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457c8996 | 1 | // SPDX-License-Identifier: GPL-2.0-only |
1da177e4 LT |
2 | /* |
3 | * linux/mm/swap.c | |
4 | * | |
5 | * Copyright (C) 1991, 1992, 1993, 1994 Linus Torvalds | |
6 | */ | |
7 | ||
8 | /* | |
183ff22b | 9 | * This file contains the default values for the operation of the |
1da177e4 | 10 | * Linux VM subsystem. Fine-tuning documentation can be found in |
57043247 | 11 | * Documentation/admin-guide/sysctl/vm.rst. |
1da177e4 LT |
12 | * Started 18.12.91 |
13 | * Swap aging added 23.2.95, Stephen Tweedie. | |
14 | * Buffermem limits added 12.3.98, Rik van Riel. | |
15 | */ | |
16 | ||
17 | #include <linux/mm.h> | |
18 | #include <linux/sched.h> | |
19 | #include <linux/kernel_stat.h> | |
20 | #include <linux/swap.h> | |
21 | #include <linux/mman.h> | |
22 | #include <linux/pagemap.h> | |
23 | #include <linux/pagevec.h> | |
24 | #include <linux/init.h> | |
b95f1b31 | 25 | #include <linux/export.h> |
1da177e4 | 26 | #include <linux/mm_inline.h> |
1da177e4 | 27 | #include <linux/percpu_counter.h> |
3565fce3 | 28 | #include <linux/memremap.h> |
1da177e4 LT |
29 | #include <linux/percpu.h> |
30 | #include <linux/cpu.h> | |
31 | #include <linux/notifier.h> | |
e0bf68dd | 32 | #include <linux/backing-dev.h> |
66e1707b | 33 | #include <linux/memcontrol.h> |
5a0e3ad6 | 34 | #include <linux/gfp.h> |
a27bb332 | 35 | #include <linux/uio.h> |
822fc613 | 36 | #include <linux/hugetlb.h> |
33c3fc71 | 37 | #include <linux/page_idle.h> |
b01b2141 | 38 | #include <linux/local_lock.h> |
1da177e4 | 39 | |
64d6519d LS |
40 | #include "internal.h" |
41 | ||
c6286c98 MG |
42 | #define CREATE_TRACE_POINTS |
43 | #include <trace/events/pagemap.h> | |
44 | ||
1da177e4 LT |
45 | /* How many pages do we try to swap or page in/out together? */ |
46 | int page_cluster; | |
47 | ||
b01b2141 IM |
48 | /* Protecting only lru_rotate.pvec which requires disabling interrupts */ |
49 | struct lru_rotate { | |
50 | local_lock_t lock; | |
51 | struct pagevec pvec; | |
52 | }; | |
53 | static DEFINE_PER_CPU(struct lru_rotate, lru_rotate) = { | |
54 | .lock = INIT_LOCAL_LOCK(lock), | |
55 | }; | |
56 | ||
57 | /* | |
58 | * The following struct pagevec are grouped together because they are protected | |
59 | * by disabling preemption (and interrupts remain enabled). | |
60 | */ | |
61 | struct lru_pvecs { | |
62 | local_lock_t lock; | |
63 | struct pagevec lru_add; | |
64 | struct pagevec lru_deactivate_file; | |
65 | struct pagevec lru_deactivate; | |
66 | struct pagevec lru_lazyfree; | |
a4a921aa | 67 | #ifdef CONFIG_SMP |
b01b2141 | 68 | struct pagevec activate_page; |
a4a921aa | 69 | #endif |
b01b2141 IM |
70 | }; |
71 | static DEFINE_PER_CPU(struct lru_pvecs, lru_pvecs) = { | |
72 | .lock = INIT_LOCAL_LOCK(lock), | |
73 | }; | |
902aaed0 | 74 | |
b221385b AB |
75 | /* |
76 | * This path almost never happens for VM activity - pages are normally | |
77 | * freed via pagevecs. But it gets used by networking. | |
78 | */ | |
920c7a5d | 79 | static void __page_cache_release(struct page *page) |
b221385b AB |
80 | { |
81 | if (PageLRU(page)) { | |
f4b7e272 | 82 | pg_data_t *pgdat = page_pgdat(page); |
fa9add64 HD |
83 | struct lruvec *lruvec; |
84 | unsigned long flags; | |
b221385b | 85 | |
f4b7e272 AR |
86 | spin_lock_irqsave(&pgdat->lru_lock, flags); |
87 | lruvec = mem_cgroup_page_lruvec(page, pgdat); | |
309381fe | 88 | VM_BUG_ON_PAGE(!PageLRU(page), page); |
b221385b | 89 | __ClearPageLRU(page); |
fa9add64 | 90 | del_page_from_lru_list(page, lruvec, page_off_lru(page)); |
f4b7e272 | 91 | spin_unlock_irqrestore(&pgdat->lru_lock, flags); |
b221385b | 92 | } |
62906027 | 93 | __ClearPageWaiters(page); |
91807063 AA |
94 | } |
95 | ||
96 | static void __put_single_page(struct page *page) | |
97 | { | |
98 | __page_cache_release(page); | |
7ae88534 | 99 | mem_cgroup_uncharge(page); |
2d4894b5 | 100 | free_unref_page(page); |
b221385b AB |
101 | } |
102 | ||
91807063 | 103 | static void __put_compound_page(struct page *page) |
1da177e4 | 104 | { |
91807063 | 105 | compound_page_dtor *dtor; |
1da177e4 | 106 | |
822fc613 NH |
107 | /* |
108 | * __page_cache_release() is supposed to be called for thp, not for | |
109 | * hugetlb. This is because hugetlb page does never have PageLRU set | |
110 | * (it's never listed to any LRU lists) and no memcg routines should | |
111 | * be called for hugetlb (it has a separate hugetlb_cgroup.) | |
112 | */ | |
113 | if (!PageHuge(page)) | |
114 | __page_cache_release(page); | |
91807063 AA |
115 | dtor = get_compound_page_dtor(page); |
116 | (*dtor)(page); | |
117 | } | |
118 | ||
ddc58f27 | 119 | void __put_page(struct page *page) |
8519fb30 | 120 | { |
71389703 DW |
121 | if (is_zone_device_page(page)) { |
122 | put_dev_pagemap(page->pgmap); | |
123 | ||
124 | /* | |
125 | * The page belongs to the device that created pgmap. Do | |
126 | * not return it to page allocator. | |
127 | */ | |
128 | return; | |
129 | } | |
130 | ||
8519fb30 | 131 | if (unlikely(PageCompound(page))) |
ddc58f27 KS |
132 | __put_compound_page(page); |
133 | else | |
91807063 | 134 | __put_single_page(page); |
1da177e4 | 135 | } |
ddc58f27 | 136 | EXPORT_SYMBOL(__put_page); |
70b50f94 | 137 | |
1d7ea732 | 138 | /** |
7682486b RD |
139 | * put_pages_list() - release a list of pages |
140 | * @pages: list of pages threaded on page->lru | |
1d7ea732 AZ |
141 | * |
142 | * Release a list of pages which are strung together on page.lru. Currently | |
143 | * used by read_cache_pages() and related error recovery code. | |
1d7ea732 AZ |
144 | */ |
145 | void put_pages_list(struct list_head *pages) | |
146 | { | |
147 | while (!list_empty(pages)) { | |
148 | struct page *victim; | |
149 | ||
f86196ea | 150 | victim = lru_to_page(pages); |
1d7ea732 | 151 | list_del(&victim->lru); |
09cbfeaf | 152 | put_page(victim); |
1d7ea732 AZ |
153 | } |
154 | } | |
155 | EXPORT_SYMBOL(put_pages_list); | |
156 | ||
18022c5d MG |
157 | /* |
158 | * get_kernel_pages() - pin kernel pages in memory | |
