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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> |
1da177e4 | 38 | |
64d6519d LS |
39 | #include "internal.h" |
40 | ||
c6286c98 MG |
41 | #define CREATE_TRACE_POINTS |
42 | #include <trace/events/pagemap.h> | |
43 | ||
1da177e4 LT |
44 | /* How many pages do we try to swap or page in/out together? */ |
45 | int page_cluster; | |
46 | ||
13f7f789 | 47 | static DEFINE_PER_CPU(struct pagevec, lru_add_pvec); |
f84f9504 | 48 | static DEFINE_PER_CPU(struct pagevec, lru_rotate_pvecs); |
cc5993bd | 49 | static DEFINE_PER_CPU(struct pagevec, lru_deactivate_file_pvecs); |
9c276cc6 | 50 | static DEFINE_PER_CPU(struct pagevec, lru_deactivate_pvecs); |
f7ad2a6c | 51 | static DEFINE_PER_CPU(struct pagevec, lru_lazyfree_pvecs); |
a4a921aa ML |
52 | #ifdef CONFIG_SMP |
53 | static DEFINE_PER_CPU(struct pagevec, activate_page_pvecs); | |
54 | #endif | |
902aaed0 | 55 | |
b221385b AB |
56 | /* |
57 | * This path almost never happens for VM activity - pages are normally | |
58 | * freed via pagevecs. But it gets used by networking. | |
59 | */ | |
920c7a5d | 60 | static void __page_cache_release(struct page *page) |
b221385b AB |
61 | { |
62 | if (PageLRU(page)) { | |
f4b7e272 | 63 | pg_data_t *pgdat = page_pgdat(page); |
fa9add64 HD |
64 | struct lruvec *lruvec; |
65 | unsigned long flags; | |
b221385b | 66 | |
f4b7e272 AR |
67 | spin_lock_irqsave(&pgdat->lru_lock, flags); |
68 | lruvec = mem_cgroup_page_lruvec(page, pgdat); | |
309381fe | 69 | VM_BUG_ON_PAGE(!PageLRU(page), page); |
b221385b | 70 | __ClearPageLRU(page); |
fa9add64 | 71 | del_page_from_lru_list(page, lruvec, page_off_lru(page)); |
f4b7e272 | 72 | spin_unlock_irqrestore(&pgdat->lru_lock, flags); |
b221385b | 73 | } |
62906027 | 74 | __ClearPageWaiters(page); |
91807063 AA |
75 | } |
76 | ||
77 | static void __put_single_page(struct page *page) | |
78 | { | |
79 | __page_cache_release(page); | |
7ae88534 | 80 | mem_cgroup_uncharge(page); |
2d4894b5 | 81 | free_unref_page(page); |
b221385b AB |
82 | } |
83 | ||
91807063 | 84 | static void __put_compound_page(struct page *page) |
1da177e4 | 85 | { |
91807063 | 86 | compound_page_dtor *dtor; |
1da177e4 | 87 | |
822fc613 NH |
88 | /* |
89 | * __page_cache_release() is supposed to be called for thp, not for | |
90 | * hugetlb. This is because hugetlb page does never have PageLRU set | |
91 | * (it's never listed to any LRU lists) and no memcg routines should | |
92 | * be called for hugetlb (it has a separate hugetlb_cgroup.) | |
93 | */ | |
94 | if (!PageHuge(page)) | |
95 | __page_cache_release(page); | |
91807063 AA |
96 | dtor = get_compound_page_dtor(page); |
97 | (*dtor)(page); | |
98 | } | |
99 | ||
ddc58f27 | 100 | void __put_page(struct page *page) |
8519fb30 | 101 | { |
71389703 DW |
102 | if (is_zone_device_page(page)) { |
103 | put_dev_pagemap(page->pgmap); | |
104 | ||
105 | /* | |
106 | * The page belongs to the device that created pgmap. Do | |
107 | * not return it to page allocator. | |
108 | */ | |
109 | return; | |
110 | } | |
111 | ||
8519fb30 | 112 | if (unlikely(PageCompound(page))) |
ddc58f27 KS |
113 | __put_compound_page(page); |
114 | else | |
91807063 | 115 | __put_single_page(page); |
1da177e4 | 116 | } |
ddc58f27 | 117 | EXPORT_SYMBOL(__put_page); |
70b50f94 | 118 | |
1d7ea732 | 119 | /** |
7682486b RD |
120 | * put_pages_list() - release a list of pages |
121 | * @pages: list of pages threaded on page->lru | |
1d7ea732 AZ |
122 | * |
123 | * Release a list of pages which are strung together on page.lru. Currently | |
124 | * used by read_cache_pages() and related error recovery code. | |
1d7ea732 AZ |
125 | */ |
126 | void put_pages_list(struct list_head *pages) | |
127 | { | |
128 | while (!list_empty(pages)) { | |
129 | struct page *victim; | |
130 | ||
f86196ea | 131 | victim = lru_to_page(pages); |
1d7ea732 | 132 | list_del(&victim->lru); |
09cbfeaf | 133 | put_page(victim); |
1d7ea732 AZ |
134 | } |
135 | } | |
136 | EXPORT_SYMBOL(put_pages_list); | |
137 | ||
18022c5d MG |
138 | /* |
139 | * get_kernel_pages() - pin kernel pages in memory | |
140 | * @kiov: An array of struct kvec structures | |
141 | * @nr_segs: number of segments to pin | |
142 | * @write: pinning for read/write, currently ignored | |
143 | * @pages: array that receives pointers to the pages pinned. | |
144 | * Should be at least nr_segs long. | |
145 | * | |
146 | * Returns number of pages pinned. This may be fewer than the number | |
147 | * requested. If nr_pages is 0 or negative, returns 0. If no pages | |
148 | * were pinned, returns -errno. Each page returned must be released | |
149 | * with a put_page() call when it is finished with. | |
150 | */ | |
151 | int get_kernel_pages(const struct kvec *kiov, int nr_segs, int write, | |
152 | struct page **pages) | |
153 | { | |
154 | int seg; | |
155 | ||
156 | for (seg = 0; seg < nr_segs; seg++) { | |
157 | if (WARN_ON(kiov[seg].iov_len != PAGE_SIZE)) | |
158 | return seg; | |
159 | ||
5a178119 | 160 | pages[seg] = kmap_to_page(kiov[seg].iov_base); |
09cbfeaf | 161 | get_page(pages[seg]); |
18022c5d MG |
162 | } |
163 | ||
164 | return seg; | |
165 | } | |
166 | EXPORT_SYMBOL_GPL(get_kernel_pages); | |
167 | ||
168 | /* | |
169 | * get_kernel_page() - pin a kernel page in memory | |
170 | * @start: starting kernel address | |
171 | * @write: pinning for read/write, currently ignored | |
