From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([140.186.70.92]:41640) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1RJkxG-0006KA-Cg for qemu-devel@nongnu.org; Fri, 28 Oct 2011 07:50:35 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1RJkxF-0006py-9x for qemu-devel@nongnu.org; Fri, 28 Oct 2011 07:50:34 -0400 Received: from mx1.redhat.com ([209.132.183.28]:46250) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1RJkxF-0006pQ-1M for qemu-devel@nongnu.org; Fri, 28 Oct 2011 07:50:33 -0400 Message-ID: <4EAA9700.6030605@redhat.com> Date: Fri, 28 Oct 2011 13:50:24 +0200 From: Paolo Bonzini MIME-Version: 1.0 References: <1316443033-6489-1-git-send-email-freddy77@gmail.com> <4EA95BFF.6070807@redhat.com> <20111027135731.GA21052@stefanha-thinkpad.localdomain> <4EA96776.6020807@redhat.com> <4EA96B82.6070507@redhat.com> <4EAA9310.2030705@redhat.com> In-Reply-To: <4EAA9310.2030705@redhat.com> Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Subject: Re: [Qemu-devel] [PATCH v2] block: avoid SIGUSR2 List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Kevin Wolf Cc: Lucas Meneghel Rodrigues , aliguori@us.ibm.com, Stefan Hajnoczi , qemu-devel@nongnu.org, Frediano Ziglio , Cleber Rosa On 10/28/2011 01:33 PM, Kevin Wolf wrote: > I'm afraid that we can only avoid things like this reliably if we > convert all devices to be direct users of AIO/coroutines. The current > block layer infrastructure doesn't emulate the behaviour of bdrv_read > accurately as bottom halves can be run in the nested main loop. > > For floppy, the following seems to be a quick fix (Lucas, Cleber, does > this solve your problems?), though it's not very satisfying. And I'm not > quite sure yet why it doesn't always happen with kill() in > posix-aio-compat.c. Another "fix" is to change idle bottom halves (at least the one in hw/dma.c) to 10ms timers. Paolo