From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mailman by lists.gnu.org with tmda-scanned (Exim 4.43) id 1MIi6z-0005BW-3t for qemu-devel@nongnu.org; Mon, 22 Jun 2009 07:54:57 -0400 Received: from exim by lists.gnu.org with spam-scanned (Exim 4.43) id 1MIi6u-000596-Hs for qemu-devel@nongnu.org; Mon, 22 Jun 2009 07:54:56 -0400 Received: from [199.232.76.173] (port=35055 helo=monty-python.gnu.org) by lists.gnu.org with esmtp (Exim 4.43) id 1MIi6u-00058y-BM for qemu-devel@nongnu.org; Mon, 22 Jun 2009 07:54:52 -0400 Received: from mx2.redhat.com ([66.187.237.31]:40896) by monty-python.gnu.org with esmtp (Exim 4.60) (envelope-from ) id 1MIi6t-00071g-PK for qemu-devel@nongnu.org; Mon, 22 Jun 2009 07:54:52 -0400 Message-ID: <4A3F7139.20401@redhat.com> Date: Mon, 22 Jun 2009 14:55:37 +0300 From: Avi Kivity MIME-Version: 1.0 Subject: Re: [Qemu-devel] [PATCH] block-raw: Make cache=off default again References: <1245669483-7076-1-git-send-email-kwolf@redhat.com> <20090622113524.GA13583@lst.de> <4A3F6EA3.2010303@redhat.com> In-Reply-To: <4A3F6EA3.2010303@redhat.com> Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit List-Id: qemu-devel.nongnu.org List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Kevin Wolf Cc: Christoph Hellwig , qemu-devel@nongnu.org On 06/22/2009 02:44 PM, Kevin Wolf wrote: > I haven't done real benchmarks for some time, but my simple test cases > like "run mke2fs on an empty image" have shown great improvement (at > least on IDE, for virtio I haven't understood yet what influences the > size of its requests - you should have received a private mail from Dor > about this). Possibly we could even enable cache=off for qcow2 now. > > IIUC, you have a nice setup to measure block performance now. Maybe > you'd like to let it run with qcow2 and cache=wb/none? > Were your refcount-combining patches merged? I don't see them, and performance will suck without them. -- error compiling committee.c: too many arguments to function