159 | * @kiov: An array of struct kvec structures | |
160 | * @nr_segs: number of segments to pin | |
161 | * @write: pinning for read/write, currently ignored | |
162 | * @pages: array that receives pointers to the pages pinned. | |
163 | * Should be at least nr_segs long. | |
164 | * | |
165 | * Returns number of pages pinned. This may be fewer than the number | |
166 | * requested. If nr_pages is 0 or negative, returns 0. If no pages | |
167 | * were pinned, returns -errno. Each page returned must be released | |
168 | * with a put_page() call when it is finished with. | |
169 | */ | |
170 | int get_kernel_pages(const struct kvec *kiov, int nr_segs, int write, | |
171 | struct page **pages) | |
172 | { | |
173 | int seg; | |
174 | ||
175 | for (seg = 0; seg < nr_segs; seg++) { | |
176 | if (WARN_ON(kiov[seg].iov_len != PAGE_SIZE)) | |
177 | return seg; | |
178 | ||
5a178119 | 179 | pages[seg] = kmap_to_page(kiov[seg].iov_base); |
09cbfeaf | 180 | get_page(pages[seg]); |
18022c5d MG |
181 | } |
182 | ||
183 | return seg; | |
184 | } | |
185 | EXPORT_SYMBOL_GPL(get_kernel_pages); | |
186 | ||
187 | /* | |
188 | * get_kernel_page() - pin a kernel page in memory | |
189 | * @start: starting kernel address | |
190 | * @write: pinning for read/write, currently ignored | |
191 | * @pages: array that receives pointer to the page pinned. | |
192 | * Must be at least nr_segs long. | |
193 | * | |
194 | * Returns 1 if page is pinned. If the page was not pinned, returns | |
195 | * -errno. The page returned must be released with a put_page() call | |
196 | * when it is finished with. | |
197 | */ | |
198 | int get_kernel_page(unsigned long start, int write, struct page **pages) | |
199 | { | |
200 | const struct kvec kiov = { | |
201 | .iov_base = (void *)start, | |
202 | .iov_len = PAGE_SIZE | |
203 | }; | |
204 | ||
205 | return get_kernel_pages(&kiov, 1, write, pages); | |
206 | } | |
207 | EXPORT_SYMBOL_GPL(get_kernel_page); | |
208 | ||
3dd7ae8e | 209 | static void pagevec_lru_move_fn(struct pagevec *pvec, |
fa9add64 HD |
210 | void (*move_fn)(struct page *page, struct lruvec *lruvec, void *arg), |
211 | void *arg) | |
902aaed0 HH |
212 | { |
213 | int i; | |
68eb0731 | 214 | struct pglist_data *pgdat = NULL; |
fa9add64 | 215 | struct lruvec *lruvec; |
3dd7ae8e | 216 | unsigned long flags = 0; |
902aaed0 HH |
217 | |
218 | for (i = 0; i < pagevec_count(pvec); i++) { | |
219 | struct page *page = pvec->pages[i]; | |
68eb0731 | 220 | struct pglist_data *pagepgdat = page_pgdat(page); |
902aaed0 | 221 | |
68eb0731 MG |
222 | if (pagepgdat != pgdat) { |
223 | if (pgdat) | |
224 | spin_unlock_irqrestore(&pgdat->lru_lock, flags); | |
225 | pgdat = pagepgdat; | |
226 | spin_lock_irqsave(&pgdat->lru_lock, flags); | |
902aaed0 | 227 | } |
3dd7ae8e | 228 | |
68eb0731 | 229 | lruvec = mem_cgroup_page_lruvec(page, pgdat); |
fa9add64 | 230 | (*move_fn)(page, lruvec, arg); |
902aaed0 | 231 | } |
68eb0731 MG |
232 | if (pgdat) |
233 | spin_unlock_irqrestore(&pgdat->lru_lock, flags); | |
c6f92f9f | 234 | release_pages(pvec->pages, pvec->nr); |
83896fb5 | 235 | pagevec_reinit(pvec); |
d8505dee SL |
236 | } |
237 | ||
fa9add64 HD |
238 | static void pagevec_move_tail_fn(struct page *page, struct lruvec *lruvec, |
239 | void *arg) | |
3dd7ae8e SL |
240 | { |
241 | int *pgmoved = arg; | |
3dd7ae8e | 242 | |
c55e8d03 JW |
243 | if (PageLRU(page) && !PageUnevictable(page)) { |
244 | del_page_from_lru_list(page, lruvec, page_lru(page)); | |
245 | ClearPageActive(page); | |
246 | add_page_to_lru_list_tail(page, lruvec, page_lru(page)); | |
3dd7ae8e SL |
247 | (*pgmoved)++; |
248 | } | |
249 | } | |
250 | ||
251 | /* | |
252 | * pagevec_move_tail() must be called with IRQ disabled. | |
253 | * Otherwise this may cause nasty races. | |
254 | */ | |
255 | static void pagevec_move_tail(struct pagevec *pvec) | |
256 | { | |
257 | int pgmoved = 0; | |
258 | ||
259 | pagevec_lru_move_fn(pvec, pagevec_move_tail_fn, &pgmoved); | |
260 | __count_vm_events(PGROTATED, pgmoved); | |
261 | } | |
262 | ||
1da177e4 LT |
263 | /* |
264 | * Writeback is about to end against a page which has been marked for immediate | |
265 | * reclaim. If it still appears to be reclaimable, move it to the tail of the | |
902aaed0 | 266 | * inactive list. |
1da177e4 | 267 | */ |
3dd7ae8e | 268 | void rotate_reclaimable_page(struct page *page) |
1da177e4 | 269 | { |
c55e8d03 | 270 | if (!PageLocked(page) && !PageDirty(page) && |
894bc310 | 271 | !PageUnevictable(page) && PageLRU(page)) { |
ac6aadb2 MS |
272 | struct pagevec *pvec; |
273 | unsigned long flags; | |
274 | ||
09cbfeaf | 275 | get_page(page); |
b01b2141 IM |
276 | local_lock_irqsave(&lru_rotate.lock, flags); |
277 | pvec = this_cpu_ptr(&lru_rotate.pvec); | |
8f182270 | 278 | if (!pagevec_add(pvec, page) || PageCompound(page)) |
ac6aadb2 | 279 | pagevec_move_tail(pvec); |
b01b2141 | 280 | local_unlock_irqrestore(&lru_rotate.lock, flags); |
ac6aadb2 | 281 | } |
1da177e4 LT |
282 | } |
283 | ||
fa9add64 | 284 | static void update_page_reclaim_stat(struct lruvec *lruvec, |
3e2f41f1 KM |
285 | int file, int rotated) |
286 | { | |
fa9add64 | 287 | struct zone_reclaim_stat *reclaim_stat = &lruvec->reclaim_stat; |
3e2f41f1 KM |
288 | |
289 | reclaim_stat->recent_scanned[file]++; | |
290 | if (rotated) | |
291 | reclaim_stat->recent_rotated[file]++; | |
3e2f41f1 KM |
292 | } |
293 | ||
fa9add64 HD |
294 | static void __activate_page(struct page *page, struct lruvec *lruvec, |
295 | void *arg) | |
1da177e4 | 296 | { |
744ed144 | 297 | if (PageLRU(page) && !PageActive(page) && !PageUnevictable(page)) { |
9de4f22a | 298 | int file = page_is_file_lru(page); |
7a608572 | 299 | int lru = page_lru_base_type(page); |
744ed144 | 300 | |
fa9add64 | 301 | del_page_from_lru_list(page, lruvec, lru); |
7a608572 LT |
302 | SetPageActive(page); |
303 | lru += LRU_ACTIVE; | |
fa9add64 | 304 | add_page_to_lru_list(page, lruvec, lru); |
24b7e581 | 305 | trace_mm_lru_activate(page); |
4f98a2fe | 306 | |
fa9add64 HD |
307 | __count_vm_event(PGACTIVATE); |
