maximum number of pages | |
585 | * | |
586 | * pagevec_lookup() will search for and return a group of up to @nr_pages pages | |
587 | * in the mapping. The pages are placed in @pvec. pagevec_lookup() takes a | |
588 | * reference against the pages in @pvec. | |
589 | * | |
590 | * The search returns a group of mapping-contiguous pages with ascending | |
591 | * indexes. There may be holes in the indices due to not-present pages. | |
592 | * | |
593 | * pagevec_lookup() returns the number of pages which were found. | |
594 | */ | |
595 | unsigned pagevec_lookup(struct pagevec *pvec, struct address_space *mapping, | |
596 | pgoff_t start, unsigned nr_pages) | |
597 | { | |
598 | pvec->nr = find_get_pages(mapping, start, nr_pages, pvec->pages); | |
599 | return pagevec_count(pvec); | |
600 | } | |
601 | ||
78539fdf CH |
602 | EXPORT_SYMBOL(pagevec_lookup); |
603 | ||
1da177e4 LT |
604 | unsigned pagevec_lookup_tag(struct pagevec *pvec, struct address_space *mapping, |
605 | pgoff_t *index, int tag, unsigned nr_pages) | |
606 | { | |
607 | pvec->nr = find_get_pages_tag(mapping, index, tag, | |
608 | nr_pages, pvec->pages); | |
609 | return pagevec_count(pvec); | |
610 | } | |
611 | ||
7f285701 | 612 | EXPORT_SYMBOL(pagevec_lookup_tag); |
1da177e4 | 613 | |
1da177e4 LT |
614 | /* |
615 | * Perform any setup for the swap system | |
616 | */ | |
617 | void __init swap_setup(void) | |
618 | { | |
4481374c | 619 | unsigned long megs = totalram_pages >> (20 - PAGE_SHIFT); |
1da177e4 | 620 | |
e0bf68dd PZ |
621 | #ifdef CONFIG_SWAP |
622 | bdi_init(swapper_space.backing_dev_info); | |
623 | #endif | |
624 | ||
1da177e4 LT |
625 | /* Use a smaller cluster for small-memory machines */ |
626 | if (megs < 16) | |
627 | page_cluster = 2; | |
628 | else | |
629 | page_cluster = 3; | |
630 | /* | |
631 | * Right now other parts of the system means that we | |
632 | * _really_ don't want to cluster much more | |
633 | */ | |
1da177e4 | 634 | } |