From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mailman by lists.gnu.org with tmda-scanned (Exim 4.43) id 1MIhoD-0001rA-Sa for qemu-devel@nongnu.org; Mon, 22 Jun 2009 07:35:33 -0400 Received: from exim by lists.gnu.org with spam-scanned (Exim 4.43) id 1MIho9-0001pt-C5 for qemu-devel@nongnu.org; Mon, 22 Jun 2009 07:35:33 -0400 Received: from [199.232.76.173] (port=53457 helo=monty-python.gnu.org) by lists.gnu.org with esmtp (Exim 4.43) id 1MIho8-0001pq-Jq for qemu-devel@nongnu.org; Mon, 22 Jun 2009 07:35:28 -0400 Received: from verein.lst.de ([213.95.11.210]:56708) by monty-python.gnu.org with esmtps (TLS-1.0:DHE_RSA_3DES_EDE_CBC_SHA1:24) (Exim 4.60) (envelope-from ) id 1MIho8-0007Lm-4R for qemu-devel@nongnu.org; Mon, 22 Jun 2009 07:35:28 -0400 Date: Mon, 22 Jun 2009 13:35:24 +0200 From: Christoph Hellwig Subject: Re: [Qemu-devel] [PATCH] block-raw: Make cache=off default again Message-ID: <20090622113524.GA13583@lst.de> References: <1245669483-7076-1-git-send-email-kwolf@redhat.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1245669483-7076-1-git-send-email-kwolf@redhat.com> List-Id: qemu-devel.nongnu.org List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Kevin Wolf Cc: qemu-devel@nongnu.org On Mon, Jun 22, 2009 at 01:18:03PM +0200, Kevin Wolf wrote: > Since the patch that suggested it woudl revert qcow2 to writeback caching, in > fact none of the drivers has had cache=off as default any more. This patch > restores the desired behaviour. Looks good to me. I still quite hate that BDRV_O_CACHE_DEF thing, just makes it too complicated for drivers to get it right. Btw, what is the performance for qcow2 without write-back caching with all your improvements?