From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755977Ab3KVRSD (ORCPT ); Fri, 22 Nov 2013 12:18:03 -0500 Received: from zene.cmpxchg.org ([85.214.230.12]:38996 "EHLO zene.cmpxchg.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753113Ab3KVRSB (ORCPT ); Fri, 22 Nov 2013 12:18:01 -0500 From: Johannes Weiner To: Andrew Morton Cc: Michal Hocko , linux-mm@kvack.org, cgroups@vger.kernel.org, linux-kernel@vger.kernel.org Subject: [patch] mm: memcg: do not declare OOM from __GFP_NOFAIL allocations Date: Fri, 22 Nov 2013 12:17:56 -0500 Message-Id: <1385140676-5677-1-git-send-email-hannes@cmpxchg.org> X-Mailer: git-send-email 1.8.4.2 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 84235de394d9 ("fs: buffer: move allocation failure loop into the allocator") started recognizing __GFP_NOFAIL in memory cgroups but forgot to disable the OOM killer. Any task that does not fail allocation will also not enter the OOM completion path. So don't declare an OOM state in this case or it'll be leaked and the task be able to bypass the limit until the next userspace-triggered page fault cleans up the OOM state. Reported-by: William Dauchy Signed-off-by: Johannes Weiner Cc: stable@kernel.org # 3.12 --- mm/memcontrol.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/mm/memcontrol.c b/mm/memcontrol.c index 13b9d0f..cc4f9cb 100644 --- a/mm/memcontrol.c +++ b/mm/memcontrol.c @@ -2677,6 +2677,9 @@ static int __mem_cgroup_try_charge(struct mm_struct *mm, if (unlikely(task_in_memcg_oom(current))) goto bypass; + if (gfp_mask & __GFP_NOFAIL) + oom = false; + /* * We always charge the cgroup the mm_struct belongs to. * The mm_struct's mem_cgroup changes on task migration if the -- 1.8.4.2