From mboxrd@z Thu Jan 1 00:00:00 1970 From: "Michael S. Tsirkin" Subject: Re: Network performance with small packets Date: Wed, 2 Feb 2011 08:29:50 +0200 Message-ID: <20110202062950.GD3818@redhat.com> References: <1296594585.26937.817.camel@localhost.localdomain> <20110201212411.GD30770@redhat.com> <1296595955.26937.822.camel@localhost.localdomain> <20110201214211.GB31105@redhat.com> <1296597185.26937.829.camel@localhost.localdomain> <20110201215603.GA31348@redhat.com> <1296601197.26937.833.camel@localhost.localdomain> <20110202044002.GB3818@redhat.com> <1296626748.26937.852.camel@localhost.localdomain> <1296627549.26937.856.camel@localhost.localdomain> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: Sridhar Samudrala , Steve Dobbelstein , David Miller , kvm@vger.kernel.org, mashirle@linux.vnet.ibm.com, netdev@vger.kernel.org To: Shirley Ma Return-path: Received: from mx1.redhat.com ([209.132.183.28]:24654 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752425Ab1BBGaH (ORCPT ); Wed, 2 Feb 2011 01:30:07 -0500 Content-Disposition: inline In-Reply-To: <1296627549.26937.856.camel@localhost.localdomain> Sender: netdev-owner@vger.kernel.org List-ID: On Tue, Feb 01, 2011 at 10:19:09PM -0800, Shirley Ma wrote: > On Tue, 2011-02-01 at 22:05 -0800, Shirley Ma wrote: > > > > The way I am changing is only when netif queue has stopped, then we > > start to count num_free descriptors to send the signal to wake netif > > queue. > > I forgot to mention, the code change I am making is in guest kernel, in > xmit call back only wake up the queue when it's stopped && num_free >= > 1/2 *vq->num, I add a new API in virtio_ring. Interesting. Yes, I agree an API extension would be helpful. However, wouldn't just the signaling reduction be enough, without guest changes? > However vhost signaling reduction is needed as well. The patch I > submitted a while ago showed both CPUs and BW improvement. > > Thanks > Shirley Which patch was that? -- MST