308 | update_page_reclaim_stat(lruvec, file, 1); | |
1da177e4 | 309 | } |
eb709b0d SL |
310 | } |
311 | ||
312 | #ifdef CONFIG_SMP | |
eb709b0d SL |
313 | static void activate_page_drain(int cpu) |
314 | { | |
b01b2141 | 315 | struct pagevec *pvec = &per_cpu(lru_pvecs.activate_page, cpu); |
eb709b0d SL |
316 | |
317 | if (pagevec_count(pvec)) | |
318 | pagevec_lru_move_fn(pvec, __activate_page, NULL); | |
319 | } | |
320 | ||
5fbc4616 CM |
321 | static bool need_activate_page_drain(int cpu) |
322 | { | |
b01b2141 | 323 | return pagevec_count(&per_cpu(lru_pvecs.activate_page, cpu)) != 0; |
5fbc4616 CM |
324 | } |
325 | ||
eb709b0d SL |
326 | void activate_page(struct page *page) |
327 | { | |
800d8c63 | 328 | page = compound_head(page); |
eb709b0d | 329 | if (PageLRU(page) && !PageActive(page) && !PageUnevictable(page)) { |
b01b2141 | 330 | struct pagevec *pvec; |
eb709b0d | 331 | |
b01b2141 IM |
332 | local_lock(&lru_pvecs.lock); |
333 | pvec = this_cpu_ptr(&lru_pvecs.activate_page); | |
09cbfeaf | 334 | get_page(page); |
8f182270 | 335 | if (!pagevec_add(pvec, page) || PageCompound(page)) |
eb709b0d | 336 | pagevec_lru_move_fn(pvec, __activate_page, NULL); |
b01b2141 | 337 | local_unlock(&lru_pvecs.lock); |
eb709b0d SL |
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 | { | |
f4b7e272 | 348 | pg_data_t *pgdat = page_pgdat(page); |
eb709b0d | 349 | |
800d8c63 | 350 | page = compound_head(page); |
f4b7e272 AR |
351 | spin_lock_irq(&pgdat->lru_lock); |
352 | __activate_page(page, mem_cgroup_page_lruvec(page, pgdat), NULL); | |
353 | spin_unlock_irq(&pgdat->lru_lock); | |
1da177e4 | 354 | } |
eb709b0d | 355 | #endif |
1da177e4 | 356 | |
059285a2 MG |
357 | static void __lru_cache_activate_page(struct page *page) |
358 | { | |
b01b2141 | 359 | struct pagevec *pvec; |
059285a2 MG |
360 | int i; |
361 | ||
b01b2141 IM |
362 | local_lock(&lru_pvecs.lock); |
363 | pvec = this_cpu_ptr(&lru_pvecs.lru_add); | |
364 | ||
059285a2 MG |
365 | /* |
366 | * Search backwards on the optimistic assumption that the page being | |
367 | * activated has just been added to this pagevec. Note that only | |
368 | * the local pagevec is examined as a !PageLRU page could be in the | |
369 | * process of being released, reclaimed, migrated or on a remote | |
370 | * pagevec that is currently being drained. Furthermore, marking | |
371 | * a remote pagevec's page PageActive potentially hits a race where | |
372 | * a page is marked PageActive just after it is added to the inactive | |
373 | * list causing accounting errors and BUG_ON checks to trigger. | |
374 | */ | |
375 | for (i = pagevec_count(pvec) - 1; i >= 0; i--) { | |
376 | struct page *pagevec_page = pvec->pages[i]; | |
377 | ||
378 | if (pagevec_page == page) { | |
379 | SetPageActive(page); | |
380 | break; | |
381 | } | |
382 | } | |
383 | ||
b01b2141 | 384 | local_unlock(&lru_pvecs.lock); |
059285a2 MG |
385 | } |
386 | ||
1da177e4 LT |
387 | /* |
388 | * Mark a page as having seen activity. | |
389 | * | |
390 | * inactive,unreferenced -> inactive,referenced | |
391 | * inactive,referenced -> active,unreferenced | |
392 | * active,unreferenced -> active,referenced | |
eb39d618 HD |
393 | * |
394 | * When a newly allocated page is not yet visible, so safe for non-atomic ops, | |
395 | * __SetPageReferenced(page) may be substituted for mark_page_accessed(page). | |
1da177e4 | 396 | */ |
920c7a5d | 397 | void mark_page_accessed(struct page *page) |
1da177e4 | 398 | { |
e90309c9 | 399 | page = compound_head(page); |
059285a2 | 400 | |
a1100a74 FW |
401 | if (!PageReferenced(page)) { |
402 | SetPageReferenced(page); | |
403 | } else if (PageUnevictable(page)) { | |
404 | /* | |
405 | * Unevictable pages are on the "LRU_UNEVICTABLE" list. But, | |
406 | * this list is never rotated or maintained, so marking an | |
407 | * evictable page accessed has no effect. | |
408 | */ | |
409 | } else if (!PageActive(page)) { | |
059285a2 MG |
410 | /* |
411 | * If the page is on the LRU, queue it for activation via | |
b01b2141 | 412 | * lru_pvecs.activate_page. Otherwise, assume the page is on a |
059285a2 MG |
413 | * pagevec, mark it active and it'll be moved to the active |
414 | * LRU on the next drain. | |
415 | */ | |
416 | if (PageLRU(page)) | |
417 | activate_page(page); | |
418 | else | |
419 | __lru_cache_activate_page(page); | |
1da177e4 | 420 | ClearPageReferenced(page); |
9de4f22a | 421 | if (page_is_file_lru(page)) |
a528910e | 422 | workingset_activation(page); |
1da177e4 | 423 | } |
33c3fc71 VD |
424 | if (page_is_idle(page)) |
425 | clear_page_idle(page); | |
1da177e4 | 426 | } |
1da177e4 LT |
427 | EXPORT_SYMBOL(mark_page_accessed); |
428 | ||
2329d375 | 429 | static void __lru_cache_add(struct page *page) |
1da177e4 | 430 | { |
b01b2141 | 431 | struct pagevec *pvec; |
13f7f789 | 432 | |
b01b2141 IM |
433 | local_lock(&lru_pvecs.lock); |
434 | pvec = this_cpu_ptr(&lru_pvecs.lru_add); | |
09cbfeaf | 435 | get_page(page); |
8f182270 | 436 | if (!pagevec_add(pvec, page) || PageCompound(page)) |
a0b8cab3 | 437 | __pagevec_lru_add(pvec); |
b01b2141 | 438 | local_unlock(&lru_pvecs.lock); |
1da177e4 | 439 | } |
2329d375 JZ |
440 | |
441 | /** | |
e02a9f04 | 442 | * lru_cache_add_anon - add a page to the page lists |
2329d375 JZ |
443 | * @page: the page to add |
444 | */ | |
445 | void lru_cache_add_anon(struct page *page) | |
446 | { | |
6fb81a17 MG |
447 | if (PageActive(page)) |
448 | ClearPageActive(page); | |
2329d375 JZ |
449 | __lru_cache_add(page); |
450 | } | |
451 | ||
452 | void lru_cache_add_file(struct page *page) | |
453 | { | |
6fb81a17 MG |
454 | if (PageActive(page)) |
455 | ClearPageActive(page); | |
2329d375 JZ |
456 | __lru_cache_add(page); |
457 | } | |
458 | EXPORT_SYMBOL(lru_cache_add_file); | |
1da177e4 | 459 | |
f04e9ebb | 460 | /** |
c53954a0 | 461 | * lru_cache_add - add a page to a page list |
f04e9ebb | 462 | * @page: the page to be added to the LRU. |
2329d375 JZ |
463 | * |
464 | * Queue the page for addition to the LRU via pagevec. The decision on whether | |
