From mboxrd@z Thu Jan 1 00:00:00 1970 From: Glauber Costa Subject: Re: [PATCH v2 2/6] reuse env stop and stopped states Date: Mon, 27 Jul 2009 21:48:22 -0300 Message-ID: <20090728004822.GQ4776@poweredge.glommer> References: <1248214392-12533-1-git-send-email-glommer@redhat.com> <1248214392-12533-2-git-send-email-glommer@redhat.com> <1248214392-12533-3-git-send-email-glommer@redhat.com> <4A6DCB33.5020008@redhat.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: kvm@vger.kernel.org, Marcelo Tosatti To: Avi Kivity Return-path: Received: from mx2.redhat.com ([66.187.237.31]:34130 "EHLO mx2.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752492AbZG1AlY (ORCPT ); Mon, 27 Jul 2009 20:41:24 -0400 Received: from int-mx2.corp.redhat.com (int-mx2.corp.redhat.com [172.16.27.26]) by mx2.redhat.com (8.13.8/8.13.8) with ESMTP id n6S0fOBp019960 for ; Mon, 27 Jul 2009 20:41:24 -0400 Content-Disposition: inline In-Reply-To: <4A6DCB33.5020008@redhat.com> Sender: kvm-owner@vger.kernel.org List-ID: On Mon, Jul 27, 2009 at 06:43:47PM +0300, Avi Kivity wrote: > On 07/22/2009 01:13 AM, Glauber Costa wrote: >> qemu CPUState already provides "stop" and "stopped" states. And they >> mean exactly that. There is no need for us to provide our own. >> >> > > This patch (known as dd0e1c1a589 in qemu-kvm.git) breaks reboot. My > test case is FC6 i386 -smp 2, running the reboot command in rc.local. > In about 15 minutes qemu hangs hard. Please check what's gone wrong. I found out that doing kill -38 makes it run again, so we're likely hanging somewhere while holding qemu_mutex. The state of the process is "D", so we're holding qemu_mutex, and then calling something that can block. It's hard for me to believe that this patch introduced it. At best, it might have made it more likely. Also, I also verified that it sometimes takes a while until it happen for the first time. Are you sure this is the first patch that makes it happen?