11da177e4SLinus Torvalds /* 21da177e4SLinus Torvalds * linux/mm/swap.c 31da177e4SLinus Torvalds * 41da177e4SLinus Torvalds * Copyright (C) 1991, 1992, 1993, 1994 Linus Torvalds 51da177e4SLinus Torvalds */ 61da177e4SLinus Torvalds 71da177e4SLinus Torvalds /* 8183ff22bSSimon Arlott * This file contains the default values for the operation of the 91da177e4SLinus Torvalds * Linux VM subsystem. Fine-tuning documentation can be found in 101da177e4SLinus Torvalds * Documentation/sysctl/vm.txt. 111da177e4SLinus Torvalds * Started 18.12.91 121da177e4SLinus Torvalds * Swap aging added 23.2.95, Stephen Tweedie. 131da177e4SLinus Torvalds * Buffermem limits added 12.3.98, Rik van Riel. 141da177e4SLinus Torvalds */ 151da177e4SLinus Torvalds 161da177e4SLinus Torvalds #include <linux/mm.h> 171da177e4SLinus Torvalds #include <linux/sched.h> 181da177e4SLinus Torvalds #include <linux/kernel_stat.h> 191da177e4SLinus Torvalds #include <linux/swap.h> 201da177e4SLinus Torvalds #include <linux/mman.h> 211da177e4SLinus Torvalds #include <linux/pagemap.h> 221da177e4SLinus Torvalds #include <linux/pagevec.h> 231da177e4SLinus Torvalds #include <linux/init.h> 241da177e4SLinus Torvalds #include <linux/module.h> 251da177e4SLinus Torvalds #include <linux/mm_inline.h> 261da177e4SLinus Torvalds #include <linux/buffer_head.h> /* for try_to_release_page() */ 271da177e4SLinus Torvalds #include <linux/percpu_counter.h> 281da177e4SLinus Torvalds #include <linux/percpu.h> 291da177e4SLinus Torvalds #include <linux/cpu.h> 301da177e4SLinus Torvalds #include <linux/notifier.h> 31e0bf68ddSPeter Zijlstra #include <linux/backing-dev.h> 3266e1707bSBalbir Singh #include <linux/memcontrol.h> 33*5a0e3ad6STejun Heo #include <linux/gfp.h> 341da177e4SLinus Torvalds 3564d6519dSLee Schermerhorn #include "internal.h" 3664d6519dSLee Schermerhorn 371da177e4SLinus Torvalds /* How many pages do we try to swap or page in/out together? */ 381da177e4SLinus Torvalds int page_cluster; 391da177e4SLinus Torvalds 40f04e9ebbSKOSAKI Motohiro static DEFINE_PER_CPU(struct pagevec[NR_LRU_LISTS], lru_add_pvecs); 41f84f9504SVegard Nossum static DEFINE_PER_CPU(struct pagevec, lru_rotate_pvecs); 42902aaed0SHisashi Hifumi 43b221385bSAdrian Bunk /* 44b221385bSAdrian Bunk * This path almost never happens for VM activity - pages are normally 45b221385bSAdrian Bunk * freed via pagevecs. But it gets used by networking. 46b221385bSAdrian Bunk */ 47920c7a5dSHarvey Harrison static void __page_cache_release(struct page *page) 48b221385bSAdrian Bunk { 49b221385bSAdrian Bunk if (PageLRU(page)) { 50b221385bSAdrian Bunk unsigned long flags; 51b221385bSAdrian Bunk struct zone *zone = page_zone(page); 52b221385bSAdrian Bunk 53b221385bSAdrian Bunk spin_lock_irqsave(&zone->lru_lock, flags); 54b221385bSAdrian Bunk VM_BUG_ON(!PageLRU(page)); 55b221385bSAdrian Bunk __ClearPageLRU(page); 56b221385bSAdrian Bunk del_page_from_lru(zone, page); 57b221385bSAdrian Bunk spin_unlock_irqrestore(&zone->lru_lock, flags); 58b221385bSAdrian Bunk } 59fc91668eSLi Hong free_hot_cold_page(page, 0); 60b221385bSAdrian Bunk } 61b221385bSAdrian Bunk 628519fb30SNick Piggin static void put_compound_page(struct page *page) 631da177e4SLinus Torvalds { 64d85f3385SChristoph Lameter page = compound_head(page); 651da177e4SLinus Torvalds if (put_page_testzero(page)) { 