[dpdk-dev] [PATCH] doc: announce xstats api change for 16.07

[Thomas Monjalon]

2016-04-06 09:02, Van Haaren, Harry:
> + David Harton,
> 
> > From: Thomas Monjalon [mailto:thomas.monjalon at 6wind.com]
> > Subject: Re: [dpdk-dev] [PATCH] doc: announce xstats api change for 16.07
> > 2016-04-05 18:58, Harry van Haaren:
> > > +* ABI change is planned for the xstats API
> 
> > Have you already submitted a RFC patch to let us have an opinion on the change?
> > We need, at least, to see the structure changes.
> 
> This API break is to allow changing the API of xstats given the conversation that was on-list, as discussed in this thread:
> 
> http://thread.gmane.org/gmane.comp.networking.dpdk.devel/31728/focus=31903
> 
> The issue we are going to fix is that currently PMDs copy strings when retrieving statistics, which causes unnecessary overhead. The implementation is not decided yet, but using an int->value mapping seems logical.

I am not sure performance is so much critical when retrieving statistics.
The extended stats can be infinitely extended. So a string identifier seems
a lot more natural.
I do not agree to add a new numeric identifier in the API each time a driver
wants to report a specific statistic for debugging purpose.

> The rte_eth_xstats struct size may be modified, and the API to retrieve statistics will be modified.