Re: [PATCH v8 4/4] perf tools: add support for libpfm4

Ian Rogers
2020-04-14T18:14:26Z

On Tue, Apr 14, 2020 at 8:21 AM Jiri Olsa <jolsa@redhat.com> wrote:
>
> On Sat, Apr 11, 2020 at 12:46:31AM -0700, Ian Rogers wrote:
>
> SNIP
>
> > TAG_FOLDERS= . ../lib ../include
> > TAG_FILES= ../../include/uapi/linux/perf_event.h
> > diff --git a/tools/perf/builtin-list.c b/tools/perf/builtin-list.c
> > index 965ef017496f..7b64cd34266e 100644
> > --- a/tools/perf/builtin-list.c
> > +++ b/tools/perf/builtin-list.c
> > @@ -18,6 +18,10 @@
> > #include <subcmd/parse-options.h>
> > #include <stdio.h>
> >
> > +#ifdef HAVE_LIBPFM
> > +#include "util/pfm.h"
> > +#endif
>
> so we have the HAVE_LIBPFM you could do the:
>
> #ifdef HAVE_LIBPFM
> #else
> #endif
>
> in util/pfm.h and add stubs for libpfm_initialize and others
> in case HAVE_LIBPFM is not defined.. that clear out all the
> #ifdefs in the change
>
>
> SNIP
>
> > diff --git a/tools/perf/tests/builtin-test.c b/tools/perf/tests/builtin-test.c
> > index b6322eb0f423..8b323151f22c 100644
> > --- a/tools/perf/tests/builtin-test.c
> > +++ b/tools/perf/tests/builtin-test.c
> > @@ -313,6 +313,15 @@ static struct test generic_tests[] = {
> > .desc = "maps__merge_in",
> > .func = test__maps__merge_in,
> > },
> > + {
> > + .desc = "Test libpfm4 support",
> > + .func = test__pfm,
> > + .subtest = {
> > + .skip_if_fail = true,
> > + .get_nr = test__pfm_subtest_get_nr,
> > + .get_desc = test__pfm_subtest_get_desc,
> > + }
>
> awesome :)
>
> SNIP
>
> > diff --git a/tools/perf/util/evsel.c b/tools/perf/util/evsel.c
> > index d23db6755f51..83ad76d3d2be 100644
> > --- a/tools/perf/util/evsel.c
> > +++ b/tools/perf/util/evsel.c
> > @@ -2447,9 +2447,15 @@ bool perf_evsel__fallback(struct evsel *evsel, int err,
> > const char *sep = ":";
> >
> > /* Is there already the separator in the name. */
> > +#ifndef HAVE_LIBPFM
> > if (strchr(name, '/') ||
> > strchr(name, ':'))
> > sep = "";
> > +#else
> > + if (strchr(name, '/') ||
> > + (strchr(name, ':') && !evsel->is_libpfm_event))
> > + sep = "";
> > +#endif
>
>
> ^^^^^^^^
>
> >
> > if (asprintf(&new_name, "%s%su", name, sep) < 0)
> > return false;
> > diff --git a/tools/perf/util/evsel.h b/tools/perf/util/evsel.h
> > index 53187c501ee8..397d335d5e24 100644
> > --- a/tools/perf/util/evsel.h
> > +++ b/tools/perf/util/evsel.h
> > @@ -76,6 +76,9 @@ struct evsel {
> > bool ignore_missing_thread;
> > bool forced_leader;
> > bool use_uncore_alias;
> > +#ifdef HAVE_LIBPFM
> > + bool is_libpfm_event;
> > +#endif
>
> perhaps we could had this one in unconditionaly,
> because I think we have some members like that
> for aux tracing.. and that would remove the #ifdef
> above
>
>
> SNIP
>
> >
> > +#ifdef HAVE_LIBPFM
> > +struct evsel *parse_events__pfm_add_event(int idx, struct perf_event_attr *attr,
> > + char *name, struct perf_pmu *pmu)
> > +{
> > + return __add_event(NULL, &idx, attr, false, name, pmu, NULL, false,
> > + NULL);
> > +}
> > +#endif
>
> could you instead add parse_events__add_event and call it from pfm code?

I wasn't clear whether this was just a name change given the different
arguments on existing functions. Hopefully everything is addressed in
the v9 set:
https://lore.kernel.org/lkml/20200414181054.22435-2-irogers@google.com/T/#m32fc3e3605e49b01e12418f59ef3977cab0561ed

Thanks,
Ian

> SNIP
>
> > + pmu = perf_pmu__find_by_type((unsigned int)attr.type);
> > + evsel = parse_events__pfm_add_event(evlist->core.nr_entries,
> > + &attr, q, pmu);
> > + if (evsel == NULL)
> > + goto error;
> > +
> > + evsel->is_libpfm_event = true;
> > +
> > + evlist__add(evlist, evsel);
> > +
> > + if (grp_evt == 0)
> > + grp_leader = evsel;
> > +
> > + if (grp_evt > -1) {
> > + evsel->leader = grp_leader;
> > + grp_leader->core.nr_members++;
> > + grp_evt++;
> > + }
> > +
> > + if (*sep == '}') {
> > + if (grp_evt < 0) {
> > + ui__error("cannot close a non-existing event group\n");
> > + goto error;
> > + }
> > + evlist->nr_groups++;
> > + grp_leader = NULL;
> > + grp_evt = -1;
> > + }
> > + evsel->is_libpfm_event = true;
>
> seems to be set twice in here
>
>
> > + }
> > + return 0;
> > +error:
> > + free(p_orig);
> > + return -1;
> > +}
> > +
> > +static const char *srcs[PFM_ATTR_CTRL_MAX] = {
> > + [PFM_ATTR_CTRL_UNKNOWN] = "???",
> > + [PFM_ATTR_CTRL_PMU] = "PMU",
> > + [PFM_ATTR_CTRL_PERF_EVENT] = "perf_event",
> > +};
>
> SNIP
>
> thanks,
> jirka
>