Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1 | /* |
| 2 | * linux/mm/swap.c |
| 3 | * |
| 4 | * Copyright (C) 1991, 1992, 1993, 1994 Linus Torvalds |
| 5 | */ |
| 6 | |
| 7 | /* |
Simon Arlott | 183ff22 | 2007-10-20 01:27:18 +0200 | [diff] [blame] | 8 | * This file contains the default values for the operation of the |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 9 | * Linux VM subsystem. Fine-tuning documentation can be found in |
| 10 | * Documentation/sysctl/vm.txt. |
| 11 | * Started 18.12.91 |
| 12 | * Swap aging added 23.2.95, Stephen Tweedie. |
| 13 | * Buffermem limits added 12.3.98, Rik van Riel. |
| 14 | */ |
| 15 | |
| 16 | #include <linux/mm.h> |
| 17 | #include <linux/sched.h> |
| 18 | #include <linux/kernel_stat.h> |
| 19 | #include <linux/swap.h> |
| 20 | #include <linux/mman.h> |
| 21 | #include <linux/pagemap.h> |
| 22 | #include <linux/pagevec.h> |
| 23 | #include <linux/init.h> |
Paul Gortmaker | b95f1b31 | 2011-10-16 02:01:52 -0400 | [diff] [blame] | 24 | #include <linux/export.h> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 25 | #include <linux/mm_inline.h> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 26 | #include <linux/percpu_counter.h> |
| 27 | #include <linux/percpu.h> |
| 28 | #include <linux/cpu.h> |
| 29 | #include <linux/notifier.h> |
Peter Zijlstra | e0bf68d | 2007-10-16 23:25:46 -0700 | [diff] [blame] | 30 | #include <linux/backing-dev.h> |
Balbir Singh | 66e1707 | 2008-02-07 00:13:56 -0800 | [diff] [blame] | 31 | #include <linux/memcontrol.h> |
Tejun Heo | 5a0e3ad | 2010-03-24 17:04:11 +0900 | [diff] [blame] | 32 | #include <linux/gfp.h> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 33 | |
Lee Schermerhorn | 64d6519 | 2008-10-18 20:26:52 -0700 | [diff] [blame] | 34 | #include "internal.h" |
| 35 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 36 | /* How many pages do we try to swap or page in/out together? */ |
| 37 | int page_cluster; |
| 38 | |
KOSAKI Motohiro | f04e9eb | 2008-10-18 20:26:19 -0700 | [diff] [blame] | 39 | static DEFINE_PER_CPU(struct pagevec[NR_LRU_LISTS], lru_add_pvecs); |
Vegard Nossum | f84f9504 | 2008-07-23 21:28:14 -0700 | [diff] [blame] | 40 | static DEFINE_PER_CPU(struct pagevec, lru_rotate_pvecs); |
Minchan Kim | 3156018 | 2011-03-22 16:32:52 -0700 | [diff] [blame] | 41 | static DEFINE_PER_CPU(struct pagevec, lru_deactivate_pvecs); |
Hisashi Hifumi | 902aaed | 2007-10-16 01:24:52 -0700 | [diff] [blame] | 42 | |
Adrian Bunk | b221385 | 2006-09-25 23:31:02 -0700 | [diff] [blame] | 43 | /* |
| 44 | * This path almost never happens for VM activity - pages are normally |
| 45 | * freed via pagevecs. But it gets used by networking. |
| 46 | */ |
Harvey Harrison | 920c7a5 | 2008-02-04 22:29:26 -0800 | [diff] [blame] | 47 | static void __page_cache_release(struct page *page) |
Adrian Bunk | b221385 | 2006-09-25 23:31:02 -0700 | [diff] [blame] | 48 | { |
| 49 | if (PageLRU(page)) { |
| 50 | unsigned long flags; |
| 51 | struct zone *zone = page_zone(page); |
| 52 | |
| 53 | spin_lock_irqsave(&zone->lru_lock, flags); |
| 54 | VM_BUG_ON(!PageLRU(page)); |
| 55 | __ClearPageLRU(page); |
| 56 | del_page_from_lru(zone, page); |
| 57 | spin_unlock_irqrestore(&zone->lru_lock, flags); |
| 58 | } |
Andrea Arcangeli | 9180706 | 2011-01-13 15:46:32 -0800 | [diff] [blame] | 59 | } |
| 60 | |
| 61 | static void __put_single_page(struct page *page) |
| 62 | { |
| 63 | __page_cache_release(page); |
Li Hong | fc91668 | 2010-03-05 13:41:54 -0800 | [diff] [blame] | 64 | free_hot_cold_page(page, 0); |
Adrian Bunk | b221385 | 2006-09-25 23:31:02 -0700 | [diff] [blame] | 65 | } |
| 66 | |
Andrea Arcangeli | 9180706 | 2011-01-13 15:46:32 -0800 | [diff] [blame] | 67 | static void __put_compound_page(struct page *page) |
| 68 | { |
| 69 | compound_page_dtor *dtor; |
| 70 | |
| 71 | __page_cache_release(page); |
| 72 | dtor = get_compound_page_dtor(page); |
| 73 | (*dtor)(page); |
| 74 | } |
| 75 | |
Nick Piggin | 8519fb3 | 2006-02-07 12:58:52 -0800 | [diff] [blame] | 76 | static void put_compound_page(struct page *page) |
| 77 | { |
Andrea Arcangeli | 9180706 | 2011-01-13 15:46:32 -0800 | [diff] [blame] | 78 | if (unlikely(PageTail(page))) { |
| 79 | /* __split_huge_page_refcount can run under us */ |
Andrea Arcangeli | 70b50f9 | 2011-11-02 13:36:59 -0700 | [diff] [blame] | 80 | struct page *page_head = compound_trans_head(page); |
| 81 | |
| 82 | if (likely(page != page_head && |
| 83 | get_page_unless_zero(page_head))) { |
Andrea Arcangeli | 9180706 | 2011-01-13 15:46:32 -0800 | [diff] [blame] | 84 | unsigned long flags; |
| 85 | /* |
Andrea Arcangeli | 70b50f9 | 2011-11-02 13:36:59 -0700 | [diff] [blame] | 86 | * page_head wasn't a dangling pointer but it |
| 87 | * may not be a head page anymore by the time |
| 88 | * we obtain the lock. That is ok as long as it |
| 89 | * can't be freed from under us. |
Andrea Arcangeli | 9180706 | 2011-01-13 15:46:32 -0800 | [diff] [blame] | 90 | */ |
Andrea Arcangeli | 9180706 | 2011-01-13 15:46:32 -0800 | [diff] [blame] | 91 | flags = compound_lock_irqsave(page_head); |
| 92 | if (unlikely(!PageTail(page))) { |
| 93 | /* __split_huge_page_refcount run before us */ |
| 94 | compound_unlock_irqrestore(page_head, flags); |
| 95 | VM_BUG_ON(PageHead(page_head)); |
