Commit 68cb1567 authored by Ian Rogers's avatar Ian Rogers Committed by Arnaldo Carvalho de Melo
Browse files

perf tool_pmu: Fix aggregation on duration_time 



evsel__count_has_error() fails counters when the enabled or running time
are 0. The duration_time event reads 0 when the cpu_map_idx != 0 to
avoid aggregating time over CPUs. Change the enable and running time
to always have a ratio of 100% so that evsel__count_has_error won't
fail.

Before:
```
$ sudo /tmp/perf/perf stat --per-core -a -M UNCORE_FREQ sleep 1

 Performance counter stats for 'system wide':

S0-D0-C0              1      2,615,819,485      UNC_CLOCK.SOCKET                 #     2.61 UNCORE_FREQ
S0-D0-C0              2      <not counted>      duration_time

       1.002111784 seconds time elapsed
```

After:
```
$ perf stat --per-core -a -M UNCORE_FREQ sleep 1

 Performance counter stats for 'system wide':

S0-D0-C0              1        758,160,296      UNC_CLOCK.SOCKET                 #     0.76 UNCORE_FREQ
S0-D0-C0              2      1,003,438,246      duration_time

       1.002486017 seconds time elapsed
```

Note: the metric reads the value a different way and isn't impacted.

Fixes: 240505b2 ("perf tool_pmu: Factor tool events into their own PMU")
Reported-by: default avatarStephane Eranian <eranian@google.com>
Reviewed-by: default avatarJames Clark <james.clark@linaro.org>
Signed-off-by: default avatarIan Rogers <irogers@google.com>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Ian Rogers <irogers@google.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Kan Liang <kan.liang@linux.intel.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Richter <tmricht@linux.ibm.com>
Link: https://lore.kernel.org/r/20250423050358.94310-1-irogers@google.com


Signed-off-by: default avatarArnaldo Carvalho de Melo <acme@redhat.com>
parent b1b26ce8

tools/perf/util/tool_pmu.c

+7 −1
Original line number Diff line number Diff line
@@ -486,8 +486,14 @@ int evsel__tool_pmu_read(struct evsel *evsel, int cpu_map_idx, int thread) 
		delta_start *= 1000000000 / ticks_per_sec;

	}

	count->val    = delta_start;

	count->ena    = count->run = delta_start;

	count->lost   = 0;

	/*

	 * The values of enabled and running must make a ratio of 100%. The

	 * exact values don't matter as long as they are non-zero to avoid

	 * issues with evsel__count_has_error.

	 */

	count->ena++;

	count->run++;

	return 0;

}