Re: [PATCH RFC net-next 1/2] drivers: net: virtio_net: Add tx_timeout stats field

[Julian Wiedmann <jwi@linux.ibm.com>]

On 06.10.19 20:45, jcfaracco@gmail.com wrote:
> From: Julio Faracco <jcfaracco@gmail.com>
> 
> For debug purpose of TX timeout events, a tx_timeout entry was added to
> monitor this special case: when dev_watchdog identifies a tx_timeout and
> throw an exception. We can both consider this event as an error, but
> driver should report as a tx_timeout statistic.
> 

Hi Julio,
dev_watchdog() updates txq->trans_timeout, why isn't that sufficient?


> Signed-off-by: Julio Faracco <jcfaracco@gmail.com>
> Signed-off-by: Daiane Mendes <dnmendes76@gmail.com>
> Cc: Jason Wang <jasowang@redhat.com>
> ---
>  drivers/net/virtio_net.c | 6 +++++-
>  1 file changed, 5 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/net/virtio_net.c b/drivers/net/virtio_net.c
> index 4f3de0ac8b0b..27f9b212c9f5 100644
> --- a/drivers/net/virtio_net.c
> +++ b/drivers/net/virtio_net.c
> @@ -75,6 +75,7 @@ struct virtnet_sq_stats {
>  	u64 xdp_tx;
>  	u64 xdp_tx_drops;
>  	u64 kicks;
> +	u64 tx_timeouts;
>  };
>  
>  struct virtnet_rq_stats {
> @@ -98,6 +99,7 @@ static const struct virtnet_stat_desc virtnet_sq_stats_desc[] = {
>  	{ "xdp_tx",		VIRTNET_SQ_STAT(xdp_tx) },
>  	{ "xdp_tx_drops",	VIRTNET_SQ_STAT(xdp_tx_drops) },
>  	{ "kicks",		VIRTNET_SQ_STAT(kicks) },
> +	{ "tx_timeouts",	VIRTNET_SQ_STAT(tx_timeouts) },
>  };
>  
>  static const struct virtnet_stat_desc virtnet_rq_stats_desc[] = {
> @@ -1721,7 +1723,7 @@ static void virtnet_stats(struct net_device *dev,
>  	int i;
>  
>  	for (i = 0; i < vi->max_queue_pairs; i++) {
> -		u64 tpackets, tbytes, rpackets, rbytes, rdrops;
> +		u64 tpackets, tbytes, terrors, rpackets, rbytes, rdrops;
>  		struct receive_queue *rq = &vi->rq[i];
>  		struct send_queue *sq = &vi->sq[i];
>  
> @@ -1729,6 +1731,7 @@ static void virtnet_stats(struct net_device *dev,
>  			start = u64_stats_fetch_begin_irq(&sq->stats.syncp);
>  			tpackets = sq->stats.packets;
>  			tbytes   = sq->stats.bytes;
> +			terrors  = sq->stats.tx_timeouts;
>  		} while (u64_stats_fetch_retry_irq(&sq->stats.syncp, start));
>  
>  		do {
> @@ -1743,6 +1746,7 @@ static void virtnet_stats(struct net_device *dev,
>  		tot->rx_bytes   += rbytes;
>  		tot->tx_bytes   += tbytes;
>  		tot->rx_dropped += rdrops;
> +		tot->tx_errors  += terrors;
>  	}
>  
>  	tot->tx_dropped = dev->stats.tx_dropped;
>