From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:37666) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1YznXo-0008ET-8R for qemu-devel@nongnu.org; Tue, 02 Jun 2015 10:51:57 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1YznXi-0003sd-EO for qemu-devel@nongnu.org; Tue, 02 Jun 2015 10:51:56 -0400 Received: from mail-wi0-x22a.google.com ([2a00:1450:400c:c05::22a]:35552) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1YznXi-0003sW-91 for qemu-devel@nongnu.org; Tue, 02 Jun 2015 10:51:50 -0400 Received: by wikd7 with SMTP id d7so16136693wik.0 for ; Tue, 02 Jun 2015 07:51:49 -0700 (PDT) Sender: Paolo Bonzini Message-ID: <556DC302.5090409@redhat.com> Date: Tue, 02 Jun 2015 16:51:46 +0200 From: Paolo Bonzini MIME-Version: 1.0 References: <556DBF87.2020908@de.ibm.com> In-Reply-To: <556DBF87.2020908@de.ibm.com> Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 7bit Subject: Re: [Qemu-devel] "iothread: release iothread around aio_poll" causes random hangs at startup List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Christian Borntraeger Cc: Kevin Wolf , qemu-devel , Stefan Hajnoczi On 02/06/2015 16:36, Christian Borntraeger wrote: > commit a0710f7995f914e3044e5899bd8ff6c43c62f916 > Author: Paolo Bonzini > AuthorDate: Fri Feb 20 17:26:52 2015 +0100 > Commit: Kevin Wolf > CommitDate: Tue Apr 28 15:36:08 2015 +0200 > > iothread: release iothread around aio_poll > > to cause a problem with hanging guests. > > Having many guests all with a kernel/ramdisk (via -kernel) and > several null block devices will result in hangs. All hanging > guests are in partition detection code waiting for an I/O to return > so very early maybe even the first I/O. > > Reverting that commit "fixes" the hangs. > Any ideas? Stefan, please revert it as I will not have time to look at it until well into 2.4 soft freeze. Paolo