From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1759503Ab1D0QuE (ORCPT ); Wed, 27 Apr 2011 12:50:04 -0400 Received: from bedivere.hansenpartnership.com ([66.63.167.143]:35133 "EHLO bedivere.hansenpartnership.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753280Ab1D0QuC (ORCPT ); Wed, 27 Apr 2011 12:50:02 -0400 Subject: Re: [BUG] fatal hang untarring 90GB file, possibly writeback related. From: James Bottomley To: Chris Mason Cc: linux-fsdevel , linux-mm , linux-kernel In-Reply-To: <1303921583-sup-4021@think> References: <1303920553.2583.7.camel@mulgrave.site> <1303921583-sup-4021@think> Content-Type: text/plain; charset="UTF-8" Date: Wed, 27 Apr 2011 11:50:00 -0500 Message-ID: <1303923000.2583.8.camel@mulgrave.site> Mime-Version: 1.0 X-Mailer: Evolution 2.32.1 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, 2011-04-27 at 12:33 -0400, Chris Mason wrote: > Probably easier to debug with a sysrq-l and sysrq-w. Yes, just enabling them for the repro ... I didn't echo 1 > /proc/sys/kernel/sysrq first time around > If you get stuck > on the filesystem, it is probably waiting on ram, which it probably > can't get because kswapd is spinning. Eventually everyone backs up > waiting for the transaction that never ends. If we're really lucky it > is just GFP_KERNEL where it should NOFS. > > Since you're often stuck in different spots inside shrink_slab, we're > probably not stuck on a lock. But, trying with lock debugging, lockdep > enabled and preempt on is a good idea to rule out locking mistakes. > > Does the fedora debug kernel enable preempt? No ... I've taken the Fedora 15 kernel config directly from their install CD for this (with a bit of munging to get it to work on -rc4) James From mboxrd@z Thu Jan 1 00:00:00 1970 From: James Bottomley Subject: Re: [BUG] fatal hang untarring 90GB file, possibly writeback related. Date: Wed, 27 Apr 2011 11:50:00 -0500 Message-ID: <1303923000.2583.8.camel@mulgrave.site> References: <1303920553.2583.7.camel@mulgrave.site> <1303921583-sup-4021@think> Mime-Version: 1.0 Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: 7bit Cc: linux-fsdevel , linux-mm , linux-kernel To: Chris Mason Return-path: In-Reply-To: <1303921583-sup-4021@think> Sender: owner-linux-mm@kvack.org List-Id: linux-fsdevel.vger.kernel.org On Wed, 2011-04-27 at 12:33 -0400, Chris Mason wrote: > Probably easier to debug with a sysrq-l and sysrq-w. Yes, just enabling them for the repro ... I didn't echo 1 > /proc/sys/kernel/sysrq first time around > If you get stuck > on the filesystem, it is probably waiting on ram, which it probably > can't get because kswapd is spinning. Eventually everyone backs up > waiting for the transaction that never ends. If we're really lucky it > is just GFP_KERNEL where it should NOFS. > > Since you're often stuck in different spots inside shrink_slab, we're > probably not stuck on a lock. But, trying with lock debugging, lockdep > enabled and preempt on is a good idea to rule out locking mistakes. > > Does the fedora debug kernel enable preempt? No ... I've taken the Fedora 15 kernel config directly from their install CD for this (with a bit of munging to get it to work on -rc4) James -- 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/ . Fight unfair telecom internet charges in Canada: sign http://stopthemeter.ca/ Don't email: email@kvack.org From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail172.messagelabs.com (mail172.messagelabs.com [216.82.254.3]) by kanga.kvack.org (Postfix) with SMTP id C2FC16B0012 for ; Wed, 27 Apr 2011 12:50:03 -0400 (EDT) Subject: Re: [BUG] fatal hang untarring 90GB file, possibly writeback related. From: James Bottomley In-Reply-To: <1303921583-sup-4021@think> References: <1303920553.2583.7.camel@mulgrave.site> <1303921583-sup-4021@think> Content-Type: text/plain; charset="UTF-8" Date: Wed, 27 Apr 2011 11:50:00 -0500 Message-ID: <1303923000.2583.8.camel@mulgrave.site> Mime-Version: 1.0 Content-Transfer-Encoding: 7bit Sender: owner-linux-mm@kvack.org List-ID: To: Chris Mason Cc: linux-fsdevel , linux-mm , linux-kernel On Wed, 2011-04-27 at 12:33 -0400, Chris Mason wrote: > Probably easier to debug with a sysrq-l and sysrq-w. Yes, just enabling them for the repro ... I didn't echo 1 > /proc/sys/kernel/sysrq first time around > If you get stuck > on the filesystem, it is probably waiting on ram, which it probably > can't get because kswapd is spinning. Eventually everyone backs up > waiting for the transaction that never ends. If we're really lucky it > is just GFP_KERNEL where it should NOFS. > > Since you're often stuck in different spots inside shrink_slab, we're > probably not stuck on a lock. But, trying with lock debugging, lockdep > enabled and preempt on is a good idea to rule out locking mistakes. > > Does the fedora debug kernel enable preempt? No ... I've taken the Fedora 15 kernel config directly from their install CD for this (with a bit of munging to get it to work on -rc4) James -- 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/ . Fight unfair telecom internet charges in Canada: sign http://stopthemeter.ca/ Don't email: email@kvack.org