From mboxrd@z Thu Jan 1 00:00:00 1970 From: Anthony Liguori Subject: Re: [PATCH 0/9][RFC] KVM virtio_net performance Date: Thu, 24 Jul 2008 13:29:25 -0500 Message-ID: <4888CA05.4010909@codemonkey.ws> References: <1216899979-32532-1-git-send-email-markmc@redhat.com> <1216918431.19183.10.camel@muff> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Cc: kvm@vger.kernel.org, Herbert Xu , Rusty Russell To: Mark McLoughlin Return-path: Received: from py-out-1112.google.com ([64.233.166.180]:10216 "EHLO py-out-1112.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752035AbYGXS35 (ORCPT ); Thu, 24 Jul 2008 14:29:57 -0400 Received: by py-out-1112.google.com with SMTP id p76so2208757pyb.10 for ; Thu, 24 Jul 2008 11:29:56 -0700 (PDT) In-Reply-To: <1216918431.19183.10.camel@muff> Sender: kvm-owner@vger.kernel.org List-ID: Mark McLoughlin wrote: > Hey, > One all all-important thing I forgot to include was a comparison with > lguest :-) > Hey Mark, This patch set is really great! I guess the hard part now is deciding what all we want to apply. Do you have a suggestion of which patches you think are worth applying? BTW, do you have native and guest loopback numbers to compare where we stand with native? > netperf, 10x20s runs (Gb/s) | guest->host | host->guest > -----------------------------+----------------------------+--------------------------- > KVM | 4.230/ 4.619/ 4.780/ 0.155 | 8.140/ 8.578/ 8.770/ 0.162 > lguest | 5.700/ 5.926/ 6.150/ 0.132 | 8.680/ 9.073/ 9.320/ 0.205 > > ping -f -c 100000 (ms) | guest->host | host->guest > -----------------------------+----------------------------+--------------------------- > KVM | 0.199/ 0.326/ 7.698/ 0.744 | 0.199/ 0.245/ 0.402/ 0.022 > lguest | 0.022/ 0.055/ 0.467/ 0.019 | 0.019/ 0.046/89.249/ 0.448 > > > So, puppies gets you an extra 1.3Gb/s guest->host, .5Gb/s host->guest > and much better latency. > I'm surprised lguest gets an extra 1.3gb guest->host. Any idea of where we're loosing it? > Actually, I guess the main reason for the latency difference is that > when lguest gets notified on the tx ring, it immediately sends whatever > is available and then starts a timer. KVM doesn't send anything until > it's tx timer fires or the ring is full. > Yes, we should definitely do that. It will make ping appear to be a lot faster than it really is :-) Regards, Anthony Liguori > Cheers, > Mark. > > -- > To unsubscribe from this list: send the line "unsubscribe kvm" in > the body of a message to majordomo@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html >