Re: [PATCHv4 00/19] perf metric: Add support to reuse metric

[John Garry]

On 01/08/2020 12:40, Paul A. Clarke wrote:
> > v4 changes:
> >    - removed acks from patch because it changed a bit
> >      with the last fixes:
> >        perf metric: Collect referenced metrics in struct metric_ref_node
> >    - fixed runtime metrics [Kajol Jain]
> >    - increased recursion depth [Paul A. Clarke]
> >    - changed patches due to dependencies:
> >        perf metric: Collect referenced metrics in struct metric_ref_node
> >        perf metric: Add recursion check when processing nested metrics
> >        perf metric: Rename struct egroup to metric
> >        perf metric: Rename group_list to metric_list
> >
> > Also available in here:
> >    git://git.kernel.org/pub/scm/linux/kernel/git/jolsa/perf.git
> >    perf/metric
> I built and ran from the above git branch, and things seem to work.
> Indeed, I was able to apply my changes to exploit the new capabilities
> via modifications to tools/perf/pmu-events/arch/powerpc/power9/metrics.json,
> as I posted earlier (and will submit once this set gets merged).

Hi Paul,

I was just wondering: Does perf subtest 10.3 work ok for you with the 
metric reuse?

That's "Parsing of PMU event table metrics" subtest.

Hi Jirka,

If I add something like this:
    {
        "BriefDescription": "dummy test1",
        "MetricExpr": "Bad_Speculation + Frontend_Bound",
        "MetricGroup": "TopdownL1",
        "MetricName": "dummytest",
        "PublicDescription": "dummy test2"
    },

I get "Parse event failed metric 'dummytest' id 'bad_speculation' expr 
'bad_speculation + frontend_bound'"

Thanks,
john

> Tested-by: Paul A. Clarke<pc@xxxxxxxxxx>
>
> One thing I noted, but which also occurs without these patches, is that
> the perf metrics are not computed unless run as root:
> --
> $ perf stat --metrics br_misprediction_percent command
>
>   Performance counter stats for 'command':
>
>       1,823,530,051      pm_br_pred:u
>           2,662,705      pm_br_mpred_cmpl:u
>
> $ /usr/bin/sudo perf stat --metrics br_misprediction_percent command
>
>   Performance counter stats for 'command':
>
>       1,824,655,269      pm_br_pred                #     0.09 br_misprediction_percent
>           1,654,466      pm_br_mpred_cmpl
> --