172 | * @pages: array that receives pointer to the page pinned. | |
173 | * Must be at least nr_segs long. | |
174 | * | |
175 | * Returns 1 if page is pinned. If the page was not pinned, returns | |
176 | * -errno. The page returned must be released with a put_page() call | |
177 | * when it is finished with. | |
178 | */ | |
179 | int get_kernel_page(unsigned long start, int write, struct page **pages) | |
180 | { | |
181 | const struct kvec kiov = { | |
182 | .iov_base = (void *)start, | |
183 | .iov_len = PAGE_SIZE | |
184 | }; | |
185 | ||
186 | return get_kernel_pages(&kiov, 1, write, pages); | |
187 | } | |
188 | EXPORT_SYMBOL_GPL(get_kernel_page); | |
189 | ||
3dd7ae8e | 190 | static void pagevec_lru_move_fn(struct pagevec *pvec, |
fa9add64 HD |
191 | void (*move_fn)(struct page *page, struct lruvec *lruvec, void *arg), |
192 | void *arg) | |
902aaed0 HH |
193 | { |
194 | int i; | |
68eb0731 | 195 | struct pglist_data *pgdat = NULL; |
fa9add64 | 196 | struct lruvec *lruvec; |
3dd7ae8e | 197 | unsigned long flags = 0; |
902aaed0 HH |
198 | |
199 | for (i = 0; i < pagevec_count(pvec); i++) { | |
200 | struct page *page = pvec->pages[i]; | |
68eb0731 | 201 | struct pglist_data *pagepgdat = page_pgdat(page); |
902aaed0 | 202 | |
68eb0731 MG |
203 | if (pagepgdat != pgdat) { |
204 | if (pgdat) | |
205 | spin_unlock_irqrestore(&pgdat->lru_lock, flags); | |
206 | pgdat = pagepgdat; | |
207 | spin_lock_irqsave(&pgdat->lru_lock, flags); | |
902aaed0 | 208 | } |
3dd7ae8e | 209 | |
68eb0731 | 210 | lruvec = mem_cgroup_page_lruvec(page, pgdat); |
fa9add64 | 211 | (*move_fn)(page, lruvec, arg); |
902aaed0 | 212 | } |
68eb0731 MG |
213 | if (pgdat) |
214 | spin_unlock_irqrestore(&pgdat->lru_lock, flags); | |
c6f92f9f | 215 | release_pages(pvec->pages, pvec->nr); |
83896fb5 | 216 | pagevec_reinit(pvec); |
d8505dee SL |
217 | } |
218 | ||
fa9add64 HD |
219 | static void pagevec_move_tail_fn(struct page *page, struct lruvec *lruvec, |
220 | void *arg) | |
3dd7ae8e SL |
221 | { |
222 | int *pgmoved = arg; | |
3dd7ae8e | 223 | |
c55e8d03 JW |
224 | if (PageLRU(page) && !PageUnevictable(page)) { |
225 | del_page_from_lru_list(page, lruvec, page_lru(page)); | |
226 | ClearPageActive(page); | |
227 | add_page_to_lru_list_tail(page, lruvec, page_lru(page)); | |
3dd7ae8e SL |
228 | (*pgmoved)++; |
229 | } | |
230 | } | |
231 | ||
232 | /* | |
233 | * pagevec_move_tail() must be called with IRQ disabled. | |
234 | * Otherwise this may cause nasty races. | |
235 | */ | |
236 | static void pagevec_move_tail(struct pagevec *pvec) | |
237 | { | |
238 | int pgmoved = 0; | |
239 | ||
240 | pagevec_lru_move_fn(pvec, pagevec_move_tail_fn, &pgmoved); | |
241 | __count_vm_events(PGROTATED, pgmoved); | |
242 | } | |
243 | ||
1da177e4 LT |
244 | /* |
245 | * Writeback is about to end against a page which has been marked for immediate | |
246 | * reclaim. If it still appears to be reclaimable, move it to the tail of the | |
902aaed0 | 247 | * inactive list. |
1da177e4 | 248 | */ |
3dd7ae8e | 249 | void rotate_reclaimable_page(struct page *page) |
1da177e4 | 250 | { |
c55e8d03 | 251 | if (!PageLocked(page) && !PageDirty(page) && |
894bc310 | 252 | !PageUnevictable(page) && PageLRU(page)) { |
ac6aadb2 MS |
253 | struct pagevec *pvec; |
254 | unsigned long flags; | |
255 | ||
09cbfeaf | 256 | get_page(page); |
ac6aadb2 | 257 | local_irq_save(flags); |
7c8e0181 | 258 | pvec = this_cpu_ptr(&lru_rotate_pvecs); |
8f182270 | 259 | if (!pagevec_add(pvec, page) || PageCompound(page)) |
ac6aadb2 MS |
260 | pagevec_move_tail(pvec); |
261 | local_irq_restore(flags); | |
262 | } | |
1da177e4 LT |
263 | } |
264 | ||
fa9add64 | 265 | static void update_page_reclaim_stat(struct lruvec *lruvec, |
3e2f41f1 KM |
266 | int file, int rotated) |
267 | { | |
fa9add64 | 268 | struct zone_reclaim_stat *reclaim_stat = &lruvec->reclaim_stat; |
3e2f41f1 KM |
269 | |
270 | reclaim_stat->recent_scanned[file]++; | |
271 | if (rotated) | |
272 | reclaim_stat->recent_rotated[file]++; | |
3e2f41f1 KM |
273 | } |
274 | ||
fa9add64 HD |
275 | static void __activate_page(struct page *page, struct lruvec *lruvec, |
276 | void *arg) | |
1da177e4 | 277 | { |
744ed144 | 278 | if (PageLRU(page) && !PageActive(page) && !PageUnevictable(page)) { |
7a608572 LT |
279 | int file = page_is_file_cache(page); |
280 | int lru = page_lru_base_type(page); | |
744ed144 | 281 | |
fa9add64 | 282 | del_page_from_lru_list(page, lruvec, lru); |
7a608572 LT |
283 | SetPageActive(page); |
284 | lru += LRU_ACTIVE; | |
fa9add64 | 285 | add_page_to_lru_list(page, lruvec, lru); |
24b7e581 | 286 | trace_mm_lru_activate(page); |
4f98a2fe | 287 | |
fa9add64 HD |
288 | __count_vm_event(PGACTIVATE); |
289 | update_page_reclaim_stat(lruvec, file, 1); | |
1da177e4 | 290 | } |
eb709b0d SL |
291 | } |
292 | ||
293 | #ifdef CONFIG_SMP | |
eb709b0d SL |
294 | static void activate_page_drain(int cpu) |
295 | { | |
296 | struct pagevec *pvec = &per_cpu(activate_page_pvecs, cpu); | |
297 | ||
298 | if (pagevec_count(pvec)) | |
299 | pagevec_lru_move_fn(pvec, __activate_page, NULL); | |
300 | } | |
301 | ||
5fbc4616 CM |
302 | static bool need_activate_page_drain(int cpu) |
303 | { | |
304 | return pagevec_count(&per_cpu(activate_page_pvecs, cpu)) != 0; | |
305 | } | |
306 | ||
eb709b0d SL |
307 | void activate_page(struct page *page) |
308 | { | |
800d8c63 | 309 | page = compound_head(page); |
eb709b0d SL |
