From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751556AbaFDIkA (ORCPT ); Wed, 4 Jun 2014 04:40:00 -0400 Received: from atrey.karlin.mff.cuni.cz ([195.113.26.193]:56853 "EHLO atrey.karlin.mff.cuni.cz" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750860AbaFDIj5 (ORCPT ); Wed, 4 Jun 2014 04:39:57 -0400 Date: Wed, 4 Jun 2014 10:39:55 +0200 From: Pavel Machek To: Paolo Valente Cc: Tejun Heo , Jens Axboe , Li Zefan , Fabio Checconi , Arianna Avanzini , linux-kernel@vger.kernel.org, containers@lists.linux-foundation.org, cgroups@vger.kernel.org Subject: Re: [PATCH RFC - TAKE TWO - 00/12] New version of the BFQ I/O Scheduler Message-ID: <20140604083955.GA878@amd.pavel.ucw.cz> References: <20140528221929.GG1419@htj.dyndns.org> <1401354343-5527-1-git-send-email-paolo.valente@unimore.it> <20140530160712.GG24871@htj.dyndns.org> <464F6CBE-A63E-46EF-A90D-BF8450430444@unimore.it> <20140530232804.GA5057@htj.dyndns.org> <20140602111432.GA3737@amd.pavel.ucw.cz> <20140602130226.GA14654@amd.pavel.ucw.cz> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.5.20 (2009-06-14) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi! > > Like this: I applied patch over today's git... > > > > I only see last bits of panic... > > > > Call trace: > > __bfq_bfqq_expire > > bfq_bfqq_expire > > bfq_dispatch_requests > > sci_request_fn > > ... > > EIP: T.1839+0x26 > > Any ideas? > > > > We have tried to think about ways to trigger this failure, but in vain. Unfortunately, so far no user has reported any failure with this last version of bfq either. Finally, we have gone through a new static analysis, but also in this case uselessly. > > So, if you are willing to retry, we have put online a version of the code filled with many BUG_ONs. I hope they can make it easier to track down the bug. The archive is here: > http://algogroup.unimore.it/people/paolo/disk_sched/debugging-patches/3.15.0-rc8-v7rc5.tgz > BUG: Unable to handle kernel paging request ad dee22fa0 IP: bfq_del_bfqq_busy+0x4d ... Tainted: GW 3.15.0-rc8+ ... Call trace: __bfq_bfqq_expire bfq_bfqq_expire ? bfq_bfqq_expire ? bfq_bfqq_expire bfq_idle_slice_timer call_timer_fn ... > Should this attempt be useless as well, I will, if you do not mind, try by asking you more details about your system and reproducing your configuration as much as I can. > See the preivous email... Best regards, Pavel -- (english) http://www.livejournal.com/~pavelmachek (cesky, pictures) http://atrey.karlin.mff.cuni.cz/~pavel/picture/horses/blog.html From mboxrd@z Thu Jan 1 00:00:00 1970 From: Pavel Machek Subject: Re: [PATCH RFC - TAKE TWO - 00/12] New version of the BFQ I/O Scheduler Date: Wed, 4 Jun 2014 10:39:55 +0200 Message-ID: <20140604083955.GA878@amd.pavel.ucw.cz> References: <20140528221929.GG1419@htj.dyndns.org> <1401354343-5527-1-git-send-email-paolo.valente@unimore.it> <20140530160712.GG24871@htj.dyndns.org> <464F6CBE-A63E-46EF-A90D-BF8450430444@unimore.it> <20140530232804.GA5057@htj.dyndns.org> <20140602111432.GA3737@amd.pavel.ucw.cz> <20140602130226.GA14654@amd.pavel.ucw.cz> Mime-Version: 1.0 Return-path: Content-Disposition: inline In-Reply-To: Sender: cgroups-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org List-ID: Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: Paolo Valente Cc: Tejun Heo , Jens Axboe , Li Zefan , Fabio Checconi , Arianna Avanzini , linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, containers-cunTk1MwBs9QetFLy7KEm3xJsTq8ys+cHZ5vskTnxNA@public.gmane.org, cgroups-u79uwXL29TY76Z2rM5mHXA@public.gmane.org Hi! > > Like this: I applied patch over today's git... > > > > I only see last bits of panic... > > > > Call trace: > > __bfq_bfqq_expire > > bfq_bfqq_expire > > bfq_dispatch_requests > > sci_request_fn > > ... > > EIP: T.1839+0x26 > > Any ideas? > > > > We have tried to think about ways to trigger this failure, but in vain. Unfortunately, so far no user has reported any failure with this last version of bfq either. Finally, we have gone through a new static analysis, but also in this case uselessly. > > So, if you are willing to retry, we have put online a version of the code filled with many BUG_ONs. I hope they can make it easier to track down the bug. The archive is here: > http://algogroup.unimore.it/people/paolo/disk_sched/debugging-patches/3.15.0-rc8-v7rc5.tgz > BUG: Unable to handle kernel paging request ad dee22fa0 IP: bfq_del_bfqq_busy+0x4d ... Tainted: GW 3.15.0-rc8+ ... Call trace: __bfq_bfqq_expire bfq_bfqq_expire ? bfq_bfqq_expire ? bfq_bfqq_expire bfq_idle_slice_timer call_timer_fn ... > Should this attempt be useless as well, I will, if you do not mind, try by asking you more details about your system and reproducing your configuration as much as I can. > See the preivous email... Best regards, Pavel -- (english) http://www.livejournal.com/~pavelmachek (cesky, pictures) http://atrey.karlin.mff.cuni.cz/~pavel/picture/horses/blog.html