Date:   Thu, 16 Dec 2021 01:31:03 -0500
From:   "Michael S. Tsirkin" <mst@redhat.com>
To:     Wenliang Wang <wangwenliang.1995@bytedance.com>
Cc:     jasowang@redhat.com, davem@davemloft.net, kuba@kernel.org,
        virtualization@lists.linux-foundation.org, netdev@vger.kernel.org,
        linux-kernel@vger.kernel.org
Subject: Re: [PATCH] virtio_net: fix rx_drops stat for small pkts
Message-ID: <20211216013056-mutt-send-email-mst@kernel.org>
References: <20211216031135.3182660-1-wangwenliang.1995@bytedance.com>
MIME-Version: 1.0
Content-Type: text/plain; charset=us-ascii
Content-Disposition: inline
In-Reply-To: <20211216031135.3182660-1-wangwenliang.1995@bytedance.com>
Precedence: bulk

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