310 | if (PageLRU(page) && !PageActive(page) && !PageUnevictable(page)) { |
311 | struct pagevec *pvec = &get_cpu_var(activate_page_pvecs); | |
312 | ||
09cbfeaf | 313 | get_page(page); |
8f182270 | 314 | if (!pagevec_add(pvec, page) || PageCompound(page)) |
eb709b0d SL |
315 | pagevec_lru_move_fn(pvec, __activate_page, NULL); |
316 | put_cpu_var(activate_page_pvecs); | |
317 | } | |
318 | } | |
319 | ||
320 | #else | |
321 | static inline void activate_page_drain(int cpu) | |
322 | { | |
323 | } | |
324 | ||
325 | void activate_page(struct page *page) | |
326 | { | |
f4b7e272 | 327 | pg_data_t *pgdat = page_pgdat(page); |
eb709b0d | 328 | |
800d8c63 | 329 | page = compound_head(page); |
f4b7e272 AR |
330 | spin_lock_irq(&pgdat->lru_lock); |
331 | __activate_page(page, mem_cgroup_page_lruvec(page, pgdat), NULL); | |
332 | spin_unlock_irq(&pgdat->lru_lock); | |
1da177e4 | 333 | } |
eb709b0d | 334 | #endif |
1da177e4 | 335 | |
059285a2 MG |
336 | static void __lru_cache_activate_page(struct page *page) |
337 | { | |
338 | struct pagevec *pvec = &get_cpu_var(lru_add_pvec); | |
339 | int i; | |
340 | ||
341 | /* | |
342 | * Search backwards on the optimistic assumption that the page being | |
343 | * activated has just been added to this pagevec. Note that only | |
344 | * the local pagevec is examined as a !PageLRU page could be in the | |
345 | * process of being released, reclaimed, migrated or on a remote | |
346 | * pagevec that is currently being drained. Furthermore, marking | |
347 | * a remote pagevec's page PageActive potentially hits a race where | |
348 | * a page is marked PageActive just after it is added to the inactive | |
349 | * list causing accounting errors and BUG_ON checks to trigger. | |
350 | */ | |
351 | for (i = pagevec_count(pvec) - 1; i >= 0; i--) { | |
352 | struct page *pagevec_page = pvec->pages[i]; | |
353 | ||
354 | if (pagevec_page == page) { | |
355 | SetPageActive(page); | |
356 | break; | |
357 | } | |
358 | } | |
359 | ||
360 | put_cpu_var(lru_add_pvec); | |
361 | } | |
362 | ||
1da177e4 LT |
363 | /* |
364 | * Mark a page as having seen activity. | |
365 | * | |
366 | * inactive,unreferenced -> inactive,referenced | |
367 | * inactive,referenced -> active,unreferenced | |
368 | * active,unreferenced -> active,referenced | |
eb39d618 HD |
369 | * |
370 | * When a newly allocated page is not yet visible, so safe for non-atomic ops, | |
371 | * __SetPageReferenced(page) may be substituted for mark_page_accessed(page). | |
1da177e4 | 372 | */ |
920c7a5d | 373 | void mark_page_accessed(struct page *page) |
1da177e4 | 374 | { |
e90309c9 | 375 | page = compound_head(page); |
894bc310 | 376 | if (!PageActive(page) && !PageUnevictable(page) && |
059285a2 MG |
377 | PageReferenced(page)) { |
378 | ||
379 | /* | |
380 | * If the page is on the LRU, queue it for activation via | |
381 | * activate_page_pvecs. Otherwise, assume the page is on a | |
382 | * pagevec, mark it active and it'll be moved to the active | |
383 | * LRU on the next drain. | |
384 | */ | |
385 | if (PageLRU(page)) | |
386 | activate_page(page); | |
387 | else | |
388 | __lru_cache_activate_page(page); | |
1da177e4 | 389 | ClearPageReferenced(page); |
a528910e JW |
390 | if (page_is_file_cache(page)) |
391 | workingset_activation(page); | |
1da177e4 LT |
392 | } else if (!PageReferenced(page)) { |
393 | SetPageReferenced(page); | |
394 | } | |
33c3fc71 VD |
395 | if (page_is_idle(page)) |
396 | clear_page_idle(page); | |
1da177e4 | 397 | } |
1da177e4 LT |
398 | EXPORT_SYMBOL(mark_page_accessed); |
399 | ||
2329d375 | 400 | static void __lru_cache_add(struct page *page) |
1da177e4 | 401 | { |
13f7f789 MG |
402 | struct pagevec *pvec = &get_cpu_var(lru_add_pvec); |
403 | ||
09cbfeaf | 404 | get_page(page); |
8f182270 | 405 | if (!pagevec_add(pvec, page) || PageCompound(page)) |
a0b8cab3 | 406 | __pagevec_lru_add(pvec); |
13f7f789 | 407 | put_cpu_var(lru_add_pvec); |
1da177e4 | 408 | } |
2329d375 JZ |
409 | |
410 | /** | |
e02a9f04 | 411 | * lru_cache_add_anon - add a page to the page lists |
2329d375 JZ |
412 | * @page: the page to add |
413 | */ | |
414 | void lru_cache_add_anon(struct page *page) | |
415 | { | |
6fb81a17 MG |
416 | if (PageActive(page)) |
417 | ClearPageActive(page); | |
2329d375 JZ |
418 | __lru_cache_add(page); |
419 | } | |
420 | ||
421 | void lru_cache_add_file(struct page *page) | |
422 | { | |
6fb81a17 MG |
423 | if (PageActive(page)) |
424 | ClearPageActive(page); | |
2329d375 JZ |
425 | __lru_cache_add(page); |
426 | } | |
427 | EXPORT_SYMBOL(lru_cache_add_file); | |
1da177e4 | 428 | |
f04e9ebb | 429 | /** |
c53954a0 | 430 | * lru_cache_add - add a page to a page list |
f04e9ebb | 431 | * @page: the page to be added to the LRU. |
2329d375 JZ |
432 | * |
433 | * Queue the page for addition to the LRU via pagevec. The decision on whether | |
434 | * to add the page to the [in]active [file|anon] list is deferred until the | |
435 | * pagevec is drained. This gives a chance for the caller of lru_cache_add() | |
436 | * have the page added to the active list using mark_page_accessed(). | |
f04e9ebb | 437 | */ |
c53954a0 | 438 | void lru_cache_add(struct page *page) |
1da177e4 | 439 | { |
309381fe SL |
440 | VM_BUG_ON_PAGE(PageActive(page) && PageUnevictable(page), page); |
441 | VM_BUG_ON_PAGE(PageLRU(page), page); | |
c53954a0 | 442 | __lru_cache_add(page); |
1da177e4 LT |
443 | } |
444 | ||
00501b53 JW |