Andrea Arcangeli | 9180706 | 2011-01-13 15:46:32 -0800 | [diff] [blame] | 96 | if (put_page_testzero(page_head)) |
| 97 | __put_single_page(page_head); |
| 98 | out_put_single: |
| 99 | if (put_page_testzero(page)) |
| 100 | __put_single_page(page); |
| 101 | return; |
| 102 | } |
| 103 | VM_BUG_ON(page_head != page->first_page); |
| 104 | /* |
| 105 | * We can release the refcount taken by |
Andrea Arcangeli | 70b50f9 | 2011-11-02 13:36:59 -0700 | [diff] [blame] | 106 | * get_page_unless_zero() now that |
| 107 | * __split_huge_page_refcount() is blocked on |
| 108 | * the compound_lock. |
Andrea Arcangeli | 9180706 | 2011-01-13 15:46:32 -0800 | [diff] [blame] | 109 | */ |
| 110 | if (put_page_testzero(page_head)) |
| 111 | VM_BUG_ON(1); |
| 112 | /* __split_huge_page_refcount will wait now */ |
Andrea Arcangeli | 70b50f9 | 2011-11-02 13:36:59 -0700 | [diff] [blame] | 113 | VM_BUG_ON(page_mapcount(page) <= 0); |
| 114 | atomic_dec(&page->_mapcount); |
Andrea Arcangeli | 9180706 | 2011-01-13 15:46:32 -0800 | [diff] [blame] | 115 | VM_BUG_ON(atomic_read(&page_head->_count) <= 0); |
Andrea Arcangeli | 70b50f9 | 2011-11-02 13:36:59 -0700 | [diff] [blame] | 116 | VM_BUG_ON(atomic_read(&page->_count) != 0); |
Andrea Arcangeli | 9180706 | 2011-01-13 15:46:32 -0800 | [diff] [blame] | 117 | compound_unlock_irqrestore(page_head, flags); |
Andrea Arcangeli | a95a82e | 2011-01-13 15:46:33 -0800 | [diff] [blame] | 118 | if (put_page_testzero(page_head)) { |
| 119 | if (PageHead(page_head)) |
| 120 | __put_compound_page(page_head); |
| 121 | else |
| 122 | __put_single_page(page_head); |
| 123 | } |
Andrea Arcangeli | 9180706 | 2011-01-13 15:46:32 -0800 | [diff] [blame] | 124 | } else { |
| 125 | /* page_head is a dangling pointer */ |
| 126 | VM_BUG_ON(PageTail(page)); |
| 127 | goto out_put_single; |
| 128 | } |
| 129 | } else if (put_page_testzero(page)) { |
| 130 | if (PageHead(page)) |
| 131 | __put_compound_page(page); |
| 132 | else |
| 133 | __put_single_page(page); |
Nick Piggin | 8519fb3 | 2006-02-07 12:58:52 -0800 | [diff] [blame] | 134 | } |
| 135 | } |
| 136 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 137 | void put_page(struct page *page) |
| 138 | { |
Nick Piggin | 8519fb3 | 2006-02-07 12:58:52 -0800 | [diff] [blame] | 139 | if (unlikely(PageCompound(page))) |
| 140 | put_compound_page(page); |
| 141 | else if (put_page_testzero(page)) |
Andrea Arcangeli | 9180706 | 2011-01-13 15:46:32 -0800 | [diff] [blame] | 142 | __put_single_page(page); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 143 | } |
| 144 | EXPORT_SYMBOL(put_page); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 145 | |
Andrea Arcangeli | 70b50f9 | 2011-11-02 13:36:59 -0700 | [diff] [blame] | 146 | /* |
| 147 | * This function is exported but must not be called by anything other |
| 148 | * than get_page(). It implements the slow path of get_page(). |
| 149 | */ |
| 150 | bool __get_page_tail(struct page *page) |
| 151 | { |
| 152 | /* |
| 153 | * This takes care of get_page() if run on a tail page |
| 154 | * returned by one of the get_user_pages/follow_page variants. |
| 155 | * get_user_pages/follow_page itself doesn't need the compound |
| 156 | * lock because it runs __get_page_tail_foll() under the |
| 157 | * proper PT lock that already serializes against |
| 158 | * split_huge_page(). |
| 159 | */ |
| 160 | unsigned long flags; |
| 161 | bool got = false; |
| 162 | struct page *page_head = compound_trans_head(page); |
| 163 | |
| 164 | if (likely(page != page_head && get_page_unless_zero(page_head))) { |
| 165 | /* |
| 166 | * page_head wasn't a dangling pointer but it |
| 167 | * may not be a head page anymore by the time |
| 168 | * we obtain the lock. That is ok as long as it |
| 169 | * can't be freed from under us. |
| 170 | */ |
| 171 | flags = compound_lock_irqsave(page_head); |
| 172 | /* here __split_huge_page_refcount won't run anymore */ |
| 173 | if (likely(PageTail(page))) { |
| 174 | __get_page_tail_foll(page, false); |
| 175 | got = true; |
| 176 | } |
| 177 | compound_unlock_irqrestore(page_head, flags); |
| 178 | if (unlikely(!got)) |
| 179 | put_page(page_head); |
| 180 | } |
| 181 | return got; |
| 182 | } |
| 183 | EXPORT_SYMBOL(__get_page_tail); |
| 184 | |
Alexander Zarochentsev | 1d7ea73 | 2006-08-13 23:24:27 -0700 | [diff] [blame] | 185 | /** |
Randy Dunlap | 7682486 | 2008-03-19 17:00:40 -0700 | [diff] [blame] | 186 | * put_pages_list() - release a list of pages |
| 187 | * @pages: list of pages threaded on page->lru |
Alexander Zarochentsev | 1d7ea73 | 2006-08-13 23:24:27 -0700 | [diff] [blame] | 188 | * |
| 189 | * Release a list of pages which are strung together on page.lru. Currently |
| 190 | * used by read_cache_pages() and related error recovery code. |
Alexander Zarochentsev | 1d7ea73 | 2006-08-13 23:24:27 -0700 | [diff] [blame] | 191 | */ |
| 192 | void put_pages_list(struct list_head *pages) |
| 193 | { |
| 194 | while (!list_empty(pages)) { |
| 195 | struct page *victim; |
| 196 | |
| 197 | victim = list_entry(pages->prev, struct page, lru); |
| 198 | list_del(&victim->lru); |
| 199 | page_cache_release(victim); |
| 200 | } |
| 201 | } |
| 202 | EXPORT_SYMBOL(put_pages_list); |
| 203 | |
Shaohua Li | 3dd7ae8 | 2011-03-22 16:33:45 -0700 | [diff] [blame] | 204 | static void pagevec_lru_move_fn(struct pagevec *pvec, |