6633f2ef89SAndy Whitcroft compound_page_dtor *dtor; 671da177e4SLinus Torvalds 6833f2ef89SAndy Whitcroft dtor = get_compound_page_dtor(page); 691da177e4SLinus Torvalds (*dtor)(page); 701da177e4SLinus Torvalds } 711da177e4SLinus Torvalds } 728519fb30SNick Piggin 738519fb30SNick Piggin void put_page(struct page *page) 748519fb30SNick Piggin { 758519fb30SNick Piggin if (unlikely(PageCompound(page))) 768519fb30SNick Piggin put_compound_page(page); 778519fb30SNick Piggin else if (put_page_testzero(page)) 781da177e4SLinus Torvalds __page_cache_release(page); 791da177e4SLinus Torvalds } 801da177e4SLinus Torvalds EXPORT_SYMBOL(put_page); 811da177e4SLinus Torvalds 821d7ea732SAlexander Zarochentsev /** 837682486bSRandy Dunlap * put_pages_list() - release a list of pages 847682486bSRandy Dunlap * @pages: list of pages threaded on page->lru 851d7ea732SAlexander Zarochentsev * 861d7ea732SAlexander Zarochentsev * Release a list of pages which are strung together on page.lru. Currently 871d7ea732SAlexander Zarochentsev * used by read_cache_pages() and related error recovery code. 881d7ea732SAlexander Zarochentsev */ 891d7ea732SAlexander Zarochentsev void put_pages_list(struct list_head *pages) 901d7ea732SAlexander Zarochentsev { 911d7ea732SAlexander Zarochentsev while (!list_empty(pages)) { 921d7ea732SAlexander Zarochentsev struct page *victim; 931d7ea732SAlexander Zarochentsev 941d7ea732SAlexander Zarochentsev victim = list_entry(pages->prev, struct page, lru); 951d7ea732SAlexander Zarochentsev list_del(&victim->lru); 961d7ea732SAlexander Zarochentsev page_cache_release(victim); 971d7ea732SAlexander Zarochentsev } 981d7ea732SAlexander Zarochentsev } 991d7ea732SAlexander Zarochentsev EXPORT_SYMBOL(put_pages_list); 1001d7ea732SAlexander Zarochentsev 1011da177e4SLinus Torvalds /* 102902aaed0SHisashi Hifumi * pagevec_move_tail() must be called with IRQ disabled. 103902aaed0SHisashi Hifumi * Otherwise this may cause nasty races. 104902aaed0SHisashi Hifumi */ 105902aaed0SHisashi Hifumi static void pagevec_move_tail(struct pagevec *pvec) 106902aaed0SHisashi Hifumi { 107902aaed0SHisashi Hifumi int i; 108902aaed0SHisashi Hifumi int pgmoved = 0; 109902aaed0SHisashi Hifumi struct zone *zone = NULL; 110902aaed0SHisashi Hifumi 111902aaed0SHisashi Hifumi for (i = 0; i < pagevec_count(pvec); i++) { 112902aaed0SHisashi Hifumi struct page *page = pvec->pages[i]; 113902aaed0SHisashi Hifumi struct zone *pagezone = page_zone(page); 114902aaed0SHisashi Hifumi 115902aaed0SHisashi Hifumi if (pagezone != zone) { 116902aaed0SHisashi Hifumi if (zone) 117902aaed0SHisashi Hifumi spin_unlock(&zone->lru_lock); 118902aaed0SHisashi Hifumi zone = pagezone; 119902aaed0SHisashi Hifumi spin_lock(&zone->lru_lock); 120902aaed0SHisashi Hifumi } 121894bc310SLee Schermerhorn if (PageLRU(page) && !PageActive(page) && !PageUnevictable(page)) { 122401a8e1cSJohannes Weiner int lru = page_lru_base_type(page); 1234f98a2feSRik van Riel list_move_tail(&page->lru, &zone->lru[lru].list); 124902aaed0SHisashi Hifumi pgmoved++; 125902aaed0SHisashi Hifumi } 126902aaed0SHisashi Hifumi } 127902aaed0SHisashi Hifumi if (zone) 128902aaed0SHisashi Hifumi spin_unlock(&zone->lru_lock); 129902aaed0SHisashi Hifumi __count_vm_events(PGROTATED, pgmoved); 130902aaed0SHisashi Hifumi release_pages(pvec->pages, pvec->nr, pvec->cold); 