From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:43807) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1WVH6Y-0006Kz-D3 for qemu-devel@nongnu.org; Wed, 02 Apr 2014 05:05:11 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1WVH6T-0004yt-IB for qemu-devel@nongnu.org; Wed, 02 Apr 2014 05:05:06 -0400 Received: from mx1.redhat.com ([209.132.183.28]:52802) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1WVH6T-0004wC-7U for qemu-devel@nongnu.org; Wed, 02 Apr 2014 05:05:01 -0400 Date: Wed, 2 Apr 2014 10:04:51 +0100 From: "Dr. David Alan Gilbert" Message-ID: <20140402090450.GA2586@work-vm> References: <20140327225242.GA5005@onthe.net.au> <5334B44E.4080300@beyond.pl> <20140327235918.GA7689@onthe.net.au> <533929D3.30109@beyond.pl> <20140402054144.GA31323@onthe.net.au> <533BCE40.8060908@beyond.pl> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <533BCE40.8060908@beyond.pl> Subject: Re: [Qemu-devel] Unresponsive linux guest once migrated List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Marcin Gibu??a Cc: qemu-devel@nongnu.org * Marcin Gibu??a (m.gibula@beyond.pl) wrote: > >It's looking good so far, after a few migrations (it takes a while to test > >because I'm waiting at least 5 hours between migrations). I'll be happier > >once I've done a couple of weeks of this without any failures! > > Does anyone have any hints how to debug this thing? :( > > I've tried to put hanged guest under gdb and found it's looped deep > inside kernel time management functions. Disabling kvmclock suggests > it is somehow related to its corruption during migration. It happens > on both old and new versions of guest kernels. > > Any hints from developers are welcome:) Can you give: 1) A backtrace from the guest thread apply all bt full in gdb 2) What's the earliest/newest qemu versions you've seen this on? 3) What guest OS are you running? 4) What host OS are you running? 5) What CPU are you running on? 6) What does your qemu command line look like? 7) How exactly are you migrating? 8) You talk about having to wait a few hours to trigger it - do you have a more exact description of a test? 9) Is there any output from qemu stderr/stdout in your qemu logs? Dave -- Dr. David Alan Gilbert / dgilbert@redhat.com / Manchester, UK