Re: [dpdk-users] e1000 port stats

["Van Haaren, Harry" <harry.van.haaren@intel.com>]

From: Sridhar.V.Iyer [mailto:sridhariyer@versa-networks.com] 
> From gdb (KVM e1000), I see that the control is going to em_ethdev.c and not igb_ethdev.c (where the patch you provided applies). I added a similar patch in em_ethdev.c, but that didn’t help.
>
> However, when I apply the following patch, I seem to get the correct byte count:
>
> sridhar@sridhar-dev1:~/devel/15.2R1$ git diff
> diff --git a/usr/lib/DPDK/lib/librte_pmd_e1000/em_ethdev.c b/usr/lib/DPDK/lib/librte_pmd_e1000/em_ethdev.c
> index 8f9921c..83076ab 100644
> --- a/usr/lib/DPDK/lib/librte_pmd_e1000/em_ethdev.c
> +++ b/usr/lib/DPDK/lib/librte_pmd_e1000/em_ethdev.c
> @@ -828,8 +828,10 @@ eth_em_stats_get(struct rte_eth_dev *dev, struct rte_eth_stats *rte_stats)
>         stats->roc += E1000_READ_REG(hw, E1000_ROC);
>         stats->rjc += E1000_READ_REG(hw, E1000_RJC);
>
> -       stats->tor += E1000_READ_REG(hw, E1000_TORH);
> -       stats->tot += E1000_READ_REG(hw, E1000_TOTH);
> +       stats->tor += E1000_READ_REG(hw, E1000_TORL);
> +       stats->tor += ((uint64_t)E1000_READ_REG(hw, E1000_TORH) << 32);
> +       stats->tot += E1000_READ_REG(hw, E1000_TOTL);
> +       stats->tot += ((uint64_t)E1000_READ_REG(hw, E1000_TOTH) << 32);
> 
>         stats->tpr += E1000_READ_REG(hw, E1000_TPR);
>         stats->tpt += E1000_READ_REG(hw, E1000_TPT);

This part looks good - fixes reading the register for em pf driver.

Send this snippet as a patch to dev@dpdk.org - it is a valuable addition. Perhaps wait until after 2.2 has been released - then a new development window will open for PMD patches like this one.


> @@ -882,8 +884,8 @@ eth_em_stats_get(struct rte_eth_dev *dev, struct rte_eth_stats *rte_stats)
>
>        rte_stats->ipackets = stats->gprc;
>        rte_stats->opackets = stats->gptc;
> -       rte_stats->ibytes   = stats->gorc;
> -       rte_stats->obytes   = stats->gotc;
> +       rte_stats->ibytes   = stats->tor;
> +       rte_stats->obytes   = stats->tot;
>
> GORC/GOTC account for good octets and TOR/TOT account for total octets. The packets are being delivered to the application, so they >  aren’t being dropped.

This part makes an assumption that because you're not dropping packets now, means they will never be dropped. This is not a valid assumption: when a CPU gets overloaded packets will get dropped, which will invalidate the statistics: we need to find a better solution.

Cheers, -Harry