Re: [PATCH v5 2/2] ethdev: support xstats reset telemetry command

[Stephen Hemminger <stephen@networkplumber.org>]

On Tue, 4 Jul 2023 14:41:27 +0800
fengchengwen <fengchengwen@huawei.com> wrote:

> > A general comment about telemetry:
> > 
> > If an application exposes telemetry through an end user facing API, e.g. http(s) REST, it would be nice if non-read-only telemetry paths are easy to identify by following some DPDK standard convention, so the application does not need to manually maintain an allow-list of read-only paths.  
> 
> +1 for this point.
> 
> > 
> > Bruce's documentation about trace/log/telemetry/dump might also need to be updated regarding non-read-only telemetry actions.  
> 
> I just check Bruce's patch [1], and notice that the telemetry callback must be 'read-only': (Telemetry callbacks should not modify any program state, but be "read-only").
> 
> From internal product usage, we think xstats-reset is valid to identify problem, but this callback is not read-only.
> 
> We think telemetry callback should not limit to 'read-only'. Perhaps we could develop some strategy to better manage non-read-only callbacks (just like Morten's advise).
> 
> [1]: https://patchwork.dpdk.org/project/dpdk/patch/20230620170728.74117-3-bruce.richardson@intel.com/

This patch set had functional test failures, and there never was a good conclusion about allowing telemetry to do reset.

If you want to keep going with it, go through the feedback and resubmit.