Subject: Re: [PATCH vhost 21/22] virtio_net: update tx timeout record

From: "Michael S. Tsirkin" <[email-masked]>
Date: Thu, 12 Oct 2023 05:10:55 -0400

On Wed, Oct 11, 2023 at 05:27:27PM +0800, Xuan Zhuo wrote:
> If send queue sent some packets, we update the tx timeout
> record to prevent the tx timeout.
> 
> Signed-off-by: Xuan Zhuo <[email-masked]>
> ---
>  drivers/net/virtio/xsk.c | 10 ++++++++++
>  1 file changed, 10 insertions(+)
> 
> diff --git a/drivers/net/virtio/xsk.c b/drivers/net/virtio/xsk.c
> index 7abd46bb0e3d..e605f860edb6 100644
> --- a/drivers/net/virtio/xsk.c
> +++ b/drivers/net/virtio/xsk.c
> @@ -274,6 +274,16 @@ bool virtnet_xsk_xmit(struct virtnet_sq *sq, struct xsk_buff_pool *pool,
>  
>  	virtnet_xsk_check_queue(sq);
>  
> +	if (stats.packets) {
> +		struct netdev_queue *txq;
> +		struct virtnet_info *vi;
> +
> +		vi = sq->vq->vdev->priv;
> +
> +		txq = netdev_get_tx_queue(vi->dev, sq - vi->sq);
> +		txq_trans_cond_update(txq);
> +	}
> +
>  	u64_stats_update_begin(&sq->stats.syncp);
>  	sq->stats.packets += stats.packets;
>  	sq->stats.bytes += stats.bytes;

I don't get what this is doing. Is there some kind of race here you
are trying to address? And what introduced the race?

> -- 
> 2.32.0.3.g01195cf9f