From mboxrd@z Thu Jan 1 00:00:00 1970 From: Konrad Rzeszutek Wilk Subject: Re: Sending packet at fixed rate really bad performance Date: Mon, 28 Sep 2009 12:44:28 -0400 Message-ID: <20090928164427.GA10292@phenom.dumpdata.com> References: <20090928141731.GA7107@phenom.dumpdata.com> Mime-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Content-Transfer-Encoding: quoted-printable Return-path: Content-Disposition: inline In-Reply-To: List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , Sender: xen-devel-bounces@lists.xensource.com Errors-To: xen-devel-bounces@lists.xensource.com To: Marco Tizzoni Cc: xen-devel@lists.xensource.com List-Id: xen-devel@lists.xenproject.org On Mon, Sep 28, 2009 at 06:28:04PM +0200, Marco Tizzoni wrote: > On Mon, Sep 28, 2009 at 4:17 PM, Konrad Rzeszutek Wilk > wrote: > > Lets narrow this down a bit. =A0You are comparing two different syste= ms > > with potentially different interfaces. Lets concentrate on one machin= e > > first. Is the performance on your Athlon 64 without Xen (meaning you > > boot without Xen) in the same ball-park figure? > > I want to make sure we can eliminate the hardware being at fault here= . >=20 > I've already done many tests to isolate the problem before writing here= . > I've tried to use a different nic, different LAN, different switch and > loopback as well, same results. The problem you described was with two guests. Were those two guests on two different machines or on the same box? > Anyway forget aboout Athlon and let compare the same software, on the > same hardware with linux and xenolinux. >=20 > I've connected two pc running linux via a cross-cable and made some > tests. The test achieves good results in this case for rate over 10k > packets/second. > On xenolinux (credit and sedf behaviour the same) the performance are > really bad, 250 packets/second (as before). > This is with two machines, each connected via cross-cable, running the sa= me version of Linux, and each running under Xen, correct? The tests executin= g under dom0 on both machines? =20 > Also I've just modified my software to not send packets, but simply > count, so no sendto() is involved. Same low rate. >=20 > May be there's something wrong in my code (not yet finished). Attached > you can find it if you want have a look or try to reproduce this > issue. >=20 > thx, > Marco > _______________________________________________ > Xen-devel mailing list > Xen-devel@lists.xensource.com > http://lists.xensource.com/xen-devel