On 01/21/2013 07:25 PM, Wanlong Gao wrote:
> Split out the clean affinity function to virtnet_clean_affinity().
>
> Cc: Rusty Russell <rusty@xxxxxxxxxxxxxxx>
> Cc: "Michael S. Tsirkin" <mst@xxxxxxxxxx>
> Cc: Jason Wang <jasowang@xxxxxxxxxx>
> Cc: Eric Dumazet <erdnetdev@xxxxxxxxx>
> Cc: virtualization@xxxxxxxxxxxxxxxxxxxxxxxxxx
> Cc: netdev@xxxxxxxxxxxxxxx
> Signed-off-by: Wanlong Gao <gaowanlong@xxxxxxxxxxxxxx>
> ---
> V5->V6: NEW
>
> drivers/net/virtio_net.c | 67 +++++++++++++++++++++++++++---------------------
> 1 file changed, 38 insertions(+), 29 deletions(-)
>
> diff --git a/drivers/net/virtio_net.c b/drivers/net/virtio_net.c
> index 70cd957..1a35a8c 100644
> --- a/drivers/net/virtio_net.c
> +++ b/drivers/net/virtio_net.c
> @@ -1016,48 +1016,57 @@ static int virtnet_vlan_rx_kill_vid(struct net_device *dev, u16 vid)
> return 0;
> }
>
> -static void virtnet_set_affinity(struct virtnet_info *vi, bool set)
> +static void virtnet_clean_affinity(struct virtnet_info *vi, long hcpu)
> {
> int i;
> int cpu;
>
> - /* In multiqueue mode, when the number of cpu is equal to the number of
> - * queue pairs, we let the queue pairs to be private to one cpu by
> - * setting the affinity hint to eliminate the contention.
> - */
> - if ((vi->curr_queue_pairs == 1 ||
> - vi->max_queue_pairs != num_online_cpus()) && set) {
> - if (vi->affinity_hint_set)
> - set = false;
> - else
> - return;
> - }
> -
> - if (set) {
> - 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;
> - i++;
> - }
> -
> - vi->affinity_hint_set = true;
> - } else {
> - for(i = 0; i < vi->max_queue_pairs; i++) {
> + if (vi->affinity_hint_set) {
> + for (i = 0; i < vi->max_queue_pairs; i++) {
> virtqueue_set_affinity(vi->rq[i].vq, -1);
> virtqueue_set_affinity(vi->sq[i].vq, -1);
> }
>
> i = 0;
> - for_each_online_cpu(cpu)
> + for_each_online_cpu(cpu) {
> + if (cpu == hcpu)
> + continue;
> *per_cpu_ptr(vi->vq_index, cpu) =
> ++i % vi->curr_queue_pairs;
> + }
>
Some questions here:
- Did we need reset the affinity of the queue here like the this?
virtqueue_set_affinity(vi->sq[*per_cpu_ptr(vi->vq_index, hcpu)], -1);
virtqueue_set_affinity(vi->rq[*per_cpu_ptr(vi->vq_index, hcpu)], -1);
- Looks like we need also reset the percpu index when
vi->affinity_hint_set is false.
- Does this really need this reset? Consider we're going to reset the
percpu in CPU_DEAD?
Thanks
> vi->affinity_hint_set = false;
> }
> }
>
> +static void virtnet_set_affinity(struct virtnet_info *vi)
> +{
> + int i;
> + int cpu;
> +
> + /* In multiqueue mode, when the number of cpu is equal to the number of
> + * queue pairs, we let the queue pairs to be private to one cpu by
> + * setting the affinity hint to eliminate the contention.
> + */
> + if (vi->curr_queue_pairs == 1 ||
> + vi->max_queue_pairs != num_online_cpus()) {
> + if (vi->affinity_hint_set)
> + virtnet_clean_affinity(vi, -1);
> + else
> + 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;
> + i++;
> + }
> +
> + vi->affinity_hint_set = true;
> +}
> +
> static void virtnet_get_ringparam(struct net_device *dev,
> struct ethtool_ringparam *ring)
> {
> @@ -1105,7 +1114,7 @@ static int virtnet_set_channels(struct net_device *dev,
> netif_set_real_num_rx_queues(dev, queue_pairs);
>
> get_online_cpus();
> - virtnet_set_affinity(vi, true);
> + virtnet_set_affinity(vi);
> put_online_cpus();
> }
>
> @@ -1274,7 +1283,7 @@ static void virtnet_del_vqs(struct virtnet_info *vi)
> {
> struct virtio_device *vdev = vi->vdev;
>
> - virtnet_set_affinity(vi, false);
> + virtnet_clean_affinity(vi, -1);
>
> vdev->config->del_vqs(vdev);
>
> @@ -1398,7 +1407,7 @@ static int init_vqs(struct virtnet_info *vi)
> goto err_free;
>
> get_online_cpus();
> - virtnet_set_affinity(vi, true);
> + virtnet_set_affinity(vi);
> put_online_cpus();
>
> return 0;
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