From mboxrd@z Thu Jan 1 00:00:00 1970 From: Ian Campbell Subject: Re: [Xen-devel] [PATCH 0/4] Implement persistent grant in xen-netfront/netback Date: Thu, 15 Nov 2012 11:15:06 +0000 Message-ID: <1352978106.3499.101.camel@zakaz.uk.xensource.com> References: <1352962987-541-1-git-send-email-annie.li@oracle.com> <20121115074057.GO8912@reaktio.net> <50A4AA06.8080900@oracle.com> <50A4CA51.8080208@citrix.com> Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: QUOTED-PRINTABLE Cc: ANNIE LI , Pasi =?ISO-8859-1?Q?K=E4rkk=E4inen?= , "netdev@vger.kernel.org" , "xen-devel@lists.xensource.com" , "konrad.wilk@oracle.com" To: Roger Pau Monne Return-path: Received: from smtp.ctxuk.citrix.com ([62.200.22.115]:29151 "EHLO SMTP.EU.CITRIX.COM" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1423250Ab2KOLP0 (ORCPT ); Thu, 15 Nov 2012 06:15:26 -0500 In-Reply-To: <50A4CA51.8080208@citrix.com> Sender: netdev-owner@vger.kernel.org List-ID: On Thu, 2012-11-15 at 10:56 +0000, Roger Pau Monne wrote: > On 15/11/12 09:38, ANNIE LI wrote: > >=20 > >=20 > > On 2012-11-15 15:40, Pasi K=C3=A4rkk=C3=A4inen wrote: > >> Hello, > >> > >> On Thu, Nov 15, 2012 at 03:03:07PM +0800, Annie Li wrote: > >>> This patch implements persistent grants for xen-netfront/netback.= This > >>> mechanism maintains page pools in netback/netfront, these page po= ols is used to > >>> save grant pages which are mapped. This way improve performance w= hich is wasted > >>> when doing grant operations. > >>> > >>> Current netback/netfront does map/unmap grant operations frequent= ly when > >>> transmitting/receiving packets, and grant operations costs much c= pu clock. In > >>> this patch, netfront/netback maps grant pages when needed and the= n saves them > >>> into a page pool for future use. All these pages will be unmapped= when > >>> removing/releasing the net device. > >>> > >> Do you have performance numbers available already? with/without pe= rsistent grants? > > I have some simple netperf/netserver test result with/without persi= stent=20 > > grants, > >=20 > > Following is result of with persistent grant patch, > >=20 > > Guests, Sum, Avg, Min, Max > > 1, 15106.4, 15106.4, 15106.36, 15106.36 > > 2, 13052.7, 6526.34, 6261.81, 6790.86 > > 3, 12675.1, 6337.53, 6220.24, 6454.83 > > 4, 13194, 6596.98, 6274.70, 6919.25 > >=20 > >=20 > > Following are result of without persistent patch > >=20 > > Guests, Sum, Avg, Min, Max > > 1, 10864.1, 10864.1, 10864.10, 10864.10 > > 2, 10898.5, 5449.24, 4862.08, 6036.40 > > 3, 10734.5, 5367.26, 5261.43, 5473.08 > > 4, 10924, 5461.99, 5314.84, 5609.14 >=20 > In the block case, performance improvement is seen when using a large > number of guests, could you perform the same benchmark increasing the > number of guests to 15? It would also be nice to see some analysis of the numbers which justify why this change is a good one without every reviewer having to evaluate the raw data themselves. In fact this should really be part of the commit message. Ian.