465 | * to add the page to the [in]active [file|anon] list is deferred until the | |
466 | * pagevec is drained. This gives a chance for the caller of lru_cache_add() | |
467 | * have the page added to the active list using mark_page_accessed(). | |
f04e9ebb | 468 | */ |
c53954a0 | 469 | void lru_cache_add(struct page *page) |
1da177e4 | 470 | { |
309381fe SL |
471 | VM_BUG_ON_PAGE(PageActive(page) && PageUnevictable(page), page); |
472 | VM_BUG_ON_PAGE(PageLRU(page), page); | |
c53954a0 | 473 | __lru_cache_add(page); |
1da177e4 LT |
474 | } |
475 | ||
00501b53 JW |
476 | /** |
477 | * lru_cache_add_active_or_unevictable | |
478 | * @page: the page to be added to LRU | |
479 | * @vma: vma in which page is mapped for determining reclaimability | |
480 | * | |
481 | * Place @page on the active or unevictable LRU list, depending on its | |
482 | * evictability. Note that if the page is not evictable, it goes | |
483 | * directly back onto it's zone's unevictable list, it does NOT use a | |
484 | * per cpu pagevec. | |
485 | */ | |
486 | void lru_cache_add_active_or_unevictable(struct page *page, | |
487 | struct vm_area_struct *vma) | |
488 | { | |
489 | VM_BUG_ON_PAGE(PageLRU(page), page); | |
490 | ||
9c4e6b1a | 491 | if (likely((vma->vm_flags & (VM_LOCKED | VM_SPECIAL)) != VM_LOCKED)) |
00501b53 | 492 | SetPageActive(page); |
9c4e6b1a | 493 | else if (!TestSetPageMlocked(page)) { |
00501b53 JW |
494 | /* |
495 | * We use the irq-unsafe __mod_zone_page_stat because this | |
496 | * counter is not modified from interrupt context, and the pte | |
497 | * lock is held(spinlock), which implies preemption disabled. | |
498 | */ | |
499 | __mod_zone_page_state(page_zone(page), NR_MLOCK, | |
500 | hpage_nr_pages(page)); | |
501 | count_vm_event(UNEVICTABLE_PGMLOCKED); | |
502 | } | |
9c4e6b1a | 503 | lru_cache_add(page); |
00501b53 JW |
504 | } |
505 | ||
31560180 MK |
506 | /* |
507 | * If the page can not be invalidated, it is moved to the | |
508 | * inactive list to speed up its reclaim. It is moved to the | |
509 | * head of the list, rather than the tail, to give the flusher | |
510 | * threads some time to write it out, as this is much more | |
511 | * effective than the single-page writeout from reclaim. | |
278df9f4 MK |
512 | * |
513 | * If the page isn't page_mapped and dirty/writeback, the page | |
514 | * could reclaim asap using PG_reclaim. | |
515 | * | |
516 | * 1. active, mapped page -> none | |
517 | * 2. active, dirty/writeback page -> inactive, head, PG_reclaim | |
518 | * 3. inactive, mapped page -> none | |
519 | * 4. inactive, dirty/writeback page -> inactive, head, PG_reclaim | |
520 | * 5. inactive, clean -> inactive, tail | |
521 | * 6. Others -> none | |
522 | * | |
523 | * In 4, why it moves inactive's head, the VM expects the page would | |
524 | * be write it out by flusher threads as this is much more effective | |
525 | * than the single-page writeout from reclaim. | |
31560180 | 526 | */ |
cc5993bd | 527 | static void lru_deactivate_file_fn(struct page *page, struct lruvec *lruvec, |
fa9add64 | 528 | void *arg) |
31560180 MK |
529 | { |
530 | int lru, file; | |
278df9f4 | 531 | bool active; |
31560180 | 532 | |
278df9f4 | 533 | if (!PageLRU(page)) |
31560180 MK |
534 | return; |
535 | ||
bad49d9c MK |
536 | if (PageUnevictable(page)) |
537 | return; | |
538 | ||
31560180 MK |
539 | /* Some processes are using the page */ |
540 | if (page_mapped(page)) | |
541 | return; | |
542 | ||
278df9f4 | 543 | active = PageActive(page); |
9de4f22a | 544 | file = page_is_file_lru(page); |
31560180 | 545 | lru = page_lru_base_type(page); |
fa9add64 HD |
546 | |
547 | del_page_from_lru_list(page, lruvec, lru + active); | |
31560180 MK |
548 | ClearPageActive(page); |
549 | ClearPageReferenced(page); | |
31560180 | 550 | |
278df9f4 MK |
551 | if (PageWriteback(page) || PageDirty(page)) { |
552 | /* | |
553 | * PG_reclaim could be raced with end_page_writeback | |
554 | * It can make readahead confusing. But race window | |
555 | * is _really_ small and it's non-critical problem. | |
556 | */ | |
e7a1aaf2 | 557 | add_page_to_lru_list(page, lruvec, lru); |
278df9f4 MK |
558 | SetPageReclaim(page); |
559 | } else { | |
560 | /* | |
561 | * The page's writeback ends up during pagevec | |
562 | * We moves tha page into tail of inactive. | |
563 | */ | |
e7a1aaf2 | 564 | add_page_to_lru_list_tail(page, lruvec, lru); |
278df9f4 MK |
565 | __count_vm_event(PGROTATED); |
566 | } | |
567 | ||
568 | if (active) | |
569 | __count_vm_event(PGDEACTIVATE); | |
fa9add64 | 570 | update_page_reclaim_stat(lruvec, file, 0); |
31560180 MK |
571 | } |
572 | ||
9c276cc6 MK |
573 | static void lru_deactivate_fn(struct page *page, struct lruvec *lruvec, |
574 | void *arg) | |
575 | { | |
576 | if (PageLRU(page) && PageActive(page) && !PageUnevictable(page)) { | |
9de4f22a | 577 | int file = page_is_file_lru(page); |
9c276cc6 MK |
578 | int lru = page_lru_base_type(page); |
579 | ||
580 | del_page_from_lru_list(page, lruvec, lru + LRU_ACTIVE); | |
581 | ClearPageActive(page); | |
582 | ClearPageReferenced(page); | |
583 | add_page_to_lru_list(page, lruvec, lru); | |
584 | ||
585 | __count_vm_events(PGDEACTIVATE, hpage_nr_pages(page)); | |
586 | update_page_reclaim_stat(lruvec, file, 0); | |
587 | } | |
588 | } | |
10853a03 | 589 | |
f7ad2a6c | 590 | static void lru_lazyfree_fn(struct page *page, struct lruvec *lruvec, |
10853a03 MK |
591 | void *arg) |
592 | { | |
f7ad2a6c | 593 | if (PageLRU(page) && PageAnon(page) && PageSwapBacked(page) && |
24c92eb7 | 594 | !PageSwapCache(page) && !PageUnevictable(page)) { |
f7ad2a6c | 595 | bool active = PageActive(page); |
10853a03 | 596 | |
f7ad2a6c SL |
597 | del_page_from_lru_list(page, lruvec, |
598 | LRU_INACTIVE_ANON + active); | |
10853a03 MK |
599 | ClearPageActive(page); |
600 | ClearPageReferenced(page); | |
f7ad2a6c | 601 | /* |
9de4f22a HY |
602 | * Lazyfree pages are clean anonymous pages. They have |
