On Thu, Nov 24, 2011 at 09:06:19AM +0900, KAMEZAWA Hiroyuki wrote: > On Wed, 23 Nov 2011 16:42:29 +0100 > Johannes Weiner <hannes@xxxxxxxxxxx> wrote: > > > From: Johannes Weiner <jweiner@xxxxxxxxxx> > > > > mem_cgroup_uncharge_page() is only called on either freshly allocated > > pages without page->mapping or on rmapped PageAnon() pages. There is > > no need to check for a page->mapping that is not an anon_vma. > > > > Signed-off-by: Johannes Weiner <jweiner@xxxxxxxxxx> > > For making our assumption clearer to readers of codes, > VM_BUG_ON(page->mapping && !PageAnon(page)) please. Yep, delta patch below. > Anyway, > Acked-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@xxxxxxxxxxxxxx> Thanks! --- From: Johannes Weiner <jweiner@xxxxxxxxxx> Subject: mm: memcg: remove unneeded checks from uncharge_page() fix Document page state assumptions and catch if they are violated in uncharge_page(). Signed-off-by: Johannes Weiner <jweiner@xxxxxxxxxx> --- mm/memcontrol.c | 1 + 1 files changed, 1 insertions(+), 0 deletions(-) diff --git a/mm/memcontrol.c b/mm/memcontrol.c index 2f1fdc4..872dae1 100644 --- a/mm/memcontrol.c +++ b/mm/memcontrol.c @@ -2992,6 +2992,7 @@ void mem_cgroup_uncharge_page(struct page *page) /* early check. */ if (page_mapped(page)) return; + VM_BUG_ON(page->mapping && !PageAnon(page)); __mem_cgroup_uncharge_common(page, MEM_CGROUP_CHARGE_TYPE_MAPPED); } -- 1.7.6.4 -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@xxxxxxxxx. For more info on Linux MM, see: http://www.linux-mm.org/ . Fight unfair telecom internet charges in Canada: sign http://stopthemeter.ca/ Don't email: <a href=mailto:"dont@xxxxxxxxx";> email@xxxxxxxxx </a>