Re: [PATCH v3 2/7] ixgbe: add functions to get and reset xstats

[Olivier MATZ <olivier.matz@6wind.com>]

Hi Maryam,

On 06/26/2015 02:59 PM, Maryam Tahhan wrote:
> Implement ixgbe_dev_xstats_reset and ixgbe_dev_xstats_get.
> 
> Signed-off-by: Maryam Tahhan <maryam.tahhan@intel.com>
> ---
>  drivers/net/ixgbe/ixgbe_ethdev.c | 85 ++++++++++++++++++++++++++++++++++++++++
>  1 file changed, 85 insertions(+)
> 
> diff --git a/drivers/net/ixgbe/ixgbe_ethdev.c b/drivers/net/ixgbe/ixgbe_ethdev.c
> index 927021f..0f62bcb 100644
> --- a/drivers/net/ixgbe/ixgbe_ethdev.c
> +++ b/drivers/net/ixgbe/ixgbe_ethdev.c
> @@ -131,7 +131,10 @@ static int ixgbe_dev_link_update(struct rte_eth_dev *dev,
>  				int wait_to_complete);
>  static void ixgbe_dev_stats_get(struct rte_eth_dev *dev,
>  				struct rte_eth_stats *stats);
> +static int ixgbe_dev_xstats_get(struct rte_eth_dev *dev,
> +				struct rte_eth_xstats *xstats, unsigned n);
>  static void ixgbe_dev_stats_reset(struct rte_eth_dev *dev);
> +static void ixgbe_dev_xstats_reset(struct rte_eth_dev *dev);
>  static int ixgbe_dev_queue_stats_mapping_set(struct rte_eth_dev *eth_dev,
>  					     uint16_t queue_id,
>  					     uint8_t stat_idx,
> @@ -334,7 +337,9 @@ static const struct eth_dev_ops ixgbe_eth_dev_ops = {
>  	.allmulticast_disable = ixgbe_dev_allmulticast_disable,
>  	.link_update          = ixgbe_dev_link_update,
>  	.stats_get            = ixgbe_dev_stats_get,
> +	.xstats_get           = ixgbe_dev_xstats_get,
>  	.stats_reset          = ixgbe_dev_stats_reset,
> +	.xstats_reset         = ixgbe_dev_xstats_reset,
>  	.queue_stats_mapping_set = ixgbe_dev_queue_stats_mapping_set,
>  	.dev_infos_get        = ixgbe_dev_info_get,
>  	.mtu_set              = ixgbe_dev_mtu_set,
> @@ -414,6 +419,33 @@ static const struct eth_dev_ops ixgbevf_eth_dev_ops = {
>  	.set_mc_addr_list     = ixgbe_dev_set_mc_addr_list,
>  };
>  
> +/* store statistics names and its offset in stats structure  */ struct
> +rte_ixgbe_xstats_name_off {
> +	char name[RTE_ETH_XSTATS_NAME_SIZE];
> +	unsigned offset;
> +};
> +
> +static const struct rte_ixgbe_xstats_name_off rte_ixgbe_stats_strings[] = {
> +	{"rx_illegal_byte_err", offsetof(struct ixgbe_hw_stats, errbc)},
> +	{"rx_len_err", offsetof(struct ixgbe_hw_stats, rlec)},
> +	{"rx_undersize_count", offsetof(struct ixgbe_hw_stats, ruc)},
> +	{"rx_oversize_count", offsetof(struct ixgbe_hw_stats, roc)},
> +	{"rx_fragment_count", offsetof(struct ixgbe_hw_stats, rfc)},
> +	{"rx_jabber_count", offsetof(struct ixgbe_hw_stats, rjc)},
> +	{"l3_l4_xsum_error", offsetof(struct ixgbe_hw_stats, xec)},
> +	{"mac_local_fault", offsetof(struct ixgbe_hw_stats, mlfc)},
> +	{"mac_remote_fault", offsetof(struct ixgbe_hw_stats, mrfc)},
> +	{"mac_short_pkt_discard", offsetof(struct ixgbe_hw_stats, mspdc)},
> +	{"fccrc_error", offsetof(struct ixgbe_hw_stats, fccrc)},
> +	{"fcoe_drop", offsetof(struct ixgbe_hw_stats, fcoerpdc)},
> +	{"fc_last_error", offsetof(struct ixgbe_hw_stats, fclast)},
> +	{"rx_broadcast_packets", offsetof(struct ixgbe_hw_stats, bprc)},
> +	{"mgmt_pkts_dropped", offsetof(struct ixgbe_hw_stats, mngpdc)},
> +};
> +
> +#define RTE_NB_XSTATS (sizeof(rte_ixgbe_stats_strings) /	\
> +		sizeof(rte_ixgbe_stats_strings[0]))
> +

