[PATCH] perf stat: Fix the hard-coded metrics calculation on the hybrid

From: kan . liang
Date: Wed Jun 05 2024 - 12:10:32 EST


From: Kan Liang <kan.liang@xxxxxxxxxxxxxxx>

The hard-coded metrics is wrongly calculated on the hybrid machine.

$ perf stat -e cycles,instructions -a sleep 1

Performance counter stats for 'system wide':

18,205,487 cpu_atom/cycles/
9,733,603 cpu_core/cycles/
9,423,111 cpu_atom/instructions/ # 0.52 insn per cycle
4,268,965 cpu_core/instructions/ # 0.23 insn per cycle

The insn per cycle for cpu_core should be 4,268,965 / 9,733,603 = 0.44.

When finding the metric events, the find_stat() doesn't take the PMU
type into account. The cpu_atom/cycles/ is wrongly used to calculate
the IPC of the cpu_core.

Fixes: 0a57b910807a ("perf stat: Use counts rather than saved_value")
Reported-by: "Khalil, Amiri" <amiri.khalil@xxxxxxxxx>
Signed-off-by: Kan Liang <kan.liang@xxxxxxxxxxxxxxx>
Cc: stable@xxxxxxxxxxxxxxx
---
tools/perf/util/stat-shadow.c | 4 ++++
1 file changed, 4 insertions(+)

diff --git a/tools/perf/util/stat-shadow.c b/tools/perf/util/stat-shadow.c
index 3466aa952442..4d0edc061f1a 100644
--- a/tools/perf/util/stat-shadow.c
+++ b/tools/perf/util/stat-shadow.c
@@ -176,6 +176,10 @@ static double find_stat(const struct evsel *evsel, int aggr_idx, enum stat_type
if (type != evsel__stat_type(cur))
continue;

+ /* Ignore if not the PMU we're looking for. */
+ if (evsel->pmu != cur->pmu)
+ continue;
+
aggr = &cur->stats->aggr[aggr_idx];
if (type == STAT_NSECS)
return aggr->counts.val;
--
2.35.1