[PATCH 6.8 426/715] perf metric: Don't remove scale from counts

Sasha Levin
2024-03-24T22:41:59Z

From: Ian Rogers <irogers@google.com>

[ Upstream commit 6d6be5eb45b423a37d746d3ee0fd0c78f76ead9f ]

Counts were switched from the scaled saved value form to the
aggregated count to avoid double accounting. When this happened the
removing of scaling for a count should have been removed, however, it
wasn't and this wasn't observed as it normally doesn't matter because
a counter's scale is 1. A problem was observed with RAPL events that
are scaled.

Fixes: 37cc8ad77cf8 ("perf metric: Directly use counts rather than saved_value")
Signed-off-by: Ian Rogers <irogers@google.com>
Reviewed-by: Kan Liang <kan.liang@linux.intel.com>
Cc: K Prateek Nayak <kprateek.nayak@amd.com>
Cc: James Clark <james.clark@arm.com>
Cc: Kaige Ye <ye@kaige.org>
Cc: John Garry <john.g.garry@oracle.com>
Signed-off-by: Namhyung Kim <namhyung@kernel.org>
Link: https://lore.kernel.org/r/20240209204947.3873294-5-irogers@google.com
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
tools/perf/util/stat-shadow.c | 7 +------
1 file changed, 1 insertion(+), 6 deletions(-)

diff --git a/tools/perf/util/stat-shadow.c b/tools/perf/util/stat-shadow.c
index e31426167852a..cf573ff3fa84f 100644
--- a/tools/perf/util/stat-shadow.c
+++ b/tools/perf/util/stat-shadow.c
@@ -414,12 +414,7 @@ static int prepare_metric(struct evsel **metric_events,
val = NAN;
source_count = 0;
} else {
- /*
- * If an event was scaled during stat gathering,
- * reverse the scale before computing the
- * metric.
- */
- val = aggr->counts.val * (1.0 / metric_events[i]->scale);
+ val = aggr->counts.val;
source_count = evsel__source_count(metric_events[i]);
}
}
--
2.43.0