445 | /** |
446 | * lru_cache_add_active_or_unevictable | |
447 | * @page: the page to be added to LRU | |
448 | * @vma: vma in which page is mapped for determining reclaimability | |
449 | * | |
450 | * Place @page on the active or unevictable LRU list, depending on its | |
451 | * evictability. Note that if the page is not evictable, it goes | |
452 | * directly back onto it's zone's unevictable list, it does NOT use a | |
453 | * per cpu pagevec. | |
454 | */ | |
455 | void lru_cache_add_active_or_unevictable(struct page *page, | |
456 | struct vm_area_struct *vma) | |
457 | { | |
458 | VM_BUG_ON_PAGE(PageLRU(page), page); | |
459 | ||
9c4e6b1a | 460 | if (likely((vma->vm_flags & (VM_LOCKED | VM_SPECIAL)) != VM_LOCKED)) |
00501b53 | 461 | SetPageActive(page); |
9c4e6b1a | 462 | else if (!TestSetPageMlocked(page)) { |
00501b53 JW |
463 | /* |
464 | * We use the irq-unsafe __mod_zone_page_stat because this | |
465 | * counter is not modified from interrupt context, and the pte | |
466 | * lock is held(spinlock), which implies preemption disabled. | |
467 | */ | |
468 | __mod_zone_page_state(page_zone(page), NR_MLOCK, | |
469 | hpage_nr_pages(page)); | |
470 | count_vm_event(UNEVICTABLE_PGMLOCKED); | |
471 | } | |
9c4e6b1a | 472 | lru_cache_add(page); |
00501b53 JW |
473 | } |
474 | ||
31560180 MK |
475 | /* |
476 | * If the page can not be invalidated, it is moved to the | |
477 | * inactive list to speed up its reclaim. It is moved to the | |
478 | * head of the list, rather than the tail, to give the flusher | |
479 | * threads some time to write it out, as this is much more | |
480 | * effective than the single-page writeout from reclaim. | |
278df9f4 MK |
481 | * |
482 | * If the page isn't page_mapped and dirty/writeback, the page | |
483 | * could reclaim asap using PG_reclaim. | |
484 | * | |
485 | * 1. active, mapped page -> none | |
486 | * 2. active, dirty/writeback page -> inactive, head, PG_reclaim | |
487 | * 3. inactive, mapped page -> none | |
488 | * 4. inactive, dirty/writeback page -> inactive, head, PG_reclaim | |
489 | * 5. inactive, clean -> inactive, tail | |
490 | * 6. Others -> none | |
491 | * | |
492 | * In 4, why it moves inactive's head, the VM expects the page would | |
493 | * be write it out by flusher threads as this is much more effective | |
494 | * than the single-page writeout from reclaim. | |
31560180 | 495 | */ |
cc5993bd | 496 | static void lru_deactivate_file_fn(struct page *page, struct lruvec *lruvec, |
fa9add64 | 497 | void *arg) |
31560180 MK |
498 | { |
499 | int lru, file; | |
278df9f4 | 500 | bool active; |
31560180 | 501 | |
278df9f4 | 502 | if (!PageLRU(page)) |
31560180 MK |
503 | return; |
504 | ||
bad49d9c MK |
505 | if (PageUnevictable(page)) |
506 | return; | |
507 | ||
31560180 MK |
508 | /* Some processes are using the page */ |
509 | if (page_mapped(page)) | |
510 | return; | |
511 | ||
278df9f4 | 512 | active = PageActive(page); |
31560180 MK |
513 | file = page_is_file_cache(page); |
514 | lru = page_lru_base_type(page); | |
fa9add64 HD |
515 | |
516 | del_page_from_lru_list(page, lruvec, lru + active); | |
31560180 MK |
517 | ClearPageActive(page); |
518 | ClearPageReferenced(page); | |
31560180 | 519 | |
278df9f4 MK |
520 | if (PageWriteback(page) || PageDirty(page)) { |
521 | /* | |
522 | * PG_reclaim could be raced with end_page_writeback | |
523 | * It can make readahead confusing. But race window | |
524 | * is _really_ small and it's non-critical problem. | |
525 | */ | |
e7a1aaf2 | 526 | add_page_to_lru_list(page, lruvec, lru); |
278df9f4 MK |
527 | SetPageReclaim(page); |
528 | } else { | |
529 | /* | |
530 | * The page's writeback ends up during pagevec | |
531 | * We moves tha page into tail of inactive. | |
532 | */ | |
e7a1aaf2 | 533 | add_page_to_lru_list_tail(page, lruvec, lru); |
278df9f4 MK |
534 | __count_vm_event(PGROTATED); |
535 | } | |
536 | ||
537 | if (active) | |
538 | __count_vm_event(PGDEACTIVATE); | |
fa9add64 | 539 | update_page_reclaim_stat(lruvec, file, 0); |
31560180 MK |
540 | } |
541 | ||
9c276cc6 MK |
542 | static void lru_deactivate_fn(struct page *page, struct lruvec *lruvec, |
543 | void *arg) | |
544 | { | |
545 | if (PageLRU(page) && PageActive(page) && !PageUnevictable(page)) { | |
546 | int file = page_is_file_cache(page); | |
547 | int lru = page_lru_base_type(page); | |
548 | ||
549 | del_page_from_lru_list(page, lruvec, lru + LRU_ACTIVE); | |
550 | ClearPageActive(page); | |
551 | ClearPageReferenced(page); | |
552 | add_page_to_lru_list(page, lruvec, lru); | |
553 | ||
554 | __count_vm_events(PGDEACTIVATE, hpage_nr_pages(page)); | |
555 | update_page_reclaim_stat(lruvec, file, 0); | |
556 | } | |
557 | } | |
10853a03 | 558 | |
f7ad2a6c | 559 | static void lru_lazyfree_fn(struct page *page, struct lruvec *lruvec, |
10853a03 MK |
560 | void *arg) |
561 | { | |
f7ad2a6c | 562 | if (PageLRU(page) && PageAnon(page) && PageSwapBacked(page) && |
24c92eb7 | 563 | !PageSwapCache(page) && !PageUnevictable(page)) { |
f7ad2a6c | 564 | bool active = PageActive(page); |
10853a03 | 565 | |
f7ad2a6c SL |
566 | del_page_from_lru_list(page, lruvec, |
567 | LRU_INACTIVE_ANON + active); | |
10853a03 MK |
568 | ClearPageActive(page); |
569 | ClearPageReferenced(page); | |
f7ad2a6c SL |
570 | /* |
571 | * lazyfree pages are clean anonymous pages. They have | |
572 | * SwapBacked flag cleared to distinguish normal anonymous | |
