From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mailman by lists.gnu.org with tmda-scanned (Exim 4.43) id 1NUMJA-00048V-5Q for qemu-devel@nongnu.org; Mon, 11 Jan 2010 10:35:56 -0500 Received: from exim by lists.gnu.org with spam-scanned (Exim 4.43) id 1NUMJ5-00044T-Eo for qemu-devel@nongnu.org; Mon, 11 Jan 2010 10:35:55 -0500 Received: from [199.232.76.173] (port=59109 helo=monty-python.gnu.org) by lists.gnu.org with esmtp (Exim 4.43) id 1NUMJ5-00044P-7v for qemu-devel@nongnu.org; Mon, 11 Jan 2010 10:35:51 -0500 Received: from mx1.redhat.com ([209.132.183.28]:64564) by monty-python.gnu.org with esmtp (Exim 4.60) (envelope-from ) id 1NUMJ4-0000jj-F1 for qemu-devel@nongnu.org; Mon, 11 Jan 2010 10:35:50 -0500 Message-ID: <4B4B454E.10000@redhat.com> Date: Mon, 11 Jan 2010 17:35:42 +0200 From: Avi Kivity MIME-Version: 1.0 Subject: Re: [Qemu-devel] Re: [RFC][PATCH] performance improvement for windows guests, running on top of virtio block device References: <1263195647.2005.44.camel@localhost> <4B4AE1BD.4000400@redhat.com> <20100111134248.GA25622@lst.de> <4B4B2C5F.7050403@codemonkey.ws> <4B4B35AF.3010706@redhat.com> <4B4B3796.1010106@codemonkey.ws> <4B4B39D4.8060405@redhat.com> <4B4B4013.9030706@codemonkey.ws> <4B4B4199.9050603@redhat.com> <4B4B424B.2070300@codemonkey.ws> <4B4B445E.8070209@redhat.com> <4B4B449C.9090002@codemonkey.ws> In-Reply-To: <4B4B449C.9090002@codemonkey.ws> 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: Anthony Liguori Cc: Vadim Rozenfeld , Dor Laor , qemu-devel , Christoph Hellwig On 01/11/2010 05:32 PM, Anthony Liguori wrote: > On 01/11/2010 09:31 AM, Avi Kivity wrote: >> On 01/11/2010 05:22 PM, Anthony Liguori wrote: >>> >>> Based on our experiences with virtio-net, what I'd suggest is to >>> make a lot of tunable options (ring size, various tx mitigation >>> schemes, timeout durations, etc) and then we can do some deep >>> performance studies to see how things interact with each other. >>> >>> I think we should do that before making any changes because I'm >>> deeply concerned that we'll introduce significant performance >>> regressions. >>> >> >> I agree. We can start with this patch, with a tunable depth, >> defaulting to current behaviour. > > I wouldn't be opposed to that provided we made it clear that these > options were not supported long term. I don't want management tools > (like libvirt) to start relying on them. > x-option-name for experimental options? -device disk,if=virtio,x-queue-depth-suppress-notify=4 -- error compiling committee.c: too many arguments to function