DPDK patches and discussions
 help / color / mirror / Atom feed
From: Kyle Larose <eomereadig@gmail.com>
To: Wei Zhao1 <wei.zhao1@intel.com>
Cc: dev@dpdk.org
Subject: Re: [dpdk-dev] [PATCH v2] net/i40e: fix Rx statistic inconsistent
Date: Fri, 29 Jul 2016 13:16:53 -0400	[thread overview]
Message-ID: <CAMFWN9mU7_NekFioMUMOkTER=MWihuHo2Ksk7gF-6W86dwnRxA@mail.gmail.com> (raw)
In-Reply-To: <1469782239-48758-1-git-send-email-wei.zhao1@intel.com>

On Fri, Jul 29, 2016 at 4:50 AM, Wei Zhao1 <wei.zhao1@intel.com> wrote:
> rx_good_bytes and rx_good_packets statistic is inconsistent when port
> stopped,ipackets statistic is minus the discard packets but rx_bytes
> statistic not.Also,i40e has no statistic of discard bytes, so we have to
> delete discard packets item from rx_good_packets statistic.
>
> Fixes: 9aace75fc82e ("i40e: fix statistics")
>
> Signed-off-by: Wei Zhao1 <wei.zhao1@intel.com>
> ---
>  drivers/net/i40e/i40e_ethdev.c | 3 +--
>  1 file changed, 1 insertion(+), 2 deletions(-)
>
> diff --git a/drivers/net/i40e/i40e_ethdev.c b/drivers/net/i40e/i40e_ethdev.c
> index 11a5804..553dfd9 100644
> --- a/drivers/net/i40e/i40e_ethdev.c
> +++ b/drivers/net/i40e/i40e_ethdev.c
> @@ -2319,8 +2319,7 @@ i40e_dev_stats_get(struct rte_eth_dev *dev, struct rte_eth_stats *stats)
>
>         stats->ipackets = pf->main_vsi->eth_stats.rx_unicast +
>                         pf->main_vsi->eth_stats.rx_multicast +
> -                       pf->main_vsi->eth_stats.rx_broadcast -
> -                       pf->main_vsi->eth_stats.rx_discards;
> +                       pf->main_vsi->eth_stats.rx_broadcast;
>         stats->opackets = pf->main_vsi->eth_stats.tx_unicast +
>                         pf->main_vsi->eth_stats.tx_multicast +
>                         pf->main_vsi->eth_stats.tx_broadcast;
> --
> 2.5.5
>

Is it not worse to report a received packet when no packet was
actually received by the upper layers under normal operations than to
ensure that packets and  bytes are consistent when an interface is
stopped? It seems like the first case is much more likely to occur
than the second.

Are we just introducing a new issue to fix another?

How does this behaviour compare to other NICs? Does the ixgbe report
discarded packets in its ipackets? My reading of the driver is that it
does not. In fact, it does something interesting to deal with the
problem:

from: http://dpdk.org/browse/dpdk/tree/drivers/net/ixgbe/ixgbe_ethdev.c

/*
* An errata states that gprc actually counts good + missed packets:
* Workaround to set gprc to summated queue packet receives
*/
hw_stats->gprc = *total_qprc;

total_gprc is equal to the sum of the qprc per queue. Can we do
something similar on the i40e instead of adding unicast, mulitcast and
broadcast?

  reply	other threads:[~2016-07-29 17:16 UTC|newest]

Thread overview: 8+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2016-07-29  8:50 Wei Zhao1
2016-07-29 17:16 ` Kyle Larose [this message]
2016-08-01  8:58   ` Zhao1, Wei
2016-08-02  3:27   ` Zhao1, Wei
2016-08-02  6:59     ` Zhao1, Wei
2016-08-02 16:22       ` Kyle Larose
2016-08-09  2:18         ` Zhao1, Wei
2016-08-22 11:10           ` Thomas Monjalon

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to='CAMFWN9mU7_NekFioMUMOkTER=MWihuHo2Ksk7gF-6W86dwnRxA@mail.gmail.com' \
    --to=eomereadig@gmail.com \
    --cc=dev@dpdk.org \
    --cc=wei.zhao1@intel.com \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).