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authorKAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>2008-10-18 20:28:09 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2008-10-20 08:52:38 -0700
commitb7abea9630bc8ffc663a751e46680db25c4cdf8d (patch)
treeb37d5ba073ccea31328812c74598872d49a85735 /mm/migrate.c
parent073e587ec2cc377867e53d8b8959738a8e16cff6 (diff)
memcg: make page->mapping NULL before uncharge
This patch tries to make page->mapping to be NULL before mem_cgroup_uncharge_cache_page() is called. "page->mapping == NULL" is a good check for "whether the page is still radix-tree or not". This patch also adds BUG_ON() to mem_cgroup_uncharge_cache_page(); Signed-off-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Reviewed-by: Daisuke Nishimura <nishimura@mxp.nes.nec.co.jp> Cc: Balbir Singh <balbir@linux.vnet.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'mm/migrate.c')
-rw-r--r--mm/migrate.c9
1 files changed, 7 insertions, 2 deletions
diff --git a/mm/migrate.c b/mm/migrate.c
index 11c6c56ec01..6602941bfab 100644
--- a/mm/migrate.c
+++ b/mm/migrate.c
@@ -330,8 +330,6 @@ static int migrate_page_move_mapping(struct address_space *mapping,
__inc_zone_page_state(newpage, NR_FILE_PAGES);
spin_unlock_irq(&mapping->tree_lock);
- if (!PageSwapCache(newpage))
- mem_cgroup_uncharge_cache_page(page);
return 0;
}
@@ -341,6 +339,8 @@ static int migrate_page_move_mapping(struct address_space *mapping,
*/
static void migrate_page_copy(struct page *newpage, struct page *page)
{
+ int anon;
+
copy_highpage(newpage, page);
if (PageError(page))
@@ -378,8 +378,13 @@ static void migrate_page_copy(struct page *newpage, struct page *page)
#endif
ClearPagePrivate(page);
set_page_private(page, 0);
+ /* page->mapping contains a flag for PageAnon() */
+ anon = PageAnon(page);
page->mapping = NULL;
+ if (!anon) /* This page was removed from radix-tree. */
+ mem_cgroup_uncharge_cache_page(page);
+
/*
* If any waiters have accumulated on the new page then
* wake them up.