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authorLee Schermerhorn <lee.schermerhorn@hp.com>2008-10-18 20:26:53 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2008-10-20 08:52:31 -0700
commit985737cf2ea096ea946aed82c7484d40defc71a8 (patch)
treeb96dc3b8c28f743857a7a1fff25472d6e0f60120
parentaf936a1606246a10c145feac3770f6287f483f02 (diff)
downloadlinux-985737cf2ea096ea946aed82c7484d40defc71a8.tar.bz2
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 <lee.schermerhorn@hp.com> Signed-off-by: Rik van Riel <riel@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
-rw-r--r--include/linux/vmstat.h1
-rw-r--r--mm/internal.h17
-rw-r--r--mm/page_alloc.c1
-rw-r--r--mm/vmstat.c1
4 files changed, 20 insertions, 0 deletions
diff --git a/include/linux/vmstat.h b/include/linux/vmstat.h
index 05b805020be2..9cd3ab0f554d 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 1cfbf2e2bc9e..e4e728bdf324 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 5886586fde6c..cfbadad75d1d 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 9e28abc0a0b9..9343227c5c60 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
};