573 | * pages | |
574 | */ | |
575 | ClearPageSwapBacked(page); | |
576 | add_page_to_lru_list(page, lruvec, LRU_INACTIVE_FILE); | |
10853a03 | 577 | |
f7ad2a6c | 578 | __count_vm_events(PGLAZYFREE, hpage_nr_pages(page)); |
2262185c | 579 | count_memcg_page_event(page, PGLAZYFREE); |
f7ad2a6c | 580 | update_page_reclaim_stat(lruvec, 1, 0); |
10853a03 MK |
581 | } |
582 | } | |
583 | ||
902aaed0 HH |
584 | /* |
585 | * Drain pages out of the cpu's pagevecs. | |
586 | * Either "cpu" is the current CPU, and preemption has already been | |
587 | * disabled; or "cpu" is being hot-unplugged, and is already dead. | |
588 | */ | |
f0cb3c76 | 589 | void lru_add_drain_cpu(int cpu) |
1da177e4 | 590 | { |
13f7f789 | 591 | struct pagevec *pvec = &per_cpu(lru_add_pvec, cpu); |
1da177e4 | 592 | |
13f7f789 | 593 | if (pagevec_count(pvec)) |
a0b8cab3 | 594 | __pagevec_lru_add(pvec); |
902aaed0 HH |
595 | |
596 | pvec = &per_cpu(lru_rotate_pvecs, cpu); | |
597 | if (pagevec_count(pvec)) { | |
598 | unsigned long flags; | |
599 | ||
600 | /* No harm done if a racing interrupt already did this */ | |
601 | local_irq_save(flags); | |
602 | pagevec_move_tail(pvec); | |
603 | local_irq_restore(flags); | |
604 | } | |
31560180 | 605 | |
cc5993bd | 606 | pvec = &per_cpu(lru_deactivate_file_pvecs, cpu); |
31560180 | 607 | if (pagevec_count(pvec)) |
cc5993bd | 608 | pagevec_lru_move_fn(pvec, lru_deactivate_file_fn, NULL); |
eb709b0d | 609 | |
9c276cc6 MK |
610 | pvec = &per_cpu(lru_deactivate_pvecs, cpu); |
611 | if (pagevec_count(pvec)) | |
612 | pagevec_lru_move_fn(pvec, lru_deactivate_fn, NULL); | |
613 | ||
f7ad2a6c | 614 | pvec = &per_cpu(lru_lazyfree_pvecs, cpu); |
10853a03 | 615 | if (pagevec_count(pvec)) |
f7ad2a6c | 616 | pagevec_lru_move_fn(pvec, lru_lazyfree_fn, NULL); |
10853a03 | 617 | |
eb709b0d | 618 | activate_page_drain(cpu); |
31560180 MK |
619 | } |
620 | ||
621 | /** | |
cc5993bd | 622 | * deactivate_file_page - forcefully deactivate a file page |
31560180 MK |
623 | * @page: page to deactivate |
624 | * | |
625 | * This function hints the VM that @page is a good reclaim candidate, | |
626 | * for example if its invalidation fails due to the page being dirty | |
627 | * or under writeback. | |
628 | */ | |
cc5993bd | 629 | void deactivate_file_page(struct page *page) |
31560180 | 630 | { |
821ed6bb | 631 | /* |
cc5993bd MK |
632 | * In a workload with many unevictable page such as mprotect, |
633 | * unevictable page deactivation for accelerating reclaim is pointless. | |
821ed6bb MK |
634 | */ |
635 | if (PageUnevictable(page)) | |
636 | return; | |
637 | ||
31560180 | 638 | if (likely(get_page_unless_zero(page))) { |
cc5993bd | 639 | struct pagevec *pvec = &get_cpu_var(lru_deactivate_file_pvecs); |
31560180 | 640 | |
8f182270 | 641 | if (!pagevec_add(pvec, page) || PageCompound(page)) |
cc5993bd MK |
642 | pagevec_lru_move_fn(pvec, lru_deactivate_file_fn, NULL); |
643 | put_cpu_var(lru_deactivate_file_pvecs); | |
31560180 | 644 | } |
80bfed90 AM |
645 | } |
646 | ||
9c276cc6 MK |
647 | /* |
648 | * deactivate_page - deactivate a page | |
649 | * @page: page to deactivate | |
650 | * | |
651 | * deactivate_page() moves @page to the inactive list if @page was on the active | |
652 | * list and was not an unevictable page. This is done to accelerate the reclaim | |
653 | * of @page. | |
654 | */ | |
655 | void deactivate_page(struct page *page) | |
656 | { | |
657 | if (PageLRU(page) && PageActive(page) && !PageUnevictable(page)) { | |
658 | struct pagevec *pvec = &get_cpu_var(lru_deactivate_pvecs); | |
659 | ||
660 | get_page(page); | |
661 | if (!pagevec_add(pvec, page) || PageCompound(page)) | |
662 | pagevec_lru_move_fn(pvec, lru_deactivate_fn, NULL); | |
663 | put_cpu_var(lru_deactivate_pvecs); | |
664 | } | |
665 | } | |
666 | ||
10853a03 | 667 | /** |
f7ad2a6c | 668 | * mark_page_lazyfree - make an anon page lazyfree |
10853a03 MK |
669 | * @page: page to deactivate |
670 | * | |
f7ad2a6c SL |
671 | * mark_page_lazyfree() moves @page to the inactive file list. |
672 | * This is done to accelerate the reclaim of @page. | |
10853a03 | 673 | */ |
f7ad2a6c | 674 | void mark_page_lazyfree(struct page *page) |
10853a03 | 675 | { |
f7ad2a6c | 676 | if (PageLRU(page) && PageAnon(page) && PageSwapBacked(page) && |
24c92eb7 | 677 | !PageSwapCache(page) && !PageUnevictable(page)) { |
f7ad2a6c | 678 | struct pagevec *pvec = &get_cpu_var(lru_lazyfree_pvecs); |
10853a03 | 679 | |
09cbfeaf | 680 | get_page(page); |
8f182270 | 681 | if (!pagevec_add(pvec, page) || PageCompound(page)) |
f7ad2a6c SL |
682 | pagevec_lru_move_fn(pvec, lru_lazyfree_fn, NULL); |
683 | put_cpu_var(lru_lazyfree_pvecs); | |
10853a03 MK |
684 | } |
685 | } | |
686 | ||
80bfed90 AM |
687 | void lru_add_drain(void) |
688 | { | |
f0cb3c76 | 689 | lru_add_drain_cpu(get_cpu()); |
80bfed90 | 690 | put_cpu(); |
1da177e4 LT |
691 | } |
692 | ||
6ea183d6 MH |
693 | #ifdef CONFIG_SMP |
694 | ||
695 | static DEFINE_PER_CPU(struct work_struct, lru_add_drain_work); | |
696 | ||
c4028958 | 697 | static void lru_add_drain_per_cpu(struct work_struct *dummy) |
053837fc NP |
698 | { |
699 | lru_add_drain(); | |
700 | } | |
701 | ||
9852a721 MH |
702 | /* |
703 | * Doesn't need any cpu hotplug locking because we do rely on per-cpu | |
704 | * kworkers being shut down before our page_alloc_cpu_dead callback is | |
705 | * executed on the offlined cpu. | |
