From mboxrd@z Thu Jan 1 00:00:00 1970 From: Avi Kivity Subject: Re: [PATCH 0/12] virtio_net perf patches Date: Tue, 12 Aug 2008 16:51:56 +0300 Message-ID: <48A1957C.4070007@qumranet.com> References: <1218485535-877-1-git-send-email-markmc@redhat.com> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Cc: kvm@vger.kernel.org To: Mark McLoughlin Return-path: Received: from il.qumranet.com ([212.179.150.194]:24865 "EHLO il.qumranet.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752154AbYHLNv5 (ORCPT ); Tue, 12 Aug 2008 09:51:57 -0400 In-Reply-To: <1218485535-877-1-git-send-email-markmc@redhat.com> Sender: kvm-owner@vger.kernel.org List-ID: Mark McLoughlin wrote: > Hi Avi, > Here's the set of patches that I think make sense to apply. > > I've left out Anthony's zero-copy patch since I wasn't seeing > a measurable difference with it, it's quite invasive and isn't safe > with the "drop the global mutex during tapfd read()" patch. > > I left that mutex patch 'til last since you may still be > nervous about concurrency issues and also the posix-timers kernel race > that it triggers. > I'm nervous, but let's see what happens. Worst case we make it conditional. > Another change since the first round of patches is that it > took a bit of ugly hackery to handle the case where IFF_VNET_HDR > is supported and we're using e.g. e1000. Since it's difficult to > only enable IFF_VNET_HDR when we're using virtio_net_hdr, I went with > this approach. > > Thanks, applied all... > Lastly, I need to add a "vnet_hdr=on" param to "-net tap" so > that we can know if the supplied tap fd has IFF_VNET_HDR enabled. > There's no interface to query that on the fd right now, and even if > I did cook up a patch it probably wouldn't make 2.6.27. > except for this, as I agree with Anthony. I think it can make it into 2.6.27, but if it doesn't, libvirt should simply not enable vnet_hdr unless it is sure qemu can query for the feature. -- error compiling committee.c: too many arguments to function