From mboxrd@z Thu Jan 1 00:00:00 1970 Date: Tue, 17 Jun 2008 18:15:27 +0900 From: Daisuke Nishimura Subject: Re: [Bad page] trying to free locked page? (Re: [PATCH][RFC] fix kernel BUG at mm/migrate.c:719! in 2.6.26-rc5-mm3) Message-Id: <20080617181527.5bcbbccc.nishimura@mxp.nes.nec.co.jp> In-Reply-To: <20080617180314.2d1b0efa.kamezawa.hiroyu@jp.fujitsu.com> References: <20080611225945.4da7bb7f.akpm@linux-foundation.org> <20080617163501.7cf411ee.nishimura@mxp.nes.nec.co.jp> <20080617164709.de4db070.nishimura@mxp.nes.nec.co.jp> <20080617180314.2d1b0efa.kamezawa.hiroyu@jp.fujitsu.com> Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: owner-linux-mm@kvack.org Return-Path: To: KAMEZAWA Hiroyuki Cc: Andrew Morton , Rik van Riel , Lee Schermerhorn , Kosaki Motohiro , Nick Piggin , linux-mm@kvack.org, linux-kernel@vger.kernel.org, kernel-testers@vger.kernel.org List-ID: On Tue, 17 Jun 2008 18:03:14 +0900, KAMEZAWA Hiroyuki wrote: > On Tue, 17 Jun 2008 16:47:09 +0900 > Daisuke Nishimura wrote: > > > On Tue, 17 Jun 2008 16:35:01 +0900, Daisuke Nishimura wrote: > > > Hi. > > > > > > I got this bug while migrating pages only a few times > > > via memory_migrate of cpuset. > > > > > > Unfortunately, even if this patch is applied, > > > I got bad_page problem after hundreds times of page migration > > > (I'll report it in another mail). > > > But I believe something like this patch is needed anyway. > > > > > > > I got bad_page after hundreds times of page migration. > > It seems that a locked page is being freed. > > > Good catch, and I think your investigation in the last e-mail was correct. > I'd like to dig this...but it seems some kind of big fix is necessary. > Did this happen under page-migraion by cpuset-task-move test ? > Yes. I made 2 cpuset directories, run some processes in each cpusets, and run a script like below infinitely to move tasks and migrate pages. --- #!/bin/bash G1=$1 G2=$2 move_task() { for pid in $1 do echo $pid >$2/tasks 2>/dev/null done } G1_TASK=`cat ${G1}/tasks` G2_TASK=`cat ${G2}/tasks` move_task "${G1_TASK}" ${G2} & move_task "${G2_TASK}" ${G1} & wait --- I got this bad_page after running this script for about 600 times. Thanks, Daisuke Nishimura. -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: email@kvack.org