706 | * Calling this function with cpu hotplug locks held can actually lead | |
707 | * to obscure indirect dependencies via WQ context. | |
708 | */ | |
709 | void lru_add_drain_all(void) | |
053837fc | 710 | { |
5fbc4616 CM |
711 | static DEFINE_MUTEX(lock); |
712 | static struct cpumask has_work; | |
713 | int cpu; | |
714 | ||
ce612879 MH |
715 | /* |
716 | * Make sure nobody triggers this path before mm_percpu_wq is fully | |
717 | * initialized. | |
718 | */ | |
719 | if (WARN_ON(!mm_percpu_wq)) | |
720 | return; | |
721 | ||
5fbc4616 | 722 | mutex_lock(&lock); |
5fbc4616 CM |
723 | cpumask_clear(&has_work); |
724 | ||
725 | for_each_online_cpu(cpu) { | |
726 | struct work_struct *work = &per_cpu(lru_add_drain_work, cpu); | |
727 | ||
728 | if (pagevec_count(&per_cpu(lru_add_pvec, cpu)) || | |
729 | pagevec_count(&per_cpu(lru_rotate_pvecs, cpu)) || | |
cc5993bd | 730 | pagevec_count(&per_cpu(lru_deactivate_file_pvecs, cpu)) || |
9c276cc6 | 731 | pagevec_count(&per_cpu(lru_deactivate_pvecs, cpu)) || |
f7ad2a6c | 732 | pagevec_count(&per_cpu(lru_lazyfree_pvecs, cpu)) || |
5fbc4616 CM |
733 | need_activate_page_drain(cpu)) { |
734 | INIT_WORK(work, lru_add_drain_per_cpu); | |
ce612879 | 735 | queue_work_on(cpu, mm_percpu_wq, work); |
5fbc4616 CM |
736 | cpumask_set_cpu(cpu, &has_work); |
737 | } | |
738 | } | |
739 | ||
740 | for_each_cpu(cpu, &has_work) | |
741 | flush_work(&per_cpu(lru_add_drain_work, cpu)); | |
742 | ||
5fbc4616 | 743 | mutex_unlock(&lock); |
053837fc | 744 | } |
6ea183d6 MH |
745 | #else |
746 | void lru_add_drain_all(void) | |
747 | { | |
748 | lru_add_drain(); | |
749 | } | |
750 | #endif | |
053837fc | 751 | |
aabfb572 | 752 | /** |
ea1754a0 | 753 | * release_pages - batched put_page() |
aabfb572 MH |
754 | * @pages: array of pages to release |
755 | * @nr: number of pages | |
1da177e4 | 756 | * |
aabfb572 MH |
757 | * Decrement the reference count on all the pages in @pages. If it |
758 | * fell to zero, remove the page from the LRU and free it. | |
1da177e4 | 759 | */ |
c6f92f9f | 760 | void release_pages(struct page **pages, int nr) |
1da177e4 LT |
761 | { |
762 | int i; | |
cc59850e | 763 | LIST_HEAD(pages_to_free); |
599d0c95 | 764 | struct pglist_data *locked_pgdat = NULL; |
fa9add64 | 765 | struct lruvec *lruvec; |
902aaed0 | 766 | unsigned long uninitialized_var(flags); |
aabfb572 | 767 | unsigned int uninitialized_var(lock_batch); |
1da177e4 | 768 | |
1da177e4 LT |
769 | for (i = 0; i < nr; i++) { |
770 | struct page *page = pages[i]; | |
1da177e4 | 771 | |
aabfb572 MH |
772 | /* |
773 | * Make sure the IRQ-safe lock-holding time does not get | |
774 | * excessive with a continuous string of pages from the | |
599d0c95 | 775 | * same pgdat. The lock is held only if pgdat != NULL. |
aabfb572 | 776 | */ |
599d0c95 MG |
777 | if (locked_pgdat && ++lock_batch == SWAP_CLUSTER_MAX) { |
778 | spin_unlock_irqrestore(&locked_pgdat->lru_lock, flags); | |
779 | locked_pgdat = NULL; | |
aabfb572 MH |
780 | } |
781 | ||
6fcb52a5 | 782 | if (is_huge_zero_page(page)) |
aa88b68c | 783 | continue; |
aa88b68c | 784 | |
c5d6c45e | 785 | if (is_zone_device_page(page)) { |
df6ad698 JG |
786 | if (locked_pgdat) { |
787 | spin_unlock_irqrestore(&locked_pgdat->lru_lock, | |
788 | flags); | |
789 | locked_pgdat = NULL; | |
790 | } | |
c5d6c45e IW |
791 | /* |
792 | * ZONE_DEVICE pages that return 'false' from | |
793 | * put_devmap_managed_page() do not require special | |
794 | * processing, and instead, expect a call to | |
795 | * put_page_testzero(). | |
796 | */ | |
797 | if (put_devmap_managed_page(page)) | |
798 | continue; | |
df6ad698 JG |
799 | } |
800 | ||
ddc58f27 | 801 | page = compound_head(page); |
b5810039 | 802 | if (!put_page_testzero(page)) |
1da177e4 LT |
803 | continue; |
804 | ||
ddc58f27 | 805 | if (PageCompound(page)) { |
599d0c95 MG |
806 | if (locked_pgdat) { |
807 | spin_unlock_irqrestore(&locked_pgdat->lru_lock, flags); | |
808 | locked_pgdat = NULL; | |
ddc58f27 KS |
809 | } |
810 | __put_compound_page(page); | |
811 | continue; | |
812 | } | |
813 | ||
46453a6e | 814 | if (PageLRU(page)) { |
599d0c95 | 815 | struct pglist_data *pgdat = page_pgdat(page); |
894bc310 | 816 | |
599d0c95 MG |
817 | if (pgdat != locked_pgdat) { |
818 | if (locked_pgdat) | |
819 | spin_unlock_irqrestore(&locked_pgdat->lru_lock, | |
902aaed0 | 820 | flags); |
aabfb572 | 821 | lock_batch = 0; |
599d0c95 MG |
822 | locked_pgdat = pgdat; |
823 | spin_lock_irqsave(&locked_pgdat->lru_lock, flags); | |
46453a6e | 824 | } |
fa9add64 | 825 | |
599d0c95 | 826 | lruvec = mem_cgroup_page_lruvec(page, locked_pgdat); |
309381fe | 827 | VM_BUG_ON_PAGE(!PageLRU(page), page); |
67453911 | 828 | __ClearPageLRU(page); |
fa9add64 | 829 | del_page_from_lru_list(page, lruvec, page_off_lru(page)); |
46453a6e NP |
830 | } |
831 | ||
c53954a0 | 832 | /* Clear Active bit in case of parallel mark_page_accessed */ |
e3741b50 | 833 | __ClearPageActive(page); |
62906027 | 834 | __ClearPageWaiters(page); |
c53954a0 | 835 | |
cc59850e | 836 | list_add(&page->lru, &pages_to_free); |
1da177e4 | 837 | } |
599d0c95 MG |
838 | if (locked_pgdat) |
839 | spin_unlock_irqrestore(&locked_pgdat->lru_lock, flags); | |
1da177e4 | 840 | |
747db954 | 841 | mem_cgroup_uncharge_list(&pages_to_free); |
2d4894b5 | 842 | free_unref_page_list(&pages_to_free); |
1da177e4 | 843 | } |
0be8557b | 844 | EXPORT_SYMBOL(release_pages); |
1da177e4 LT |
