From mboxrd@z Thu Jan 1 00:00:00 1970 From: Shirley Ma Subject: Re: Network performance with small packets Date: Tue, 01 Feb 2011 22:19:09 -0800 Message-ID: <1296627549.26937.856.camel@localhost.localdomain> References: <20110128121616.GA8374@redhat.com> <1296523838.30191.39.camel@sridhar.beaverton.ibm.com> <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> Mime-Version: 1.0 Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: 7bit Cc: Sridhar Samudrala , Steve Dobbelstein , David Miller , kvm@vger.kernel.org, mashirle@linux.vnet.ibm.com, netdev@vger.kernel.org To: "Michael S. Tsirkin" Return-path: Received: from e36.co.us.ibm.com ([32.97.110.154]:35036 "EHLO e36.co.us.ibm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752425Ab1BBGTT (ORCPT ); Wed, 2 Feb 2011 01:19:19 -0500 In-Reply-To: <1296626748.26937.852.camel@localhost.localdomain> Sender: kvm-owner@vger.kernel.org List-ID: 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. However vhost signaling reduction is needed as well. The patch I submitted a while ago showed both CPUs and BW improvement. Thanks Shirley