131902aaed0SHisashi Hifumi pagevec_reinit(pvec); 132902aaed0SHisashi Hifumi } 133902aaed0SHisashi Hifumi 134902aaed0SHisashi Hifumi /* 1351da177e4SLinus Torvalds * Writeback is about to end against a page which has been marked for immediate 1361da177e4SLinus Torvalds * reclaim. If it still appears to be reclaimable, move it to the tail of the 137902aaed0SHisashi Hifumi * inactive list. 1381da177e4SLinus Torvalds */ 139ac6aadb2SMiklos Szeredi void rotate_reclaimable_page(struct page *page) 1401da177e4SLinus Torvalds { 141ac6aadb2SMiklos Szeredi if (!PageLocked(page) && !PageDirty(page) && !PageActive(page) && 142894bc310SLee Schermerhorn !PageUnevictable(page) && PageLRU(page)) { 143902aaed0SHisashi Hifumi struct pagevec *pvec; 1441da177e4SLinus Torvalds unsigned long flags; 1451da177e4SLinus Torvalds 146902aaed0SHisashi Hifumi page_cache_get(page); 147902aaed0SHisashi Hifumi local_irq_save(flags); 148902aaed0SHisashi Hifumi pvec = &__get_cpu_var(lru_rotate_pvecs); 149902aaed0SHisashi Hifumi if (!pagevec_add(pvec, page)) 150902aaed0SHisashi Hifumi pagevec_move_tail(pvec); 151902aaed0SHisashi Hifumi local_irq_restore(flags); 152ac6aadb2SMiklos Szeredi } 1531da177e4SLinus Torvalds } 1541da177e4SLinus Torvalds 1553e2f41f1SKOSAKI Motohiro static void update_page_reclaim_stat(struct zone *zone, struct page *page, 1563e2f41f1SKOSAKI Motohiro int file, int rotated) 1573e2f41f1SKOSAKI Motohiro { 1583e2f41f1SKOSAKI Motohiro struct zone_reclaim_stat *reclaim_stat = &zone->reclaim_stat; 1593e2f41f1SKOSAKI Motohiro struct zone_reclaim_stat *memcg_reclaim_stat; 1603e2f41f1SKOSAKI Motohiro 1613e2f41f1SKOSAKI Motohiro memcg_reclaim_stat = mem_cgroup_get_reclaim_stat_from_page(page); 1623e2f41f1SKOSAKI Motohiro 1633e2f41f1SKOSAKI Motohiro reclaim_stat->recent_scanned[file]++; 1643e2f41f1SKOSAKI Motohiro if (rotated) 1653e2f41f1SKOSAKI Motohiro reclaim_stat->recent_rotated[file]++; 1663e2f41f1SKOSAKI Motohiro 1673e2f41f1SKOSAKI Motohiro if (!memcg_reclaim_stat) 1683e2f41f1SKOSAKI Motohiro return; 1693e2f41f1SKOSAKI Motohiro 1703e2f41f1SKOSAKI Motohiro memcg_reclaim_stat->recent_scanned[file]++; 1713e2f41f1SKOSAKI Motohiro if (rotated) 1723e2f41f1SKOSAKI Motohiro memcg_reclaim_stat->recent_rotated[file]++; 1733e2f41f1SKOSAKI Motohiro } 1743e2f41f1SKOSAKI Motohiro 1751da177e4SLinus Torvalds /* 1761da177e4SLinus Torvalds * FIXME: speed this up? 1771da177e4SLinus Torvalds */ 178920c7a5dSHarvey Harrison void activate_page(struct page *page) 1791da177e4SLinus Torvalds { 1801da177e4SLinus Torvalds struct zone *zone = page_zone(page); 1811da177e4SLinus Torvalds 1821da177e4SLinus Torvalds spin_lock_irq(&zone->lru_lock); 183894bc310SLee Schermerhorn if (PageLRU(page) && !PageActive(page) && !PageUnevictable(page)) { 1844f98a2feSRik van Riel int file = page_is_file_cache(page); 185401a8e1cSJohannes Weiner int lru = page_lru_base_type(page); 1864f98a2feSRik van Riel del_page_from_lru_list(zone, page, lru); 1874f98a2feSRik van Riel 1881da177e4SLinus Torvalds SetPageActive(page); 1894f98a2feSRik van Riel lru += LRU_ACTIVE; 1904f98a2feSRik van Riel add_page_to_lru_list(zone, page, lru); 191f8891e5eSChristoph Lameter __count_vm_event(PGACTIVATE); 1924f98a2feSRik van Riel 1936c0b1351SJohannes Weiner update_page_reclaim_stat(zone, page, file, 1); 1941da177e4SLinus Torvalds } 1951da177e4SLinus Torvalds spin_unlock_irq(&zone->lru_lock); 1961da177e4SLinus Torvalds } 1971da177e4SLinus Torvalds 1981da177e4SLinus Torvalds /* 1991da177e4SLinus Torvalds * Mark a page as having seen activity. 