Messages in this thread Patch in this message | | | Date | Wed, 25 Jun 2008 19:09:06 +0900 | From | KOSAKI Motohiro <> | Subject | [-mm][PATCH 8/10] fix shmem page migration incorrectness on memcgroup |
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= From: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
mem_cgroup_uncharge() against old page is done after radix-tree-replacement. And there were special handling to ingore swap-cache page. But, shmem can be swap-cache and file-cache at the same time. Chekcing PageSwapCache() is not correct here. Check PageAnon() instead.
Signed-off-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Acked-by: Daisuke Nishimura <nishimura@mxp.nes.nec.co.jp> Signed-off-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
--- mm/migrate.c | 11 +++++++++-- 1 file changed, 9 insertions(+), 2 deletions(-)
Index: b/mm/migrate.c =================================================================== --- a/mm/migrate.c +++ b/mm/migrate.c @@ -332,7 +332,13 @@ static int migrate_page_move_mapping(str __inc_zone_page_state(newpage, NR_FILE_PAGES); spin_unlock_irq(&mapping->tree_lock); - if (!PageSwapCache(newpage)) + + /* + * The page is removed from radix-tree implicitly. + * We uncharge it here but swap cache of anonymous page should be + * uncharged by mem_cgroup_ucharge_page(). + */ + if (!PageAnon(newpage)) mem_cgroup_uncharge_cache_page(page); return 0; @@ -381,7 +387,8 @@ static void migrate_page_copy(struct pag /* * SwapCache is removed implicitly. Uncharge against swapcache * should be called after ClearPageSwapCache() because - * mem_cgroup_uncharge_page checks the flag. + * mem_cgroup_uncharge_page checks the flag. shmem's swap cache + * is uncharged before here. */ mem_cgroup_uncharge_page(page); }
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