| 205 | void (*move_fn)(struct page *page, void *arg), |
| 206 | void *arg) |
Hisashi Hifumi | 902aaed | 2007-10-16 01:24:52 -0700 | [diff] [blame] | 207 | { |
| 208 | int i; |
Hisashi Hifumi | 902aaed | 2007-10-16 01:24:52 -0700 | [diff] [blame] | 209 | struct zone *zone = NULL; |
Shaohua Li | 3dd7ae8 | 2011-03-22 16:33:45 -0700 | [diff] [blame] | 210 | unsigned long flags = 0; |
Hisashi Hifumi | 902aaed | 2007-10-16 01:24:52 -0700 | [diff] [blame] | 211 | |
| 212 | for (i = 0; i < pagevec_count(pvec); i++) { |
| 213 | struct page *page = pvec->pages[i]; |
| 214 | struct zone *pagezone = page_zone(page); |
| 215 | |
| 216 | if (pagezone != zone) { |
| 217 | if (zone) |
Shaohua Li | 3dd7ae8 | 2011-03-22 16:33:45 -0700 | [diff] [blame] | 218 | spin_unlock_irqrestore(&zone->lru_lock, flags); |
Hisashi Hifumi | 902aaed | 2007-10-16 01:24:52 -0700 | [diff] [blame] | 219 | zone = pagezone; |
Shaohua Li | 3dd7ae8 | 2011-03-22 16:33:45 -0700 | [diff] [blame] | 220 | spin_lock_irqsave(&zone->lru_lock, flags); |
Hisashi Hifumi | 902aaed | 2007-10-16 01:24:52 -0700 | [diff] [blame] | 221 | } |
Shaohua Li | 3dd7ae8 | 2011-03-22 16:33:45 -0700 | [diff] [blame] | 222 | |
| 223 | (*move_fn)(page, arg); |
Hisashi Hifumi | 902aaed | 2007-10-16 01:24:52 -0700 | [diff] [blame] | 224 | } |
| 225 | if (zone) |
Shaohua Li | 3dd7ae8 | 2011-03-22 16:33:45 -0700 | [diff] [blame] | 226 | spin_unlock_irqrestore(&zone->lru_lock, flags); |
Linus Torvalds | 83896fb | 2011-01-17 14:42:34 -0800 | [diff] [blame] | 227 | release_pages(pvec->pages, pvec->nr, pvec->cold); |
| 228 | pagevec_reinit(pvec); |
Shaohua Li | d8505de | 2011-01-13 15:47:33 -0800 | [diff] [blame] | 229 | } |
| 230 | |
Shaohua Li | 3dd7ae8 | 2011-03-22 16:33:45 -0700 | [diff] [blame] | 231 | static void pagevec_move_tail_fn(struct page *page, void *arg) |
| 232 | { |
| 233 | int *pgmoved = arg; |
Shaohua Li | 3dd7ae8 | 2011-03-22 16:33:45 -0700 | [diff] [blame] | 234 | |
| 235 | if (PageLRU(page) && !PageActive(page) && !PageUnevictable(page)) { |
| 236 | enum lru_list lru = page_lru_base_type(page); |
Johannes Weiner | 925b767 | 2012-01-12 17:18:15 -0800 | [diff] [blame] | 237 | struct lruvec *lruvec; |
| 238 | |
| 239 | lruvec = mem_cgroup_lru_move_lists(page_zone(page), |
| 240 | page, lru, lru); |
| 241 | list_move_tail(&page->lru, &lruvec->lists[lru]); |
Shaohua Li | 3dd7ae8 | 2011-03-22 16:33:45 -0700 | [diff] [blame] | 242 | (*pgmoved)++; |
| 243 | } |
| 244 | } |
| 245 | |
| 246 | /* |
| 247 | * pagevec_move_tail() must be called with IRQ disabled. |
| 248 | * Otherwise this may cause nasty races. |
| 249 | */ |
| 250 | static void pagevec_move_tail(struct pagevec *pvec) |
| 251 | { |
| 252 | int pgmoved = 0; |
| 253 | |
| 254 | pagevec_lru_move_fn(pvec, pagevec_move_tail_fn, &pgmoved); |
| 255 | __count_vm_events(PGROTATED, pgmoved); |
| 256 | } |
| 257 | |
Hisashi Hifumi | 902aaed | 2007-10-16 01:24:52 -0700 | [diff] [blame] | 258 | /* |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 259 | * Writeback is about to end against a page which has been marked for immediate |
| 260 | * reclaim. If it still appears to be reclaimable, move it to the tail of the |
Hisashi Hifumi | 902aaed | 2007-10-16 01:24:52 -0700 | [diff] [blame] | 261 | * inactive list. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 262 | */ |
Shaohua Li | 3dd7ae8 | 2011-03-22 16:33:45 -0700 | [diff] [blame] | 263 | void rotate_reclaimable_page(struct page *page) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 264 | { |
Miklos Szeredi | ac6aadb | 2008-04-28 02:12:38 -0700 | [diff] [blame] | 265 | if (!PageLocked(page) && !PageDirty(page) && !PageActive(page) && |
Lee Schermerhorn | 894bc31 | 2008-10-18 20:26:39 -0700 | [diff] [blame] | 266 | !PageUnevictable(page) && PageLRU(page)) { |
Miklos Szeredi | ac6aadb | 2008-04-28 02:12:38 -0700 | [diff] [blame] | 267 | struct pagevec *pvec; |
| 268 | unsigned long flags; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 269 | |
Miklos Szeredi | ac6aadb | 2008-04-28 02:12:38 -0700 | [diff] [blame] | 270 | page_cache_get(page); |
| 271 | local_irq_save(flags); |
| 272 | pvec = &__get_cpu_var(lru_rotate_pvecs); |
| 273 | if (!pagevec_add(pvec, page)) |
| 274 | pagevec_move_tail(pvec); |
| 275 | local_irq_restore(flags); |
| 276 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 277 | } |
| 278 | |
KOSAKI Motohiro | 3e2f41f | 2009-01-07 18:08:20 -0800 | [diff] [blame] | 279 | static void update_page_reclaim_stat(struct zone *zone, struct page *page, |
| 280 | int file, int rotated) |
| 281 | { |
| 282 | struct zone_reclaim_stat *reclaim_stat = &zone->reclaim_stat; |
| 283 | struct zone_reclaim_stat *memcg_reclaim_stat; |
| 284 | |
| 285 | memcg_reclaim_stat = mem_cgroup_get_reclaim_stat_from_page(page); |
| 286 | |
| 287 | reclaim_stat->recent_scanned[file]++; |
| 288 | if (rotated) |
| 289 | reclaim_stat->recent_rotated[file]++; |
| 290 | |
| 291 | if (!memcg_reclaim_stat) |
| 292 | return; |
| 293 | |
| 294 | memcg_reclaim_stat->recent_scanned[file]++; |
| 295 | if (rotated) |
| 296 | memcg_reclaim_stat->recent_rotated[file]++; |
| 297 | } |
| 298 | |
Shaohua Li | eb709b0 | 2011-05-24 17:12:55 -0700 | [diff] [blame] | 299 | static void __activate_page(struct page *page, void *arg) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 300 | { |
