Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1764023AbZAUPAy (ORCPT ); Wed, 21 Jan 2009 10:00:54 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1754745AbZAUPAG (ORCPT ); Wed, 21 Jan 2009 10:00:06 -0500 Received: from mx2.redhat.com ([66.187.237.31]:57368 "EHLO mx2.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1763312AbZAUPAC (ORCPT ); Wed, 21 Jan 2009 10:00:02 -0500 Message-ID: <49773848.4080409@redhat.com> Date: Wed, 21 Jan 2009 16:59:20 +0200 From: Avi Kivity User-Agent: Thunderbird 2.0.0.19 (X11/20090105) MIME-Version: 1.0 To: Kevin Shanahan CC: Steven Rostedt , Ingo Molnar , "Rafael J. Wysocki" , Linux Kernel Mailing List , Kernel Testers List , Mike Galbraith , Peter Zijlstra , =?ISO-8859-1?Q?Fr=E9d=E9ric_Weisbecker?= , bugme-daemon@bugzilla.kernel.org Subject: Re: [Bug #12465] KVM guests stalling on 2.6.28 (bisected) References: <1232410363.4768.21.camel@kulgan.wumi.org.au> <20090120113546.GA26571@elte.hu> <1232455343.4895.4.camel@kulgan.wumi.org.au> <20090120125652.GA1457@elte.hu> <20090120130714.GA11048@elte.hu> <49760E2D.2060109@redhat.com> <1232547932.4895.119.camel@kulgan.wumi.org.au> <49773275.3020203@redhat.com> <1232549502.4895.124.camel@kulgan.wumi.org.au> In-Reply-To: <1232549502.4895.124.camel@kulgan.wumi.org.au> Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1248 Lines: 35 Kevin Shanahan wrote: >>> --- hermes-old.wumi.org.au ping statistics --- >>> 900 packets transmitted, 900 received, 0% packet loss, time 899326ms >>> rtt min/avg/max/mdev = 0.093/0.157/3.611/0.117 ms >>> >>> So, a _huge_ difference. But what does it mean? >>> >> It means, a scheduling problem. Can you run the latency tracer (which >> only works with realtime priority), so we can tell if it is (a) kvm >> failing to wake up the vcpu properly or (b) the scheduler delaying the >> vcpu from running. >> > > Sorry, but are you sure that's going to be useful? > > If it only works on realtime threads and I'm not seeing the problem when > running kvm with realtime priority, is this going to tell you what you > want to know? > > Not trying to be difficult, but that just didn't make sense to me. > You're right, wasn't thinking properly. This is a tough one. I'll see if I can think of something. Ingo, any ideas? -- error compiling committee.c: too many arguments to function -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/