perf parse-events: Don't reorder ungrouped events by PMU

The pmu_group_name by default returns "cpu" which on non-hybrid/ARM
means that ungrouped software, and hardware events are all going to
sort by the original insertion index.

However, on hybrid and ARM wildcard expansion may mean the PMU name is
set and events will be unnecessarily reordered - triggering the
reordering warning.

Signed-off-by: Ian Rogers <[email protected]>
Tested-by: Kan Liang <[email protected]>
Cc: Adrian Hunter <[email protected]>
Cc: Ahmad Yasin <[email protected]>
Cc: Alexander Shishkin <[email protected]>
Cc: Andi Kleen <[email protected]>
Cc: Athira Rajeev <[email protected]>
Cc: Caleb Biggers <[email protected]>
Cc: Edward Baker <[email protected]>
Cc: Florian Fischer <[email protected]>
Cc: Ingo Molnar <[email protected]>
Cc: James Clark <[email protected]>
Cc: Jiri Olsa <[email protected]>
Cc: John Garry <[email protected]>
Cc: Kajol Jain <[email protected]>
Cc: Kang Minchul <[email protected]>
Cc: Leo Yan <[email protected]>
Cc: Mark Rutland <[email protected]>
Cc: Namhyung Kim <[email protected]>
Cc: Perry Taylor <[email protected]>
Cc: Peter Zijlstra <[email protected]>
Cc: Ravi Bangoria <[email protected]>
Cc: Rob Herring <[email protected]>
Cc: Samantha Alt <[email protected]>
Cc: Stephane Eranian <[email protected]>
Cc: Sumanth Korikkar <[email protected]>
Cc: Suzuki Poulouse <[email protected]>
Cc: Thomas Richter <[email protected]>
Cc: Tiezhu Yang <[email protected]>
Cc: Weilin Wang <[email protected]>
Cc: Xing Zhengjun <[email protected]>
Cc: Yang Jihong <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Arnaldo Carvalho de Melo <[email protected]>

Author: captain5050

tools/perf/util/parse-events.c

@@ -2140,25 +2140,32 @@ static int evlist__cmp(void *state, const struct list_head *l, const struct list
 	int *leader_idx = state;
 	int lhs_leader_idx = *leader_idx, rhs_leader_idx = *leader_idx, ret;
 	const char *lhs_pmu_name, *rhs_pmu_name;
+	bool lhs_has_group = false, rhs_has_group = false;
 
 	/*
 	 * First sort by grouping/leader. Read the leader idx only if the evsel
 	 * is part of a group, as -1 indicates no group.
 	 */
-	if (lhs_core->leader != lhs_core || lhs_core->nr_members > 1)
+	if (lhs_core->leader != lhs_core || lhs_core->nr_members > 1) {
+		lhs_has_group = true;
 		lhs_leader_idx = lhs_core->leader->idx;
-	if (rhs_core->leader != rhs_core || rhs_core->nr_members > 1)
+	}
+	if (rhs_core->leader != rhs_core || rhs_core->nr_members > 1) {
+		rhs_has_group = true;
 		rhs_leader_idx = rhs_core->leader->idx;
+	}
 
 	if (lhs_leader_idx != rhs_leader_idx)
 		return lhs_leader_idx - rhs_leader_idx;
 
-	/* Group by PMU. Groups can't span PMUs. */
-	lhs_pmu_name = evsel__group_pmu_name(lhs);
-	rhs_pmu_name = evsel__group_pmu_name(rhs);
-	ret = strcmp(lhs_pmu_name, rhs_pmu_name);
-	if (ret)
-		return ret;
+	/* Group by PMU if there is a group. Groups can't span PMUs. */
+	if (lhs_has_group && rhs_has_group) {
+		lhs_pmu_name = evsel__group_pmu_name(lhs);
+		rhs_pmu_name = evsel__group_pmu_name(rhs);
+		ret = strcmp(lhs_pmu_name, rhs_pmu_name);
+		if (ret)
+			return ret;
+	}
 
 	/* Architecture specific sorting. */
 	return arch_evlist__cmp(lhs, rhs);