From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mailman by lists.gnu.org with tmda-scanned (Exim 4.43) id 1NUMLi-0006BJ-1Q for qemu-devel@nongnu.org; Mon, 11 Jan 2010 10:38:34 -0500 Received: from exim by lists.gnu.org with spam-scanned (Exim 4.43) id 1NUMLd-00065x-2B for qemu-devel@nongnu.org; Mon, 11 Jan 2010 10:38:33 -0500 Received: from [199.232.76.173] (port=52712 helo=monty-python.gnu.org) by lists.gnu.org with esmtp (Exim 4.43) id 1NUMLc-00065V-OZ for qemu-devel@nongnu.org; Mon, 11 Jan 2010 10:38:28 -0500 Received: from mx20.gnu.org ([199.232.41.8]:11432) by monty-python.gnu.org with esmtps (TLS-1.0:RSA_AES_256_CBC_SHA1:32) (Exim 4.60) (envelope-from ) id 1NUMLc-0001q0-CS for qemu-devel@nongnu.org; Mon, 11 Jan 2010 10:38:28 -0500 Received: from mail-gx0-f223.google.com ([209.85.217.223]) by mx20.gnu.org with esmtp (Exim 4.60) (envelope-from ) id 1NUMLb-0001GN-Lo for qemu-devel@nongnu.org; Mon, 11 Jan 2010 10:38:27 -0500 Received: by gxk23 with SMTP id 23so24798174gxk.2 for ; Mon, 11 Jan 2010 07:38:26 -0800 (PST) Message-ID: <4B4B45F0.1060606@codemonkey.ws> Date: Mon, 11 Jan 2010 09:38:24 -0600 From: Anthony Liguori 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> <4B4B454E.10000@redhat.com> In-Reply-To: <4B4B454E.10000@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: Avi Kivity Cc: Vadim Rozenfeld , Dor Laor , qemu-devel , Christoph Hellwig On 01/11/2010 09:35 AM, Avi Kivity wrote: > 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 Sounds reasonable to me. Regards, Anthony Liguori