603 | * PG_swapbacked flag cleared, to distinguish them from normal | |
604 | * anonymous pages | |
f7ad2a6c SL |
605 | */ |
606 | ClearPageSwapBacked(page); | |
607 | add_page_to_lru_list(page, lruvec, LRU_INACTIVE_FILE); | |
10853a03 | 608 | |
f7ad2a6c | 609 | __count_vm_events(PGLAZYFREE, hpage_nr_pages(page)); |
2262185c | 610 | count_memcg_page_event(page, PGLAZYFREE); |
f7ad2a6c | 611 | update_page_reclaim_stat(lruvec, 1, 0); |
10853a03 MK |
612 | } |
613 | } | |
614 | ||
902aaed0 HH |
615 | /* |
616 | * Drain pages out of the cpu's pagevecs. | |
617 | * Either "cpu" is the current CPU, and preemption has already been | |
618 | * disabled; or "cpu" is being hot-unplugged, and is already dead. | |
619 | */ | |
f0cb3c76 | 620 | void lru_add_drain_cpu(int cpu) |
1da177e4 | 621 | { |
b01b2141 | 622 | struct pagevec *pvec = &per_cpu(lru_pvecs.lru_add, cpu); |
1da177e4 | 623 | |
13f7f789 | 624 | if (pagevec_count(pvec)) |
a0b8cab3 | 625 | __pagevec_lru_add(pvec); |
902aaed0 | 626 | |
b01b2141 | 627 | pvec = &per_cpu(lru_rotate.pvec, cpu); |
902aaed0 HH |
628 | if (pagevec_count(pvec)) { |
629 | unsigned long flags; | |
630 | ||
631 | /* No harm done if a racing interrupt already did this */ | |
b01b2141 | 632 | local_lock_irqsave(&lru_rotate.lock, flags); |
902aaed0 | 633 | pagevec_move_tail(pvec); |
b01b2141 | 634 | local_unlock_irqrestore(&lru_rotate.lock, flags); |
902aaed0 | 635 | } |
31560180 | 636 | |
b01b2141 | 637 | pvec = &per_cpu(lru_pvecs.lru_deactivate_file, cpu); |
31560180 | 638 | if (pagevec_count(pvec)) |
cc5993bd | 639 | pagevec_lru_move_fn(pvec, lru_deactivate_file_fn, NULL); |
eb709b0d | 640 | |
b01b2141 | 641 | pvec = &per_cpu(lru_pvecs.lru_deactivate, cpu); |
9c276cc6 MK |
642 | if (pagevec_count(pvec)) |
643 | pagevec_lru_move_fn(pvec, lru_deactivate_fn, NULL); | |
644 | ||
b01b2141 | 645 | pvec = &per_cpu(lru_pvecs.lru_lazyfree, cpu); |
10853a03 | 646 | if (pagevec_count(pvec)) |
f7ad2a6c | 647 | pagevec_lru_move_fn(pvec, lru_lazyfree_fn, NULL); |
10853a03 | 648 | |
eb709b0d | 649 | activate_page_drain(cpu); |
31560180 MK |
650 | } |
651 | ||
652 | /** | |
cc5993bd | 653 | * deactivate_file_page - forcefully deactivate a file page |
31560180 MK |
654 | * @page: page to deactivate |
655 | * | |
656 | * This function hints the VM that @page is a good reclaim candidate, | |
657 | * for example if its invalidation fails due to the page being dirty | |
658 | * or under writeback. | |
659 | */ | |
cc5993bd | 660 | void deactivate_file_page(struct page *page) |
31560180 | 661 | { |
821ed6bb | 662 | /* |
cc5993bd MK |
663 | * In a workload with many unevictable page such as mprotect, |
664 | * unevictable page deactivation for accelerating reclaim is pointless. | |
821ed6bb MK |
665 | */ |
666 | if (PageUnevictable(page)) | |
667 | return; | |
668 | ||
31560180 | 669 | if (likely(get_page_unless_zero(page))) { |
b01b2141 IM |
670 | struct pagevec *pvec; |
671 | ||
672 | local_lock(&lru_pvecs.lock); | |
673 | pvec = this_cpu_ptr(&lru_pvecs.lru_deactivate_file); | |
31560180 | 674 | |
8f182270 | 675 | if (!pagevec_add(pvec, page) || PageCompound(page)) |
cc5993bd | 676 | pagevec_lru_move_fn(pvec, lru_deactivate_file_fn, NULL); |
b01b2141 | 677 | local_unlock(&lru_pvecs.lock); |
31560180 | 678 | } |
80bfed90 AM |
679 | } |
680 | ||
9c276cc6 MK |
681 | /* |
682 | * deactivate_page - deactivate a page | |
683 | * @page: page to deactivate | |
684 | * | |
685 | * deactivate_page() moves @page to the inactive list if @page was on the active | |
686 | * list and was not an unevictable page. This is done to accelerate the reclaim | |
687 | * of @page. | |
688 | */ | |
689 | void deactivate_page(struct page *page) | |
690 | { | |
691 | if (PageLRU(page) && PageActive(page) && !PageUnevictable(page)) { | |
b01b2141 | 692 | struct pagevec *pvec; |
9c276cc6 | 693 | |
b01b2141 IM |
694 | local_lock(&lru_pvecs.lock); |
695 | pvec = this_cpu_ptr(&lru_pvecs.lru_deactivate); | |
9c276cc6 MK |
696 | get_page(page); |
697 | if (!pagevec_add(pvec, page) || PageCompound(page)) | |
698 | pagevec_lru_move_fn(pvec, lru_deactivate_fn, NULL); | |
b01b2141 | 699 | local_unlock(&lru_pvecs.lock); |
9c276cc6 MK |
700 | } |
701 | } | |
702 | ||
10853a03 | 703 | /** |
f7ad2a6c | 704 | * mark_page_lazyfree - make an anon page lazyfree |
10853a03 MK |
705 | * @page: page to deactivate |
706 | * | |
f7ad2a6c SL |
707 | * mark_page_lazyfree() moves @page to the inactive file list. |
708 | * This is done to accelerate the reclaim of @page. | |
10853a03 | 709 | */ |
f7ad2a6c | 710 | void mark_page_lazyfree(struct page *page) |
10853a03 | 711 | { |
f7ad2a6c | 712 | if (PageLRU(page) && PageAnon(page) && PageSwapBacked(page) && |
24c92eb7 | 713 | !PageSwapCache(page) && !PageUnevictable(page)) { |
b01b2141 | 714 | struct pagevec *pvec; |
10853a03 | 715 | |
b01b2141 IM |
716 | local_lock(&lru_pvecs.lock); |
717 | pvec = this_cpu_ptr(&lru_pvecs.lru_lazyfree); | |
09cbfeaf | 718 | get_page(page); |
8f182270 | 719 | if (!pagevec_add(pvec, page) || PageCompound(page)) |
f7ad2a6c | 720 | pagevec_lru_move_fn(pvec, lru_lazyfree_fn, NULL); |
b01b2141 | 721 | local_unlock(&lru_pvecs.lock); |
10853a03 MK |
722 | } |
723 | } | |
724 | ||
80bfed90 AM |
725 | void lru_add_drain(void) |
726 | { | |
b01b2141 IM |
727 | local_lock(&lru_pvecs.lock); |
728 | lru_add_drain_cpu(smp_processor_id()); | |
729 | local_unlock(&lru_pvecs.lock); | |
730 | } | |
731 | ||
732 | void lru_add_drain_cpu_zone(struct zone *zone) | |
733 | { | |
734 | local_lock(&lru_pvecs.lock); | |
735 | lru_add_drain_cpu(smp_processor_id()); | |
736 | drain_local_pages(zone); | |
737 | local_unlock(&lru_pvecs.lock); | |
1da177e4 LT |
738 | } |
739 | ||
6ea183d6 MH |
740 | #ifdef CONFIG_SMP |
741 | ||
742 | static DEFINE_PER_CPU(struct work_struct, lru_add_drain_work); | |
743 | ||
c4028958 | 744 | static void lru_add_drain_per_cpu(struct work_struct *dummy) |
053837fc NP |
745 | { |
746 | lru_add_drain(); | |
747 | } | |
748 | ||
9852a721 MH |
749 | /* |
750 | * Doesn't need any cpu hotplug locking because we do rely on per-cpu | |
