From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S933511Ab2GFDSL (ORCPT ); Thu, 5 Jul 2012 23:18:11 -0400 Received: from mx1.redhat.com ([209.132.183.28]:23560 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932465Ab2GFDSJ (ORCPT ); Thu, 5 Jul 2012 23:18:09 -0400 Message-ID: <4FF65966.9040600@redhat.com> Date: Fri, 06 Jul 2012 11:20:06 +0800 From: Jason Wang User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:10.0.1) Gecko/20120210 Thunderbird/10.0.1 MIME-Version: 1.0 To: Sasha Levin CC: mst@redhat.com, mashirle@us.ibm.com, krkumar2@in.ibm.com, habanero@linux.vnet.ibm.com, rusty@rustcorp.com.au, netdev@vger.kernel.org, linux-kernel@vger.kernel.org, virtualization@lists.linux-foundation.org, edumazet@google.com, tahm@linux.vnet.ibm.com, jwhan@filewood.snu.ac.kr, davem@davemloft.net, akong@redhat.com, kvm@vger.kernel.org, sri@us.ibm.com Subject: Re: [net-next RFC V5 5/5] virtio_net: support negotiating the number of queues through ctrl vq References: <1341484194-8108-1-git-send-email-jasowang@redhat.com> <1341484194-8108-6-git-send-email-jasowang@redhat.com> <1341492679.18786.18.camel@lappy> In-Reply-To: <1341492679.18786.18.camel@lappy> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 07/05/2012 08:51 PM, Sasha Levin wrote: > On Thu, 2012-07-05 at 18:29 +0800, Jason Wang wrote: >> @@ -1387,6 +1404,10 @@ static int virtnet_probe(struct virtio_device *vdev) >> if (virtio_has_feature(vdev, VIRTIO_NET_F_CTRL_VQ)) >> vi->has_cvq = true; >> >> + /* Use single tx/rx queue pair as default */ >> + vi->num_queue_pairs = 1; >> + vi->total_queue_pairs = num_queue_pairs; > The code is using this "default" even if the amount of queue pairs it > wants was specified during initialization. This basically limits any > device to use 1 pair when starting up. > Yes, currently the virtio-net driver would use 1 txq/txq by default since multiqueue may not outperform in all kinds of workload. So it's better to keep it as default and let user enable multiqueue by ethtool -L.