| 301 | struct zone *zone = page_zone(page); |
| 302 | |
Linus Torvalds | 7a60857 | 2011-01-17 14:42:19 -0800 | [diff] [blame] | 303 | if (PageLRU(page) && !PageActive(page) && !PageUnevictable(page)) { |
| 304 | int file = page_is_file_cache(page); |
| 305 | int lru = page_lru_base_type(page); |
| 306 | del_page_from_lru_list(zone, page, lru); |
| 307 | |
| 308 | SetPageActive(page); |
| 309 | lru += LRU_ACTIVE; |
| 310 | add_page_to_lru_list(zone, page, lru); |
| 311 | __count_vm_event(PGACTIVATE); |
| 312 | |
| 313 | update_page_reclaim_stat(zone, page, file, 1); |
| 314 | } |
Shaohua Li | eb709b0 | 2011-05-24 17:12:55 -0700 | [diff] [blame] | 315 | } |
| 316 | |
| 317 | #ifdef CONFIG_SMP |
| 318 | static DEFINE_PER_CPU(struct pagevec, activate_page_pvecs); |
| 319 | |
| 320 | static void activate_page_drain(int cpu) |
| 321 | { |
| 322 | struct pagevec *pvec = &per_cpu(activate_page_pvecs, cpu); |
| 323 | |
| 324 | if (pagevec_count(pvec)) |
| 325 | pagevec_lru_move_fn(pvec, __activate_page, NULL); |
| 326 | } |
| 327 | |
| 328 | void activate_page(struct page *page) |
| 329 | { |
| 330 | if (PageLRU(page) && !PageActive(page) && !PageUnevictable(page)) { |
| 331 | struct pagevec *pvec = &get_cpu_var(activate_page_pvecs); |
| 332 | |
| 333 | page_cache_get(page); |
| 334 | if (!pagevec_add(pvec, page)) |
| 335 | pagevec_lru_move_fn(pvec, __activate_page, NULL); |
| 336 | put_cpu_var(activate_page_pvecs); |
| 337 | } |
| 338 | } |
| 339 | |
| 340 | #else |
| 341 | static inline void activate_page_drain(int cpu) |
| 342 | { |
| 343 | } |
| 344 | |
| 345 | void activate_page(struct page *page) |
| 346 | { |
| 347 | struct zone *zone = page_zone(page); |
| 348 | |
| 349 | spin_lock_irq(&zone->lru_lock); |
| 350 | __activate_page(page, NULL); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 351 | spin_unlock_irq(&zone->lru_lock); |
| 352 | } |
Shaohua Li | eb709b0 | 2011-05-24 17:12:55 -0700 | [diff] [blame] | 353 | #endif |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 354 | |
| 355 | /* |
| 356 | * Mark a page as having seen activity. |
| 357 | * |
| 358 | * inactive,unreferenced -> inactive,referenced |
| 359 | * inactive,referenced -> active,unreferenced |
| 360 | * active,unreferenced -> active,referenced |
| 361 | */ |
Harvey Harrison | 920c7a5 | 2008-02-04 22:29:26 -0800 | [diff] [blame] | 362 | void mark_page_accessed(struct page *page) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 363 | { |
Lee Schermerhorn | 894bc31 | 2008-10-18 20:26:39 -0700 | [diff] [blame] | 364 | if (!PageActive(page) && !PageUnevictable(page) && |
| 365 | PageReferenced(page) && PageLRU(page)) { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 366 | activate_page(page); |
| 367 | ClearPageReferenced(page); |
| 368 | } else if (!PageReferenced(page)) { |
| 369 | SetPageReferenced(page); |
| 370 | } |
| 371 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 372 | EXPORT_SYMBOL(mark_page_accessed); |
| 373 | |
KOSAKI Motohiro | f04e9eb | 2008-10-18 20:26:19 -0700 | [diff] [blame] | 374 | void __lru_cache_add(struct page *page, enum lru_list lru) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 375 | { |
KOSAKI Motohiro | f04e9eb | 2008-10-18 20:26:19 -0700 | [diff] [blame] | 376 | struct pagevec *pvec = &get_cpu_var(lru_add_pvecs)[lru]; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 377 | |
| 378 | page_cache_get(page); |
| 379 | if (!pagevec_add(pvec, page)) |
Hugh Dickins | 5095ae83 | 2012-01-12 17:19:58 -0800 | [diff] [blame] | 380 | __pagevec_lru_add(pvec, lru); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 381 | put_cpu_var(lru_add_pvecs); |
| 382 | } |
Miklos Szeredi | 47846b0 | 2010-05-25 15:06:06 +0200 | [diff] [blame] | 383 | EXPORT_SYMBOL(__lru_cache_add); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 384 | |
KOSAKI Motohiro | f04e9eb | 2008-10-18 20:26:19 -0700 | [diff] [blame] | 385 | /** |
| 386 | * lru_cache_add_lru - add a page to a page list |
| 387 | * @page: the page to be added to the LRU. |
| 388 | * @lru: the LRU list to which the page is added. |
| 389 | */ |
| 390 | void lru_cache_add_lru(struct page *page, enum lru_list lru) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 391 | { |
KOSAKI Motohiro | f04e9eb | 2008-10-18 20:26:19 -0700 | [diff] [blame] | 392 | if (PageActive(page)) { |
Lee Schermerhorn | 894bc31 | 2008-10-18 20:26:39 -0700 | [diff] [blame] | 393 | VM_BUG_ON(PageUnevictable(page)); |
KOSAKI Motohiro | f04e9eb | 2008-10-18 20:26:19 -0700 | [diff] [blame] | 394 | ClearPageActive(page); |
Lee Schermerhorn | 894bc31 | 2008-10-18 20:26:39 -0700 | [diff] [blame] | 395 | } else if (PageUnevictable(page)) { |
| 396 | VM_BUG_ON(PageActive(page)); |
| 397 | ClearPageUnevictable(page); |
KOSAKI Motohiro | f04e9eb | 2008-10-18 20:26:19 -0700 | [diff] [blame] | 398 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 399 | |
Lee Schermerhorn | 894bc31 | 2008-10-18 20:26:39 -0700 | [diff] [blame] | 400 | VM_BUG_ON(PageLRU(page) || PageActive(page) || PageUnevictable(page)); |
KOSAKI Motohiro | f04e9eb | 2008-10-18 20:26:19 -0700 | [diff] [blame] | 401 | __lru_cache_add(page, lru); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 402 | } |
| 403 | |
Lee Schermerhorn | 894bc31 | 2008-10-18 20:26:39 -0700 | [diff] [blame] | 404 | /** |