751 | * kworkers being shut down before our page_alloc_cpu_dead callback is | |
752 | * executed on the offlined cpu. | |
753 | * Calling this function with cpu hotplug locks held can actually lead | |
754 | * to obscure indirect dependencies via WQ context. | |
755 | */ | |
756 | void lru_add_drain_all(void) | |
053837fc | 757 | { |
eef1a429 | 758 | static seqcount_t seqcount = SEQCNT_ZERO(seqcount); |
5fbc4616 CM |
759 | static DEFINE_MUTEX(lock); |
760 | static struct cpumask has_work; | |
eef1a429 | 761 | int cpu, seq; |
5fbc4616 | 762 | |
ce612879 MH |
763 | /* |
764 | * Make sure nobody triggers this path before mm_percpu_wq is fully | |
765 | * initialized. | |
766 | */ | |
767 | if (WARN_ON(!mm_percpu_wq)) | |
768 | return; | |
769 | ||
eef1a429 KK |
770 | seq = raw_read_seqcount_latch(&seqcount); |
771 | ||
5fbc4616 | 772 | mutex_lock(&lock); |
eef1a429 KK |
773 | |
774 | /* | |
775 | * Piggyback on drain started and finished while we waited for lock: | |
776 | * all pages pended at the time of our enter were drained from vectors. | |
777 | */ | |
778 | if (__read_seqcount_retry(&seqcount, seq)) | |
779 | goto done; | |
780 | ||
781 | raw_write_seqcount_latch(&seqcount); | |
782 | ||
5fbc4616 CM |
783 | cpumask_clear(&has_work); |
784 | ||
785 | for_each_online_cpu(cpu) { | |
786 | struct work_struct *work = &per_cpu(lru_add_drain_work, cpu); | |
787 | ||
b01b2141 IM |
788 | if (pagevec_count(&per_cpu(lru_pvecs.lru_add, cpu)) || |
789 | pagevec_count(&per_cpu(lru_rotate.pvec, cpu)) || | |
790 | pagevec_count(&per_cpu(lru_pvecs.lru_deactivate_file, cpu)) || | |
791 | pagevec_count(&per_cpu(lru_pvecs.lru_deactivate, cpu)) || | |
792 | pagevec_count(&per_cpu(lru_pvecs.lru_lazyfree, cpu)) || | |
5fbc4616 CM |
793 | need_activate_page_drain(cpu)) { |
794 | INIT_WORK(work, lru_add_drain_per_cpu); | |
ce612879 | 795 | queue_work_on(cpu, mm_percpu_wq, work); |
5fbc4616 CM |
796 | cpumask_set_cpu(cpu, &has_work); |
797 | } | |
798 | } | |
799 | ||
800 | for_each_cpu(cpu, &has_work) | |
801 | flush_work(&per_cpu(lru_add_drain_work, cpu)); | |
802 | ||
eef1a429 | 803 | done: |
5fbc4616 | 804 | mutex_unlock(&lock); |
053837fc | 805 | } |
6ea183d6 MH |
806 | #else |
807 | void lru_add_drain_all(void) | |
808 | { | |
809 | lru_add_drain(); | |
810 | } | |
811 | #endif | |
053837fc | 812 | |
aabfb572 | 813 | /** |
ea1754a0 | 814 | * release_pages - batched put_page() |
aabfb572 MH |
815 | * @pages: array of pages to release |
816 | * @nr: number of pages | |
1da177e4 | 817 | * |
aabfb572 MH |
818 | * Decrement the reference count on all the pages in @pages. If it |
819 | * fell to zero, remove the page from the LRU and free it. | |
1da177e4 | 820 | */ |
c6f92f9f | 821 | void release_pages(struct page **pages, int nr) |
1da177e4 LT |
822 | { |
823 | int i; | |
cc59850e | 824 | LIST_HEAD(pages_to_free); |
599d0c95 | 825 | struct pglist_data *locked_pgdat = NULL; |
fa9add64 | 826 | struct lruvec *lruvec; |
902aaed0 | 827 | unsigned long uninitialized_var(flags); |
aabfb572 | 828 | unsigned int uninitialized_var(lock_batch); |
1da177e4 | 829 | |
1da177e4 LT |
830 | for (i = 0; i < nr; i++) { |
831 | struct page *page = pages[i]; | |
1da177e4 | 832 | |
aabfb572 MH |
833 | /* |
834 | * Make sure the IRQ-safe lock-holding time does not get | |
835 | * excessive with a continuous string of pages from the | |
599d0c95 | 836 | * same pgdat. The lock is held only if pgdat != NULL. |
aabfb572 | 837 | */ |
599d0c95 MG |
838 | if (locked_pgdat && ++lock_batch == SWAP_CLUSTER_MAX) { |
839 | spin_unlock_irqrestore(&locked_pgdat->lru_lock, flags); | |
840 | locked_pgdat = NULL; | |
aabfb572 MH |
841 | } |
842 | ||
6fcb52a5 | 843 | if (is_huge_zero_page(page)) |
aa88b68c | 844 | continue; |
aa88b68c | 845 | |
c5d6c45e | 846 | if (is_zone_device_page(page)) { |
df6ad698 JG |
847 | if (locked_pgdat) { |
848 | spin_unlock_irqrestore(&locked_pgdat->lru_lock, | |
849 | flags); | |
850 | locked_pgdat = NULL; | |
851 | } | |
c5d6c45e IW |
852 | /* |
853 | * ZONE_DEVICE pages that return 'false' from | |
854 | * put_devmap_managed_page() do not require special | |
855 | * processing, and instead, expect a call to | |
856 | * put_page_testzero(). | |
857 | */ | |
07d80269 JH |
858 | if (page_is_devmap_managed(page)) { |
859 | put_devmap_managed_page(page); | |
c5d6c45e | 860 | continue; |
07d80269 | 861 | } |
df6ad698 JG |
862 | } |
863 | ||
ddc58f27 | 864 | page = compound_head(page); |
b5810039 | 865 | if (!put_page_testzero(page)) |
1da177e4 LT |
866 | continue; |
867 | ||
ddc58f27 | 868 | if (PageCompound(page)) { |
599d0c95 MG |
869 | if (locked_pgdat) { |
870 | spin_unlock_irqrestore(&locked_pgdat->lru_lock, flags); | |
871 | locked_pgdat = NULL; | |
ddc58f27 KS |
872 | } |
873 | __put_compound_page(page); | |
874 | continue; | |
875 | } | |
876 | ||
46453a6e | 877 | if (PageLRU(page)) { |
599d0c95 | 878 | struct pglist_data *pgdat = page_pgdat(page); |
894bc310 | 879 | |
599d0c95 MG |
880 | if (pgdat != locked_pgdat) { |
881 | if (locked_pgdat) | |
882 | spin_unlock_irqrestore(&locked_pgdat->lru_lock, | |
902aaed0 | 883 | flags); |
aabfb572 | 884 | lock_batch = 0; |
599d0c95 MG |
885 | locked_pgdat = pgdat; |
886 | spin_lock_irqsave(&locked_pgdat->lru_lock, flags); | |
46453a6e | 887 | } |
fa9add64 | 888 | |
599d0c95 | 889 | lruvec = mem_cgroup_page_lruvec(page, locked_pgdat); |
309381fe | 890 | VM_BUG_ON_PAGE(!PageLRU(page), page); |
67453911 | 891 | __ClearPageLRU(page); |
fa9add64 | 892 | del_page_from_lru_list(page, lruvec, page_off_lru(page)); |
46453a6e NP |
893 | } |
894 | ||
c53954a0 | 895 | /* Clear Active bit in case of parallel mark_page_accessed */ |
e3741b50 | 896 | __ClearPageActive(page); |
62906027 | 897 | __ClearPageWaiters(page); |
c53954a0 | 898 | |
cc59850e | 899 | list_add(&page->lru, &pages_to_free); |
1da177e4 | 900 | } |
599d0c95 MG |
901 | if (locked_pgdat) |
902 | spin_unlock_irqrestore(&locked_pgdat->lru_lock, flags); | |
1da177e4 | 903 | |
747db954 | 904 | mem_cgroup_uncharge_list(&pages_to_free); |
