From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([208.118.235.92]:38426) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1TtaXT-0002pK-MU for qemu-devel@nongnu.org; Fri, 11 Jan 2013 04:04:37 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1TtaXR-0001iC-Ns for qemu-devel@nongnu.org; Fri, 11 Jan 2013 04:04:35 -0500 Received: from mail-pa0-f43.google.com ([209.85.220.43]:59550) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1TtaXR-0001hG-GM for qemu-devel@nongnu.org; Fri, 11 Jan 2013 04:04:33 -0500 Received: by mail-pa0-f43.google.com with SMTP id fb10so901217pad.2 for ; Fri, 11 Jan 2013 01:04:32 -0800 (PST) Message-ID: <50EFD597.90106@gmail.com> Date: Fri, 11 Jan 2013 17:04:23 +0800 From: Liu Yuan MIME-Version: 1.0 References: <871023743.4876151.1357894809949.JavaMail.root@redhat.com> In-Reply-To: <871023743.4876151.1357894809949.JavaMail.root@redhat.com> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit Subject: Re: [Qemu-devel] [PATCH] sheepdog: implement direct write semantics List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Paolo Bonzini Cc: Kevin Wolf , Stefan Hajnoczi , qemu-devel@nongnu.org, MORITA Kazutaka On 01/11/2013 05:00 PM, Paolo Bonzini wrote: > That's not correct. Try hdparm with an IDE disk, or sysfs with a SCSI > disk (recent kernels will also support sysfs with an IDE or virtio-blk > disk) and you'll see that it changes. Okay, at least at startup, even with cache=writehtough set, I saw bdrv_enable_write_cache() returns true from sd_open(). So you mean this will be reset later (after sd_open())? Thanks, Yuan