| 405 | * add_page_to_unevictable_list - add a page to the unevictable list |
| 406 | * @page: the page to be added to the unevictable list |
| 407 | * |
| 408 | * Add page directly to its zone's unevictable list. To avoid races with |
| 409 | * tasks that might be making the page evictable, through eg. munlock, |
| 410 | * munmap or exit, while it's not on the lru, we want to add the page |
| 411 | * while it's locked or otherwise "invisible" to other tasks. This is |
| 412 | * difficult to do when using the pagevec cache, so bypass that. |
| 413 | */ |
| 414 | void add_page_to_unevictable_list(struct page *page) |
| 415 | { |
| 416 | struct zone *zone = page_zone(page); |
| 417 | |
| 418 | spin_lock_irq(&zone->lru_lock); |
| 419 | SetPageUnevictable(page); |
| 420 | SetPageLRU(page); |
| 421 | add_page_to_lru_list(zone, page, LRU_UNEVICTABLE); |
| 422 | spin_unlock_irq(&zone->lru_lock); |
| 423 | } |
| 424 | |
Hisashi Hifumi | 902aaed | 2007-10-16 01:24:52 -0700 | [diff] [blame] | 425 | /* |
Minchan Kim | 3156018 | 2011-03-22 16:32:52 -0700 | [diff] [blame] | 426 | * If the page can not be invalidated, it is moved to the |
| 427 | * inactive list to speed up its reclaim. It is moved to the |
| 428 | * head of the list, rather than the tail, to give the flusher |
| 429 | * threads some time to write it out, as this is much more |
| 430 | * effective than the single-page writeout from reclaim. |
Minchan Kim | 278df9f | 2011-03-22 16:32:54 -0700 | [diff] [blame] | 431 | * |
| 432 | * If the page isn't page_mapped and dirty/writeback, the page |
| 433 | * could reclaim asap using PG_reclaim. |
| 434 | * |
| 435 | * 1. active, mapped page -> none |
| 436 | * 2. active, dirty/writeback page -> inactive, head, PG_reclaim |
| 437 | * 3. inactive, mapped page -> none |
| 438 | * 4. inactive, dirty/writeback page -> inactive, head, PG_reclaim |
| 439 | * 5. inactive, clean -> inactive, tail |
| 440 | * 6. Others -> none |
| 441 | * |
| 442 | * In 4, why it moves inactive's head, the VM expects the page would |
| 443 | * be write it out by flusher threads as this is much more effective |
| 444 | * than the single-page writeout from reclaim. |
Minchan Kim | 3156018 | 2011-03-22 16:32:52 -0700 | [diff] [blame] | 445 | */ |
Shaohua Li | 3dd7ae8 | 2011-03-22 16:33:45 -0700 | [diff] [blame] | 446 | static void lru_deactivate_fn(struct page *page, void *arg) |
Minchan Kim | 3156018 | 2011-03-22 16:32:52 -0700 | [diff] [blame] | 447 | { |
| 448 | int lru, file; |
Minchan Kim | 278df9f | 2011-03-22 16:32:54 -0700 | [diff] [blame] | 449 | bool active; |
Shaohua Li | 3dd7ae8 | 2011-03-22 16:33:45 -0700 | [diff] [blame] | 450 | struct zone *zone = page_zone(page); |
Minchan Kim | 3156018 | 2011-03-22 16:32:52 -0700 | [diff] [blame] | 451 | |
Minchan Kim | 278df9f | 2011-03-22 16:32:54 -0700 | [diff] [blame] | 452 | if (!PageLRU(page)) |
Minchan Kim | 3156018 | 2011-03-22 16:32:52 -0700 | [diff] [blame] | 453 | return; |
| 454 | |
Minchan Kim | bad49d9 | 2011-05-11 15:13:30 -0700 | [diff] [blame] | 455 | if (PageUnevictable(page)) |
| 456 | return; |
| 457 | |
Minchan Kim | 3156018 | 2011-03-22 16:32:52 -0700 | [diff] [blame] | 458 | /* Some processes are using the page */ |
| 459 | if (page_mapped(page)) |
| 460 | return; |
| 461 | |
Minchan Kim | 278df9f | 2011-03-22 16:32:54 -0700 | [diff] [blame] | 462 | active = PageActive(page); |
| 463 | |
Minchan Kim | 3156018 | 2011-03-22 16:32:52 -0700 | [diff] [blame] | 464 | file = page_is_file_cache(page); |
| 465 | lru = page_lru_base_type(page); |
Minchan Kim | 278df9f | 2011-03-22 16:32:54 -0700 | [diff] [blame] | 466 | del_page_from_lru_list(zone, page, lru + active); |
Minchan Kim | 3156018 | 2011-03-22 16:32:52 -0700 | [diff] [blame] | 467 | ClearPageActive(page); |
| 468 | ClearPageReferenced(page); |
| 469 | add_page_to_lru_list(zone, page, lru); |
Minchan Kim | 3156018 | 2011-03-22 16:32:52 -0700 | [diff] [blame] | 470 | |
Minchan Kim | 278df9f | 2011-03-22 16:32:54 -0700 | [diff] [blame] | 471 | if (PageWriteback(page) || PageDirty(page)) { |
| 472 | /* |
| 473 | * PG_reclaim could be raced with end_page_writeback |
| 474 | * It can make readahead confusing. But race window |
| 475 | * is _really_ small and it's non-critical problem. |
| 476 | */ |
| 477 | SetPageReclaim(page); |
| 478 | } else { |
Johannes Weiner | 925b767 | 2012-01-12 17:18:15 -0800 | [diff] [blame] | 479 | struct lruvec *lruvec; |
Minchan Kim | 278df9f | 2011-03-22 16:32:54 -0700 | [diff] [blame] | 480 | /* |
| 481 | * The page's writeback ends up during pagevec |
| 482 | * We moves tha page into tail of inactive. |
| 483 | */ |
Johannes Weiner | 925b767 | 2012-01-12 17:18:15 -0800 | [diff] [blame] | 484 | lruvec = mem_cgroup_lru_move_lists(zone, page, lru, lru); |
| 485 | list_move_tail(&page->lru, &lruvec->lists[lru]); |
Minchan Kim | 278df9f | 2011-03-22 16:32:54 -0700 | [diff] [blame] | 486 | __count_vm_event(PGROTATED); |
| 487 | } |
| 488 | |
| 489 | if (active) |
| 490 | __count_vm_event(PGDEACTIVATE); |
Minchan Kim | 3156018 | 2011-03-22 16:32:52 -0700 | [diff] [blame] | 491 | update_page_reclaim_stat(zone, page, file, 0); |
| 492 | } |
| 493 | |
Minchan Kim | 3156018 | 2011-03-22 16:32:52 -0700 | [diff] [blame] | 494 | /* |
Hisashi Hifumi | 902aaed | 2007-10-16 01:24:52 -0700 | [diff] [blame] | 495 | * Drain pages out of the cpu's pagevecs. |
