From: Stephen Hemminger <shemminger@vyatta.com>
To: Jason Wang <jasowang@redhat.com>
Cc: Sasha Levin <levinsasha928@gmail.com>,
krkumar2@in.ibm.com, habanero@linux.vnet.ibm.com,
mashirle@us.ibm.com, kvm@vger.kernel.org, mst@redhat.com,
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, sri@us.ibm.com
Subject: Re: [net-next RFC V5 5/5] virtio_net: support negotiating the number of queues through ctrl vq
Date: Thu, 5 Jul 2012 23:38:16 -0700 [thread overview]
Message-ID: <20120705233816.3ec0b827@nehalam.linuxnetplumber.net> (raw)
In-Reply-To: <4FF65966.9040600@redhat.com>
On Fri, 06 Jul 2012 11:20:06 +0800
Jason Wang <jasowang@redhat.com> wrote:
> 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.
>
I would prefer that the driver sized number of queues based on number
of online CPU's. That is what real hardware does. What kind of workload
are you doing? If it is some DBMS benchmark then maybe the issue is that
some CPU's need to be reserved.
next prev parent reply other threads:[~2012-07-06 6:38 UTC|newest]
Thread overview: 46+ messages / expand[flat|nested] mbox.gz Atom feed top
2012-07-05 10:29 [net-next RFC V5 0/5] Multiqueue virtio-net Jason Wang
2012-07-05 10:29 ` [net-next RFC V5 1/5] virtio_net: Introduce VIRTIO_NET_F_MULTIQUEUE Jason Wang
2012-07-05 10:29 ` [net-next RFC V5 2/5] virtio_ring: move queue_index to vring_virtqueue Jason Wang
2012-07-05 11:40 ` Sasha Levin
2012-07-06 3:17 ` Jason Wang
2012-07-26 8:20 ` Paolo Bonzini
2012-07-30 3:30 ` Jason Wang
2012-07-05 10:29 ` [net-next RFC V5 3/5] virtio: intorduce an API to set affinity for a virtqueue Jason Wang
2012-07-27 14:38 ` Paolo Bonzini
2012-07-29 20:40 ` Michael S. Tsirkin
2012-07-30 6:27 ` Paolo Bonzini
2012-08-09 15:14 ` Paolo Bonzini
2012-08-09 15:13 ` Paolo Bonzini
2012-08-09 15:35 ` Avi Kivity
2012-07-05 10:29 ` [net-next RFC V5 4/5] virtio_net: multiqueue support Jason Wang
2012-07-05 20:02 ` Amos Kong
2012-07-06 7:45 ` Jason Wang
2012-07-20 13:40 ` Michael S. Tsirkin
2012-07-21 12:02 ` Sasha Levin
2012-07-23 5:54 ` Jason Wang
2012-07-23 9:28 ` Sasha Levin
2012-07-30 3:29 ` Jason Wang
2012-07-29 9:44 ` Michael S. Tsirkin
2012-07-30 3:26 ` Jason Wang
2012-07-30 13:00 ` Sasha Levin
2012-07-23 5:48 ` Jason Wang
2012-07-29 9:50 ` Michael S. Tsirkin
2012-07-30 5:15 ` Jason Wang
2012-07-05 10:29 ` [net-next RFC V5 5/5] virtio_net: support negotiating the number of queues through ctrl vq Jason Wang
2012-07-05 12:51 ` Sasha Levin
2012-07-05 20:07 ` Amos Kong
2012-07-06 7:46 ` Jason Wang
2012-07-06 3:20 ` Jason Wang
2012-07-06 6:38 ` Stephen Hemminger [this message]
2012-07-06 9:26 ` Jason Wang
2012-07-06 8:10 ` Sasha Levin
2012-07-09 20:13 ` Ben Hutchings
2012-07-20 12:33 ` Michael S. Tsirkin
2012-07-23 5:32 ` Jason Wang
2012-07-05 17:45 ` [net-next RFC V5 0/5] Multiqueue virtio-net Rick Jones
2012-07-06 7:42 ` Jason Wang
2012-07-06 16:23 ` Rick Jones
2012-07-09 3:23 ` Jason Wang
2012-07-09 16:46 ` Rick Jones
2012-07-08 8:19 ` Ronen Hod
2012-07-09 5:35 ` Jason Wang
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=20120705233816.3ec0b827@nehalam.linuxnetplumber.net \
--to=shemminger@vyatta.com \
--cc=davem@davemloft.net \
--cc=edumazet@google.com \
--cc=habanero@linux.vnet.ibm.com \
--cc=jasowang@redhat.com \
--cc=jwhan@filewood.snu.ac.kr \
--cc=krkumar2@in.ibm.com \
--cc=kvm@vger.kernel.org \
--cc=levinsasha928@gmail.com \
--cc=linux-kernel@vger.kernel.org \
--cc=mashirle@us.ibm.com \
--cc=mst@redhat.com \
--cc=netdev@vger.kernel.org \
--cc=sri@us.ibm.com \
--cc=tahm@linux.vnet.ibm.com \
--cc=virtualization@lists.linux-foundation.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).