From mboxrd@z Thu Jan 1 00:00:00 1970 From: Paolo Bonzini Subject: Re: Live migration locks up 3.2 guests in do_timer(ticks ~ 500000) Date: Mon, 08 Sep 2014 10:18:06 +0200 Message-ID: <540D663E.2070905@redhat.com> References: <20140908055416.GE23305@hydra.tuxags.com> Mime-Version: 1.0 Content-Type: text/plain; charset=windows-1252 Content-Transfer-Encoding: 7bit To: kvm@vger.kernel.org Return-path: Received: from mail-we0-f169.google.com ([74.125.82.169]:61170 "EHLO mail-we0-f169.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752980AbaIHISL (ORCPT ); Mon, 8 Sep 2014 04:18:11 -0400 Received: by mail-we0-f169.google.com with SMTP id w61so291082wes.28 for ; Mon, 08 Sep 2014 01:18:10 -0700 (PDT) Received: from yakj.usersys.redhat.com (net-2-35-196-143.cust.vodafonedsl.it. [2.35.196.143]) by mx.google.com with ESMTPSA id ju1sm10254802wjc.1.2014.09.08.01.18.08 for (version=TLSv1.2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Mon, 08 Sep 2014 01:18:09 -0700 (PDT) In-Reply-To: <20140908055416.GE23305@hydra.tuxags.com> Sender: kvm-owner@vger.kernel.org List-ID: Il 08/09/2014 07:54, Matt Mullins ha scritto: > It also seems to happen reliably when the guest has been running for a while; > it's easily reproducible with guests that have been up ~1 day, and I've > reproduced it in VMs with an uptime of ~20 hours. I haven't yet figured out a > lower-bound, which makes the testing cycle a little longer for me. > > The guests that I reliably reproduce this on are Ubuntu 12.04 guests running > the current 3.2 kernel that Canonical distributes. Recent Fedora kernels > (3.14+, IIRC) don't seem to busy-spin this way, though I haven't tested this > case exhaustively, and I haven't written down very good notes for the tests I > have done with Fedora. What host are you running? Paolo