| 496 | * Either "cpu" is the current CPU, and preemption has already been |
| 497 | * disabled; or "cpu" is being hot-unplugged, and is already dead. |
| 498 | */ |
| 499 | static void drain_cpu_pagevecs(int cpu) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 500 | { |
KOSAKI Motohiro | f04e9eb | 2008-10-18 20:26:19 -0700 | [diff] [blame] | 501 | struct pagevec *pvecs = per_cpu(lru_add_pvecs, cpu); |
Hisashi Hifumi | 902aaed | 2007-10-16 01:24:52 -0700 | [diff] [blame] | 502 | struct pagevec *pvec; |
KOSAKI Motohiro | f04e9eb | 2008-10-18 20:26:19 -0700 | [diff] [blame] | 503 | int lru; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 504 | |
KOSAKI Motohiro | f04e9eb | 2008-10-18 20:26:19 -0700 | [diff] [blame] | 505 | for_each_lru(lru) { |
| 506 | pvec = &pvecs[lru - LRU_BASE]; |
| 507 | if (pagevec_count(pvec)) |
Hugh Dickins | 5095ae83 | 2012-01-12 17:19:58 -0800 | [diff] [blame] | 508 | __pagevec_lru_add(pvec, lru); |
KOSAKI Motohiro | f04e9eb | 2008-10-18 20:26:19 -0700 | [diff] [blame] | 509 | } |
Hisashi Hifumi | 902aaed | 2007-10-16 01:24:52 -0700 | [diff] [blame] | 510 | |
| 511 | pvec = &per_cpu(lru_rotate_pvecs, cpu); |
| 512 | if (pagevec_count(pvec)) { |
| 513 | unsigned long flags; |
| 514 | |
| 515 | /* No harm done if a racing interrupt already did this */ |
| 516 | local_irq_save(flags); |
| 517 | pagevec_move_tail(pvec); |
| 518 | local_irq_restore(flags); |
| 519 | } |
Minchan Kim | 3156018 | 2011-03-22 16:32:52 -0700 | [diff] [blame] | 520 | |
| 521 | pvec = &per_cpu(lru_deactivate_pvecs, cpu); |
| 522 | if (pagevec_count(pvec)) |
Shaohua Li | 3dd7ae8 | 2011-03-22 16:33:45 -0700 | [diff] [blame] | 523 | pagevec_lru_move_fn(pvec, lru_deactivate_fn, NULL); |
Shaohua Li | eb709b0 | 2011-05-24 17:12:55 -0700 | [diff] [blame] | 524 | |
| 525 | activate_page_drain(cpu); |
Minchan Kim | 3156018 | 2011-03-22 16:32:52 -0700 | [diff] [blame] | 526 | } |
| 527 | |
| 528 | /** |
| 529 | * deactivate_page - forcefully deactivate a page |
| 530 | * @page: page to deactivate |
| 531 | * |
| 532 | * This function hints the VM that @page is a good reclaim candidate, |
| 533 | * for example if its invalidation fails due to the page being dirty |
| 534 | * or under writeback. |
| 535 | */ |
| 536 | void deactivate_page(struct page *page) |
| 537 | { |
Minchan Kim | 821ed6b | 2011-05-24 17:12:31 -0700 | [diff] [blame] | 538 | /* |
| 539 | * In a workload with many unevictable page such as mprotect, unevictable |
| 540 | * page deactivation for accelerating reclaim is pointless. |
| 541 | */ |
| 542 | if (PageUnevictable(page)) |
| 543 | return; |
| 544 | |
Minchan Kim | 3156018 | 2011-03-22 16:32:52 -0700 | [diff] [blame] | 545 | if (likely(get_page_unless_zero(page))) { |
| 546 | struct pagevec *pvec = &get_cpu_var(lru_deactivate_pvecs); |
| 547 | |
| 548 | if (!pagevec_add(pvec, page)) |
Shaohua Li | 3dd7ae8 | 2011-03-22 16:33:45 -0700 | [diff] [blame] | 549 | pagevec_lru_move_fn(pvec, lru_deactivate_fn, NULL); |
Minchan Kim | 3156018 | 2011-03-22 16:32:52 -0700 | [diff] [blame] | 550 | put_cpu_var(lru_deactivate_pvecs); |
| 551 | } |
Andrew Morton | 80bfed9 | 2006-01-06 00:11:14 -0800 | [diff] [blame] | 552 | } |
| 553 | |
| 554 | void lru_add_drain(void) |
| 555 | { |
Hisashi Hifumi | 902aaed | 2007-10-16 01:24:52 -0700 | [diff] [blame] | 556 | drain_cpu_pagevecs(get_cpu()); |
Andrew Morton | 80bfed9 | 2006-01-06 00:11:14 -0800 | [diff] [blame] | 557 | put_cpu(); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 558 | } |
| 559 | |
David Howells | c402895 | 2006-11-22 14:57:56 +0000 | [diff] [blame] | 560 | static void lru_add_drain_per_cpu(struct work_struct *dummy) |
Nick Piggin | 053837f | 2006-01-18 17:42:27 -0800 | [diff] [blame] | 561 | { |
| 562 | lru_add_drain(); |
| 563 | } |
| 564 | |
| 565 | /* |
| 566 | * Returns 0 for success |
| 567 | */ |
| 568 | int lru_add_drain_all(void) |
| 569 | { |
David Howells | c402895 | 2006-11-22 14:57:56 +0000 | [diff] [blame] | 570 | return schedule_on_each_cpu(lru_add_drain_per_cpu); |
Nick Piggin | 053837f | 2006-01-18 17:42:27 -0800 | [diff] [blame] | 571 | } |
| 572 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 573 | /* |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 574 | * Batched page_cache_release(). Decrement the reference count on all the |
| 575 | * passed pages. If it fell to zero then remove the page from the LRU and |
| 576 | * free it. |
| 577 | * |
| 578 | * Avoid taking zone->lru_lock if possible, but if it is taken, retain it |
| 579 | * for the remainder of the operation. |
| 580 | * |
Fernando Luis Vazquez Cao | ab33dc0 | 2008-07-29 22:33:40 -0700 | [diff] [blame] | 581 | * The locking in this function is against shrink_inactive_list(): we recheck |
| 582 | * the page count inside the lock to see whether shrink_inactive_list() |
| 583 | * grabbed the page via the LRU. If it did, give up: shrink_inactive_list() |
| 584 | * will free it. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 585 | */ |
| 586 | void release_pages(struct page **pages, int nr, int cold) |
| 587 | { |
| 588 | int i; |
Konstantin Khlebnikov | cc59850 | 2012-01-10 15:07:04 -0800 | [diff] [blame] | 589 | LIST_HEAD(pages_to_free); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 590 | struct zone *zone = NULL; |
