Re: [PATCH v7 25/26] virtio_net: set the default max ring size by find_vqs()

Jason Wang
2022-03-09T09:28:48Z

在 2022/3/8 下午8:35, Xuan Zhuo 写道:
> Use virtio_find_vqs_ctx_size() to specify the maximum ring size of tx,
> rx at the same time.
>
> | rx/tx ring size
> -------------------------------------------
> speed == UNKNOWN or < 10G| 1024
> speed < 40G | 4096
> speed >= 40G | 8192
>
> Call virtnet_update_settings() once before calling init_vqs() to update
> speed.
>
> Signed-off-by: Xuan Zhuo <xuanzhuo@linux.alibaba.com>
> ---
> drivers/net/virtio_net.c | 42 ++++++++++++++++++++++++++++++++++++----
> 1 file changed, 38 insertions(+), 4 deletions(-)
>
> diff --git a/drivers/net/virtio_net.c b/drivers/net/virtio_net.c
> index ffff323dcef0..f1bdc6ce21c3 100644
> --- a/drivers/net/virtio_net.c
> +++ b/drivers/net/virtio_net.c
> @@ -2977,6 +2977,29 @@ static unsigned int mergeable_min_buf_len(struct virtnet_info *vi, struct virtqu
> (unsigned int)GOOD_PACKET_LEN);
> }
>
> +static void virtnet_config_sizes(struct virtnet_info *vi, u32 *sizes)
> +{
> + u32 i, rx_size, tx_size;
> +
> + if (vi->speed == SPEED_UNKNOWN || vi->speed < SPEED_10000) {
> + rx_size = 1024;
> + tx_size = 1024;
> +
> + } else if (vi->speed < SPEED_40000) {
> + rx_size = 1024 * 4;
> + tx_size = 1024 * 4;
> +
> + } else {
> + rx_size = 1024 * 8;
> + tx_size = 1024 * 8;
> + }
> +
> + for (i = 0; i < vi->max_queue_pairs; i++) {
> + sizes[rxq2vq(i)] = rx_size;
> + sizes[txq2vq(i)] = tx_size;
> + }
> +}
> +
> static int virtnet_find_vqs(struct virtnet_info *vi)
> {
> vq_callback_t **callbacks;
> @@ -2984,6 +3007,7 @@ static int virtnet_find_vqs(struct virtnet_info *vi)
> int ret = -ENOMEM;
> int i, total_vqs;
> const char **names;
> + u32 *sizes;
> bool *ctx;
>
> /* We expect 1 RX virtqueue followed by 1 TX virtqueue, followed by
> @@ -3011,10 +3035,15 @@ static int virtnet_find_vqs(struct virtnet_info *vi)
> ctx = NULL;
> }
>
> + sizes = kmalloc_array(total_vqs, sizeof(*sizes), GFP_KERNEL);
> + if (!sizes)
> + goto err_sizes;
> +
> /* Parameters for control virtqueue, if any */
> if (vi->has_cvq) {
> callbacks[total_vqs - 1] = NULL;
> names[total_vqs - 1] = "control";
> + sizes[total_vqs - 1] = 0;

Nit: Do we need a sane value for the control vq? (e.g 64)

Thanks

> }
>
> /* Allocate/initialize parameters for send/receive virtqueues */
> @@ -3029,8 +3058,10 @@ static int virtnet_find_vqs(struct virtnet_info *vi)
> ctx[rxq2vq(i)] = true;
> }
>
> - ret = virtio_find_vqs_ctx(vi->vdev, total_vqs, vqs, callbacks,
> - names, ctx, NULL);
> + virtnet_config_sizes(vi, sizes);
> +
> + ret = virtio_find_vqs_ctx_size(vi->vdev, total_vqs, vqs, callbacks,
> + names, ctx, NULL, sizes);
> if (ret)
> goto err_find;
>
> @@ -3050,6 +3081,8 @@ static int virtnet_find_vqs(struct virtnet_info *vi)
>
>
> err_find:
> + kfree(sizes);
> +err_sizes:
> kfree(ctx);
> err_ctx:
> kfree(names);
> @@ -3368,6 +3401,9 @@ static int virtnet_probe(struct virtio_device *vdev)
> vi->curr_queue_pairs = num_online_cpus();
> vi->max_queue_pairs = max_queue_pairs;
>
> + virtnet_init_settings(dev);
> + virtnet_update_settings(vi);
> +
> /* Allocate/initialize the rx/tx queues, and invoke find_vqs */
> err = init_vqs(vi);
> if (err)
> @@ -3380,8 +3416,6 @@ static int virtnet_probe(struct virtio_device *vdev)
> netif_set_real_num_tx_queues(dev, vi->curr_queue_pairs);
> netif_set_real_num_rx_queues(dev, vi->curr_queue_pairs);
>
> - virtnet_init_settings(dev);
> -
> if (virtio_has_feature(vdev, VIRTIO_NET_F_STANDBY)) {
> vi->failover = net_failover_create(vi->dev);
> if (IS_ERR(vi->failover)) {