Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752496Ab1EIGyj (ORCPT ); Mon, 9 May 2011 02:54:39 -0400 Received: from fgwmail6.fujitsu.co.jp ([192.51.44.36]:57330 "EHLO fgwmail6.fujitsu.co.jp" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751114Ab1EIGyh (ORCPT ); Mon, 9 May 2011 02:54:37 -0400 X-SecurityPolicyCheck-FJ: OK by FujitsuOutboundMailChecker v1.3.1 From: KOSAKI Motohiro To: CAI Qian Subject: Re: [PATCH] mm: check zone->all_unreclaimable in all_unreclaimable() Cc: kosaki.motohiro@jp.fujitsu.com, avagin@gmail.com, Andrey Vagin , Andrew Morton , Mel Gorman , linux-mm@kvack.org, linux-kernel@vger.kernel.org, Minchan Kim In-Reply-To: <1593977838.225469.1304473119444.JavaMail.root@zmail06.collab.prod.int.phx2.redhat.com> References: <4D72580D.4000208@gmail.com> <1593977838.225469.1304473119444.JavaMail.root@zmail06.collab.prod.int.phx2.redhat.com> Message-Id: <20110509155612.1648.A69D9226@jp.fujitsu.com> MIME-Version: 1.0 Content-Type: text/plain; charset="US-ASCII" Content-Transfer-Encoding: 7bit X-Mailer: Becky! ver. 2.56.05 [ja] Date: Mon, 9 May 2011 15:54:34 +0900 (JST) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2450 Lines: 77 > > > ----- Original Message ----- > > On 03/05/2011 06:20 PM, Minchan Kim wrote: > > > On Sat, Mar 05, 2011 at 02:44:16PM +0300, Andrey Vagin wrote: > > >> Check zone->all_unreclaimable in all_unreclaimable(), otherwise the > > >> kernel may hang up, because shrink_zones() will do nothing, but > > >> all_unreclaimable() will say, that zone has reclaimable pages. > > >> > > >> do_try_to_free_pages() > > >> shrink_zones() > > >> for_each_zone > > >> if (zone->all_unreclaimable) > > >> continue > > >> if !all_unreclaimable(zonelist, sc) > > >> return 1 > > >> > > >> __alloc_pages_slowpath() > > >> retry: > > >> did_some_progress = do_try_to_free_pages(page) > > >> ... > > >> if (!page&& did_some_progress) > > >> retry; > > >> > > >> Signed-off-by: Andrey Vagin > > >> --- > > >> mm/vmscan.c | 2 ++ > > >> 1 files changed, 2 insertions(+), 0 deletions(-) > > >> > > >> diff --git a/mm/vmscan.c b/mm/vmscan.c > > >> index 6771ea7..1c056f7 100644 > > >> --- a/mm/vmscan.c > > >> +++ b/mm/vmscan.c > > >> @@ -2002,6 +2002,8 @@ static bool all_unreclaimable(struct zonelist > > >> *zonelist, > > >> > > >> for_each_zone_zonelist_nodemask(zone, z, zonelist, > > >> gfp_zone(sc->gfp_mask), sc->nodemask) { > > >> + if (zone->all_unreclaimable) > > >> + continue; > > >> if (!populated_zone(zone)) > > >> continue; > > >> if (!cpuset_zone_allowed_hardwall(zone, GFP_KERNEL)) > > > > > > zone_reclaimable checks it. Isn't it enough? > > I sent one more patch [PATCH] mm: skip zombie in OOM-killer. > > This two patches are enough. > > > Does the hang up really happen or see it by code review? > > Yes. You can reproduce it for help the attached python program. It's > > not > > very clever:) > > It make the following actions in loop: > > 1. fork > > 2. mmap > > 3. touch memory > > 4. read memory > > 5. munmmap > > > > >> -- > > >> 1.7.1 > I have tested this for the latest mainline kernel using the reproducer > attached, the system just hung or deadlock after oom. The whole oom > trace is here. > http://people.redhat.com/qcai/oom.log > > Did I miss anything? Can you please try commit 929bea7c714220fc76ce3f75bef9056477c28e74? -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/