Re: [dpdk-dev] [PATCH 2/2] net/cxgbe: remove queue stats from basic stats

[Rahul Lakkireddy <rahul.lakkireddy@chelsio.com>]

Hi Andrew,

On Thursday, July 07/01/21, 2021 at 17:50:19 +0300, Andrew Rybchenko wrote:
> On 6/3/21 6:30 PM, Rahul Lakkireddy wrote:
> > Remove queue stats from basic stats because they're now available
> > via xstats API. Also remove RTE_ETH_DEV_AUTOFILL_QUEUE_XSTATS flag.
> > 
> > Signed-off-by: Rahul Lakkireddy <rahul.lakkireddy@chelsio.com>
> > ---
> >  drivers/net/cxgbe/cxgbe_ethdev.c | 18 +++---------------
> >  1 file changed, 3 insertions(+), 15 deletions(-)
> > 
> > diff --git a/drivers/net/cxgbe/cxgbe_ethdev.c b/drivers/net/cxgbe/cxgbe_ethdev.c
> > index 8dee3fc3b6..141a2de808 100644
> > --- a/drivers/net/cxgbe/cxgbe_ethdev.c
> > +++ b/drivers/net/cxgbe/cxgbe_ethdev.c
> > @@ -747,22 +747,12 @@ static int cxgbe_dev_stats_get(struct rte_eth_dev *eth_dev,
> >  	eth_stats->oerrors  = ps.tx_error_frames;
> >  
> >  	for (i = 0; i < pi->n_rx_qsets; i++) {
> > -		struct sge_eth_rxq *rxq =
> > -			&s->ethrxq[pi->first_rxqset + i];
> > +		struct sge_eth_rxq *rxq = &s->ethrxq[pi->first_rxqset + i];
> >  
> > -		eth_stats->q_ipackets[i] = rxq->stats.pkts;
> > -		eth_stats->q_ibytes[i] = rxq->stats.rx_bytes;
> > -		eth_stats->ipackets += eth_stats->q_ipackets[i];
> > -		eth_stats->ibytes += eth_stats->q_ibytes[i];
> > +		eth_stats->ipackets += rxq->stats.pkts;
> > +		eth_stats->ibytes += rxq->stats.rx_bytes;
> >  	}
> >  
> > -	for (i = 0; i < pi->n_tx_qsets; i++) {
> > -		struct sge_eth_txq *txq =
> > -			&s->ethtxq[pi->first_txqset + i];
> > -
> > -		eth_stats->q_opackets[i] = txq->stats.pkts;
> > -		eth_stats->q_obytes[i] = txq->stats.tx_bytes;
> > -	}
> >  	return 0;
> >  }
> >  
> > @@ -1697,8 +1687,6 @@ static int eth_cxgbe_dev_init(struct rte_eth_dev *eth_dev)
> >  		return 0;
> >  	}
> >  
> > -	eth_dev->data->dev_flags |= RTE_ETH_DEV_AUTOFILL_QUEUE_XSTATS;
> > -
> >  	snprintf(name, sizeof(name), "cxgbeadapter%d", eth_dev->data->port_id);
> >  	adapter = rte_zmalloc(name, sizeof(*adapter), 0);
> >  	if (!adapter)
> > 
> 
> As I understand it is correct to remove
> RTE_ETH_DEV_AUTOFILL_QUEUE_XSTATS to avoid duplication of per-queue
> stats in xstats. But I don't understand why per-queue
> stats are removed from basic stats. It still makes sense and
> useful. Am I missing something?

The per-queue stats are being removed from basic stats here because
these will be removed from rte_eth_stats, as per the below deprecation
notice.

* ethdev: Queue specific stats fields will be removed from ``struct rte_eth_stats``.
  Mentioned fields are: ``q_ipackets``, ``q_opackets``, ``q_ibytes``, ``q_obytes``,
  ``q_errors``.
  Instead queue stats will be received via xstats API. Current method support
  will be limited to maximum 256 queues.
  Also compile time flag ``RTE_ETHDEV_QUEUE_STAT_CNTRS`` will be removed.

Thanks,
Rahul