Re: [dpdk-dev] [PATCH v4] add drop statistic for af_packet

[Ferruh Yigit <ferruh.yigit@intel.com>]

On 11/29/2019 2:59 PM, Vadim Podovinnikov wrote:
> Signed-off-by: Vadim Podovinnikov <podovinnikov@protei.ru>
> ---
>  drivers/net/af_packet/rte_eth_af_packet.c | 33 +++++++++++++++++------
>  1 file changed, 25 insertions(+), 8 deletions(-)
> 
> diff --git a/drivers/net/af_packet/rte_eth_af_packet.c b/drivers/net/af_packet/rte_eth_af_packet.c
> index eee0fbce2..2aa7c0fcc 100644
> --- a/drivers/net/af_packet/rte_eth_af_packet.c
> +++ b/drivers/net/af_packet/rte_eth_af_packet.c
> @@ -52,6 +52,7 @@ struct pkt_rx_queue {
>  
>  	volatile unsigned long rx_pkts;
>  	volatile unsigned long rx_bytes;
> +	volatile unsigned long rx_drop;
>  };
>  
>  struct pkt_tx_queue {
> @@ -322,6 +323,25 @@ eth_dev_info(struct rte_eth_dev *dev, struct rte_eth_dev_info *dev_info)
>  	return 0;
>  }
>  
> +static void
> +fill_eth_drop_stats(struct rte_eth_dev *dev)
> +{
> +	unsigned int i, imax;
> +	struct pmd_internals *internal = dev->data->dev_private;
> +	socklen_t sock_len = sizeof(struct tpacket_stats);
> +	struct tpacket_stats st;
> +
> +	imax = (internal->nb_queues < RTE_ETHDEV_QUEUE_STAT_CNTRS ?
> +			internal->nb_queues : RTE_ETHDEV_QUEUE_STAT_CNTRS);
> +	for (i = 0; i < imax; i++) {
> +		memset(&st, 0, sock_len);
> +		int rc = getsockopt(internal->rx_queue[i].sockfd, SOL_PACKET,
> +					PACKET_STATISTICS, &st, &sock_len);
> +		if (rc == 0)
> +			internal->rx_queue[i].rx_drop += st.tp_drops;
> +	}
> +}
> +
>  static int
>  eth_stats_get(struct rte_eth_dev *dev, struct rte_eth_stats *igb_stats)
>  {
> @@ -329,22 +349,18 @@ eth_stats_get(struct rte_eth_dev *dev, struct rte_eth_stats *igb_stats)
>  	unsigned long rx_total = 0, tx_total = 0, tx_err_total = 0;
>  	unsigned long rx_bytes_total = 0, tx_bytes_total = 0, rx_drop = 0;
>  	const struct pmd_internals *internal = dev->data->dev_private;
> -	socklen_t sock_len = sizeof(struct tpacket_stats);
> -	struct tpacket_stats st;
> +
> +	fill_eth_drop_stats(dev);

There is already a loop per queue, instead of maxing a function for all queues
and duplicate 'imax' calculation, what about making a function that gets the
queue_id as parameter and called in the blow loop?

>  
>  	imax = (internal->nb_queues < RTE_ETHDEV_QUEUE_STAT_CNTRS ?
>  	        internal->nb_queues : RTE_ETHDEV_QUEUE_STAT_CNTRS);
>  	for (i = 0; i < imax; i++) {
>  		igb_stats->q_ipackets[i] = internal->rx_queue[i].rx_pkts;
>  		igb_stats->q_ibytes[i] = internal->rx_queue[i].rx_bytes;
> +		igb_stats->q_errors[i] = internal->rx_queue[i].rx_drop;

'q_errors' is for the packets that are received but erroneous, what is the
af_packet 'tp_drops' stats for? Is it for wrong packets or the packets dropped
because receive rate was too high?

>  		rx_total += igb_stats->q_ipackets[i];
>  		rx_bytes_total += igb_stats->q_ibytes[i];
> -
> -		memset(&st, 0, sock_len);
> -		int rc = getsockopt(internal->rx_queue[i].sockfd, SOL_PACKET,
> -					PACKET_STATISTICS, &st, &sock_len);
> -		if (rc == 0)
> -			rx_drop += st.tp_drops;

The patch looks like on top of your previous version, please make new versions
always on top of latest head, so not incremental patches but from scratch each time.

> +		rx_drop += igb_stats->q_errors[i];

What are you doing with 'rx_drop'? Not using it at all?

>  	}
>  
>  	imax = (internal->nb_queues < RTE_ETHDEV_QUEUE_STAT_CNTRS ?
> @@ -375,6 +391,7 @@ eth_stats_reset(struct rte_eth_dev *dev)
>  	for (i = 0; i < internal->nb_queues; i++) {
>  		internal->rx_queue[i].rx_pkts = 0;
>  		internal->rx_queue[i].rx_bytes = 0;
> +		internal->rx_queue[i].rx_drop = 0;
>  	}
>  
>  	for (i = 0; i < internal->nb_queues; i++) {
>