From mboxrd@z Thu Jan 1 00:00:00 1970 From: Anthony Liguori Subject: Re: [PATCH 1/2] vhost: allow multiple workers threads Date: Mon, 05 Mar 2012 07:21:45 -0600 Message-ID: <4F54BDE9.5080505@codemonkey.ws> References: <1329519726-25763-1-git-send-email-aliguori@us.ibm.com> <1329519726-25763-2-git-send-email-aliguori@us.ibm.com> <20120219144145.GA16620@redhat.com> <20120220192708.GA18308@redhat.com> <4F42A2FB.7000501@us.ibm.com> <20120220210005.GA19278@redhat.com> <1329786250.13141.9.camel@localhost.localdomain> <20120221032147.GB2502@redhat.com> <1329796998.13141.26.camel@localhost.localdomain> Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit Cc: "Michael S. Tsirkin" , Anthony Liguori , Tom Lendacky , netdev@vger.kernel.org, Cristian Viana To: Shirley Ma Return-path: Received: from mail-pw0-f46.google.com ([209.85.160.46]:53452 "EHLO mail-pw0-f46.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932165Ab2CENVu (ORCPT ); Mon, 5 Mar 2012 08:21:50 -0500 Received: by pbcun15 with SMTP id un15so2777156pbc.19 for ; Mon, 05 Mar 2012 05:21:50 -0800 (PST) In-Reply-To: <1329796998.13141.26.camel@localhost.localdomain> Sender: netdev-owner@vger.kernel.org List-ID: On 02/20/2012 10:03 PM, Shirley Ma wrote: > On Tue, 2012-02-21 at 05:21 +0200, Michael S. Tsirkin wrote: >> On Mon, Feb 20, 2012 at 05:04:10PM -0800, Shirley Ma wrote: >>> On Mon, 2012-02-20 at 23:00 +0200, Michael S. Tsirkin wrote: >>>> >>>> The point was really to avoid scheduler overhead >>>> as with tcp, tx and rx tend to run on the same cpu. >>> >>> We have tried different approaches in the past, like splitting vhost >>> thread to separate TX, RX threads; create per cpu vhost thread >> instead >>> of creating per VM per virtio_net vhost thread... >>> >>> We think per cpu vhost thread is a better approach based on the data >> we >>> have collected. It will reduce both vhost resource and scheduler >>> overhead. It will not depend on host scheduler, has less various. >> The >>> patch is under testing, we hope we can post it soon. >>> >>> Thanks >>> Shirley >> >> Yes, great, this is definitely interesting. I actually started with >> a per-cpu one - it did not perform well but I did not >> figure out why, switching to a single thread fixed it >> and I did not dig into it. > > The patch includes per cpu vhost thread& vhost NUMA aware scheduling Hi Shirley, Are you planning on posting these patches soon? Regards, Anthony Liguori