Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932372AbZIVQaG (ORCPT ); Tue, 22 Sep 2009 12:30:06 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S932358AbZIVQaF (ORCPT ); Tue, 22 Sep 2009 12:30:05 -0400 Received: from mail.vyatta.com ([76.74.103.46]:34415 "EHLO mail.vyatta.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932357AbZIVQaD (ORCPT ); Tue, 22 Sep 2009 12:30:03 -0400 Date: Tue, 22 Sep 2009 09:29:57 -0700 From: Stephen Hemminger To: Arnd Bergmann Cc: "Michael S. Tsirkin" , Chris Wright , Rusty Russell , virtualization@lists.linux-foundation.org, "Xin, Xiaohui" , "kvm@vger.kernel.org" , "netdev@vger.kernel.org" , "linux-kernel@vger.kernel.org" , "linux-mm@kvack.org" , "hpa@zytor.com" , "mingo@elte.hu" , "akpm@linux-foundation.org" Subject: Re: [RFC] Virtual Machine Device Queues(VMDq) support on KVM Message-ID: <20090922092957.17e68cbc@s6510> In-Reply-To: <200909221350.54847.arnd@arndb.de> References: <20090921162718.GM26034@sequoia.sous-sol.org> <20090922103807.GA2555@redhat.com> <200909221350.54847.arnd@arndb.de> Organization: Vyatta X-Mailer: Claws Mail 3.6.1 (GTK+ 2.16.1; i486-pc-linux-gnu) Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1234 Lines: 31 On Tue, 22 Sep 2009 13:50:54 +0200 Arnd Bergmann wrote: > On Tuesday 22 September 2009, Michael S. Tsirkin wrote: > > > > More importantly, when virtualizations is used with multi-queue > > > > NIC's the virtio-net NIC is a single CPU bottleneck. The virtio-net > > > > NIC should preserve the parallelism (lock free) using multiple > > > > receive/transmit queues. The number of queues should equal the > > > > number of CPUs. > > > > > > Yup, multiqueue virtio is on todo list ;-) > > > > > > > Note we'll need multiqueue tap for that to help. > > My idea for that was to open multiple file descriptors to the same > macvtap device and let the kernel figure out the right thing to > do with that. You can do the same with raw packed sockets in case > of vhost_net, but I wouldn't want to add more complexity to the > tun/tap driver for this. > > Arnd <>< Or get tap out of the way entirely. The packets should not have to go out to user space at all (see veth) -- 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/