Re: [PATCH 5/5] perf test: Add expand cgroup event test

[Namhyung Kim]

On Thu, Sep 24, 2020 at 7:36 AM Ian Rogers <irogers@xxxxxxxxxx> wrote:
>
> On Tue, Sep 22, 2020 at 7:00 PM Namhyung Kim <namhyung@xxxxxxxxxx> wrote:
> >
> > It'll expand given events for cgroups A, B and C.
> >
> >   $ ./perf test -v expansion
> >   69: Event expansion for cgroups                      :
> >   --- start ---
> >   test child forked, pid 983140
> >   metric expr 1 / IPC for CPI
> >   metric expr instructions / cycles for IPC
> >   found event instructions
> >   found event cycles
> >   adding {instructions,cycles}:W
> >   copying metric event for cgroup 'A': instructions (idx=0)
> >   copying metric event for cgroup 'B': instructions (idx=0)
> >   copying metric event for cgroup 'C': instructions (idx=0)
> >   test child finished with 0
> >   ---- end ----
> >   Event expansion for cgroups: Ok
> >
> > Cc: John Garry <john.garry@xxxxxxxxxx>
> > Signed-off-by: Namhyung Kim <namhyung@xxxxxxxxxx>
> > ---
[SNIP]
> Should this be #ifdef HAVE_LIBPFM ?

Do you mean the below function?
Actually I thought about it and ended up not using it.
Please see below..

>
> > +static int expand_libpfm_events(void)
> > +{
> > +       int ret;
> > +       struct evlist *evlist;
> > +       struct rblist metric_events;
> > +       const char event_str[] = "UNHALTED_CORE_CYCLES";
> > +       struct option opt = {
> > +               .value = &evlist,
> > +       };
> > +
> > +       symbol_conf.event_group = true;
> > +
> > +       evlist = evlist__new();
> > +       TEST_ASSERT_VAL("failed to get evlist", evlist);
> > +
> > +       ret = parse_libpfm_events_option(&opt, event_str, 0);
> > +       if (ret < 0) {
> > +               pr_debug("failed to parse libpfm event '%s', err %d\n",
> > +                        event_str, ret);
> > +               goto out;
> > +       }
> > +       if (perf_evlist__empty(evlist)) {
> > +               pr_debug("libpfm was not enabled\n");
> > +               goto out;
> > +       }

That's handled here.  The parse_libpfm_events_option()
will return 0 if HAVE_LIBPFM is not defined so evlist will be empty.

Thanks
Namhyung

> > +
> > +       rblist__init(&metric_events);
> > +       ret = test_expand_events(evlist, &metric_events);
> > +out:
> > +       evlist__delete(evlist);
> > +       return ret;
> > +}
> > +