845 | |
846 | /* | |
847 | * The pages which we're about to release may be in the deferred lru-addition | |
848 | * queues. That would prevent them from really being freed right now. That's | |
849 | * OK from a correctness point of view but is inefficient - those pages may be | |
850 | * cache-warm and we want to give them back to the page allocator ASAP. | |
851 | * | |
852 | * So __pagevec_release() will drain those queues here. __pagevec_lru_add() | |
853 | * and __pagevec_lru_add_active() call release_pages() directly to avoid | |
854 | * mutual recursion. | |
855 | */ | |
856 | void __pagevec_release(struct pagevec *pvec) | |
857 | { | |
7f0b5fb9 | 858 | if (!pvec->percpu_pvec_drained) { |
d9ed0d08 | 859 | lru_add_drain(); |
7f0b5fb9 | 860 | pvec->percpu_pvec_drained = true; |
d9ed0d08 | 861 | } |
c6f92f9f | 862 | release_pages(pvec->pages, pagevec_count(pvec)); |
1da177e4 LT |
863 | pagevec_reinit(pvec); |
864 | } | |
7f285701 SF |
865 | EXPORT_SYMBOL(__pagevec_release); |
866 | ||
12d27107 | 867 | #ifdef CONFIG_TRANSPARENT_HUGEPAGE |
71e3aac0 | 868 | /* used by __split_huge_page_refcount() */ |
fa9add64 | 869 | void lru_add_page_tail(struct page *page, struct page *page_tail, |
5bc7b8ac | 870 | struct lruvec *lruvec, struct list_head *list) |
71e3aac0 | 871 | { |
71e3aac0 | 872 | const int file = 0; |
71e3aac0 | 873 | |
309381fe SL |
874 | VM_BUG_ON_PAGE(!PageHead(page), page); |
875 | VM_BUG_ON_PAGE(PageCompound(page_tail), page); | |
876 | VM_BUG_ON_PAGE(PageLRU(page_tail), page); | |
35f3aa39 | 877 | lockdep_assert_held(&lruvec_pgdat(lruvec)->lru_lock); |
71e3aac0 | 878 | |
5bc7b8ac SL |
879 | if (!list) |
880 | SetPageLRU(page_tail); | |
71e3aac0 | 881 | |
12d27107 HD |
882 | if (likely(PageLRU(page))) |
883 | list_add_tail(&page_tail->lru, &page->lru); | |
5bc7b8ac SL |
884 | else if (list) { |
885 | /* page reclaim is reclaiming a huge page */ | |
886 | get_page(page_tail); | |
887 | list_add_tail(&page_tail->lru, list); | |
888 | } else { | |
12d27107 HD |
889 | /* |
890 | * Head page has not yet been counted, as an hpage, | |
891 | * so we must account for each subpage individually. | |
892 | * | |
e7a1aaf2 YZ |
893 | * Put page_tail on the list at the correct position |
894 | * so they all end up in order. | |
12d27107 | 895 | */ |
e7a1aaf2 YZ |
896 | add_page_to_lru_list_tail(page_tail, lruvec, |
897 | page_lru(page_tail)); | |
71e3aac0 | 898 | } |
7512102c HD |
899 | |
900 | if (!PageUnevictable(page)) | |
e180cf80 | 901 | update_page_reclaim_stat(lruvec, file, PageActive(page_tail)); |
71e3aac0 | 902 | } |
12d27107 | 903 | #endif /* CONFIG_TRANSPARENT_HUGEPAGE */ |
71e3aac0 | 904 | |
fa9add64 HD |
905 | static void __pagevec_lru_add_fn(struct page *page, struct lruvec *lruvec, |
906 | void *arg) | |
3dd7ae8e | 907 | { |
9c4e6b1a SB |
908 | enum lru_list lru; |
909 | int was_unevictable = TestClearPageUnevictable(page); | |
3dd7ae8e | 910 | |
309381fe | 911 | VM_BUG_ON_PAGE(PageLRU(page), page); |
3dd7ae8e SL |
912 | |
913 | SetPageLRU(page); | |
9c4e6b1a SB |
914 | /* |
915 | * Page becomes evictable in two ways: | |
dae966dc | 916 | * 1) Within LRU lock [munlock_vma_page() and __munlock_pagevec()]. |
9c4e6b1a SB |
917 | * 2) Before acquiring LRU lock to put the page to correct LRU and then |
918 | * a) do PageLRU check with lock [check_move_unevictable_pages] | |
919 | * b) do PageLRU check before lock [clear_page_mlock] | |
920 | * | |
921 | * (1) & (2a) are ok as LRU lock will serialize them. For (2b), we need | |
922 | * following strict ordering: | |
923 | * | |
924 | * #0: __pagevec_lru_add_fn #1: clear_page_mlock | |
925 | * | |
926 | * SetPageLRU() TestClearPageMlocked() | |
927 | * smp_mb() // explicit ordering // above provides strict | |
928 | * // ordering | |
929 | * PageMlocked() PageLRU() | |
930 | * | |
931 | * | |
932 | * if '#1' does not observe setting of PG_lru by '#0' and fails | |
933 | * isolation, the explicit barrier will make sure that page_evictable | |
934 | * check will put the page in correct LRU. Without smp_mb(), SetPageLRU | |
935 | * can be reordered after PageMlocked check and can make '#1' to fail | |
936 | * the isolation of the page whose Mlocked bit is cleared (#0 is also | |
937 | * looking at the same page) and the evictable page will be stranded | |
938 | * in an unevictable LRU. | |
939 | */ | |
940 | smp_mb(); | |
941 | ||
942 | if (page_evictable(page)) { | |
943 | lru = page_lru(page); | |
944 | update_page_reclaim_stat(lruvec, page_is_file_cache(page), | |
945 | PageActive(page)); | |
946 | if (was_unevictable) | |
947 | count_vm_event(UNEVICTABLE_PGRESCUED); | |
948 | } else { | |
949 | lru = LRU_UNEVICTABLE; | |
950 | ClearPageActive(page); | |
951 | SetPageUnevictable(page); | |
952 | if (!was_unevictable) | |
953 | count_vm_event(UNEVICTABLE_PGCULLED); | |
954 | } | |
955 | ||
fa9add64 | 956 | add_page_to_lru_list(page, lruvec, lru); |
24b7e581 | 957 | trace_mm_lru_insertion(page, lru); |
3dd7ae8e SL |
958 | } |
959 | ||
1da177e4 LT |
960 | /* |
961 | * Add the passed pages to the LRU, then drop the caller's refcount | |
962 | * on them. Reinitialises the caller's pagevec. | |
963 | */ | |
a0b8cab3 | 964 | void __pagevec_lru_add(struct pagevec *pvec) |
1da177e4 | 965 | { |
a0b8cab3 | 966 | pagevec_lru_move_fn(pvec, __pagevec_lru_add_fn, NULL); |
1da177e4 | 967 | } |
5095ae83 | 968 | EXPORT_SYMBOL(__pagevec_lru_add); |
1da177e4 | 969 | |