2001da177e4SLinus Torvalds * 2011da177e4SLinus Torvalds * inactive,unreferenced -> inactive,referenced 2021da177e4SLinus Torvalds * inactive,referenced -> active,unreferenced 2031da177e4SLinus Torvalds * active,unreferenced -> active,referenced 2041da177e4SLinus Torvalds */ 205920c7a5dSHarvey Harrison void mark_page_accessed(struct page *page) 2061da177e4SLinus Torvalds { 207894bc310SLee Schermerhorn if (!PageActive(page) && !PageUnevictable(page) && 208894bc310SLee Schermerhorn PageReferenced(page) && PageLRU(page)) { 2091da177e4SLinus Torvalds activate_page(page); 2101da177e4SLinus Torvalds ClearPageReferenced(page); 2111da177e4SLinus Torvalds } else if (!PageReferenced(page)) { 2121da177e4SLinus Torvalds SetPageReferenced(page); 2131da177e4SLinus Torvalds } 2141da177e4SLinus Torvalds } 2151da177e4SLinus Torvalds 2161da177e4SLinus Torvalds EXPORT_SYMBOL(mark_page_accessed); 2171da177e4SLinus Torvalds 218f04e9ebbSKOSAKI Motohiro void __lru_cache_add(struct page *page, enum lru_list lru) 2191da177e4SLinus Torvalds { 220f04e9ebbSKOSAKI Motohiro struct pagevec *pvec = &get_cpu_var(lru_add_pvecs)[lru]; 2211da177e4SLinus Torvalds 2221da177e4SLinus Torvalds page_cache_get(page); 2231da177e4SLinus Torvalds if (!pagevec_add(pvec, page)) 224f04e9ebbSKOSAKI Motohiro ____pagevec_lru_add(pvec, lru); 2251da177e4SLinus Torvalds put_cpu_var(lru_add_pvecs); 2261da177e4SLinus Torvalds } 2271da177e4SLinus Torvalds 228f04e9ebbSKOSAKI Motohiro /** 229f04e9ebbSKOSAKI Motohiro * lru_cache_add_lru - add a page to a page list 230f04e9ebbSKOSAKI Motohiro * @page: the page to be added to the LRU. 231f04e9ebbSKOSAKI Motohiro * @lru: the LRU list to which the page is added. 232f04e9ebbSKOSAKI Motohiro */ 233f04e9ebbSKOSAKI Motohiro void lru_cache_add_lru(struct page *page, enum lru_list lru) 2341da177e4SLinus Torvalds { 235f04e9ebbSKOSAKI Motohiro if (PageActive(page)) { 236894bc310SLee Schermerhorn VM_BUG_ON(PageUnevictable(page)); 237f04e9ebbSKOSAKI Motohiro ClearPageActive(page); 238894bc310SLee Schermerhorn } else if (PageUnevictable(page)) { 239894bc310SLee Schermerhorn VM_BUG_ON(PageActive(page)); 240894bc310SLee Schermerhorn ClearPageUnevictable(page); 241f04e9ebbSKOSAKI Motohiro } 2421da177e4SLinus Torvalds 243894bc310SLee Schermerhorn VM_BUG_ON(PageLRU(page) || PageActive(page) || PageUnevictable(page)); 244f04e9ebbSKOSAKI Motohiro __lru_cache_add(page, lru); 2451da177e4SLinus Torvalds } 2461da177e4SLinus Torvalds 247894bc310SLee Schermerhorn /** 248894bc310SLee Schermerhorn * add_page_to_unevictable_list - add a page to the unevictable list 249894bc310SLee Schermerhorn * @page: the page to be added to the unevictable list 250894bc310SLee Schermerhorn * 251894bc310SLee Schermerhorn * Add page directly to its zone's unevictable list. To avoid races with 252894bc310SLee Schermerhorn * tasks that might be making the page evictable, through eg. munlock, 253894bc310SLee Schermerhorn * munmap or exit, while it's not on the lru, we want to add the page 254894bc310SLee Schermerhorn * while it's locked or otherwise "invisible" to other tasks. This is 255894bc310SLee Schermerhorn * difficult to do when using the pagevec cache, so bypass that. 256894bc310SLee Schermerhorn */ 257894bc310SLee Schermerhorn void add_page_to_unevictable_list(struct page *page) 258894bc310SLee Schermerhorn { 259894bc310SLee Schermerhorn struct zone *zone = page_zone(page); 260894bc310SLee Schermerhorn 261894bc310SLee Schermerhorn spin_lock_irq(&zone->lru_lock); 262894bc310SLee Schermerhorn SetPageUnevictable(page); 263894bc310SLee Schermerhorn SetPageLRU(page); 264894bc310SLee Schermerhorn add_page_to_lru_list(zone, page, LRU_UNEVICTABLE); 265894bc310SLee Schermerhorn spin_unlock_irq(&zone->lru_lock); 266894bc310SLee Schermerhorn } 267894bc310SLee Schermerhorn 268902aaed0SHisashi Hifumi /* 269902aaed0SHisashi Hifumi * Drain pages out of the cpu's pagevecs. 270902aaed0SHisashi Hifumi * Either "cpu" is the current CPU, and preemption has already been 271902aaed0SHisashi Hifumi * disabled; or "cpu" is being hot-unplugged, and is already dead. 272902aaed0SHisashi Hifumi */ 273902aaed0SHisashi Hifumi static void drain_cpu_pagevecs(int cpu) 2741da177e4SLinus Torvalds { 275f04e9ebbSKOSAKI Motohiro struct pagevec *pvecs = per_cpu(lru_add_pvecs, cpu); 276902aaed0SHisashi Hifumi struct pagevec *pvec; 277f04e9ebbSKOSAKI Motohiro int lru; 2781da177e4SLinus Torvalds 279f04e9ebbSKOSAKI Motohiro for_each_lru(lru) { 280f04e9ebbSKOSAKI Motohiro pvec = &pvecs[lru - LRU_BASE]; 2811da177e4SLinus Torvalds if (pagevec_count(pvec)) 282f04e9ebbSKOSAKI Motohiro ____pagevec_lru_add(pvec, lru); 283f04e9ebbSKOSAKI Motohiro } 284902aaed0SHisashi Hifumi 285902aaed0SHisashi Hifumi pvec = &per_cpu(lru_rotate_pvecs, cpu); 286902aaed0SHisashi Hifumi if (pagevec_count(pvec)) { 287902aaed0SHisashi Hifumi unsigned long flags; 288902aaed0SHisashi Hifumi 289902aaed0SHisashi Hifumi /* No harm done if a racing interrupt already did this */ 290902aaed0SHisashi Hifumi local_irq_save(flags); 291902aaed0SHisashi Hifumi pagevec_move_tail(pvec); 292902aaed0SHisashi Hifumi local_irq_restore(flags); 293902aaed0SHisashi Hifumi } 29480bfed90SAndrew Morton } 29580bfed90SAndrew Morton 29680bfed90SAndrew Morton void lru_add_drain(void) 29780bfed90SAndrew Morton { 298902aaed0SHisashi Hifumi drain_cpu_pagevecs(get_cpu()); 29980bfed90SAndrew Morton put_cpu(); 3001da177e4SLinus Torvalds } 3011da177e4SLinus Torvalds 302c4028958SDavid Howells static void lru_add_drain_per_cpu(struct work_struct *dummy) 303053837fcSNick Piggin { 304053837fcSNick Piggin lru_add_drain(); 305053837fcSNick Piggin } 306053837fcSNick Piggin 307053837fcSNick Piggin /* 308053837fcSNick Piggin * Returns 0 for success 309053837fcSNick Piggin */ 310053837fcSNick Piggin int lru_add_drain_all(void) 311053837fcSNick Piggin { 312c4028958SDavid Howells return schedule_on_each_cpu(lru_add_drain_per_cpu); 313053837fcSNick Piggin } 314053837fcSNick Piggin 3151da177e4SLinus Torvalds /* 3161da177e4SLinus Torvalds * Batched page_cache_release(). Decrement the reference count on all the 3171da177e4SLinus Torvalds * passed pages. If it fell to zero then remove the page from the LRU and 3181da177e4SLinus Torvalds * free it. 3191da177e4SLinus Torvalds * 3201da177e4SLinus Torvalds * Avoid taking zone->lru_lock if possible, but if it is taken, retain it 3211da177e4SLinus Torvalds * for the remainder of the operation. 