Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S933343AbcK1P04 (ORCPT ); Mon, 28 Nov 2016 10:26:56 -0500 Received: from mx1.redhat.com ([209.132.183.28]:50166 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932617AbcK1P0r (ORCPT ); Mon, 28 Nov 2016 10:26:47 -0500 Date: Mon, 28 Nov 2016 10:26:44 -0500 From: Neil Horman To: Jason Wang Cc: virtualization@lists.linux-foundation.org, netdev@vger.kernel.org, linux-kernel@vger.kernel.org, Hannes Frederic Sowa , "Michael S . Tsirkin" , Jeremy Eder , Marko Myllynen , Maxime Coquelin Subject: Re: [PATCH net-next] virtio-net: enable multiqueue by default Message-ID: <20161128152644.GC14706@hmsreliant.think-freely.org> References: <1480048646-17536-1-git-send-email-jasowang@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1480048646-17536-1-git-send-email-jasowang@redhat.com> User-Agent: Mutt/1.7.1 (2016-10-04) X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.31]); Mon, 28 Nov 2016 15:26:47 +0000 (UTC) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2225 Lines: 58 On Fri, Nov 25, 2016 at 12:37:26PM +0800, Jason Wang wrote: > We use single queue even if multiqueue is enabled and let admin to > enable it through ethtool later. This is used to avoid possible > regression (small packet TCP stream transmission). But looks like an > overkill since: > > - single queue user can disable multiqueue when launching qemu > - brings extra troubles for the management since it needs extra admin > tool in guest to enable multiqueue > - multiqueue performs much better than single queue in most of the > cases > > So this patch enables multiqueue by default: if #queues is less than or > equal to #vcpu, enable as much as queue pairs; if #queues is greater > than #vcpu, enable #vcpu queue pairs. > > Cc: Hannes Frederic Sowa > Cc: Michael S. Tsirkin > Cc: Neil Horman > Cc: Jeremy Eder > Cc: Marko Myllynen > Cc: Maxime Coquelin > Signed-off-by: Jason Wang > --- > drivers/net/virtio_net.c | 9 +++++++-- > 1 file changed, 7 insertions(+), 2 deletions(-) > > diff --git a/drivers/net/virtio_net.c b/drivers/net/virtio_net.c > index d4ac7a6..a21d93a 100644 > --- a/drivers/net/virtio_net.c > +++ b/drivers/net/virtio_net.c > @@ -1886,8 +1886,11 @@ static int virtnet_probe(struct virtio_device *vdev) > if (vi->any_header_sg) > dev->needed_headroom = vi->hdr_len; > > - /* Use single tx/rx queue pair as default */ > - vi->curr_queue_pairs = 1; > + /* Enable multiqueue by default */ > + if (num_online_cpus() >= max_queue_pairs) > + vi->curr_queue_pairs = max_queue_pairs; > + else > + vi->curr_queue_pairs = num_online_cpus(); > vi->max_queue_pairs = max_queue_pairs; > > /* Allocate/initialize the rx/tx queues, and invoke find_vqs */ > @@ -1918,6 +1921,8 @@ static int virtnet_probe(struct virtio_device *vdev) > goto free_unregister_netdev; > } > > + virtnet_set_affinity(vi); > + > /* Assume link up if device can't report link status, > otherwise get link status from config. */ > if (virtio_has_feature(vi->vdev, VIRTIO_NET_F_STATUS)) { > -- > 2.7.4 > Acked-by: Neil Horman