diff options
Diffstat (limited to 'mm/swap.c')
-rw-r--r-- | mm/swap.c | 189 |
1 files changed, 143 insertions, 46 deletions
diff --git a/mm/swap.c b/mm/swap.c index c02f93611a8..a448db377cb 100644 --- a/mm/swap.c +++ b/mm/swap.c @@ -39,6 +39,7 @@ int page_cluster; static DEFINE_PER_CPU(struct pagevec[NR_LRU_LISTS], lru_add_pvecs); static DEFINE_PER_CPU(struct pagevec, lru_rotate_pvecs); +static DEFINE_PER_CPU(struct pagevec, lru_deactivate_pvecs); /* * This path almost never happens for VM activity - pages are normally @@ -178,15 +179,13 @@ void put_pages_list(struct list_head *pages) } EXPORT_SYMBOL(put_pages_list); -/* - * pagevec_move_tail() must be called with IRQ disabled. - * Otherwise this may cause nasty races. - */ -static void pagevec_move_tail(struct pagevec *pvec) +static void pagevec_lru_move_fn(struct pagevec *pvec, + void (*move_fn)(struct page *page, void *arg), + void *arg) { int i; - int pgmoved = 0; struct zone *zone = NULL; + unsigned long flags = 0; for (i = 0; i < pagevec_count(pvec); i++) { struct page *page = pvec->pages[i]; @@ -194,29 +193,50 @@ static void pagevec_move_tail(struct pagevec *pvec) if (pagezone != zone) { if (zone) - spin_unlock(&zone->lru_lock); + spin_unlock_irqrestore(&zone->lru_lock, flags); zone = pagezone; - spin_lock(&zone->lru_lock); - } - if (PageLRU(page) && !PageActive(page) && !PageUnevictable(page)) { - int lru = page_lru_base_type(page); - list_move_tail(&page->lru, &zone->lru[lru].list); - pgmoved++; + spin_lock_irqsave(&zone->lru_lock, flags); } + + (*move_fn)(page, arg); } if (zone) - spin_unlock(&zone->lru_lock); - __count_vm_events(PGROTATED, pgmoved); + spin_unlock_irqrestore(&zone->lru_lock, flags); release_pages(pvec->pages, pvec->nr, pvec->cold); pagevec_reinit(pvec); } +static void pagevec_move_tail_fn(struct page *page, void *arg) +{ + int *pgmoved = arg; + struct zone *zone = page_zone(page); + + if (PageLRU(page) && !PageActive(page) && !PageUnevictable(page)) { + enum lru_list lru = page_lru_base_type(page); + list_move_tail(&page->lru, &zone->lru[lru].list); + mem_cgroup_rotate_reclaimable_page(page); + (*pgmoved)++; + } +} + +/* + * pagevec_move_tail() must be called with IRQ disabled. + * Otherwise this may cause nasty races. + */ +static void pagevec_move_tail(struct pagevec *pvec) +{ + int pgmoved = 0; + + pagevec_lru_move_fn(pvec, pagevec_move_tail_fn, &pgmoved); + __count_vm_events(PGROTATED, pgmoved); +} + /* * Writeback is about to end against a page which has been marked for immediate * reclaim. If it still appears to be reclaimable, move it to the tail of the * inactive list. */ -void rotate_reclaimable_page(struct page *page) +void rotate_reclaimable_page(struct page *page) { if (!PageLocked(page) && !PageDirty(page) && !PageActive(page) && !PageUnevictable(page) && PageLRU(page)) { @@ -347,6 +367,71 @@ void add_page_to_unevictable_list(struct page *page) } /* + * If the page can not be invalidated, it is moved to the + * inactive list to speed up its reclaim. It is moved to the + * head of the list, rather than the tail, to give the flusher + * threads some time to write it out, as this is much more + * effective than the single-page writeout from reclaim. + * + * If the page isn't page_mapped and dirty/writeback, the page + * could reclaim asap using PG_reclaim. + * + * 1. active, mapped page -> none + * 2. active, dirty/writeback page -> inactive, head, PG_reclaim + * 3. inactive, mapped page -> none + * 4. inactive, dirty/writeback page -> inactive, head, PG_reclaim + * 5. inactive, clean -> inactive, tail + * 6. Others -> none + * + * In 4, why it moves inactive's head, the VM expects the page would + * be write it out by flusher threads as this is much more effective + * than the single-page writeout from reclaim. + */ +static void lru_deactivate_fn(struct page *page, void *arg) +{ + int lru, file; + bool active; + struct zone *zone = page_zone(page); + + if (!PageLRU(page)) + return; + + /* Some processes are using the page */ + if (page_mapped(page)) + return; + + active = PageActive(page); + + file = page_is_file_cache(page); + lru = page_lru_base_type(page); + del_page_from_lru_list(zone, page, lru + active); + ClearPageActive(page); + ClearPageReferenced(page); + add_page_to_lru_list(zone, page, lru); + + if (PageWriteback(page) || PageDirty(page)) { + /* + * PG_reclaim could be raced with end_page_writeback + * It can make readahead confusing. But race window + * is _really_ small and it's non-critical problem. + */ + SetPageReclaim(page); + } else { + /* + * The page's writeback ends up during pagevec + * We moves tha page into tail of inactive. + */ + list_move_tail(&page->lru, &zone->lru[lru].list); + mem_cgroup_rotate_reclaimable_page(page); + __count_vm_event(PGROTATED); + } + + if (active) + __count_vm_event(PGDEACTIVATE); + update_page_reclaim_stat(zone, page, file, 0); +} + +/* * Drain pages out of the cpu's pagevecs. * Either "cpu" is the current CPU, and preemption has already been * disabled; or "cpu" is being hot-unplugged, and is already dead. @@ -372,6 +457,29 @@ static void drain_cpu_pagevecs(int cpu) pagevec_move_tail(pvec); local_irq_restore(flags); } + + pvec = &per_cpu(lru_deactivate_pvecs, cpu); + if (pagevec_count(pvec)) + pagevec_lru_move_fn(pvec, lru_deactivate_fn, NULL); +} + +/** + * deactivate_page - forcefully deactivate a page + * @page: page to deactivate + * + * This function hints the VM that @page is a good reclaim candidate, + * for example if its invalidation fails due to the page being dirty + * or under writeback. + */ +void deactivate_page(struct page *page) +{ + if (likely(get_page_unless_zero(page))) { + struct pagevec *pvec = &get_cpu_var(lru_deactivate_pvecs); + + if (!pagevec_add(pvec, page)) + pagevec_lru_move_fn(pvec, lru_deactivate_fn, NULL); + put_cpu_var(lru_deactivate_pvecs); + } } void lru_add_drain(void) @@ -516,44 +624,33 @@ void lru_add_page_tail(struct zone* zone, } } +static void ____pagevec_lru_add_fn(struct page *page, void *arg) +{ + enum lru_list lru = (enum lru_list)arg; + struct zone *zone = page_zone(page); + int file = is_file_lru(lru); + int active = is_active_lru(lru); + + VM_BUG_ON(PageActive(page)); + VM_BUG_ON(PageUnevictable(page)); + VM_BUG_ON(PageLRU(page)); + + SetPageLRU(page); + if (active) + SetPageActive(page); + update_page_reclaim_stat(zone, page, file, active); + add_page_to_lru_list(zone, page, lru); +} + /* * 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, 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; - int active; - - if (pagezone != zone) { - if (zone) - spin_unlock_irq(&zone->lru_lock); - 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); - active = is_active_lru(lru); - file = is_file_lru(lru); - if (active) - SetPageActive(page); - update_page_reclaim_stat(zone, page, file, active); - add_page_to_lru_list(zone, page, lru); - } - if (zone) - spin_unlock_irq(&zone->lru_lock); - release_pages(pvec->pages, pvec->nr, pvec->cold); - pagevec_reinit(pvec); + pagevec_lru_move_fn(pvec, ____pagevec_lru_add_fn, (void *)lru); } EXPORT_SYMBOL(____pagevec_lru_add); |