From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1946118AbaD3U20 (ORCPT ); Wed, 30 Apr 2014 16:28:26 -0400 Received: from zene.cmpxchg.org ([85.214.230.12]:59945 "EHLO zene.cmpxchg.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1759533AbaD3UZ5 (ORCPT ); Wed, 30 Apr 2014 16:25:57 -0400 From: Johannes Weiner To: linux-mm@kvack.org Cc: Michal Hocko , Hugh Dickins , Tejun Heo , cgroups@vger.kernel.org, linux-kernel@vger.kernel.org Subject: [patch 2/9] mm: memcontrol: rearrange charging fast path Date: Wed, 30 Apr 2014 16:25:36 -0400 Message-Id: <1398889543-23671-3-git-send-email-hannes@cmpxchg.org> X-Mailer: git-send-email 1.9.2 In-Reply-To: <1398889543-23671-1-git-send-email-hannes@cmpxchg.org> References: <1398889543-23671-1-git-send-email-hannes@cmpxchg.org> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org The charging path currently starts out with OOM condition checks when OOM is the rarest possible case. Rearrange this code to run OOM/task dying checks only after trying the percpu charge and the res_counter charge and bail out before entering reclaim. Attempting a charge does not hurt an (oom-)killed task as much as every charge attempt having to check OOM conditions. Also, only check __GFP_NOFAIL when the charge would actually fail. Signed-off-by: Johannes Weiner --- mm/memcontrol.c | 31 ++++++++++++++++--------------- 1 file changed, 16 insertions(+), 15 deletions(-) diff --git a/mm/memcontrol.c b/mm/memcontrol.c index 75dfeb8fa98b..6ce59146fec7 100644 --- a/mm/memcontrol.c +++ b/mm/memcontrol.c @@ -2598,21 +2598,6 @@ static int mem_cgroup_try_charge(struct mem_cgroup *memcg, if (mem_cgroup_is_root(memcg)) goto done; - /* - * Unlike in global OOM situations, memcg is not in a physical - * memory shortage. Allow dying and OOM-killed tasks to - * bypass the last charges so that they can exit quickly and - * free their memory. - */ - if (unlikely(test_thread_flag(TIF_MEMDIE) || - fatal_signal_pending(current))) - goto bypass; - - if (unlikely(task_in_memcg_oom(current))) - goto nomem; - - if (gfp_mask & __GFP_NOFAIL) - oom = false; retry: if (consume_stock(memcg, nr_pages)) goto done; @@ -2634,6 +2619,19 @@ retry: goto retry; } + /* + * Unlike in global OOM situations, memcg is not in a physical + * memory shortage. Allow dying and OOM-killed tasks to + * bypass the last charges so that they can exit quickly and + * free their memory. + */ + if (unlikely(test_thread_flag(TIF_MEMDIE) || + fatal_signal_pending(current))) + goto bypass; + + if (unlikely(task_in_memcg_oom(current))) + goto nomem; + if (!(gfp_mask & __GFP_WAIT)) goto nomem; @@ -2662,6 +2660,9 @@ retry: if (mem_cgroup_wait_acct_move(mem_over_limit)) goto retry; + if (gfp_mask & __GFP_NOFAIL) + goto bypass; + if (fatal_signal_pending(current)) goto bypass; -- 1.9.2