Patch "perf metric: Don't remove scale from counts" has been added to the 6.6-stable tree

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

 



This is a note to let you know that I've just added the patch titled

    perf metric: Don't remove scale from counts

to the 6.6-stable tree which can be found at:
    http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:
     perf-metric-don-t-remove-scale-from-counts.patch
and it can be found in the queue-6.6 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.



commit 571c2269539611dfbcb1b47488b6afe00f7cbfeb
Author: Ian Rogers <irogers@xxxxxxxxxx>
Date:   Fri Feb 9 12:49:47 2024 -0800

    perf metric: Don't remove scale from counts
    
    [ 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@xxxxxxxxxx>
    Reviewed-by: Kan Liang <kan.liang@xxxxxxxxxxxxxxx>
    Cc: K Prateek Nayak <kprateek.nayak@xxxxxxx>
    Cc: James Clark <james.clark@xxxxxxx>
    Cc: Kaige Ye <ye@xxxxxxxxx>
    Cc: John Garry <john.g.garry@xxxxxxxxxx>
    Signed-off-by: Namhyung Kim <namhyung@xxxxxxxxxx>
    Link: https://lore.kernel.org/r/20240209204947.3873294-5-irogers@xxxxxxxxxx
    Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>

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]);
 			}
 		}




[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]
[Index of Archives]     [Linux USB Devel]     [Linux Audio Users]     [Yosemite News]     [Linux Kernel]     [Linux SCSI]

  Powered by Linux