From 5c49b6c3f2cc6d44f691c4aa3d22ca49bedf637b Mon Sep 17 00:00:00 2001 From: Ian Rogers Date: Tue, 18 Jul 2023 17:18:34 -0700 Subject: [PATCH] perf parse-events: Extra care around force grouped events Perf metric (topdown) events on Intel Icelake+ machines require a group, however, they may be next to events that don't require a group. Consider: cycles,slots,topdown-fe-bound The cycles event needn't be grouped but slots and topdown-fe-bound need grouping. Prior to this change, as slots and topdown-fe-bound need a group forcing and all events share the same PMU, slots and topdown-fe-bound would be forced into a group with cycles. This is a bug on two fronts, cycles wasn't supposed to be grouped and cycles can't be a group leader with a perf metric event. This change adds recognition that cycles isn't force grouped and so it shouldn't be force grouped with slots and topdown-fe-bound. Fixes: a90cc5a9eeab45ea ("perf evsel: Don't let evsel__group_pmu_name() traverse unsorted group") Signed-off-by: Ian Rogers Tested-by: Andi Kleen Cc: Adrian Hunter Cc: Alexander Shishkin Cc: Ingo Molnar Cc: Jiri Olsa Cc: Kan Liang Cc: Mark Rutland Cc: Namhyung Kim Cc: Peter Zijlstra Cc: Xing Zhengjun Link: https://lore.kernel.org/r/20230719001836.198363-2-irogers@google.com Signed-off-by: Arnaldo Carvalho de Melo --- tools/perf/util/parse-events.c | 14 ++++++++++---- 1 file changed, 10 insertions(+), 4 deletions(-) diff --git a/tools/perf/util/parse-events.c b/tools/perf/util/parse-events.c index acde097..af46835 100644 --- a/tools/perf/util/parse-events.c +++ b/tools/perf/util/parse-events.c @@ -2149,7 +2149,7 @@ static int parse_events__sort_events_and_fix_groups(struct list_head *list) int idx = 0, unsorted_idx = -1; struct evsel *pos, *cur_leader = NULL; struct perf_evsel *cur_leaders_grp = NULL; - bool idx_changed = false; + bool idx_changed = false, cur_leader_force_grouped = false; int orig_num_leaders = 0, num_leaders = 0; int ret; @@ -2190,7 +2190,7 @@ static int parse_events__sort_events_and_fix_groups(struct list_head *list) const struct evsel *pos_leader = evsel__leader(pos); const char *pos_pmu_name = pos->group_pmu_name; const char *cur_leader_pmu_name, *pos_leader_pmu_name; - bool force_grouped = arch_evsel__must_be_in_group(pos); + bool pos_force_grouped = arch_evsel__must_be_in_group(pos); /* Reset index and nr_members. */ if (pos->core.idx != idx) @@ -2206,7 +2206,8 @@ static int parse_events__sort_events_and_fix_groups(struct list_head *list) cur_leader = pos; cur_leader_pmu_name = cur_leader->group_pmu_name; - if ((cur_leaders_grp != pos->core.leader && !force_grouped) || + if ((cur_leaders_grp != pos->core.leader && + (!pos_force_grouped || !cur_leader_force_grouped)) || strcmp(cur_leader_pmu_name, pos_pmu_name)) { /* Event is for a different group/PMU than last. */ cur_leader = pos; @@ -2216,9 +2217,14 @@ static int parse_events__sort_events_and_fix_groups(struct list_head *list) * group. */ cur_leaders_grp = pos->core.leader; + /* + * Avoid forcing events into groups with events that + * don't need to be in the group. + */ + cur_leader_force_grouped = pos_force_grouped; } pos_leader_pmu_name = pos_leader->group_pmu_name; - if (strcmp(pos_leader_pmu_name, pos_pmu_name) || force_grouped) { + if (strcmp(pos_leader_pmu_name, pos_pmu_name) || pos_force_grouped) { /* * Event's PMU differs from its leader's. Groups can't * span PMUs, so update leader from the group/PMU -- 2.7.4