Messages in this thread | | | From | Ian Rogers <> | Date | Sun, 31 May 2020 17:04:47 -0700 | Subject | Re: [PATCH] perf stat: Ensure group is defined on top of the same cpu mask |
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On Sun, May 31, 2020 at 9:22 AM Jiri Olsa <jolsa@kernel.org> wrote: > > Jin Yao reported the issue (and posted first versions of this change) > with groups being defined over events with different cpu mask. > > This causes assert aborts in get_group_fd, like: > > # perf stat -M "C2_Pkg_Residency" -a -- sleep 1 > perf: util/evsel.c:1464: get_group_fd: Assertion `!(fd == -1)' failed. > Aborted > > All the events in the group have to be defined over the same > cpus so the group_fd can be found for every leader/member pair. > > Adding check to ensure this condition is met and removing the > group (with warning) if we detect mixed cpus, like: > > $ sudo perf stat -e '{power/energy-cores/,cycles},{instructions,power/energy-cores/}' > WARNING: event cpu maps do not match, disabling group: > anon group { power/energy-cores/, cycles } > anon group { instructions, power/energy-cores/ }
This is really cool! I wonder if there is a better wording for 'event cpu maps' ? It may be useful to list what the cpu maps are for the events as a diagnostic aid.
Thanks, Ian
> Fixes: 6a4bb04caacc8 ("perf tools: Enable grouping logic for parsed events") > Co-developed-by: Jin Yao <yao.jin@linux.intel.com> > Signed-off-by: Jin Yao <yao.jin@linux.intel.com> > Signed-off-by: Jiri Olsa <jolsa@kernel.org> > --- > tools/perf/builtin-stat.c | 51 +++++++++++++++++++++++++++++++++++++++ > 1 file changed, 51 insertions(+) > > diff --git a/tools/perf/builtin-stat.c b/tools/perf/builtin-stat.c > index b2b79aa161dd..512a41363d07 100644 > --- a/tools/perf/builtin-stat.c > +++ b/tools/perf/builtin-stat.c > @@ -190,6 +190,55 @@ static struct perf_stat_config stat_config = { > .big_num = true, > }; > > +static bool cpus_map_matched(struct evsel *a, struct evsel *b) > +{ > + if (!a->core.cpus && !b->core.cpus) > + return true; > + > + if (!a->core.cpus || !b->core.cpus) > + return false; > + > + if (a->core.cpus->nr != b->core.cpus->nr) > + return false; > + > + for (int i = 0; i < a->core.cpus->nr; i++) { > + if (a->core.cpus->map[i] != b->core.cpus->map[i]) > + return false; > + } > + > + return true; > +} > + > +static void evlist__check_cpu_maps(struct evlist *evlist) > +{ > + struct evsel *evsel, *pos, *leader; > + char buf[1024]; > + > + evlist__for_each_entry(evlist, evsel) { > + leader = evsel->leader; > + > + /* Check that leader matches cpus with each member. */ > + if (leader == evsel) > + continue; > + if (cpus_map_matched(leader, evsel)) > + continue; > + > + /* > + * If there's mismatch display dismantle the > + * group and warn user. > + */ > + WARN_ONCE(1, "WARNING: group events cpu maps do not match, disabling group:\n"); > + evsel__group_desc(leader, buf, sizeof(buf)); > + pr_warning(" %s\n", buf); > + > + for_each_group_evsel(pos, leader) { > + pos->leader = pos; > + pos->core.nr_members = 0; > + } > + evsel->leader->core.nr_members = 0; > + } > +} > + > static inline void diff_timespec(struct timespec *r, struct timespec *a, > struct timespec *b) > { > @@ -1962,6 +2011,8 @@ int cmd_stat(int argc, const char **argv) > } else if (argc && !strncmp(argv[0], "rep", 3)) > return __cmd_report(argc, argv); > > + evlist__check_cpu_maps(evsel_list); > + > interval = stat_config.interval; > timeout = stat_config.timeout; > > -- > 2.25.4 >
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