Maybe RTE_NB_XSTATS should be renamed in IXGBE_NB_XSTATS?


>  /**
>   * Atomically reads the link status information from global
>   * structure rte_eth_dev.
> @@ -1982,6 +2014,59 @@ ixgbe_dev_stats_reset(struct rte_eth_dev *dev)
>  	memset(stats, 0, sizeof(*stats));
>  }
>  
> +static int
> +ixgbe_dev_xstats_get(struct rte_eth_dev *dev, struct rte_eth_xstats *xstats,
> +					 unsigned n)
> +{
> +	struct ixgbe_hw *hw =
> +			IXGBE_DEV_PRIVATE_TO_HW(dev->data->dev_private);
> +	struct ixgbe_hw_stats *hw_stats =
> +			IXGBE_DEV_PRIVATE_TO_STATS(dev->data->dev_private);
> +	uint64_t total_missed_rx, total_qbrc, total_qprc, total_qprdc;
> +	uint64_t rxnfgpc, txdgpc;
> +	unsigned i, count = RTE_NB_XSTATS;
> +
> +	if (n == 0)
> +		return count;

I think it does not exactly matches the API described in rte_ethdev.h:

 * @return
 *   - positive value lower or equal to n: success. The return value
 *     is the number of entries filled in the stats table.
 *   - positive value higher than n: error, the given statistics table
 *     is too small. The return value corresponds to the size that should
 *     be given to succeed. The entries in the table are not valid and
 *     shall not be used by the caller.
 *   - negative value on error (invalid port id)

I think it should be:

  if (n < count)
    return count


> +
> +	total_missed_rx = 0;
> +	total_qbrc = 0;
> +	total_qprc = 0;
> +	total_qprdc = 0;
> +	rxnfgpc = 0;
> +	txdgpc = 0;
> +	count = 0;
> +
> +	ixgbe_read_stats_registers(hw, hw_stats, &total_missed_rx, &total_qbrc,
> +							   &total_qprc, &rxnfgpc, &txdgpc, &total_qprdc);
> +
> +	if (!xstats)
> +		return 0;

this cannot happen except if n == 0.
This condition is already tested above, and "count" should be returned.

> +
> +	/* Error stats */
> +	for (i = 0; i < RTE_NB_XSTATS; i++) {
> +		snprintf(xstats[count].name, sizeof(xstats[count].name),
> +				"%s", rte_ixgbe_stats_strings[i].name);
> +		xstats[count++].value = *(uint64_t *)(((char *)hw_stats) +
> +							rte_ixgbe_stats_strings[i].offset);
> +	}
> +
> +	return count;
> +}

Shouldn't it be xstats[i] instead of xstats[count] ?

Does it work when using "show port in test-pmd"?

> +
> +static void
> +ixgbe_dev_xstats_reset(struct rte_eth_dev *dev)
> +{
> +	struct ixgbe_hw_stats *stats =
> +			IXGBE_DEV_PRIVATE_TO_STATS(dev->data->dev_private);
> +
> +	/* HW registers are cleared on read */
> +	ixgbe_dev_xstats_get(dev, NULL, RTE_NB_XSTATS);
> +
> +	/* Reset software totals */
> +	memset(stats, 0, sizeof(*stats));
> +}
> +
>  static void
>  ixgbevf_dev_stats_get(struct rte_eth_dev *dev, struct rte_eth_stats *stats)
>  {
>