Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755053AbZLWPEJ (ORCPT ); Wed, 23 Dec 2009 10:04:09 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1752888AbZLWPEI (ORCPT ); Wed, 23 Dec 2009 10:04:08 -0500 Received: from mail-yw0-f182.google.com ([209.85.211.182]:41543 "EHLO mail-yw0-f182.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752807AbZLWPED (ORCPT ); Wed, 23 Dec 2009 10:04:03 -0500 Message-ID: <4B32315C.1000006@codemonkey.ws> Date: Wed, 23 Dec 2009 09:03:56 -0600 From: Anthony Liguori User-Agent: Mozilla/5.0 (X11; U; Linux x86_64; en-US; rv:1.9.1.5) Gecko/20091209 Fedora/3.0-4.fc12 Thunderbird/3.0 MIME-Version: 1.0 To: Andi Kleen CC: Avi Kivity , Ingo Molnar , Bartlomiej Zolnierkiewicz , Gregory Haskins , kvm@vger.kernel.org, Andrew Morton , torvalds@linux-foundation.org, "linux-kernel@vger.kernel.org" , netdev@vger.kernel.org, "alacrityvm-devel@lists.sourceforge.net" Subject: Re: [GIT PULL] AlacrityVM guest drivers for 2.6.33 References: <4B1D4F29.8020309@gmail.com> <87637zdy9g.fsf@basil.nowhere.org> <4B30E654.40702@codemonkey.ws> <200912221701.56840.bzolnier@gmail.com> <4B30F214.80206@codemonkey.ws> <20091223065129.GA19600@elte.hu> <20091223101340.GC20539@basil.fritz.box> <4B31EF65.6070000@redhat.com> <20091223121431.GF20539@basil.fritz.box> In-Reply-To: <20091223121431.GF20539@basil.fritz.box> Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1265 Lines: 32 On 12/23/2009 06:14 AM, Andi Kleen wrote: >> http://www.redhat.com/f/pdf/summit/cwright_11_open_source_virt.pdf >> >> See slide 32. This is without vhost-net. > > Thanks. Do you also have latency numbers? They'll be along the lines of the vbus numbers. But I caution people from relying too much on just netperf TCP_RR and TCP_STREAM numbers. There's a lot of heuristics in play in getting this sort of numbers. They really aren't good ways to compare different drivers. A better thing to do is look more deeply at the architectures and consider things like the amount of copying imposed, the cost of processing an exit, and the mechanisms for batching packet transmissions. The real argument that vbus needs to make IMHO is not "look how much better my netperf TCP_STREAM results are" but "we can eliminate N copies from the transmit path and virtio-net cannot" or "we require N exits to handle a submission and virtio-net requires N+M". It's too easy to tweak for benchmarks. Regards, Anthony Liguori -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/