Re: [PATCH 06/10] perf tools: Collect other metrics in struct egroup

[Jiri Olsa <jolsa@redhat.com>]

On Fri, Jun 26, 2020 at 02:48:02PM -0700, Ian Rogers wrote:
> On Fri, Jun 26, 2020 at 12:47 PM Jiri Olsa <jolsa@kernel.org> wrote:
> >
> > Collecting other metrics in struct egroup object,
> > so we can process them later on.
> >
> > The change will parse or 'other' metric names out of
> > expression and 'resolve' them.
> >
> > Every used expression needs to have 'metric:' prefix,
> > like:
> >   cache_miss_cycles = metric:dcache_miss_cpi + metric:icache_miss_cycles
> >
> > All 'other' metrics are disolved into one context,
> > meaning all 'other' metrics events and addded to
> > the parent context.
> >
> > Signed-off-by: Jiri Olsa <jolsa@kernel.org>
> > ---
> >  .../arch/x86/skylake/skl-metrics.json         |   2 +-
> >  tools/perf/util/expr.c                        |  11 ++
> >  tools/perf/util/expr.h                        |   1 +
> >  tools/perf/util/metricgroup.c                 | 158 ++++++++++++++++--
> >  4 files changed, 157 insertions(+), 15 deletions(-)
> >
> > diff --git a/tools/perf/pmu-events/arch/x86/skylake/skl-metrics.json b/tools/perf/pmu-events/arch/x86/skylake/skl-metrics.json
> > index 8704efeb8d31..71e5a2b471ac 100644
> > --- a/tools/perf/pmu-events/arch/x86/skylake/skl-metrics.json
> > +++ b/tools/perf/pmu-events/arch/x86/skylake/skl-metrics.json
> > @@ -57,7 +57,7 @@
> >      },
> >      {
> >          "BriefDescription": "Instructions Per Cycle (per Logical Processor)",
> > -        "MetricExpr": "INST_RETIRED.ANY / CPU_CLK_UNHALTED.THREAD",
> > +        "MetricExpr": "1/metric:CPI",
> >          "MetricGroup": "TopDownL1",
> >          "MetricName": "IPC"
> >      },
> > diff --git a/tools/perf/util/expr.c b/tools/perf/util/expr.c
> > index aa14c7111ecc..cd73dae4588c 100644
> > --- a/tools/perf/util/expr.c
> > +++ b/tools/perf/util/expr.c
> > @@ -150,3 +150,14 @@ int expr__find_other(const char *expr, const char *one,
> >
> >         return ret;
> >  }
> > +
> > +#define METRIC "metric:"
> > +
> > +bool expr__is_metric(const char *name, const char **metric)
> > +{
> > +       int ret = !strncmp(name, METRIC, sizeof(METRIC) - 1);
> > +
> > +       if (ret && metric)
> > +               *metric = name + sizeof(METRIC) - 1;
> > +       return ret;
> > +}
> 
> Should expr.l recognize metric:... as a different kind of token rather
> than an ID?

hm, we still want it to be returned as ID token, and the processing
code needs a way to distinguish between event and metric, so I'd think
we need to keep it, but I'll double check

thanks,
jirka