From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mailman by lists.gnu.org with tmda-scanned (Exim 4.43) id 1G6Ymo-0007RY-U8 for qemu-devel@nongnu.org; Fri, 28 Jul 2006 16:18:18 -0400 Received: from exim by lists.gnu.org with spam-scanned (Exim 4.43) id 1G6Ymn-0007PN-9d for qemu-devel@nongnu.org; Fri, 28 Jul 2006 16:18:18 -0400 Received: from [199.232.76.173] (helo=monty-python.gnu.org) by lists.gnu.org with esmtp (Exim 4.43) id 1G6Ymn-0007PG-5x for qemu-devel@nongnu.org; Fri, 28 Jul 2006 16:18:17 -0400 Received: from [66.187.233.31] (helo=mx1.redhat.com) by monty-python.gnu.org with esmtp (Exim 4.52) id 1G6Yoq-0000Gh-RX for qemu-devel@nongnu.org; Fri, 28 Jul 2006 16:20:24 -0400 Received: from int-mx1.corp.redhat.com (int-mx1.corp.redhat.com [172.16.52.254]) by mx1.redhat.com (8.12.11.20060308/8.12.11) with ESMTP id k6SKIGCP021513 for ; Fri, 28 Jul 2006 16:18:16 -0400 Message-ID: <44CA7102.1020402@redhat.com> Date: Fri, 28 Jul 2006 16:18:10 -0400 From: Rik van Riel MIME-Version: 1.0 Subject: Re: [Qemu-devel] Re: [RFC][PATCH] make sure disk writes actually hit disk References: <44CA6B76.7000004@redhat.com> In-Reply-To: Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit Reply-To: qemu-devel@nongnu.org List-Id: qemu-devel.nongnu.org List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: qemu-devel@nongnu.org Cc: alan@redhat.com Anthony Liguori wrote: > Right now Fabrice is working on rewriting the block API to be > asynchronous. There's been quite a lot of discussion about why using > threads isn't a good idea for this Agreed, AIO is the way to go in the long run. > With a proper async API, is there any reason why we would want this to be > tunable? I don't think there's much of a benefit of prematurely claiming > a write is complete especially once the SCSI emulation can support > multiple simultaneous requests. You're right. This O_SYNC bandaid should probably stay in place to prevent data corruption, until the AIO framework is ready to be used. No sense investing too much time in a fancier band-aid. -- "Debugging is twice as hard as writing the code in the first place. Therefore, if you write the code as cleverly as possible, you are, by definition, not smart enough to debug it." - Brian W. Kernighan