From mboxrd@z Thu Jan 1 00:00:00 1970 From: =?ISO-8859-1?Q?Andr=E9_Weidemann?= Subject: Re: [Qemu-devel] Qemu-KVM 0.12.3 and Multipath -> Assertion Date: Sat, 08 May 2010 11:53:26 +0200 Message-ID: <4BE53496.5090503@web.de> References: <4BDF3F94.1080608@dlh.net> <4BDFDC44.9030808@redhat.com> <4BE00750.6040804@dlh.net> <4BE01120.30608@redhat.com> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: QUOTED-PRINTABLE Cc: Peter Lieven , kvm@vger.kernel.org, qemu-devel@nongnu.org, Christoph Hellwig To: Kevin Wolf Return-path: Received: from fmmailgate02.web.de ([217.72.192.227]:44295 "EHLO fmmailgate02.web.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752209Ab0EHJxw (ORCPT ); Sat, 8 May 2010 05:53:52 -0400 In-Reply-To: <4BE01120.30608@redhat.com> Sender: kvm-owner@vger.kernel.org List-ID: Hi Kevin, On 04.05.2010 14:20, Kevin Wolf wrote: > Am 04.05.2010 13:38, schrieb Peter Lieven: >> hi kevin, >> >> i set a breakpint at bmdma_active_if. the first 2 breaks encountered >> when the last path in the multipath >> failed, but the assertion was not true. >> when i kicked one path back in the breakpoint was reached again, thi= s >> time leading to an assert. >> the stacktrace is from the point shortly before. >> >> hope this helps. > > Hm, looks like there's something wrong with cancelling requests - > bdrv_aio_cancel might decide that it completes a request (and > consequently calls the callback for it) whereas the IDE emulation > decides that it's done with the request before calling bdrv_aio_cance= l. > > I haven't looked in much detail what this could break, but does > something like this help? Your attached patch fixes the problem I had as well. I ran 3 consecutiv= e=20 tests tonight, which all finished without crashing the VM. I reported my "assertion failed" error on March 14th while doing disk=20 perfomance tests using iozone in an Ubuntu 9.10 VM with qemu-kvm 0.12.3= =2E Thank you very much. Andr=E9 From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mailman by lists.gnu.org with tmda-scanned (Exim 4.43) id 1OAgjM-0006ny-S8 for qemu-devel@nongnu.org; Sat, 08 May 2010 05:53:56 -0400 Received: from [140.186.70.92] (port=48312 helo=eggs.gnu.org) by lists.gnu.org with esmtp (Exim 4.43) id 1OAgjL-0006nq-03 for qemu-devel@nongnu.org; Sat, 08 May 2010 05:53:56 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.69) (envelope-from ) id 1OAgjJ-0000Xt-BH for qemu-devel@nongnu.org; Sat, 08 May 2010 05:53:54 -0400 Received: from fmmailgate02.web.de ([217.72.192.227]:44294) by eggs.gnu.org with esmtp (Exim 4.69) (envelope-from ) id 1OAgjJ-0000Xm-53 for qemu-devel@nongnu.org; Sat, 08 May 2010 05:53:53 -0400 Message-ID: <4BE53496.5090503@web.de> Date: Sat, 08 May 2010 11:53:26 +0200 From: =?ISO-8859-1?Q?Andr=E9_Weidemann?= MIME-Version: 1.0 Subject: Re: [Qemu-devel] Qemu-KVM 0.12.3 and Multipath -> Assertion References: <4BDF3F94.1080608@dlh.net> <4BDFDC44.9030808@redhat.com> <4BE00750.6040804@dlh.net> <4BE01120.30608@redhat.com> In-Reply-To: <4BE01120.30608@redhat.com> Content-Type: text/plain; charset=ISO-8859-1; format=flowed Sender: Andre.Weidemann@web.de Content-Transfer-Encoding: quoted-printable List-Id: qemu-devel.nongnu.org List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Kevin Wolf Cc: Peter Lieven , qemu-devel@nongnu.org, kvm@vger.kernel.org, Christoph Hellwig Hi Kevin, On 04.05.2010 14:20, Kevin Wolf wrote: > Am 04.05.2010 13:38, schrieb Peter Lieven: >> hi kevin, >> >> i set a breakpint at bmdma_active_if. the first 2 breaks encountered >> when the last path in the multipath >> failed, but the assertion was not true. >> when i kicked one path back in the breakpoint was reached again, this >> time leading to an assert. >> the stacktrace is from the point shortly before. >> >> hope this helps. > > Hm, looks like there's something wrong with cancelling requests - > bdrv_aio_cancel might decide that it completes a request (and > consequently calls the callback for it) whereas the IDE emulation > decides that it's done with the request before calling bdrv_aio_cancel. > > I haven't looked in much detail what this could break, but does > something like this help? Your attached patch fixes the problem I had as well. I ran 3 consecutive=20 tests tonight, which all finished without crashing the VM. I reported my "assertion failed" error on March 14th while doing disk=20 perfomance tests using iozone in an Ubuntu 9.10 VM with qemu-kvm 0.12.3. Thank you very much. Andr=E9