Re: [PATCH] virtio_net: fix rx_drops stat for small pkts

Re: [PATCH] virtio_net: fix rx_drops stat for small pkts

[Jason Wang]

On Thu, Dec 16, 2021 at 11:12 AM Wenliang Wang
<wangwenliang.1995@bytedance.com> wrote:
>
> We found the stat of rx drops for small pkts does not increment when
> build_skb fail, it's not coherent with other mode's rx drops stat.
>
> Signed-off-by: Wenliang Wang <wangwenliang.1995@bytedance.com>

Acked-by: Jason Wang <jasowang@redhat.com>

> ---
>  drivers/net/virtio_net.c | 9 +++------
>  1 file changed, 3 insertions(+), 6 deletions(-)
>
> diff --git a/drivers/net/virtio_net.c b/drivers/net/virtio_net.c
> index 55db6a336f7e..b107835242ad 100644
> --- a/drivers/net/virtio_net.c
> +++ b/drivers/net/virtio_net.c
> @@ -733,7 +733,7 @@ static struct sk_buff *receive_small(struct net_device *dev,
>                 pr_debug("%s: rx error: len %u exceeds max size %d\n",
>                          dev->name, len, GOOD_PACKET_LEN);
>                 dev->stats.rx_length_errors++;
> -               goto err_len;
> +               goto err;
>         }
>
>         if (likely(!vi->xdp_enabled)) {
> @@ -825,10 +825,8 @@ static struct sk_buff *receive_small(struct net_device *dev,
>
>  skip_xdp:
>         skb = build_skb(buf, buflen);
> -       if (!skb) {
> -               put_page(page);
> +       if (!skb)
>                 goto err;
> -       }
>         skb_reserve(skb, headroom - delta);
>         skb_put(skb, len);
>         if (!xdp_prog) {
> @@ -839,13 +837,12 @@ static struct sk_buff *receive_small(struct net_device *dev,
>         if (metasize)
>                 skb_metadata_set(skb, metasize);
>
> -err:
>         return skb;
>
>  err_xdp:
>         rcu_read_unlock();
>         stats->xdp_drops++;
> -err_len:
> +err:
>         stats->drops++;
>         put_page(page);
>  xdp_xmit:
> --
> 2.30.2
>

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Re: [PATCH] virtio_net: fix rx_drops stat for small pkts

[Michael S. Tsirkin]

On Thu, Dec 16, 2021 at 11:11:35AM +0800, Wenliang Wang wrote:
> We found the stat of rx drops for small pkts does not increment when
> build_skb fail, it's not coherent with other mode's rx drops stat.
> 
> Signed-off-by: Wenliang Wang <wangwenliang.1995@bytedance.com>

Acked-by: Michael S. Tsirkin <mst@redhat.com>

> ---
>  drivers/net/virtio_net.c | 9 +++------
>  1 file changed, 3 insertions(+), 6 deletions(-)
> 
> diff --git a/drivers/net/virtio_net.c b/drivers/net/virtio_net.c
> index 55db6a336f7e..b107835242ad 100644
> --- a/drivers/net/virtio_net.c
> +++ b/drivers/net/virtio_net.c
> @@ -733,7 +733,7 @@ static struct sk_buff *receive_small(struct net_device *dev,
>  		pr_debug("%s: rx error: len %u exceeds max size %d\n",
>  			 dev->name, len, GOOD_PACKET_LEN);
>  		dev->stats.rx_length_errors++;
> -		goto err_len;
> +		goto err;
>  	}
>  
>  	if (likely(!vi->xdp_enabled)) {
> @@ -825,10 +825,8 @@ static struct sk_buff *receive_small(struct net_device *dev,
>  
>  skip_xdp:
>  	skb = build_skb(buf, buflen);
> -	if (!skb) {
> -		put_page(page);
> +	if (!skb)
>  		goto err;
> -	}
>  	skb_reserve(skb, headroom - delta);
>  	skb_put(skb, len);
>  	if (!xdp_prog) {
> @@ -839,13 +837,12 @@ static struct sk_buff *receive_small(struct net_device *dev,
>  	if (metasize)
>  		skb_metadata_set(skb, metasize);
>  
> -err:
>  	return skb;
>  
>  err_xdp:
>  	rcu_read_unlock();
>  	stats->xdp_drops++;
> -err_len:
> +err:
>  	stats->drops++;
>  	put_page(page);
>  xdp_xmit:
> -- 
> 2.30.2

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