diff options
Diffstat (limited to 'mm/swap.c')
-rw-r--r-- | mm/swap.c | 188 |
1 files changed, 119 insertions, 69 deletions
diff --git a/mm/swap.c b/mm/swap.c index 9e0cb311807..b135ec90cde 100644 --- a/mm/swap.c +++ b/mm/swap.c @@ -31,11 +31,12 @@ #include <linux/backing-dev.h> #include <linux/memcontrol.h> +#include "internal.h" + /* How many pages do we try to swap or page in/out together? */ int page_cluster; -static DEFINE_PER_CPU(struct pagevec, lru_add_pvecs); -static DEFINE_PER_CPU(struct pagevec, lru_add_active_pvecs); +static DEFINE_PER_CPU(struct pagevec[NR_LRU_LISTS], lru_add_pvecs); static DEFINE_PER_CPU(struct pagevec, lru_rotate_pvecs); /* @@ -116,8 +117,9 @@ static void pagevec_move_tail(struct pagevec *pvec) zone = pagezone; spin_lock(&zone->lru_lock); } - if (PageLRU(page) && !PageActive(page)) { - list_move_tail(&page->lru, &zone->inactive_list); + if (PageLRU(page) && !PageActive(page) && !PageUnevictable(page)) { + int lru = page_is_file_cache(page); + list_move_tail(&page->lru, &zone->lru[lru].list); pgmoved++; } } @@ -136,7 +138,7 @@ static void pagevec_move_tail(struct pagevec *pvec) void rotate_reclaimable_page(struct page *page) { if (!PageLocked(page) && !PageDirty(page) && !PageActive(page) && - PageLRU(page)) { + !PageUnevictable(page) && PageLRU(page)) { struct pagevec *pvec; unsigned long flags; @@ -157,12 +159,19 @@ void activate_page(struct page *page) struct zone *zone = page_zone(page); spin_lock_irq(&zone->lru_lock); - if (PageLRU(page) && !PageActive(page)) { - del_page_from_inactive_list(zone, page); + if (PageLRU(page) && !PageActive(page) && !PageUnevictable(page)) { + int file = page_is_file_cache(page); + int lru = LRU_BASE + file; + del_page_from_lru_list(zone, page, lru); + SetPageActive(page); - add_page_to_active_list(zone, page); + lru += LRU_ACTIVE; + add_page_to_lru_list(zone, page, lru); __count_vm_event(PGACTIVATE); - mem_cgroup_move_lists(page, true); + mem_cgroup_move_lists(page, lru); + + zone->recent_rotated[!!file]++; + zone->recent_scanned[!!file]++; } spin_unlock_irq(&zone->lru_lock); } @@ -176,7 +185,8 @@ void activate_page(struct page *page) */ void mark_page_accessed(struct page *page) { - if (!PageActive(page) && PageReferenced(page) && PageLRU(page)) { + if (!PageActive(page) && !PageUnevictable(page) && + PageReferenced(page) && PageLRU(page)) { activate_page(page); ClearPageReferenced(page); } else if (!PageReferenced(page)) { @@ -186,28 +196,73 @@ void mark_page_accessed(struct page *page) EXPORT_SYMBOL(mark_page_accessed); -/** - * lru_cache_add: add a page to the page lists - * @page: the page to add - */ -void lru_cache_add(struct page *page) +void __lru_cache_add(struct page *page, enum lru_list lru) { - struct pagevec *pvec = &get_cpu_var(lru_add_pvecs); + struct pagevec *pvec = &get_cpu_var(lru_add_pvecs)[lru]; page_cache_get(page); if (!pagevec_add(pvec, page)) - __pagevec_lru_add(pvec); + ____pagevec_lru_add(pvec, lru); put_cpu_var(lru_add_pvecs); } -void lru_cache_add_active(struct page *page) +/** + * lru_cache_add_lru - add a page to a page list + * @page: the page to be added to the LRU. + * @lru: the LRU list to which the page is added. + */ +void lru_cache_add_lru(struct page *page, enum lru_list lru) { - struct pagevec *pvec = &get_cpu_var(lru_add_active_pvecs); + if (PageActive(page)) { + VM_BUG_ON(PageUnevictable(page)); + ClearPageActive(page); + } else if (PageUnevictable(page)) { + VM_BUG_ON(PageActive(page)); + ClearPageUnevictable(page); + } - page_cache_get(page); - if (!pagevec_add(pvec, page)) - __pagevec_lru_add_active(pvec); - put_cpu_var(lru_add_active_pvecs); + VM_BUG_ON(PageLRU(page) || PageActive(page) || PageUnevictable(page)); + __lru_cache_add(page, lru); +} + +/** + * add_page_to_unevictable_list - add a page to the unevictable list + * @page: the page to be added to the unevictable list + * + * Add page directly to its zone's unevictable list. To avoid races with + * tasks that might be making the page evictable, through eg. munlock, + * munmap or exit, while it's not on the lru, we want to add the page + * while it's locked or otherwise "invisible" to other tasks. This is + * difficult to do when using the pagevec cache, so bypass that. + */ +void add_page_to_unevictable_list(struct page *page) +{ + struct zone *zone = page_zone(page); + + spin_lock_irq(&zone->lru_lock); + SetPageUnevictable(page); + SetPageLRU(page); + add_page_to_lru_list(zone, page, LRU_UNEVICTABLE); + spin_unlock_irq(&zone->lru_lock); +} + +/** + * lru_cache_add_active_or_unevictable + * @page: the page to be added to LRU + * @vma: vma in which page is mapped for determining reclaimability + * + * place @page on active or