Re: [PATCH] net/gve: add support for basic stats

[Joshua Washington <joshwash@google.com>]

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Hello,

I tested it out, and the updates to testpmd seem to work.

Before applying the second patch:
  ---------------------- Forward statistics for port 0
 ----------------------
  RX-packets: 0              RX-dropped: 0             RX-total: 0
  TX-packets: 43769238       TX-dropped: 62634         TX-total: 43831872

----------------------------------------------------------------------------

  ---------------------- Forward statistics for port 1
 ----------------------
  RX-packets: 0              RX-dropped: 0             RX-total: 0
  TX-packets: 43761119       TX-dropped: 70753         TX-total: 43831872

----------------------------------------------------------------------------

  +++++++++++++++ Accumulated forward statistics for all
ports+++++++++++++++
  RX-packets: 0              RX-dropped: 0             RX-total: 0
  TX-packets: 87530357       TX-dropped: 157302        TX-total: 87687659

++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++

62634 + 70753 = 133387 != 157302

After applying the second patch:
  ---------------------- Forward statistics for port 0
 ----------------------
  RX-packets: 0              RX-dropped: 0             RX-total: 0
  TX-packets: 12590721       TX-dropped: 36638         TX-total: 12627359

----------------------------------------------------------------------------

  ---------------------- Forward statistics for port 1
 ----------------------
  RX-packets: 0              RX-dropped: 0             RX-total: 0
  TX-packets: 12596255       TX-dropped: 31746         TX-total: 12628001

----------------------------------------------------------------------------

  +++++++++++++++ Accumulated forward statistics for all
ports+++++++++++++++
  RX-packets: 0              RX-dropped: 0             RX-total: 0
  TX-packets: 25186976       TX-dropped: 68384         TX-total: 25255360

++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++

Thanks,
Josh

On Wed, Jan 18, 2023 at 8:22 AM Ferruh Yigit <ferruh.yigit@amd.com> wrote:

> On 12/19/2022 7:38 PM, Joshua Washington wrote:
> > Hello,
> >
> > As it turns out, this error actually propagates to the "total" stats as
> > well, which I assume is just calculated by adding TX-packets and
> > TX-dropped. Here are the full stats from the example that Rushil
> mentioned:
> >
> >   ---------------------- Forward statistics for port 0
> >  ----------------------
> >   RX-packets: 2453802        RX-dropped: 0             RX-total: 2453802
> >   TX-packets: 34266881       TX-dropped: 447034        TX-total: 34713915
> >
> >
> ----------------------------------------------------------------------------
> >
> >   ---------------------- Forward statistics for port 1
> >  ----------------------
> >   RX-packets: 34713915       RX-dropped: 0             RX-total: 34713915
> >   TX-packets: 2453802        TX-dropped: 0             TX-total: 2453802
> >
> >
> ----------------------------------------------------------------------------
> >
> >   +++++++++++++++ Accumulated forward statistics for all
> > ports+++++++++++++++
> >   RX-packets: 37167717       RX-dropped: 0             RX-total: 37167717
> >   TX-packets: 36720683       TX-dropped: 807630        TX-total: 37528313
> >
> >
> ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
> >
> > It can be seen that the stats for the individual ports are consistent,
> > but the TX-total and TX-dropped are not consistent with the stats for
> > the individual ports, as I believe that the TX-total and RX-total
> > accumulated stats should be equal.
> >
>
> Hi Joshua, Rushil,
>
> As I checked for it, issue may be related to testpmd stats display,
>
> While displaying per port TX-dropped value, it only takes
> 'ports_stats[pt_id].tx_dropped' into account,
> but for accumulated TX-dropped results it takes both
> 'ports_stats[pt_id].tx_dropped' & 'stats.oerrors' into account.
>
> If you can reproduce it easily, can you please test with following change:
>
>  diff --git a/app/test-pmd/testpmd.c b/app/test-pmd/testpmd.c
>  index 134d79a55547..49322d07d7d6 100644
>  --- a/app/test-pmd/testpmd.c
>  +++ b/app/test-pmd/testpmd.c
>  @@ -2056,6 +2056,8 @@ fwd_stats_display(void)
>                          fwd_cycles += fs->core_cycles;
>          }
>          for (i = 0; i < cur_fwd_config.nb_fwd_ports; i++) {
>  +               uint64_t tx_dropped = 0;
>  +
>                  pt_id = fwd_ports_ids[i];
>                  port = &ports[pt_id];
>
>  @@ -2077,8 +2079,9 @@ fwd_stats_display(void)
>                  total_recv += stats.ipackets;
>                  total_xmit += stats.opackets;
>                  total_rx_dropped += stats.imissed;
>  -               total_tx_dropped += ports_stats[pt_id].tx_dropped;
>  -               total_tx_dropped += stats.oerrors;
>  +               tx_dropped += ports_stats[pt_id].tx_dropped;
>  +               tx_dropped += stats.oerrors;
>  +               total_tx_dropped += tx_dropped;
>                  total_rx_nombuf  += stats.rx_nombuf;
>
>                  printf("\n  %s Forward statistics for port %-2d %s\n",
>  @@ -2105,8 +2108,8 @@ fwd_stats_display(void)
>
>                  printf("  TX-packets: %-14"PRIu64" TX-dropped: %-14"PRIu64
>                         "TX-total: %-"PRIu64"\n",
>  -                      stats.opackets, ports_stats[pt_id].tx_dropped,
>  -                      stats.opackets + ports_stats[pt_id].tx_dropped);
>  +                      stats.opackets, tx_dropped,
>  +                      stats.opackets + tx_dropped);
>
>                  if (record_burst_stats) {
>                          if (ports_stats[pt_id].rx_stream)
>
>
> >
> > On Mon, Dec 19, 2022 at 11:17 AM Rushil Gupta <rushilg@google.com
> > <mailto:rushilg@google.com>> wrote:
> >
> >     Hi all
> >     Josh just found out some inconsistencies in the Tx/Rx statistics sum
> >     for all ports. Not sure if we can screenshot here but it goes like
> >     this:
> >     Tx-dropped for port0: 447034
> >     Tx-dropped for port1: 0
> >     Accumulated forward statistics for all ports: 807630
> >
> >     Please note that this issue is only with Tx-dropped (not
> >     Tx-packets/Tx-total).
> >
> >
> >     On Wed, Dec 7, 2022 at 8:39 AM Stephen Hemminger
> >     <stephen@networkplumber.org <mailto:stephen@networkplumber.org>>
> wrote:
> >     >
> >     > On Wed, 7 Dec 2022 15:09:08 +0000
> >     > Ferruh Yigit <ferruh.yigit@amd.com <mailto:ferruh.yigit@amd.com>>
> >     wrote:
> >     >
> >     > > On 11/24/2022 7:33 AM, Junfeng Guo wrote:
> >     > > > Add support for dev_ops of stats_get and stats_reset.
> >     > > >
> >     > > > Queue stats update will be moved into xstat [1], but the basic
> >     stats
> >     > > > items may still be required. So we just keep the remaining
> >     ones and
> >     > > > will implement the queue stats via xstats in the coming
> release.
> >     > > >
> >     > > > [1]
> >     > > > https://elixir.bootlin.com/dpdk/v22.07/
> >     <https://elixir.bootlin.com/dpdk/v22.07/> \
> >     > > >     source/doc/guides/rel_notes/deprecation.rst#L118
> >     > > >
> >     > > > Signed-off-by: Xiaoyun Li <xiaoyun.li@intel.com
> >     <mailto:xiaoyun.li@intel.com>>
> >     > > > Signed-off-by: Junfeng Guo <junfeng.guo@intel.com
> >     <mailto:junfeng.guo@intel.com>>
> >     > >
> >     > > <...>
> >     > >
> >     > > > +static int
> >     > > > +gve_dev_stats_get(struct rte_eth_dev *dev, struct
> >     rte_eth_stats *stats)
> >     > > > +{
> >     > > > +   uint16_t i;
> >     > > > +
> >     > > > +   for (i = 0; i < dev->data->nb_tx_queues; i++) {
> >     > > > +           struct gve_tx_queue *txq = dev->data->tx_queues[i];
> >     > > > +           if (txq == NULL)
> >     > > > +                   continue;
> >     > > > +
> >     > > > +           stats->opackets += txq->packets;
> >     > > > +           stats->obytes += txq->bytes;
> >     > > > +           stats->oerrors += txq->errors;
> >     > >
> >     > > Hi Junfeng, Qi, Jingjing, Beilei,
> >     > >
> >     > > Above logic looks wrong to me, did you test it?
> >     > >
> >     > > If the 'gve_dev_stats_get()' called multiple times (without
> >     stats reset
> >     > > in between), same values will be keep added to stats.
> >     > > Some hw based implementations does this, because reading from
> stats
> >     > > registers automatically reset those registers but this shouldn't
> >     be case
> >     > > for this driver.
> >     > >
> >     > > I expect it to be something like:
> >     > >
> >     > > local_stats = 0
> >     > > foreach queue
> >     > >       local_stats += queue->stats
> >     > > stats = local_stats
> >     >
> >     > The zero of local_stats is unnecessary.
> >     > The only caller of the PMD stats_get is rte_ethdev_stats_get
> >     > and it zeros the stats structure before calling the PMD.
> >     >
> >     >
> >     > int
> >     > rte_eth_stats_get(uint16_t port_id, struct rte_eth_stats *stats)
> >     > {
> >     >         struct rte_eth_dev *dev;
> >     >
> >     >         RTE_ETH_VALID_PORTID_OR_ERR_RET(port_id, -ENODEV);
> >     >         dev = &rte_eth_devices[port_id];
> >     >
> >     >         memset(stats, 0, sizeof(*stats));
> >     > ...
> >     >         stats->rx_nombuf = dev->data->rx_mbuf_alloc_failed;
> >     >         return eth_err(port_id, (*dev->dev_ops->stats_get)(dev,
> >     stats));
> >     >
> >     > If any PMD has extra memset in their stats get that could be
> removed.
> >
> >
> >
> > --
> >
> > Joshua Washington | Software Engineer | joshwash@google.com
> > <mailto:joshwash@google.com> | (414) 366-4423
> >
>
>

-- 

Joshua Washington | Software Engineer | joshwash@google.com | (414) 366-4423

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