3221da177e4SLinus Torvalds * 323ab33dc09SFernando Luis Vazquez Cao * The locking in this function is against shrink_inactive_list(): we recheck 324ab33dc09SFernando Luis Vazquez Cao * the page count inside the lock to see whether shrink_inactive_list() 325ab33dc09SFernando Luis Vazquez Cao * grabbed the page via the LRU. If it did, give up: shrink_inactive_list() 326ab33dc09SFernando Luis Vazquez Cao * will free it. 3271da177e4SLinus Torvalds */ 3281da177e4SLinus Torvalds void release_pages(struct page **pages, int nr, int cold) 3291da177e4SLinus Torvalds { 3301da177e4SLinus Torvalds int i; 3311da177e4SLinus Torvalds struct pagevec pages_to_free; 3321da177e4SLinus Torvalds struct zone *zone = NULL; 333902aaed0SHisashi Hifumi unsigned long uninitialized_var(flags); 3341da177e4SLinus Torvalds 3351da177e4SLinus Torvalds pagevec_init(&pages_to_free, cold); 3361da177e4SLinus Torvalds for (i = 0; i < nr; i++) { 3371da177e4SLinus Torvalds struct page *page = pages[i]; 3381da177e4SLinus Torvalds 3398519fb30SNick Piggin if (unlikely(PageCompound(page))) { 3408519fb30SNick Piggin if (zone) { 341902aaed0SHisashi Hifumi spin_unlock_irqrestore(&zone->lru_lock, flags); 3428519fb30SNick Piggin zone = NULL; 3438519fb30SNick Piggin } 3448519fb30SNick Piggin put_compound_page(page); 3458519fb30SNick Piggin continue; 3468519fb30SNick Piggin } 3478519fb30SNick Piggin 348b5810039SNick Piggin if (!put_page_testzero(page)) 3491da177e4SLinus Torvalds continue; 3501da177e4SLinus Torvalds 35146453a6eSNick Piggin if (PageLRU(page)) { 35246453a6eSNick Piggin struct zone *pagezone = page_zone(page); 353894bc310SLee Schermerhorn 3541da177e4SLinus Torvalds if (pagezone != zone) { 3551da177e4SLinus Torvalds if (zone) 356902aaed0SHisashi Hifumi spin_unlock_irqrestore(&zone->lru_lock, 357902aaed0SHisashi Hifumi flags); 3581da177e4SLinus Torvalds zone = pagezone; 359902aaed0SHisashi Hifumi spin_lock_irqsave(&zone->lru_lock, flags); 3601da177e4SLinus Torvalds } 361725d704eSNick Piggin VM_BUG_ON(!PageLRU(page)); 36267453911SNick Piggin __ClearPageLRU(page); 3631da177e4SLinus Torvalds del_page_from_lru(zone, page); 36446453a6eSNick Piggin } 36546453a6eSNick Piggin 3661da177e4SLinus Torvalds if (!pagevec_add(&pages_to_free, page)) { 36746453a6eSNick Piggin if (zone) { 368902aaed0SHisashi Hifumi spin_unlock_irqrestore(&zone->lru_lock, flags); 36946453a6eSNick Piggin zone = NULL; 37046453a6eSNick Piggin } 3711da177e4SLinus Torvalds __pagevec_free(&pages_to_free); 3721da177e4SLinus Torvalds pagevec_reinit(&pages_to_free); 3731da177e4SLinus Torvalds } 3741da177e4SLinus Torvalds } 3751da177e4SLinus Torvalds if (zone) 376902aaed0SHisashi Hifumi spin_unlock_irqrestore(&zone->lru_lock, flags); 3771da177e4SLinus Torvalds 3781da177e4SLinus Torvalds pagevec_free(&pages_to_free); 3791da177e4SLinus Torvalds } 3801da177e4SLinus Torvalds 3811da177e4SLinus Torvalds /* 3821da177e4SLinus Torvalds * The pages which we're about to release may be in the deferred lru-addition 3831da177e4SLinus Torvalds * queues. That would prevent them from really being freed right now. That's 3841da177e4SLinus Torvalds * OK from a correctness point of view but is inefficient - those pages may be 3851da177e4SLinus Torvalds * cache-warm and we want to give them back to the page allocator ASAP. 3861da177e4SLinus Torvalds * 3871da177e4SLinus Torvalds * So __pagevec_release() will drain those queues here. __pagevec_lru_add() 3881da177e4SLinus Torvalds * and __pagevec_lru_add_active() call release_pages() directly to avoid 3891da177e4SLinus Torvalds * mutual recursion. 