From mboxrd@z Thu Jan 1 00:00:00 1970 From: David Vrabel Subject: Re: [PATCH 0/3 V2] xen-netback: switch to NAPI + kthread 1:1 model Date: Tue, 11 Jun 2013 11:06:43 +0100 Message-ID: <51B6F6B3.3020305@citrix.com> References: <1369654183-10536-1-git-send-email-wei.liu2@citrix.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <1369654183-10536-1-git-send-email-wei.liu2@citrix.com> List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , Sender: xen-devel-bounces@lists.xen.org Errors-To: xen-devel-bounces@lists.xen.org To: Wei Liu Cc: annie.li@oracle.com, konrad.wilk@oracle.com, Andrew Bennieston , ian.campbell@citrix.com, xen-devel@lists.xen.org List-Id: xen-devel@lists.xenproject.org On 27/05/13 12:29, Wei Liu wrote: > * This is a xen-devel only post, since we have not reached concesus on > what to add / remove in this new model. This series tries to be > conservative about adding in new feature compared to V1. > > This series implements NAPI + kthread 1:1 model for Xen netback. > > This model > - provides better scheduling fairness among vifs > - is prerequisite for implementing multiqueue for Xen network driver > > The first two patches are ground work for the third patch. First one > simplifies code in netback, second one can reduce memory footprint if we > switch to 1:1 model. > > The third patch has the real meat: > - make use of NAPI to mitigate interrupt > - kthreads are not bound to CPUs any more, so that we can take > advantage of backend scheduler and trust it to do the right thing > > Change since V1: > - No page pool in this version. Instead page tracking facility is > removed. Andrew Bennieston has done some performance measurements with (I think) the V1 series and it shows a significant decrease in performance of from-guest traffic even with only two VIFs. Andrew will be able to comment more on this. Andrew, can you also make available your results for others to review? David