From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mailman by lists.gnu.org with tmda-scanned (Exim 4.43) id 1JrJTy-0006rl-O7 for qemu-devel@nongnu.org; Wed, 30 Apr 2008 17:04:54 -0400 Received: from exim by lists.gnu.org with spam-scanned (Exim 4.43) id 1JrJTx-0006rQ-Eo for qemu-devel@nongnu.org; Wed, 30 Apr 2008 17:04:54 -0400 Received: from [199.232.76.173] (port=51686 helo=monty-python.gnu.org) by lists.gnu.org with esmtp (Exim 4.43) id 1JrJTx-0006rN-7Q for qemu-devel@nongnu.org; Wed, 30 Apr 2008 17:04:53 -0400 Received: from mo-p00-ob.rzone.de ([81.169.146.162]) by monty-python.gnu.org with esmtp (Exim 4.60) (envelope-from ) id 1JrJTg-0003Ho-Ja for qemu-devel@nongnu.org; Wed, 30 Apr 2008 17:04:53 -0400 From: Kevin Wolf Subject: Re: [Qemu-devel] [PATCH] Align file accesses with cache=off (O_DIRECT) Date: Wed, 30 Apr 2008 23:05:42 +0200 References: <4807514B.9040607@suse.de> <48186134.7070303@suse.de> In-Reply-To: MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 7bit Content-Disposition: inline Message-Id: <200804302305.42741@kevin-wolf.de> 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: Blue Swirl , Laurent Vivier Am Mittwoch, 30. April 2008 16:30:27 schrieb Blue Swirl: > Maybe the alignment could be handled like AIO and synchronous IO > emulation layers are added in bdrv_register, but at open stage? You mean to preserve the original pread if the file is opened without O_DIRECT and replace it by the emulation function only if O_DIRECT is really used? Certainly possible in some way (having a function pointer in BDRVRawState), but this won't save us anything. But maybe I'm just missing your point. How exactly do you want to handle things and what does it improve? Kevin