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

[Jason Wang <jasowang@redhat.com>]

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)) {