3901da177e4SLinus Torvalds */ 3911da177e4SLinus Torvalds void __pagevec_release(struct pagevec *pvec) 3921da177e4SLinus Torvalds { 3931da177e4SLinus Torvalds lru_add_drain(); 3941da177e4SLinus Torvalds release_pages(pvec->pages, pagevec_count(pvec), pvec->cold); 3951da177e4SLinus Torvalds pagevec_reinit(pvec); 3961da177e4SLinus Torvalds } 3971da177e4SLinus Torvalds 3987f285701SSteve French EXPORT_SYMBOL(__pagevec_release); 3997f285701SSteve French 4001da177e4SLinus Torvalds /* 4011da177e4SLinus Torvalds * Add the passed pages to the LRU, then drop the caller's refcount 4021da177e4SLinus Torvalds * on them. Reinitialises the caller's pagevec. 4031da177e4SLinus Torvalds */ 404f04e9ebbSKOSAKI Motohiro void ____pagevec_lru_add(struct pagevec *pvec, enum lru_list lru) 4051da177e4SLinus Torvalds { 4061da177e4SLinus Torvalds int i; 4071da177e4SLinus Torvalds struct zone *zone = NULL; 4086e901571SKOSAKI Motohiro 409894bc310SLee Schermerhorn VM_BUG_ON(is_unevictable_lru(lru)); 4101da177e4SLinus Torvalds 4111da177e4SLinus Torvalds for (i = 0; i < pagevec_count(pvec); i++) { 4121da177e4SLinus Torvalds struct page *page = pvec->pages[i]; 4131da177e4SLinus Torvalds struct zone *pagezone = page_zone(page); 4149ff473b9SRik van Riel int file; 4153e2f41f1SKOSAKI Motohiro int active; 4161da177e4SLinus Torvalds 4171da177e4SLinus Torvalds if (pagezone != zone) { 4181da177e4SLinus Torvalds if (zone) 4191da177e4SLinus Torvalds spin_unlock_irq(&zone->lru_lock); 4201da177e4SLinus Torvalds zone = pagezone; 4211da177e4SLinus Torvalds spin_lock_irq(&zone->lru_lock); 4221da177e4SLinus Torvalds } 423894bc310SLee Schermerhorn VM_BUG_ON(PageActive(page)); 424894bc310SLee Schermerhorn VM_BUG_ON(PageUnevictable(page)); 425725d704eSNick Piggin VM_BUG_ON(PageLRU(page)); 4268d438f96SNick Piggin SetPageLRU(page); 4273e2f41f1SKOSAKI Motohiro active = is_active_lru(lru); 4289ff473b9SRik van Riel file = is_file_lru(lru); 4293e2f41f1SKOSAKI Motohiro if (active) 4304c84cacfSNick Piggin SetPageActive(page); 4313e2f41f1SKOSAKI Motohiro update_page_reclaim_stat(zone, page, file, active); 432f04e9ebbSKOSAKI Motohiro add_page_to_lru_list(zone, page, lru); 4331da177e4SLinus Torvalds } 4341da177e4SLinus Torvalds if (zone) 4351da177e4SLinus Torvalds spin_unlock_irq(&zone->lru_lock); 4361da177e4SLinus Torvalds release_pages(pvec->pages, pvec->nr, pvec->cold); 4371da177e4SLinus Torvalds pagevec_reinit(pvec); 4381da177e4SLinus Torvalds } 4391da177e4SLinus Torvalds 440f04e9ebbSKOSAKI Motohiro EXPORT_SYMBOL(____pagevec_lru_add); 441f04e9ebbSKOSAKI Motohiro 4421da177e4SLinus Torvalds /* 4431da177e4SLinus Torvalds * Try to drop buffers from the pages in a pagevec 4441da177e4SLinus Torvalds */ 4451da177e4SLinus Torvalds void pagevec_strip(struct pagevec *pvec) 4461da177e4SLinus Torvalds { 4471da177e4SLinus Torvalds int i; 4481da177e4SLinus Torvalds 4491da177e4SLinus Torvalds for (i = 0; i < pagevec_count(pvec); i++) { 4501da177e4SLinus Torvalds struct page *page = pvec->pages[i]; 4511da177e4SLinus Torvalds 452266cf658SDavid Howells if (page_has_private(page) && trylock_page(page)) { 453266cf658SDavid