From: Rusty Russell <rusty@rustcorp•com.au>
To: Jason Wang <jasowang@redhat•com>,
netdev@vger•kernel.org, linux-kernel@vger•kernel.org,
virtualization@lists•linux-foundation.org
Cc: Jason Wang <jasowang@redhat•com>, "Michael S. Tsirkin" <mst@redhat•com>
Subject: Re: [PATCH net-next] virtio-net: switch to use XPS to choose txq
Date: Mon, 30 Sep 2013 09:05:59 +0930 [thread overview]
Message-ID: <874n932obk.fsf@rustcorp.com.au> (raw)
In-Reply-To: <1380261444-40918-1-git-send-email-jasowang@redhat.com>
Jason Wang <jasowang@redhat•com> writes:
> We used to use a percpu structure vq_index to record the cpu to queue
> mapping, this is suboptimal since it duplicates the work of XPS and
> loses all other XPS functionality such as allowing use to configure
> their own transmission steering strategy.
>
> So this patch switches to use XPS and suggest a default mapping when
> the number of cpus is equal to the number of queues. With XPS support,
> there's no need for keeping per-cpu vq_index and .ndo_select_queue(),
> so they were removed also.
>
> Cc: Rusty Russell <rusty@rustcorp•com.au>
> Cc: Michael S. Tsirkin <mst@redhat•com>
> Signed-off-by: Jason Wang <jasowang@redhat•com>
> ---
> drivers/net/virtio_net.c | 55 +++++++--------------------------------------
> 1 files changed, 9 insertions(+), 46 deletions(-)
>
> diff --git a/drivers/net/virtio_net.c b/drivers/net/virtio_net.c
> index defec2b..4102c1b 100644
> --- a/drivers/net/virtio_net.c
> +++ b/drivers/net/virtio_net.c
> @@ -127,9 +127,6 @@ struct virtnet_info {
> /* Does the affinity hint is set for virtqueues? */
> bool affinity_hint_set;
>
> - /* Per-cpu variable to show the mapping from CPU to virtqueue */
> - int __percpu *vq_index;
> -
> /* CPU hot plug notifier */
> struct notifier_block nb;
> };
> @@ -1063,7 +1060,6 @@ static int virtnet_vlan_rx_kill_vid(struct net_device *dev,
> static void virtnet_clean_affinity(struct virtnet_info *vi, long hcpu)
> {
> int i;
> - int cpu;
>
> if (vi->affinity_hint_set) {
> for (i = 0; i < vi->max_queue_pairs; i++) {
> @@ -1073,20 +1069,11 @@ static void virtnet_clean_affinity(struct virtnet_info *vi, long hcpu)
>
> vi->affinity_hint_set = false;
> }
> -
> - i = 0;
> - for_each_online_cpu(cpu) {
> - if (cpu == hcpu) {
> - *per_cpu_ptr(vi->vq_index, cpu) = -1;
> - } else {
> - *per_cpu_ptr(vi->vq_index, cpu) =
> - ++i % vi->curr_queue_pairs;
> - }
> - }
> }
>
> static void virtnet_set_affinity(struct virtnet_info *vi)
> {
> + cpumask_var_t cpumask;
> int i;
> int cpu;
>
> @@ -1100,15 +1087,21 @@ static void virtnet_set_affinity(struct virtnet_info *vi)
> return;
> }
>
> + if (!alloc_cpumask_var(&cpumask, GFP_KERNEL))
> + return;
> +
> i = 0;
> for_each_online_cpu(cpu) {
> virtqueue_set_affinity(vi->rq[i].vq, cpu);
> virtqueue_set_affinity(vi->sq[i].vq, cpu);
> - *per_cpu_ptr(vi->vq_index, cpu) = i;
> + cpumask_clear(cpumask);
> + cpumask_set_cpu(cpu, cpumask);
> + netif_set_xps_queue(vi->dev, cpumask, i);
> i++;
> }
>
> vi->affinity_hint_set = true;
> + free_cpumask_var(cpumask);
> }
Um, isn't this just cpumask_of(cpu)?
Cheers,
Rusty.
next prev parent reply other threads:[~2013-09-29 23:35 UTC|newest]
Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top
2013-09-27 5:57 [PATCH net-next] virtio-net: switch to use XPS to choose txq Jason Wang
2013-09-27 14:35 ` Michael S. Tsirkin
2013-09-29 3:14 ` Jason Wang
2013-09-29 23:35 ` Rusty Russell [this message]
2013-09-30 3:20 ` 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=874n932obk.fsf@rustcorp.com.au \
--to=rusty@rustcorp$(echo .)com.au \
--cc=jasowang@redhat$(echo .)com \
--cc=linux-kernel@vger$(echo .)kernel.org \
--cc=mst@redhat$(echo .)com \
--cc=netdev@vger$(echo .)kernel.org \
--cc=virtualization@lists$(echo .)linux-foundation.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
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