From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mailman by lists.gnu.org with tmda-scanned (Exim 4.43) id 1N0Jta-0004jg-VM for qemu-devel@nongnu.org; Tue, 20 Oct 2009 14:57:23 -0400 Received: from exim by lists.gnu.org with spam-scanned (Exim 4.43) id 1N0JtW-0004f2-83 for qemu-devel@nongnu.org; Tue, 20 Oct 2009 14:57:22 -0400 Received: from [199.232.76.173] (port=36014 helo=monty-python.gnu.org) by lists.gnu.org with esmtp (Exim 4.43) id 1N0JtV-0004eP-N0 for qemu-devel@nongnu.org; Tue, 20 Oct 2009 14:57:17 -0400 Received: from mx1.redhat.com ([209.132.183.28]:2751) by monty-python.gnu.org with esmtp (Exim 4.60) (envelope-from ) id 1N0JtU-00061j-N4 for qemu-devel@nongnu.org; Tue, 20 Oct 2009 14:57:16 -0400 Received: from int-mx04.intmail.prod.int.phx2.redhat.com (int-mx04.intmail.prod.int.phx2.redhat.com [10.5.11.17]) by mx1.redhat.com (8.13.8/8.13.8) with ESMTP id n9KIvF2N005295 for ; Tue, 20 Oct 2009 14:57:15 -0400 Message-ID: <4ADE0809.2050500@redhat.com> Date: Tue, 20 Oct 2009 20:57:13 +0200 From: Paolo Bonzini MIME-Version: 1.0 References: <20091008203740.GA20727@redhat.com> <1256063981.27918.6.camel@blaa> In-Reply-To: <1256063981.27918.6.camel@blaa> Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Subject: [Qemu-devel] Re: [PATCH] qemu: work around for "posix-aio-compat" List-Id: qemu-devel.nongnu.org List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Mark McLoughlin Cc: qemu-devel@nongnu.org, "Michael S. Tsirkin" On 10/20/2009 08:39 PM, Mark McLoughlin wrote: > On Thu, 2009-10-08 at 22:37 +0200, Michael S. Tsirkin wrote: >> With commit ee3993069ff55fa6f1c64daf1e09963e340db8e4, >> "posix-aio-compat: avoid signal race when spawning a thread" >> winxp installation on a raw format file fails >> during disk format, with a message "your >> disk may be damaged". >> >> This commit moved signal mask from aio thread to creating thread. >> It turns out if we keep the mask in aio thread as well, the problem >> disappears. It should not be needed, but since this is harmless, let's >> keep it around until someone inclined to debug pthread library internals >> can check this issue. >> >> While we are at it, convert sigprocmask to pthread_sigmask >> as per posix. > > FWIW, I just started hitting a boot hang with qemu.git and --enable-kvm > on a Fedora 11 machine with a Fedora 11 guest. > > I bisected it back to malc's commit, found this thread, applied > Michael's patch and confirmed that it fixes the problem for me too. If anybody can send me the output of compiling the "strange" file with and without the patch, both with "-fdump-tree-all -fdump-rtl-all -O2 --save-temps -g" flags, I could try debugging it in GCC. It will be huge, so bz/gz/lzip it. Paolo