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

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Message-Id: <20240605160848.4116061-1-kan.liang@linux.intel.com>
Date: Wed,  5 Jun 2024 09:08:48 -0700
From: kan.liang@...ux.intel.com
To: acme@...nel.org,
	namhyung@...nel.org,
	irogers@...gle.com,
	jolsa@...nel.org,
	adrian.hunter@...el.com,
	linux-perf-users@...r.kernel.org,
	linux-kernel@...r.kernel.org
Cc: Kan Liang <kan.liang@...ux.intel.com>,
	"Khalil, Amiri" <amiri.khalil@...el.com>,
	stable@...r.kernel.org
Subject: [PATCH] perf stat: Fix the hard-coded metrics calculation on the hybrid

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

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@...el.com>
Signed-off-by: Kan Liang <kan.liang@...ux.intel.com>
Cc: stable@...r.kernel.org
---
 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