diff options
author | Mauro Carvalho Chehab <mchehab@infradead.org> | 2008-07-27 12:25:57 -0300 |
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committer | Mauro Carvalho Chehab <mchehab@infradead.org> | 2008-07-27 12:25:57 -0300 |
commit | 50cb993ea6cd187bfed085cb3e0747066edeb02f (patch) | |
tree | 61edac62c6c5bc07c59e4369c50c6821ad77f2c0 /mm/vmscan.c | |
parent | 445c2714cf72817ab1ad3ca894c6d9b2047b3a3e (diff) | |
parent | 8be1a6d6c77ab4532e4476fdb8177030ef48b52c (diff) |
Merge ../linux-2.6
Diffstat (limited to 'mm/vmscan.c')
-rw-r--r-- | mm/vmscan.c | 85 |
1 files changed, 62 insertions, 23 deletions
diff --git a/mm/vmscan.c b/mm/vmscan.c index 967d30ccd92..8f71761bc4b 100644 --- a/mm/vmscan.c +++ b/mm/vmscan.c @@ -38,6 +38,7 @@ #include <linux/kthread.h> #include <linux/freezer.h> #include <linux/memcontrol.h> +#include <linux/delayacct.h> #include <asm/tlbflush.h> #include <asm/div64.h> @@ -390,17 +391,15 @@ static pageout_t pageout(struct page *page, struct address_space *mapping, } /* - * Attempt to detach a locked page from its ->mapping. If it is dirty or if - * someone else has a ref on the page, abort and return 0. If it was - * successfully detached, return 1. Assumes the caller has a single ref on - * this page. + * Same as remove_mapping, but if the page is removed from the mapping, it + * gets returned with a refcount of 0. */ -int remove_mapping(struct address_space *mapping, struct page *page) +static int __remove_mapping(struct address_space *mapping, struct page *page) { BUG_ON(!PageLocked(page)); BUG_ON(mapping != page_mapping(page)); - write_lock_irq(&mapping->tree_lock); + spin_lock_irq(&mapping->tree_lock); /* * The non racy check for a busy page. * @@ -426,28 +425,48 @@ int remove_mapping(struct address_space *mapping, struct page *page) * Note that if SetPageDirty is always performed via set_page_dirty, * and thus under tree_lock, then this ordering is not required. */ - if (unlikely(page_count(page) != 2)) + if (!page_freeze_refs(page, 2)) goto cannot_free; - smp_rmb(); - if (unlikely(PageDirty(page))) + /* note: atomic_cmpxchg in page_freeze_refs provides the smp_rmb */ + if (unlikely(PageDirty(page))) { + page_unfreeze_refs(page, 2); goto cannot_free; + } if (PageSwapCache(page)) { swp_entry_t swap = { .val = page_private(page) }; __delete_from_swap_cache(page); - write_unlock_irq(&mapping->tree_lock); + spin_unlock_irq(&mapping->tree_lock); swap_free(swap); - __put_page(page); /* The pagecache ref */ - return 1; + } else { + __remove_from_page_cache(page); + spin_unlock_irq(&mapping->tree_lock); } - __remove_from_page_cache(page); - write_unlock_irq(&mapping->tree_lock); - __put_page(page); return 1; cannot_free: - write_unlock_irq(&mapping->tree_lock); + spin_unlock_irq(&mapping->tree_lock); + return 0; +} + +/* + * Attempt to detach a locked page from its ->mapping. If it is dirty or if + * someone else has a ref on the page, abort and return 0. If it was + * successfully detached, return 1. Assumes the caller has a single ref on + * this page. + */ +int remove_mapping(struct address_space *mapping, struct page *page) +{ + if (__remove_mapping(mapping, page)) { + /* + * Unfreezing the refcount with 1 rather than 2 effectively + * drops the pagecache ref for us without requiring another + * atomic operation. + */ + page_unfreeze_refs(page, 1); + return 1; + } return 0; } @@ -597,18 +616,34 @@ static unsigned long shrink_page_list(struct list_head *page_list, if (PagePrivate(page)) { if (!try_to_release_page(page, sc->gfp_mask)) goto activate_locked; - if (!mapping && page_count(page) == 1) - goto free_it; + if (!mapping && page_count(page) == 1) { + unlock_page(page); + if (put_page_testzero(page)) + goto free_it; + else { + /* + * rare race with speculative reference. + * the speculative reference will free + * this page shortly, so we may + * increment nr_reclaimed here (and + * leave it off the LRU). + */ + nr_reclaimed++; + continue; + } + } } - if (!mapping || !remove_mapping(mapping, page)) + if (!mapping || !__remove_mapping(mapping, page)) goto keep_locked; -free_it: unlock_page(page); +free_it: nr_reclaimed++; - if (!pagevec_add(&freed_pvec, page)) - __pagevec_release_nonlru(&freed_pvec); + if (!pagevec_add(&freed_pvec, page)) { + __pagevec_free(&freed_pvec); + pagevec_reinit(&freed_pvec); + } continue; activate_locked: @@ -622,7 +657,7 @@ keep: } list_splice(&ret_pages, page_list); if (pagevec_count(&freed_pvec)) - __pagevec_release_nonlru(&freed_pvec); + __pagevec_free(&freed_pvec); count_vm_events(PGACTIVATE, pgactivate); return nr_reclaimed; } @@ -1316,6 +1351,8 @@ static unsigned long do_try_to_free_pages(struct zonelist *zonelist, struct zone *zone; enum zone_type high_zoneidx = gfp_zone(sc->gfp_mask); + delayacct_freepages_start(); + if (scan_global_lru(sc)) count_vm_event(ALLOCSTALL); /* @@ -1396,6 +1433,8 @@ out: } else mem_cgroup_record_reclaim_priority(sc->mem_cgroup, priority); + delayacct_freepages_end(); + return ret; } |