0cd6144a JW |
970 | /** |
971 | * pagevec_lookup_entries - gang pagecache lookup | |
972 | * @pvec: Where the resulting entries are placed | |
973 | * @mapping: The address_space to search | |
974 | * @start: The starting entry index | |
cb6f0f34 | 975 | * @nr_entries: The maximum number of pages |
0cd6144a JW |
976 | * @indices: The cache indices corresponding to the entries in @pvec |
977 | * | |
978 | * pagevec_lookup_entries() will search for and return a group of up | |
f144c390 | 979 | * to @nr_pages pages and shadow entries in the mapping. All |
0cd6144a JW |
980 | * entries are placed in @pvec. pagevec_lookup_entries() takes a |
981 | * reference against actual pages in @pvec. | |
982 | * | |
983 | * The search returns a group of mapping-contiguous entries with | |
984 | * ascending indexes. There may be holes in the indices due to | |
985 | * not-present entries. | |
986 | * | |
987 | * pagevec_lookup_entries() returns the number of entries which were | |
988 | * found. | |
989 | */ | |
990 | unsigned pagevec_lookup_entries(struct pagevec *pvec, | |
991 | struct address_space *mapping, | |
e02a9f04 | 992 | pgoff_t start, unsigned nr_entries, |
0cd6144a JW |
993 | pgoff_t *indices) |
994 | { | |
e02a9f04 | 995 | pvec->nr = find_get_entries(mapping, start, nr_entries, |
0cd6144a JW |
996 | pvec->pages, indices); |
997 | return pagevec_count(pvec); | |
998 | } | |
999 | ||
1000 | /** | |
1001 | * pagevec_remove_exceptionals - pagevec exceptionals pruning | |
1002 | * @pvec: The pagevec to prune | |
1003 | * | |
1004 | * pagevec_lookup_entries() fills both pages and exceptional radix | |
1005 | * tree entries into the pagevec. This function prunes all | |
1006 | * exceptionals from @pvec without leaving holes, so that it can be | |
1007 | * passed on to page-only pagevec operations. | |
1008 | */ | |
1009 | void pagevec_remove_exceptionals(struct pagevec *pvec) | |
1010 | { | |
1011 | int i, j; | |
1012 | ||
1013 | for (i = 0, j = 0; i < pagevec_count(pvec); i++) { | |
1014 | struct page *page = pvec->pages[i]; | |
3159f943 | 1015 | if (!xa_is_value(page)) |
0cd6144a JW |
1016 | pvec->pages[j++] = page; |
1017 | } | |
1018 | pvec->nr = j; | |
1019 | } | |
1020 | ||
1da177e4 | 1021 | /** |
b947cee4 | 1022 | * pagevec_lookup_range - gang pagecache lookup |
1da177e4 LT |
1023 | * @pvec: Where the resulting pages are placed |
1024 | * @mapping: The address_space to search | |
1025 | * @start: The starting page index | |
b947cee4 | 1026 | * @end: The final page index |
1da177e4 | 1027 | * |
e02a9f04 | 1028 | * pagevec_lookup_range() will search for & return a group of up to PAGEVEC_SIZE |
b947cee4 JK |
1029 | * pages in the mapping starting from index @start and upto index @end |
1030 | * (inclusive). The pages are placed in @pvec. pagevec_lookup() takes a | |
1da177e4 LT |
1031 | * reference against the pages in @pvec. |
1032 | * | |
1033 | * The search returns a group of mapping-contiguous pages with ascending | |
d72dc8a2 JK |
1034 | * indexes. There may be holes in the indices due to not-present pages. We |
1035 | * also update @start to index the next page for the traversal. | |
1da177e4 | 1036 | * |
b947cee4 | 1037 | * pagevec_lookup_range() returns the number of pages which were found. If this |
e02a9f04 | 1038 | * number is smaller than PAGEVEC_SIZE, the end of specified range has been |
b947cee4 | 1039 | * reached. |
1da177e4 | 1040 | */ |
b947cee4 | 1041 | unsigned pagevec_lookup_range(struct pagevec *pvec, |
397162ff | 1042 | struct address_space *mapping, pgoff_t *start, pgoff_t end) |
1da177e4 | 1043 | { |
397162ff | 1044 | pvec->nr = find_get_pages_range(mapping, start, end, PAGEVEC_SIZE, |
b947cee4 | 1045 | pvec->pages); |
1da177e4 LT |
1046 | return pagevec_count(pvec); |
1047 | } | |
b947cee4 | 1048 | EXPORT_SYMBOL(pagevec_lookup_range); |
78539fdf | 1049 | |
72b045ae JK |
1050 | unsigned pagevec_lookup_range_tag(struct pagevec *pvec, |
1051 | struct address_space *mapping, pgoff_t *index, pgoff_t end, | |
10bbd235 | 1052 | xa_mark_t tag) |
1da177e4 | 1053 | { |
72b045ae | 1054 | pvec->nr = find_get_pages_range_tag(mapping, index, end, tag, |
67fd707f | 1055 | PAGEVEC_SIZE, pvec->pages); |
1da177e4 LT |
1056 | return pagevec_count(pvec); |
1057 | } | |
72b045ae | 1058 | EXPORT_SYMBOL(pagevec_lookup_range_tag); |
1da177e4 | 1059 | |
93d3b714 JK |
1060 | unsigned pagevec_lookup_range_nr_tag(struct pagevec *pvec, |
1061 | struct address_space *mapping, pgoff_t *index, pgoff_t end, | |
10bbd235 | 1062 | xa_mark_t tag, unsigned max_pages) |
93d3b714 JK |
1063 | { |
1064 | pvec->nr = find_get_pages_range_tag(mapping, index, end, tag, | |
1065 | min_t(unsigned int, max_pages, PAGEVEC_SIZE), pvec->pages); | |
1066 | return pagevec_count(pvec); | |
1067 | } | |
1068 | EXPORT_SYMBOL(pagevec_lookup_range_nr_tag); | |
1da177e4 LT |
1069 | /* |
1070 | * Perform any setup for the swap system | |
1071 | */ | |
1072 | void __init swap_setup(void) | |
1073 | { | |
ca79b0c2 | 1074 | unsigned long megs = totalram_pages() >> (20 - PAGE_SHIFT); |
e0bf68dd | 1075 | |
1da177e4 LT |
1076 | /* Use a smaller cluster for small-memory machines */ |
1077 | if (megs < 16) | |
1078 | page_cluster = 2; | |
1079 | else | |
1080 | page_cluster = 3; | |
1081 | /* | |
1082 | * Right now other parts of the system means that we | |
1083 | * _really_ don't want to cluster much more | |
1084 | */ | |
1da177e4 | 1085 | } |