2d4894b5 | 905 | free_unref_page_list(&pages_to_free); |
1da177e4 | 906 | } |
0be8557b | 907 | EXPORT_SYMBOL(release_pages); |
1da177e4 LT |
908 | |
909 | /* | |
910 | * The pages which we're about to release may be in the deferred lru-addition | |
911 | * queues. That would prevent them from really being freed right now. That's | |
912 | * OK from a correctness point of view but is inefficient - those pages may be | |
913 | * cache-warm and we want to give them back to the page allocator ASAP. | |
914 | * | |
915 | * So __pagevec_release() will drain those queues here. __pagevec_lru_add() | |
916 | * and __pagevec_lru_add_active() call release_pages() directly to avoid | |
917 | * mutual recursion. | |
918 | */ | |
919 | void __pagevec_release(struct pagevec *pvec) | |
920 | { | |
7f0b5fb9 | 921 | if (!pvec->percpu_pvec_drained) { |
d9ed0d08 | 922 | lru_add_drain(); |
7f0b5fb9 | 923 | pvec->percpu_pvec_drained = true; |
d9ed0d08 | 924 | } |
c6f92f9f | 925 | release_pages(pvec->pages, pagevec_count(pvec)); |
1da177e4 LT |
926 | pagevec_reinit(pvec); |
927 | } | |
7f285701 SF |
928 | EXPORT_SYMBOL(__pagevec_release); |
929 | ||
12d27107 | 930 | #ifdef CONFIG_TRANSPARENT_HUGEPAGE |
71e3aac0 | 931 | /* used by __split_huge_page_refcount() */ |
fa9add64 | 932 | void lru_add_page_tail(struct page *page, struct page *page_tail, |
5bc7b8ac | 933 | struct lruvec *lruvec, struct list_head *list) |
71e3aac0 | 934 | { |
71e3aac0 | 935 | const int file = 0; |
71e3aac0 | 936 | |
309381fe SL |
937 | VM_BUG_ON_PAGE(!PageHead(page), page); |
938 | VM_BUG_ON_PAGE(PageCompound(page_tail), page); | |
939 | VM_BUG_ON_PAGE(PageLRU(page_tail), page); | |
35f3aa39 | 940 | lockdep_assert_held(&lruvec_pgdat(lruvec)->lru_lock); |
71e3aac0 | 941 | |
5bc7b8ac SL |
942 | if (!list) |
943 | SetPageLRU(page_tail); | |
71e3aac0 | 944 | |
12d27107 HD |
945 | if (likely(PageLRU(page))) |
946 | list_add_tail(&page_tail->lru, &page->lru); | |
5bc7b8ac SL |
947 | else if (list) { |
948 | /* page reclaim is reclaiming a huge page */ | |
949 | get_page(page_tail); | |
950 | list_add_tail(&page_tail->lru, list); | |
951 | } else { | |
12d27107 HD |
952 | /* |
953 | * Head page has not yet been counted, as an hpage, | |
954 | * so we must account for each subpage individually. | |
955 | * | |
e7a1aaf2 YZ |
956 | * Put page_tail on the list at the correct position |
957 | * so they all end up in order. | |
12d27107 | 958 | */ |
e7a1aaf2 YZ |
959 | add_page_to_lru_list_tail(page_tail, lruvec, |
960 | page_lru(page_tail)); | |
71e3aac0 | 961 | } |
7512102c HD |
962 | |
963 | if (!PageUnevictable(page)) | |
e180cf80 | 964 | update_page_reclaim_stat(lruvec, file, PageActive(page_tail)); |
71e3aac0 | 965 | } |
12d27107 | 966 | #endif /* CONFIG_TRANSPARENT_HUGEPAGE */ |
71e3aac0 | 967 | |
fa9add64 HD |
968 | static void __pagevec_lru_add_fn(struct page *page, struct lruvec *lruvec, |
969 | void *arg) | |
3dd7ae8e | 970 | { |
9c4e6b1a SB |
971 | enum lru_list lru; |
972 | int was_unevictable = TestClearPageUnevictable(page); | |
3dd7ae8e | 973 | |
309381fe | 974 | VM_BUG_ON_PAGE(PageLRU(page), page); |
3dd7ae8e | 975 | |
9c4e6b1a SB |
976 | /* |
977 | * Page becomes evictable in two ways: | |
dae966dc | 978 | * 1) Within LRU lock [munlock_vma_page() and __munlock_pagevec()]. |
9c4e6b1a SB |
979 | * 2) Before acquiring LRU lock to put the page to correct LRU and then |
980 | * a) do PageLRU check with lock [check_move_unevictable_pages] | |
981 | * b) do PageLRU check before lock [clear_page_mlock] | |
982 | * | |
983 | * (1) & (2a) are ok as LRU lock will serialize them. For (2b), we need | |
984 | * following strict ordering: | |
985 | * | |
986 | * #0: __pagevec_lru_add_fn #1: clear_page_mlock | |
987 | * | |
988 | * SetPageLRU() TestClearPageMlocked() | |
989 | * smp_mb() // explicit ordering // above provides strict | |
990 | * // ordering | |
991 | * PageMlocked() PageLRU() | |
992 | * | |
993 | * | |
994 | * if '#1' does not observe setting of PG_lru by '#0' and fails | |
995 | * isolation, the explicit barrier will make sure that page_evictable | |
996 | * check will put the page in correct LRU. Without smp_mb(), SetPageLRU | |
997 | * can be reordered after PageMlocked check and can make '#1' to fail | |
998 | * the isolation of the page whose Mlocked bit is cleared (#0 is also | |
999 | * looking at the same page) and the evictable page will be stranded | |
1000 | * in an unevictable LRU. | |
1001 | */ | |
9a9b6cce YS |
1002 | SetPageLRU(page); |
1003 | smp_mb__after_atomic(); | |
9c4e6b1a SB |
1004 | |
1005 | if (page_evictable(page)) { | |
1006 | lru = page_lru(page); | |
9de4f22a | 1007 | update_page_reclaim_stat(lruvec, page_is_file_lru(page), |
9c4e6b1a SB |
1008 | PageActive(page)); |
1009 | if (was_unevictable) | |
1010 | count_vm_event(UNEVICTABLE_PGRESCUED); | |
1011 | } else { | |
1012 | lru = LRU_UNEVICTABLE; | |
1013 | ClearPageActive(page); | |
1014 | SetPageUnevictable(page); | |
1015 | if (!was_unevictable) | |
1016 | count_vm_event(UNEVICTABLE_PGCULLED); | |
1017 | } | |
1018 | ||
fa9add64 | 1019 | add_page_to_lru_list(page, lruvec, lru); |
24b7e581 | 1020 | trace_mm_lru_insertion(page, lru); |
3dd7ae8e SL |
1021 | } |
1022 | ||
1da177e4 LT |
1023 | /* |
1024 | * Add the passed pages to the LRU, then drop the caller's refcount | |
1025 | * on them. Reinitialises the caller's pagevec. | |
1026 | */ | |
a0b8cab3 | 1027 | void __pagevec_lru_add(struct pagevec *pvec) |
1da177e4 | 1028 | { |
a0b8cab3 | 1029 | pagevec_lru_move_fn(pvec, __pagevec_lru_add_fn, NULL); |
1da177e4 | 1030 | } |
1da177e4 | 1031 | |
0cd6144a JW |
1032 | /** |
1033 | * pagevec_lookup_entries - gang pagecache lookup | |
1034 | * @pvec: Where the resulting entries are placed | |
1035 | * @mapping: The address_space to search | |
1036 | * @start: The starting entry index | |
cb6f0f34 | 1037 | * @nr_entries: The maximum number of pages |
0cd6144a JW |
1038 | * @indices: The cache indices corresponding to the entries in @pvec |
1039 | * | |
