Re: [dpdk-dev] [PATCH v3 4/7] ethdev: remove HW specific stats in stats structs

[Kyle Larose <eomereadig@gmail.com>]

Hi Maryam,

I was not aware of the proc_info app. Is there any documentation on dpdk.org
about it, or should I browse the code?

Thanks,

Kyle

On Fri, Jun 26, 2015 at 10:30 AM, Tahhan, Maryam <maryam.tahhan@intel.com>
wrote:

>
>
> On Fri, Jun 26, 2015 at 8:59 AM, Maryam Tahhan <maryam.tahhan@intel.com>
> wrote:
>
> Remove non generic stats in rte_stats_strings and mark the relevant
> fields in struct rte_eth_stats as deprecated.
>
> Signed-off-by: Maryam Tahhan <maryam.tahhan@intel.com>
> ---
>  doc/guides/rel_notes/abi.rst  | 11 +++++++++++
>  lib/librte_ether/rte_ethdev.c |  9 ---------
>  lib/librte_ether/rte_ethdev.h | 30 ++++++++++++++++++++----------
>  3 files changed, 31 insertions(+), 19 deletions(-)
>
> diff --git a/doc/guides/rel_notes/abi.rst b/doc/guides/rel_notes/abi.rst
> index f00a6ee..957b13f 100644
> --- a/doc/guides/rel_notes/abi.rst
> +++ b/doc/guides/rel_notes/abi.rst
> @@ -38,3 +38,14 @@ Examples of Deprecation Notices
>
>  Deprecation Notices
>  -------------------
> +* The following fields have been deprecated in rte_eth_stats:
> +  * uint64_t imissed
> +  * uint64_t ibadcrc
> +  * uint64_t ibadlen
> +  * uint64_t imcasts
> +  * uint64_t fdirmatch
> +  * uint64_t fdirmiss
> +  * uint64_t tx_pause_xon
> +  * uint64_t rx_pause_xon
> +  * uint64_t tx_pause_xoff
> +  * uint64_t rx_pause_xoff
>
>
>
> Are CRC errors (ibadcrc) truly hardware specific? Which NIC (aside from
> purely virtual ones) does not have a MAC which does frame checksumming?
> Likewise, which NIC doesn't drop because the PCI bus/cpu/etc is too busy to
> pull packets off of it (imissed)?
>
> Debugging interactions with NICs is hard enough with only CRC errors and
> missed packets to go on. Without those it is close to impossible. CRC
> errors are almost guaranteed any time a bare-metal application is deployed:
> dirty fiber, bad SFPs, etc. How will users of the application be able to
> determine why their packets are dropping if they can only see "in errors"?
>
> I understand that we want to avoid placing too much useless information
> into these statistics structures. However, without a hardware-independent
> way of accessing fairly standard networking-equipment diagnostics, I feel
> like any real-world application using DPDK will be terribly cumbersome to
> build: every single one will need to develop an abstraction layer which
> detects the attached NICs, and loads an appropriate driver to integrate
> with the xstats api.
>
>
>
> Is there any plan for such an API? If not, is it really a good idea to
> deprecate these stats?
>
> Thanks,
>
> Kyle
>
>
>
> Hi Kyle
>
>
>
> If it’s just for debug/diagnostic purposes that this information is being
> used then I would recommend using the proc_info app which is already
> integrated with xstats will give you detailed error statistics. It runs as
> a DPDK secondary process.
>
>
>
> I’m not sure about crcerrors and imissed, I had taken feedback to my
> previous version of the patches onboard and made the changes based on that.
>
>
>
> Regards
>
> Maryam
>