From: Ian Rogers <irogers@google.com>
Date: Wed, 23 Apr 2025 05:03:58 +0000 (-0700)
Subject: perf tool_pmu: Fix aggregation on duration_time
X-Git-Tag: v6.16-rc1~57^2~131
X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=68cb1567439fa325ba980f3b5b67f95d3953eafd;p=thirdparty%2Flinux.git

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: 240505b2d0adcdc8 ("perf tool_pmu: Factor tool events into their own PMU")
Reported-by: Stephane Eranian <eranian@google.com>
Reviewed-by: James Clark <james.clark@linaro.org>
Signed-off-by: Ian 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: Arnaldo Carvalho de Melo <acme@redhat.com>
---

diff --git a/tools/perf/util/tool_pmu.c b/tools/perf/util/tool_pmu.c
index 97b327d1ce4a0..727a10e3f9900 100644
--- a/tools/perf/util/tool_pmu.c
+++ b/tools/perf/util/tool_pmu.c
@@ -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;
 }