Hisashi Hifumi | 902aaed | 2007-10-16 01:24:52 -0700 | [diff] [blame] | 591 | unsigned long uninitialized_var(flags); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 592 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 593 | for (i = 0; i < nr; i++) { |
| 594 | struct page *page = pages[i]; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 595 | |
Nick Piggin | 8519fb3 | 2006-02-07 12:58:52 -0800 | [diff] [blame] | 596 | if (unlikely(PageCompound(page))) { |
| 597 | if (zone) { |
Hisashi Hifumi | 902aaed | 2007-10-16 01:24:52 -0700 | [diff] [blame] | 598 | spin_unlock_irqrestore(&zone->lru_lock, flags); |
Nick Piggin | 8519fb3 | 2006-02-07 12:58:52 -0800 | [diff] [blame] | 599 | zone = NULL; |
| 600 | } |
| 601 | put_compound_page(page); |
| 602 | continue; |
| 603 | } |
| 604 | |
Nick Piggin | b581003 | 2005-10-29 18:16:12 -0700 | [diff] [blame] | 605 | if (!put_page_testzero(page)) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 606 | continue; |
| 607 | |
Nick Piggin | 46453a6 | 2006-03-22 00:07:58 -0800 | [diff] [blame] | 608 | if (PageLRU(page)) { |
| 609 | struct zone *pagezone = page_zone(page); |
Lee Schermerhorn | 894bc31 | 2008-10-18 20:26:39 -0700 | [diff] [blame] | 610 | |
Nick Piggin | 46453a6 | 2006-03-22 00:07:58 -0800 | [diff] [blame] | 611 | if (pagezone != zone) { |
| 612 | if (zone) |
Hisashi Hifumi | 902aaed | 2007-10-16 01:24:52 -0700 | [diff] [blame] | 613 | spin_unlock_irqrestore(&zone->lru_lock, |
| 614 | flags); |
Nick Piggin | 46453a6 | 2006-03-22 00:07:58 -0800 | [diff] [blame] | 615 | zone = pagezone; |
Hisashi Hifumi | 902aaed | 2007-10-16 01:24:52 -0700 | [diff] [blame] | 616 | spin_lock_irqsave(&zone->lru_lock, flags); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 617 | } |
Nick Piggin | 725d704 | 2006-09-25 23:30:55 -0700 | [diff] [blame] | 618 | VM_BUG_ON(!PageLRU(page)); |
Nick Piggin | 6745391 | 2006-03-22 00:08:00 -0800 | [diff] [blame] | 619 | __ClearPageLRU(page); |
Nick Piggin | 46453a6 | 2006-03-22 00:07:58 -0800 | [diff] [blame] | 620 | del_page_from_lru(zone, page); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 621 | } |
Nick Piggin | 46453a6 | 2006-03-22 00:07:58 -0800 | [diff] [blame] | 622 | |
Konstantin Khlebnikov | cc59850 | 2012-01-10 15:07:04 -0800 | [diff] [blame] | 623 | list_add(&page->lru, &pages_to_free); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 624 | } |
| 625 | if (zone) |
Hisashi Hifumi | 902aaed | 2007-10-16 01:24:52 -0700 | [diff] [blame] | 626 | spin_unlock_irqrestore(&zone->lru_lock, flags); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 627 | |
Konstantin Khlebnikov | cc59850 | 2012-01-10 15:07:04 -0800 | [diff] [blame] | 628 | free_hot_cold_page_list(&pages_to_free, cold); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 629 | } |
Miklos Szeredi | 0be8557 | 2010-10-27 15:34:46 -0700 | [diff] [blame] | 630 | EXPORT_SYMBOL(release_pages); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 631 | |
| 632 | /* |
| 633 | * The pages which we're about to release may be in the deferred lru-addition |
| 634 | * queues. That would prevent them from really being freed right now. That's |
| 635 | * OK from a correctness point of view but is inefficient - those pages may be |
| 636 | * cache-warm and we want to give them back to the page allocator ASAP. |
| 637 | * |
| 638 | * So __pagevec_release() will drain those queues here. __pagevec_lru_add() |
| 639 | * and __pagevec_lru_add_active() call release_pages() directly to avoid |
| 640 | * mutual recursion. |
| 641 | */ |
| 642 | void __pagevec_release(struct pagevec *pvec) |
| 643 | { |
| 644 | lru_add_drain(); |
| 645 | release_pages(pvec->pages, pagevec_count(pvec), pvec->cold); |
| 646 | pagevec_reinit(pvec); |
| 647 | } |
Steve French | 7f28570 | 2005-11-01 10:22:55 -0800 | [diff] [blame] | 648 | EXPORT_SYMBOL(__pagevec_release); |
| 649 | |
Hugh Dickins | 12d2710 | 2012-01-12 17:19:52 -0800 | [diff] [blame] | 650 | #ifdef CONFIG_TRANSPARENT_HUGEPAGE |
Andrea Arcangeli | 71e3aac | 2011-01-13 15:46:52 -0800 | [diff] [blame] | 651 | /* used by __split_huge_page_refcount() */ |
| 652 | void lru_add_page_tail(struct zone* zone, |
| 653 | struct page *page, struct page *page_tail) |
| 654 | { |
| 655 | int active; |
| 656 | enum lru_list lru; |
| 657 | const int file = 0; |
Andrea Arcangeli | 71e3aac | 2011-01-13 15:46:52 -0800 | [diff] [blame] | 658 | |
| 659 | VM_BUG_ON(!PageHead(page)); |
| 660 | VM_BUG_ON(PageCompound(page_tail)); |
| 661 | VM_BUG_ON(PageLRU(page_tail)); |
| 662 | VM_BUG_ON(!spin_is_locked(&zone->lru_lock)); |
| 663 | |
| 664 | SetPageLRU(page_tail); |
| 665 | |
| 666 | if (page_evictable(page_tail, NULL)) { |
| 667 | if (PageActive(page)) { |
| 668 | SetPageActive(page_tail); |
| 669 | active = 1; |
| 670 | lru = LRU_ACTIVE_ANON; |
| 671 | } else { |
| 672 | active = 0; |
| 673 | lru = LRU_INACTIVE_ANON; |
| 674 | } |
| 675 | update_page_reclaim_stat(zone, page_tail, file, active); |
Andrea Arcangeli | 71e3aac | 2011-01-13 15:46:52 -0800 | [diff] [blame] | 676 | } else { |
| 677 | SetPageUnevictable(page_tail); |
Hugh Dickins | 12d2710 | 2012-01-12 17:19:52 -0800 | [diff] [blame] | 678 | lru = LRU_UNEVICTABLE; |
| 679 | } |
| 680 | |
| 681 | if (likely(PageLRU(page))) |
