From mboxrd@z Thu Jan 1 00:00:00 1970 From: Peter Lieven Subject: Re: [Qemu-devel] Re: irq problems after live migration with 0.12.4 Date: Wed, 26 May 2010 13:47:07 +0200 Message-ID: <4BFD0A3B.8010802@dlh.net> References: <4BF905B7.2040003@msgid.tls.msk.ru> <4BFBAE6D.4010507@dlh.net> <4BFC2494.7010305@msgid.tls.msk.ru> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Cc: qemu-devel@nongnu.org, kvm@vger.kernel.org To: Michael Tokarev Return-path: Received: from zion.dlh.net ([91.198.192.1]:33339 "EHLO mail.dlh.net" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1759220Ab0EZLrP (ORCPT ); Wed, 26 May 2010 07:47:15 -0400 In-Reply-To: <4BFC2494.7010305@msgid.tls.msk.ru> Sender: kvm-owner@vger.kernel.org List-ID: Michael Tokarev wrote: > 25.05.2010 15:03, Peter Lieven wrote: >> Michael Tokarev wrote: >>> 23.05.2010 13:55, Peter Lieven wrote: > [] >>>> [64442.298521] irq 10: nobody cared (try booting with the "irqpoll" >>>> option) > [] >>>> [64442.299433] handlers: >>>> [64442.299840] [] (e1000_intr+0x0/0x190 [e1000]) >>>> [64442.300046] Disabling IRQ #10 > > Apparently, for some reason, e1000_intr decided it's not > interesting IRQ or somehow wrong or not for that NIC. I > dunno. But something fishy is going on with IRQs here. > >>> See also LP bug #584131 (https://bugs.launchpad.net/bugs/584131) >>> and original Debian bug#580649 (http://bugs.debian.org/580649) > >>> Not sure if they're related... > > It looks they are actually the same thing, but happens with > different devices and/or IRQs. Either spurious, or unwanted, > or unrecognized or somesuch IRQ which is not recognized by > the irq handler, which results in disabling that IRQ by the > kernel, which is a bad thing (In your case it works because > e1000 works in 2 modes, interrupts and polling). > >> michael, do you have any ideas what i got do to debug whats happening? > > Unfortunately, no idea. I don't know neither kernel nor kvm > internals. I would be very greatful if someone with deeper knowledge would hook up. I'm also not familiar with internals, unfortunately. > >> looking at launchpad and debian bug tracker i found other bugs also >> with a maybe related problem. so this issue might be greater... > > Can you share your findings? I don't know other debian bugs which > are similar to this one. I suspect that other reports regarding crashed VMs after migration might be related. If I take my test VM with that I can trigger the bug and change the Network Adapter from e1000 to rtl8139 and leave everything else untouched the VM hangs at 100% CPU.. > > Thanks! > > /mjt > >