[PATCH 5.18 636/879] perf stat: Always keep perf metrics topdown events in a group

Greg Kroah-Hartman
2022-06-08T00:55:58Z

From: Kan Liang <kan.liang@linux.intel.com>

[ Upstream commit e8f4f794d7047dd36f090f44f12cd645fba204d2 ]

If any member in a group has a different cpu mask than the other
members, the current perf stat disables group. when the perf metrics
topdown events are part of the group, the below <not supported> error
will be triggered.

$ perf stat -e "{slots,topdown-retiring,uncore_imc_free_running_0/dclk/}" -a sleep 1
WARNING: grouped events cpus do not match, disabling group:
anon group { slots, topdown-retiring, uncore_imc_free_running_0/dclk/ }

Performance counter stats for 'system wide':

141,465,174 slots
<not supported> topdown-retiring
1,605,330,334 uncore_imc_free_running_0/dclk/

The perf metrics topdown events must always be grouped with a slots
event as leader.

Factor out evsel__remove_from_group() to only remove the regular events
from the group.

Remove evsel__must_be_in_group(), since no one use it anymore.

With the patch, the topdown events aren't broken from the group for the
splitting.

$ perf stat -e "{slots,topdown-retiring,uncore_imc_free_running_0/dclk/}" -a sleep 1
WARNING: grouped events cpus do not match, disabling group:
anon group { slots, topdown-retiring, uncore_imc_free_running_0/dclk/ }

Performance counter stats for 'system wide':

346,110,588 slots
124,608,256 topdown-retiring
1,606,869,976 uncore_imc_free_running_0/dclk/

1.003877592 seconds time elapsed

Fixes: a9a1790247bdcf3b ("perf stat: Ensure group is defined on top of the same cpu mask")
Signed-off-by: Kan Liang <kan.liang@linux.intel.com>
Acked-by: Ian Rogers <irogers@google.com>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Cc: Xing Zhengjun <zhengjun.xing@linux.intel.com>
Link: https://lore.kernel.org/r/20220518143900.1493980-3-kan.liang@linux.intel.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
tools/perf/builtin-stat.c | 7 ++-----
tools/perf/util/evlist.c | 6 +-----
tools/perf/util/evsel.c | 13 +++++++++++--
tools/perf/util/evsel.h | 2 +-
4 files changed, 15 insertions(+), 13 deletions(-)

diff --git a/tools/perf/builtin-stat.c b/tools/perf/builtin-stat.c
index a96f106dc93a..f058e8cddfa8 100644
--- a/tools/perf/builtin-stat.c
+++ b/tools/perf/builtin-stat.c
@@ -271,11 +271,8 @@ static void evlist__check_cpu_maps(struct evlist *evlist)
pr_warning(" %s: %s\n", evsel->name, buf);
}

- for_each_group_evsel(pos, leader) {
- evsel__set_leader(pos, pos);
- pos->core.nr_members = 0;
- }
- evsel->core.leader->nr_members = 0;
+ for_each_group_evsel(pos, leader)
+ evsel__remove_from_group(pos, leader);
}
}

diff --git a/tools/perf/util/evlist.c b/tools/perf/util/evlist.c
index 4804b52f2946..3084ec7e9325 100644
--- a/tools/perf/util/evlist.c
+++ b/tools/perf/util/evlist.c
@@ -1795,11 +1795,7 @@ struct evsel *evlist__reset_weak_group(struct evlist *evsel_list, struct evsel *
* them. Some events, like Intel topdown, require being
* in a group and so keep these in the group.
*/
- if (!evsel__must_be_in_group(c2) && c2 != leader) {
- evsel__set_leader(c2, c2);
- c2->core.nr_members = 0;
- leader->core.nr_members--;
- }
+ evsel__remove_from_group(c2, leader);

/*
* Set this for all former members of the group
diff --git a/tools/perf/util/evsel.c b/tools/perf/util/evsel.c
index b98882cbb286..deb428ee5e50 100644
--- a/tools/perf/util/evsel.c
+++ b/tools/perf/util/evsel.c
@@ -3083,7 +3083,16 @@ bool __weak arch_evsel__must_be_in_group(const struct evsel *evsel __maybe_unuse
return false;
}

-bool evsel__must_be_in_group(const struct evsel *evsel)
+/*
+ * Remove an event from a given group (leader).
+ * Some events, e.g., perf metrics Topdown events,
+ * must always be grouped. Ignore the events.
+ */
+void evsel__remove_from_group(struct evsel *evsel, struct evsel *leader)
{
- return arch_evsel__must_be_in_group(evsel);
+ if (!arch_evsel__must_be_in_group(evsel) && evsel != leader) {
+ evsel__set_leader(evsel, evsel);
+ evsel->core.nr_members = 0;
+ leader->core.nr_members--;
+ }
}
diff --git a/tools/perf/util/evsel.h b/tools/perf/util/evsel.h
index a36172ed4cf6..47f65f8e7c74 100644
--- a/tools/perf/util/evsel.h
+++ b/tools/perf/util/evsel.h
@@ -483,7 +483,7 @@ bool evsel__has_leader(struct evsel *evsel, struct evsel *leader);
bool evsel__is_leader(struct evsel *evsel);
void evsel__set_leader(struct evsel *evsel, struct evsel *leader);
int evsel__source_count(const struct evsel *evsel);
-bool evsel__must_be_in_group(const struct evsel *evsel);
+void evsel__remove_from_group(struct evsel *evsel, struct evsel *leader);

bool arch_evsel__must_be_in_group(const struct evsel *evsel);

--
2.35.1