| 682 | list_add_tail(&page_tail->lru, &page->lru); |
| 683 | else { |
| 684 | struct list_head *list_head; |
| 685 | /* |
| 686 | * Head page has not yet been counted, as an hpage, |
| 687 | * so we must account for each subpage individually. |
| 688 | * |
| 689 | * Use the standard add function to put page_tail on the list, |
| 690 | * but then correct its position so they all end up in order. |
| 691 | */ |
| 692 | add_page_to_lru_list(zone, page_tail, lru); |
| 693 | list_head = page_tail->lru.prev; |
| 694 | list_move_tail(&page_tail->lru, list_head); |
Andrea Arcangeli | 71e3aac | 2011-01-13 15:46:52 -0800 | [diff] [blame] | 695 | } |
| 696 | } |
Hugh Dickins | 12d2710 | 2012-01-12 17:19:52 -0800 | [diff] [blame] | 697 | #endif /* CONFIG_TRANSPARENT_HUGEPAGE */ |
Andrea Arcangeli | 71e3aac | 2011-01-13 15:46:52 -0800 | [diff] [blame] | 698 | |
Hugh Dickins | 5095ae83 | 2012-01-12 17:19:58 -0800 | [diff] [blame] | 699 | static void __pagevec_lru_add_fn(struct page *page, void *arg) |
Shaohua Li | 3dd7ae8 | 2011-03-22 16:33:45 -0700 | [diff] [blame] | 700 | { |
| 701 | enum lru_list lru = (enum lru_list)arg; |
| 702 | struct zone *zone = page_zone(page); |
| 703 | int file = is_file_lru(lru); |
| 704 | int active = is_active_lru(lru); |
| 705 | |
| 706 | VM_BUG_ON(PageActive(page)); |
| 707 | VM_BUG_ON(PageUnevictable(page)); |
| 708 | VM_BUG_ON(PageLRU(page)); |
| 709 | |
| 710 | SetPageLRU(page); |
| 711 | if (active) |
| 712 | SetPageActive(page); |
| 713 | update_page_reclaim_stat(zone, page, file, active); |
| 714 | add_page_to_lru_list(zone, page, lru); |
| 715 | } |
| 716 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 717 | /* |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 718 | * Add the passed pages to the LRU, then drop the caller's refcount |
| 719 | * on them. Reinitialises the caller's pagevec. |
| 720 | */ |
Hugh Dickins | 5095ae83 | 2012-01-12 17:19:58 -0800 | [diff] [blame] | 721 | void __pagevec_lru_add(struct pagevec *pvec, enum lru_list lru) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 722 | { |
Lee Schermerhorn | 894bc31 | 2008-10-18 20:26:39 -0700 | [diff] [blame] | 723 | VM_BUG_ON(is_unevictable_lru(lru)); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 724 | |
Hugh Dickins | 5095ae83 | 2012-01-12 17:19:58 -0800 | [diff] [blame] | 725 | pagevec_lru_move_fn(pvec, __pagevec_lru_add_fn, (void *)lru); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 726 | } |
Hugh Dickins | 5095ae83 | 2012-01-12 17:19:58 -0800 | [diff] [blame] | 727 | EXPORT_SYMBOL(__pagevec_lru_add); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 728 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 729 | /** |
| 730 | * pagevec_lookup - gang pagecache lookup |
| 731 | * @pvec: Where the resulting pages are placed |
| 732 | * @mapping: The address_space to search |
| 733 | * @start: The starting page index |
| 734 | * @nr_pages: The maximum number of pages |
| 735 | * |
| 736 | * pagevec_lookup() will search for and return a group of up to @nr_pages pages |
| 737 | * in the mapping. The pages are placed in @pvec. pagevec_lookup() takes a |
| 738 | * reference against the pages in @pvec. |
| 739 | * |
| 740 | * The search returns a group of mapping-contiguous pages with ascending |
| 741 | * indexes. There may be holes in the indices due to not-present pages. |
| 742 | * |
| 743 | * pagevec_lookup() returns the number of pages which were found. |
| 744 | */ |
| 745 | unsigned pagevec_lookup(struct pagevec *pvec, struct address_space *mapping, |
| 746 | pgoff_t start, unsigned nr_pages) |
| 747 | { |
| 748 | pvec->nr = find_get_pages(mapping, start, nr_pages, pvec->pages); |
| 749 | return pagevec_count(pvec); |
| 750 | } |
Christoph Hellwig | 78539fd | 2006-01-11 20:47:41 +1100 | [diff] [blame] | 751 | EXPORT_SYMBOL(pagevec_lookup); |
| 752 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 753 | unsigned pagevec_lookup_tag(struct pagevec *pvec, struct address_space *mapping, |
| 754 | pgoff_t *index, int tag, unsigned nr_pages) |
| 755 | { |
| 756 | pvec->nr = find_get_pages_tag(mapping, index, tag, |
| 757 | nr_pages, pvec->pages); |
| 758 | return pagevec_count(pvec); |
| 759 | } |
Steve French | 7f28570 | 2005-11-01 10:22:55 -0800 | [diff] [blame] | 760 | EXPORT_SYMBOL(pagevec_lookup_tag); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 761 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 762 | /* |
| 763 | * Perform any setup for the swap system |
| 764 | */ |
| 765 | void __init swap_setup(void) |
| 766 | { |
Jan Beulich | 4481374 | 2009-09-21 17:03:05 -0700 | [diff] [blame] | 767 | unsigned long megs = totalram_pages >> (20 - PAGE_SHIFT); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 768 | |
Peter Zijlstra | e0bf68d | 2007-10-16 23:25:46 -0700 | [diff] [blame] | 769 | #ifdef CONFIG_SWAP |
| 770 | bdi_init(swapper_space.backing_dev_info); |
| 771 | #endif |
| 772 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 773 | /* Use a smaller cluster for small-memory machines */ |
| 774 | if (megs < 16) |
| 775 | page_cluster = 2; |
| 776 | else |
| 777 | page_cluster = 3; |
| 778 | /* |
| 779 | * Right now other parts of the system means that we |
| 780 | * _really_ don't want to cluster much more |
| 781 | */ |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 782 | } |