Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754701AbZGBNlz (ORCPT ); Thu, 2 Jul 2009 09:41:55 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1753127AbZGBNlr (ORCPT ); Thu, 2 Jul 2009 09:41:47 -0400 Received: from mga03.intel.com ([143.182.124.21]:23211 "EHLO mga03.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751268AbZGBNlq (ORCPT ); Thu, 2 Jul 2009 09:41:46 -0400 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="4.42,334,1243839600"; d="scan'208";a="160906850" Date: Thu, 2 Jul 2009 20:43:52 +0800 From: Wu Fengguang To: Minchan Kim Cc: David Howells , Mel Gorman , KOSAKI Motohiro , Johannes Weiner , "riel@redhat.com" , Andrew Morton , LKML , Christoph Lameter , "peterz@infradead.org" , "tytso@mit.edu" , "linux-mm@kvack.org" , "elladan@eskimo.com" , "npiggin@suse.de" , "Barnes, Jesse" Subject: Re: Found the commit that causes the OOMs Message-ID: <20090702124351.GA7488@localhost> References: <2f11576a0906280801w417d1b9fpe10585b7a641d41b@mail.gmail.com> <20090628151026.GB25076@localhost> <20090629091741.ab815ae7.minchan.kim@barrios-desktop> <17678.1246270219@redhat.com> <20090629125549.GA22932@localhost> <29432.1246285300@redhat.com> <28c262360906290800v37f91d7av3642b1ad8b5f0477@mail.gmail.com> <20090629160725.GF5065@csn.ul.ie> <24767.1246391867@redhat.com> <20090702164106.76db077b.minchan.kim@barrios-desktop> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20090702164106.76db077b.minchan.kim@barrios-desktop> User-Agent: Mutt/1.5.18 (2008-05-17) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 3034 Lines: 95 On Thu, Jul 02, 2009 at 03:41:06PM +0800, Minchan Kim wrote: > > > On Tue, 30 Jun 2009 20:57:47 +0100 > David Howells wrote: > > > Minchan Kim wrote: > > > > > David. Doesn't it happen OOM if you revert my patch, still? > > > > It does happen, and indeed happens in v2.6.30, but requires two adjacent runs > > of msgctl11 to trigger, rather than usually triggering on the first run. If > > you interpolate the rest of LTP between the iterations, it doesn't seem to > > happen at all on v2.6.30. My guess is that with the rest of LTP interpolated, > > there's either enough time for some cleanup or something triggers a cleanup > > (the swapfile tests perhaps?). > > > > > Befor I go to the trip, I made debugging patch in a hurry. Mel and I > > > suspect to put the wrong page in lru list. > > > > > > This patch's goal is that print page's detail on active anon lru when it > > > happen OOM. Maybe you could expand your log buffer size. > > > > Do you mean to expand the dmesg buffer? That's probably unnecessary: I capture > > the kernel log over a serial port into a file on another machine. > > > > > Could you show me the information with OOM, please ? > > > > Attached. It's compressed as there was rather a lot. > > > > David > > --- > > Hi, David. > > Sorry for late response. > > I looked over your captured data when I got home but I didn't find any problem > in lru page moving scheme. > As Wu, Kosaki and Rik discussed, I think this issue is also related to process fork bomb. Yes, me think so. > When I tested msgctl11 in my machine with 2.6.31-rc1, I found that: Were you testing the no-swap case? > 2.6.31-rc1 > real 0m38.628s > user 0m10.589s > sys 1m12.613s > > vmstat > > allocstall 3196 > > 2.6.31-rc1-revert-mypatch > > real 1m17.396s > user 0m11.193s > sys 4m3.803s It's interesting that (sys > real). > vmstat > > allocstall 584 > > Sometimes I got OOM, sometime not in with 2.6.31-rc1. > > Anyway, the current kernel's test took a rather short time than my reverted patch. > In addition, the current kernel has small allocstall(direct reclaim) > > As you know, my patch was just to remove calling shrink_active_list in case of no swap. > shrink_active_list function is a big cost function. > The old shrink_active_list could throttle to fork processes by chance. > But by removing that function with my patch, we have a high > probability to make process fork bomb. Wu, KOSAKI and Rik, does it > make sense? Maybe, but I'm not sure on how to explain the time/vmstat numbers :( > So I think you were just lucky with a unnecessary routine. > Anyway, AFAIK, Rik is making throttling page reclaim. > I think it can solve your problem. Yes, with good luck :) Thanks, Fengguang -- 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/