From mboxrd@z Thu Jan 1 00:00:00 1970 From: Avi Kivity Subject: Re: strange guest slowness after some time Date: Tue, 26 May 2009 15:10:07 +0300 Message-ID: <4A1BDC1F.5050708@redhat.com> References: <49B29705.6000904@wpkg.org> <49D30801.5020201@wpkg.org> <49DA1D75.6000604@wpkg.org> <200904081019.14768.rusty@rustcorp.com.au> <4A1BD765.4080405@wpkg.org> <4A1BD8A7.9090404@redhat.com> <4A1BDB10.2030603@wpkg.org> Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit Cc: Rusty Russell , "David S. Ahern" , Felix Leimbach , kvm@vger.kernel.org, Anthony Liguori To: Tomasz Chmielewski Return-path: Received: from mx2.redhat.com ([66.187.237.31]:45147 "EHLO mx2.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752731AbZEZMK1 (ORCPT ); Tue, 26 May 2009 08:10:27 -0400 In-Reply-To: <4A1BDB10.2030603@wpkg.org> Sender: kvm-owner@vger.kernel.org List-ID: Tomasz Chmielewski wrote: > Avi Kivity wrote: >> Tomasz Chmielewski wrote: >>> >>> I still observe this "slowness" with kvm-86 after the guest is >>> running for some time (virtio_net and virtio_console seem to be >>> affected; guest restart doesn't fix it). >>> >> >> Anything in guest dmesg? > > No. > No hints in syslog, dmesg... > > > Can it be that this is more likely to happens on "busy" hosts? > We'll only know once we fix it... > It happens for me on a host where I have 16 guests running. > > > Also, as I booted the host almost 2 days ago, 2 or 3 guests didn't > start properly (16 guests were starting at the same time), with their > kernel saying: > > Kernel panic - not syncing: IO-APIC + timer doesn't work! > > Can it be related? > > After I restarted these failed guests, they started properly. > This is timing related. On a busy host you can get timeouts and thus the panics. It's unrelated. Maybe virtio is racy and a loaded host exposes the race. -- error compiling committee.c: too many arguments to function