1040 | * pagevec_lookup_entries() will search for and return a group of up | |
f144c390 | 1041 | * to @nr_pages pages and shadow entries in the mapping. All |
0cd6144a JW |
1042 | * entries are placed in @pvec. pagevec_lookup_entries() takes a |
1043 | * reference against actual pages in @pvec. | |
1044 | * | |
1045 | * The search returns a group of mapping-contiguous entries with | |
1046 | * ascending indexes. There may be holes in the indices due to | |
1047 | * not-present entries. | |
1048 | * | |
71725ed1 HD |
1049 | * Only one subpage of a Transparent Huge Page is returned in one call: |
1050 | * allowing truncate_inode_pages_range() to evict the whole THP without | |
1051 | * cycling through a pagevec of extra references. | |
1052 | * | |
0cd6144a JW |
1053 | * pagevec_lookup_entries() returns the number of entries which were |
1054 | * found. | |
1055 | */ | |
1056 | unsigned pagevec_lookup_entries(struct pagevec *pvec, | |
1057 | struct address_space *mapping, | |
e02a9f04 | 1058 | pgoff_t start, unsigned nr_entries, |
0cd6144a JW |
1059 | pgoff_t *indices) |
1060 | { | |
e02a9f04 | 1061 | pvec->nr = find_get_entries(mapping, start, nr_entries, |
0cd6144a JW |
1062 | pvec->pages, indices); |
1063 | return pagevec_count(pvec); | |
1064 | } | |
1065 | ||
1066 | /** | |
1067 | * pagevec_remove_exceptionals - pagevec exceptionals pruning | |
1068 | * @pvec: The pagevec to prune | |
1069 | * | |
1070 | * pagevec_lookup_entries() fills both pages and exceptional radix | |
1071 | * tree entries into the pagevec. This function prunes all | |
1072 | * exceptionals from @pvec without leaving holes, so that it can be | |
1073 | * passed on to page-only pagevec operations. | |
1074 | */ | |
1075 | void pagevec_remove_exceptionals(struct pagevec *pvec) | |
1076 | { | |
1077 | int i, j; | |
1078 | ||
1079 | for (i = 0, j = 0; i < pagevec_count(pvec); i++) { | |
1080 | struct page *page = pvec->pages[i]; | |
3159f943 | 1081 | if (!xa_is_value(page)) |
0cd6144a JW |
1082 | pvec->pages[j++] = page; |
1083 | } | |
1084 | pvec->nr = j; | |
1085 | } | |
1086 | ||
1da177e4 | 1087 | /** |
b947cee4 | 1088 | * pagevec_lookup_range - gang pagecache lookup |
1da177e4 LT |
1089 | * @pvec: Where the resulting pages are placed |
1090 | * @mapping: The address_space to search | |
1091 | * @start: The starting page index | |
b947cee4 | 1092 | * @end: The final page index |
1da177e4 | 1093 | * |
e02a9f04 | 1094 | * pagevec_lookup_range() will search for & return a group of up to PAGEVEC_SIZE |
b947cee4 JK |
1095 | * pages in the mapping starting from index @start and upto index @end |
1096 | * (inclusive). The pages are placed in @pvec. pagevec_lookup() takes a | |
1da177e4 LT |
1097 | * reference against the pages in @pvec. |
1098 | * | |
1099 | * The search returns a group of mapping-contiguous pages with ascending | |
d72dc8a2 JK |
1100 | * indexes. There may be holes in the indices due to not-present pages. We |
1101 | * also update @start to index the next page for the traversal. | |
1da177e4 | 1102 | * |
b947cee4 | 1103 | * pagevec_lookup_range() returns the number of pages which were found. If this |
e02a9f04 | 1104 | * number is smaller than PAGEVEC_SIZE, the end of specified range has been |
b947cee4 | 1105 | * reached. |
1da177e4 | 1106 | */ |
b947cee4 | 1107 | unsigned pagevec_lookup_range(struct pagevec *pvec, |
397162ff | 1108 | struct address_space *mapping, pgoff_t *start, pgoff_t end) |
1da177e4 | 1109 | { |
397162ff | 1110 | pvec->nr = find_get_pages_range(mapping, start, end, PAGEVEC_SIZE, |
b947cee4 | 1111 | pvec->pages); |
1da177e4 LT |
1112 | return pagevec_count(pvec); |
1113 | } | |
b947cee4 | 1114 | EXPORT_SYMBOL(pagevec_lookup_range); |
78539fdf | 1115 | |
72b045ae JK |
1116 | unsigned pagevec_lookup_range_tag(struct pagevec *pvec, |
1117 | struct address_space *mapping, pgoff_t *index, pgoff_t end, | |
10bbd235 | 1118 | xa_mark_t tag) |
1da177e4 | 1119 | { |
72b045ae | 1120 | pvec->nr = find_get_pages_range_tag(mapping, index, end, tag, |
67fd707f | 1121 | PAGEVEC_SIZE, pvec->pages); |
1da177e4 LT |
1122 | return pagevec_count(pvec); |
1123 | } | |
72b045ae | 1124 | EXPORT_SYMBOL(pagevec_lookup_range_tag); |
1da177e4 | 1125 | |
93d3b714 JK |
1126 | unsigned pagevec_lookup_range_nr_tag(struct pagevec *pvec, |
1127 | struct address_space *mapping, pgoff_t *index, pgoff_t end, | |
10bbd235 | 1128 | xa_mark_t tag, unsigned max_pages) |
93d3b714 JK |
1129 | { |
1130 | pvec->nr = find_get_pages_range_tag(mapping, index, end, tag, | |
1131 | min_t(unsigned int, max_pages, PAGEVEC_SIZE), pvec->pages); | |
1132 | return pagevec_count(pvec); | |
1133 | } | |
1134 | EXPORT_SYMBOL(pagevec_lookup_range_nr_tag); | |
1da177e4 LT |
1135 | /* |
1136 | * Perform any setup for the swap system | |
1137 | */ | |
1138 | void __init swap_setup(void) | |
1139 | { | |
ca79b0c2 | 1140 | unsigned long megs = totalram_pages() >> (20 - PAGE_SHIFT); |
e0bf68dd | 1141 | |
1da177e4 LT |
1142 | /* Use a smaller cluster for small-memory machines */ |
1143 | if (megs < 16) | |
1144 | page_cluster = 2; | |
1145 | else | |
1146 | page_cluster = 3; | |
1147 | /* | |
1148 | * Right now other parts of the system means that we | |
1149 | * _really_ don't want to cluster much more | |
1150 | */ | |
1da177e4 | 1151 | } |
07d80269 JH |
1152 | |
1153 | #ifdef CONFIG_DEV_PAGEMAP_OPS | |
1154 | void put_devmap_managed_page(struct page *page) | |
1155 | { | |
1156 | int count; | |
1157 | ||
1158 | if (WARN_ON_ONCE(!page_is_devmap_managed(page))) | |
1159 | return; | |
1160 | ||
1161 | count = page_ref_dec_return(page); | |
1162 | ||
1163 | /* | |
1164 | * devmap page refcounts are 1-based, rather than 0-based: if | |
1165 | * refcount is 1, then the page is free and the refcount is | |
1166 | * stable because nobody holds a reference on the page. | |
1167 | */ | |
1168 | if (count == 1) | |
1169 | free_devmap_managed_page(page); | |
1170 | else if (!count) | |
1171 | __put_page(page); | |
1172 | } | |
1173 | EXPORT_SYMBOL(put_devmap_managed_page); | |
1174 | #endif |