Howells if (page_has_private(page)) 4541da177e4SLinus Torvalds try_to_release_page(page, 0); 4551da177e4SLinus Torvalds unlock_page(page); 4561da177e4SLinus Torvalds } 4571da177e4SLinus Torvalds } 4581da177e4SLinus Torvalds } 4591da177e4SLinus Torvalds 4601da177e4SLinus Torvalds /** 4611da177e4SLinus Torvalds * pagevec_lookup - gang pagecache lookup 4621da177e4SLinus Torvalds * @pvec: Where the resulting pages are placed 4631da177e4SLinus Torvalds * @mapping: The address_space to search 4641da177e4SLinus Torvalds * @start: The starting page index 4651da177e4SLinus Torvalds * @nr_pages: The maximum number of pages 4661da177e4SLinus Torvalds * 4671da177e4SLinus Torvalds * pagevec_lookup() will search for and return a group of up to @nr_pages pages 4681da177e4SLinus Torvalds * in the mapping. The pages are placed in @pvec. pagevec_lookup() takes a 4691da177e4SLinus Torvalds * reference against the pages in @pvec. 4701da177e4SLinus Torvalds * 4711da177e4SLinus Torvalds * The search returns a group of mapping-contiguous pages with ascending 4721da177e4SLinus Torvalds * indexes. There may be holes in the indices due to not-present pages. 4731da177e4SLinus Torvalds * 4741da177e4SLinus Torvalds * pagevec_lookup() returns the number of pages which were found. 4751da177e4SLinus Torvalds */ 4761da177e4SLinus Torvalds unsigned pagevec_lookup(struct pagevec *pvec, struct address_space *mapping, 4771da177e4SLinus Torvalds pgoff_t start, unsigned nr_pages) 4781da177e4SLinus Torvalds { 4791da177e4SLinus Torvalds pvec->nr = find_get_pages(mapping, start, nr_pages, pvec->pages); 4801da177e4SLinus Torvalds return pagevec_count(pvec); 4811da177e4SLinus Torvalds } 4821da177e4SLinus Torvalds 48378539fdfSChristoph Hellwig EXPORT_SYMBOL(pagevec_lookup); 48478539fdfSChristoph Hellwig 4851da177e4SLinus Torvalds unsigned pagevec_lookup_tag(struct pagevec *pvec, struct address_space *mapping, 4861da177e4SLinus Torvalds pgoff_t *index, int tag, unsigned nr_pages) 4871da177e4SLinus Torvalds { 4881da177e4SLinus Torvalds pvec->nr = find_get_pages_tag(mapping, index, tag, 4891da177e4SLinus Torvalds nr_pages, pvec->pages); 4901da177e4SLinus Torvalds return pagevec_count(pvec); 4911da177e4SLinus Torvalds } 4921da177e4SLinus Torvalds 4937f285701SSteve French EXPORT_SYMBOL(pagevec_lookup_tag); 4941da177e4SLinus Torvalds 4951da177e4SLinus Torvalds /* 4961da177e4SLinus Torvalds * Perform any setup for the swap system 4971da177e4SLinus Torvalds */ 4981da177e4SLinus Torvalds void __init swap_setup(void) 4991da177e4SLinus Torvalds { 5004481374cSJan Beulich unsigned long megs = totalram_pages >> (20 - PAGE_SHIFT); 5011da177e4SLinus Torvalds 502e0bf68ddSPeter Zijlstra #ifdef CONFIG_SWAP 503e0bf68ddSPeter Zijlstra bdi_init(swapper_space.backing_dev_info); 504e0bf68ddSPeter Zijlstra #endif 505e0bf68ddSPeter Zijlstra 5061da177e4SLinus Torvalds /* Use a smaller cluster for small-memory machines */ 5071da177e4SLinus Torvalds if (megs < 16) 5081da177e4SLinus Torvalds page_cluster = 2; 5091da177e4SLinus Torvalds else 5101da177e4SLinus Torvalds page_cluster = 3; 5111da177e4SLinus Torvalds /* 5121da177e4SLinus Torvalds * Right now other parts of the system means that we 5131da177e4SLinus Torvalds * _really_ don't want to cluster much more 5141da177e4SLinus Torvalds */ 5151da177e4SLinus Torvalds } 516