From mboxrd@z Thu Jan 1 00:00:00 1970 From: Igor Mammedov Subject: Re: Re: [PATCH] blkfront: Move blkif_interrupt into a tasklet. Date: Wed, 24 Aug 2011 18:36:58 +0200 Message-ID: <4E5528AA.2090804@redhat.com> References: <1282546470-5547-1-git-send-email-daniel.stodden@citrix.com> <1282546470-5547-2-git-send-email-daniel.stodden@citrix.com> <4C802934.2000305@goop.org> <4C9B7B69.7080705@redhat.com> <4C9B7F1A.2040302@goop.org> <4C9B826B.10302@redhat.com> <4C9B9E1D.2040501@goop.org> <1313494014833-4704111.post@n5.nabble.com> <20110817023827.GA21468@dumpdata.com> <4E4B84C7.9000507@redhat.com> <20110824153605.GB8311@dumpdata.com> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <20110824153605.GB8311@dumpdata.com> List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , Sender: xen-devel-bounces@lists.xensource.com Errors-To: xen-devel-bounces@lists.xensource.com To: xen-devel@lists.xensource.com List-Id: xen-devel@lists.xenproject.org On 08/24/2011 05:36 PM, Konrad Rzeszutek Wilk wrote: > On Wed, Aug 17, 2011 at 11:07:19AM +0200, Igor Mammedov wrote: >> On 08/17/2011 04:38 AM, Konrad Rzeszutek Wilk wrote: >>> On Tue, Aug 16, 2011 at 04:26:55AM -0700, imammedo wrote: >>>> >>>> Jeremy Fitzhardinge wrote: >>>>> >>>>> Have you tried bisecting to see when this particular problem appeared? >>>>> It looks to me like something is accidentally re-enabling interrupts - >>>>> perhaps a stack overrun is corrupting the "flags" argument between a >>>>> spin_lock_irqsave()/restore pair. >>>>> >>>>> Is it only on 32-bit kernels? >>>>> >>>> ------------[ cut here ]------------ >>>> [604001.659925] WARNING: at block/blk-core.c:239 blk_start_queue+0x70/0x80() >>>> [604001.659964] Modules linked in: nfs lockd fscache auth_rpcgss nfs_acl >>>> sunrpc ip6t_REJECT nf_conntrack_ipv6 nf_conntrack_ipv4 nf_defrag_ipv4 >>>> nf_defrag_ipv6 xt_state nf_conntrack ip6table_filter ip6_tables xen_netfront >>>> pcspkr [last unloaded: scsi_wait_scan] >>>> [604001.660147] Pid: 336, comm: udevd Tainted: G W 3.0.0+ #50 >>>> [604001.660181] Call Trace: >>>> [604001.660209] [] warn_slowpath_common+0x72/0xa0 >>>> [604001.660243] [] ? blk_start_queue+0x70/0x80 >>>> [604001.660275] [] ? blk_start_queue+0x70/0x80 >>>> [604001.660310] [] warn_slowpath_null+0x22/0x30 >>>> [604001.660343] [] blk_start_queue+0x70/0x80 >>>> [604001.660379] [] kick_pending_request_queues+0x21/0x30 >>>> [604001.660417] [] blkif_interrupt+0x19f/0x2b0 >>>> ... >>>> ------------[ cut here ]------------ >>>> >>>> I've debugged a bit blk-core warning and can say: >>>> - Yes, It is 32-bit PAE kernel and happens only with it so far. >>>> - Affects PV xen guest, bare-metal and kvm configs are not affected. >>>> - Upstream kernel is affected as well. >>>> - Reproduces on xen 4.1.1 and 3.1.2 hosts >>> >>> And the dom0 is 2.6.18 right? This problem is not present >>> when you use a 3.0 dom0? >> >> For xen 4.1.1 testing, I've used as dom0 Jeremy's 2.6.32.43 > > Jeremy pointed me to this: > https://patchwork.kernel.org/patch/1091772/ > (and http://groups.google.com/group/linux.kernel/browse_thread/thread/39a397566cafc979) > which looks to have a similar backtrack. > > Perhaps Peter's fix solves the issue? I've applied patches: sched-separate-the-scheduler-entry-for-preemption.patch sched-move-blk_schedule_flush_plug-out-of-__schedule.patch block-shorten-interrupt-disabled-regions.patch Unfortunately these patches don't help, the problem is still there. >> >> -- >> Thanks, >> Igor >> >> _______________________________________________ >> Xen-devel mailing list >> Xen-devel@lists.xensource.com >> http://lists.xensource.com/xen-devel > > _______________________________________________ > Xen-devel mailing list > Xen-devel@lists.xensource.com > http://lists.xensource.com/xen-devel -- Thanks, Igor