From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([208.118.235.92]:54545) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1Te3nV-0004lY-Aq for qemu-devel@nongnu.org; Thu, 29 Nov 2012 08:05:06 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1Te3nT-0001RA-Ve for qemu-devel@nongnu.org; Thu, 29 Nov 2012 08:04:57 -0500 Received: from mx1.redhat.com ([209.132.183.28]:19593) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1Te3nT-0001Qy-Nx for qemu-devel@nongnu.org; Thu, 29 Nov 2012 08:04:55 -0500 Date: Thu, 29 Nov 2012 18:34:46 +0530 From: Amit Shah Message-ID: <20121129130446.GA4429@amit.redhat.com> References: <20121022111824.GA6916@amit.redhat.com> <1350913800.90009.YahooMailClassic@web163904.mail.gq1.yahoo.com> <20121023125503.GG19977@stefanha-thinkpad.redhat.com> <20121101091918.GA19405@amit.redhat.com> <20121101120410.GC3993@redhat.com> <20121101160721.GA9176@redhat.com> <20121127162504.GA6210@redhat.com> <20121128215308.GA23360@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20121128215308.GA23360@redhat.com> Subject: Re: [Qemu-devel] [PATCH] virtio: limit avail bytes lookahead List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: "Michael S. Tsirkin" Cc: Stefan Hajnoczi , Bug 1066055 <1066055@bugs.launchpad.net>, qemu-devel@nongnu.org, Anthony Liguori , Edivaldo de Araujo Pereira On (Wed) 28 Nov 2012 [23:53:08], Michael S. Tsirkin wrote: > On Tue, Nov 27, 2012 at 06:25:04PM +0200, Michael S. Tsirkin wrote: > > On Thu, Nov 01, 2012 at 06:07:21PM +0200, Michael S. Tsirkin wrote: > > > Commit 0d8d7690850eb0cf2b2b60933cf47669a6b6f18f introduced > > > a regression in virtio-net performance because it looks > > > into the ring aggressively while we really only care > > > about a single packet worth of buffers. > > > To fix, add parameters limiting lookahead, and > > > use in virtqueue_avail_bytes. > > > > > > Signed-off-by: Michael S. Tsirkin > > > Reported-by: Edivaldo de Araujo Pereira > > > > Ping. > > Anthony - going to apply this? > > virtio rng was added since so naturally build broke. > Here's a patch on top to fix it up. I never used virtio rng before so > could not test at this hour, but it does fix the build. > > I'll take a look at how to test it tomorrow but any > info would be appreciated. > Amit could you pls review? Looks fine, I assume you will send a v2 of the patch to Anthony? Amit