On 2024-06-06 3:34 a.m., Namhyung Kim wrote:

On Wed, Jun 5, 2024 at 10:21 AM Ian Rogers irogers@google.com wrote:

...

On Wed, Jun 5, 2024 at 9:10 AM kan.liang@linux.intel.com wrote:

...

From: Kan Liang kan.liang@linux.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@intel.com Signed-off-by: Kan Liang kan.liang@linux.intel.com

Reviewed-by: Ian Rogers irogers@google.com

Thanks, Ian

...

Cc: stable@vger.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;
  

Hmm.. Don't some metrics need events from different PMU? Like cycles per sec or branch instructions per sec..

Right.

In the hard-coded metrics, the events from a different PMU are SW_CPU_CLOCK and SW_TASK_CLOCK. They both have the stat type, STAT_NSECS. Perf should ignore the PMU checking for the type as below. I will send a V2 to fix it.

diff --git a/tools/perf/util/stat-shadow.c b/tools/perf/util/stat-shadow.c index 3466aa952442..d01335f18808 100644 --- a/tools/perf/util/stat-shadow.c +++ b/tools/perf/util/stat-shadow.c @@ -176,6 +176,9 @@ static double find_stat(const struct evsel *evsel, int aggr_idx, enum stat_type if (type != evsel__stat_type(cur)) continue;

+ if ((type != STAT_NSECS) && (evsel->pmu != cur->pmu)) + continue; + aggr = &cur->stats->aggr[aggr_idx]; if (type == STAT_NSECS) return aggr->counts.val;

Thanks, Kan

Thanks, Namhyung

...

...

•           aggr = &cur->stats->aggr[aggr_idx];
            if (type == STAT_NSECS)
                    return aggr->counts.val;
  

-- 2.35.1