From 985737cf2ea096ea946aed82c7484d40defc71a8 Mon Sep 17 00:00:00 2001 From: Lee Schermerhorn Date: Sat, 18 Oct 2008 20:26:53 -0700 Subject: mlock: count attempts to free mlocked page Allow free of mlock()ed pages. This shouldn't happen, but during developement, it occasionally did. This patch allows us to survive that condition, while keeping the statistics and events correct for debug. Signed-off-by: Lee Schermerhorn Signed-off-by: Rik van Riel Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- include/linux/vmstat.h | 1 + mm/internal.h | 17 +++++++++++++++++ mm/page_alloc.c | 1 + mm/vmstat.c | 1 + 4 files changed, 20 insertions(+) diff --git a/include/linux/vmstat.h b/include/linux/vmstat.h index 05b805020be..9cd3ab0f554 100644 --- a/include/linux/vmstat.h +++ b/include/linux/vmstat.h @@ -49,6 +49,7 @@ enum vm_event_item { PGPGIN, PGPGOUT, PSWPIN, PSWPOUT, UNEVICTABLE_PGMUNLOCKED, UNEVICTABLE_PGCLEARED, /* on COW, page truncate */ UNEVICTABLE_PGSTRANDED, /* unable to isolate on unlock */ + UNEVICTABLE_MLOCKFREED, #endif NR_VM_EVENT_ITEMS }; diff --git a/mm/internal.h b/mm/internal.h index 1cfbf2e2bc9..e4e728bdf32 100644 --- a/mm/internal.h +++ b/mm/internal.h @@ -146,6 +146,22 @@ static inline void mlock_migrate_page(struct page *newpage, struct page *page) } } +/* + * free_page_mlock() -- clean up attempts to free and mlocked() page. + * Page should not be on lru, so no need to fix that up. + * free_pages_check() will verify... + */ +static inline void free_page_mlock(struct page *page) +{ + if (unlikely(TestClearPageMlocked(page))) { + unsigned long flags; + + local_irq_save(flags); + __dec_zone_page_state(page, NR_MLOCK); + __count_vm_event(UNEVICTABLE_MLOCKFREED); + local_irq_restore(flags); + } +} #else /* CONFIG_UNEVICTABLE_LRU */ static inline int is_mlocked_vma(struct vm_area_struct *v, struct page *p) @@ -155,6 +171,7 @@ static inline int is_mlocked_vma(struct vm_area_struct *v, struct page *p) static inline void clear_page_mlock(struct page *page) { } static inline void mlock_vma_page(struct page *page) { } static inline void mlock_migrate_page(struct page *new, struct page *old) { } +static inline void free_page_mlock(struct page *page) { } #endif /* CONFIG_UNEVICTABLE_LRU */ diff --git a/mm/page_alloc.c b/mm/page_alloc.c index 5886586fde6..cfbadad75d1 100644 --- a/mm/page_alloc.c +++ b/mm/page_alloc.c @@ -454,6 +454,7 @@ static inline void __free_one_page(struct page *page, static inline int free_pages_check(struct page *page) { + free_page_mlock(page); if (unlikely(page_mapcount(page) | (page->mapping != NULL) | (page_get_page_cgroup(page) != NULL) | diff --git a/mm/vmstat.c b/mm/vmstat.c index 9e28abc0a0b..9343227c5c6 100644 --- a/mm/vmstat.c +++ b/mm/vmstat.c @@ -689,6 +689,7 @@ static const char * const vmstat_text[] = { "unevictable_pgs_munlocked", "unevictable_pgs_cleared", "unevictable_pgs_stranded", + "unevictable_pgs_mlockfreed", #endif #endif }; -- cgit v1.2.3-70-g09d2