unevictable LRU list, depending on + * page_evictable(). Note that if the page is not evictable, + * it goes directly back onto it's zone's unevictable list. It does + * NOT use a per cpu pagevec. + */ +void lru_cache_add_active_or_unevictable(struct page *page, + struct vm_area_struct *vma) +{ + if (page_evictable(page, vma)) + lru_cache_add_lru(page, LRU_ACTIVE + page_is_file_cache(page)); + else + add_page_to_unevictable_list(page); } /* @@ -217,15 +272,15 @@ void lru_cache_add_active(struct page *page) */ static void drain_cpu_pagevecs(int cpu) { + struct pagevec *pvecs = per_cpu(lru_add_pvecs, cpu); struct pagevec *pvec; + int lru; - pvec = &per_cpu(lru_add_pvecs, cpu); - if (pagevec_count(pvec)) - __pagevec_lru_add(pvec); - - pvec = &per_cpu(lru_add_active_pvecs, cpu); - if (pagevec_count(pvec)) - __pagevec_lru_add_active(pvec); + for_each_lru(lru) { + pvec = &pvecs[lru - LRU_BASE]; + if (pagevec_count(pvec)) + ____pagevec_lru_add(pvec, lru); + } pvec = &per_cpu(lru_rotate_pvecs, cpu); if (pagevec_count(pvec)) { @@ -244,7 +299,6 @@ void lru_add_drain(void) put_cpu(); } -#ifdef CONFIG_NUMA static void lru_add_drain_per_cpu(struct work_struct *dummy) { lru_add_drain(); @@ -258,18 +312,6 @@ int lru_add_drain_all(void) return schedule_on_each_cpu(lru_add_drain_per_cpu); } -#else - -/* - * Returns 0 for success - */ -int lru_add_drain_all(void) -{ - lru_add_drain(); - return 0; -} -#endif - /* * Batched page_cache_release(). Decrement the reference count on all the * passed pages. If it fell to zero then remove the page from the LRU and @@ -308,6 +350,7 @@ void release_pages(struct page **pages, int nr, int cold) if (PageLRU(page)) { struct zone *pagezone = page_zone(page); + if (pagezone != zone) { if (zone) spin_unlock_irqrestore(&zone->lru_lock, @@ -380,14 +423,16 @@ void __pagevec_release_nonlru(struct pagevec *pvec) * Add the passed pages to the LRU, then drop the caller's refcount * on them. Reinitialises the caller's pagevec. */ -void __pagevec_lru_add(struct pagevec *pvec) +void ____pagevec_lru_add(struct pagevec *pvec, enum lru_list lru) { int i; struct zone *zone = NULL; + VM_BUG_ON(is_unevictable_lru(lru)); for (i = 0; i < pagevec_count(pvec); i++) { struct page *page = pvec->pages[i]; struct zone *pagezone = page_zone(page); + int file; if (pagezone != zone) { if (zone) @@ -395,9 +440,17 @@ void __pagevec_lru_add(struct pagevec *pvec) zone = pagezone; spin_lock_irq(&zone->lru_lock); } + VM_BUG_ON(PageActive(page)); + VM_BUG_ON(PageUnevictable(page)); VM_BUG_ON(PageLRU(page)); SetPageLRU(page); - add_page_to_inactive_list(zone, page); + file = is_file_lru(lru); + zone->recent_scanned[file]++; + if (is_active_lru(lru)) { + SetPageActive(page); + zone->recent_rotated[file]++; + } + add_page_to_lru_list(zone, page, lru); } if (zone) spin_unlock_irq(&zone->lru_lock); @@ -405,48 +458,45 @@ void __pagevec_lru_add(struct pagevec *pvec) pagevec_reinit(pvec); } -EXPORT_SYMBOL(__pagevec_lru_add); +EXPORT_SYMBOL(____pagevec_lru_add); -void __pagevec_lru_add_active(struct pagevec *pvec) +/* + * Try to drop buffers from the pages in a pagevec + */ +void pagevec_strip(struct pagevec *pvec) { int i; - struct zone *zone = NULL; for (i = 0; i < pagevec_count(pvec); i++) { struct page *page = pvec->pages[i]; - struct zone *pagezone = page_zone(page); - if (pagezone != zone) { - if (zone) - spin_unlock_irq(&zone->lru_lock); - zone = pagezone; - spin_lock_irq(&zone->lru_lock); + if (PagePrivate(page) && trylock_page(page)) { + if (PagePrivate(page)) + try_to_release_page(page, 0); + unlock_page(page); } - VM_BUG_ON(PageLRU(page)); - SetPageLRU(page); - VM_BUG_ON(PageActive(page)); - SetPageActive(page); - add_page_to_active_list(zone, page); } - if (zone) - spin_unlock_irq(&zone->lru_lock); - release_pages(pvec->pages, pvec->nr, pvec->cold); - pagevec_reinit(pvec); } -/* - * Try to drop buffers from the pages in a pagevec +/** + * pagevec_swap_free - try to free swap space from the pages in a pagevec + * @pvec: pagevec with swapcache pages to free the swap space of + * + * The caller needs to hold an extra reference to each page and + * not hold the page lock on the pages. This function uses a + * trylock on the page lock so it may not always free the swap + * space associated with a page. */ -void pagevec_strip(struct pagevec *pvec) +void pagevec_swap_free(struct pagevec *pvec) { int i; for (i = 0; i < pagevec_count(pvec); i++) { struct page *page = pvec->pages[i]; - if (PagePrivate(page) && trylock_page(page)) { - if (PagePrivate(page)) - try_to_release_page(page, 0); + if (PageSwapCache(page) && trylock_page(page)) { + if (PageSwapCache(page)) + remove_exclusive_swap_page_ref(page); unlock_page(page); } } |