This is a note to let you know that I've just added the patch titled
tools/tracing/rtla: osnoise_hist: use total duration for average calculation
to the 6.1-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:
tools-tracing-rtla-osnoise_hist-use-total-duration-f.patch
and it can be found in the queue-6.1 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
commit ecd1490c40bd3866424fe8890eaa3bfef3b87a73
Author: Andreas Ziegler <br015@xxxxxxxxxx>
Date: Tue Jan 3 11:33:59 2023 +0100
tools/tracing/rtla: osnoise_hist: use total duration for average calculation
[ Upstream commit fe137a4fe0e77eb95396cfc5c3dd7df404421aa4 ]
Sampled durations must be weighted by observed quantity, to arrive at a correct
average duration value.
Perform calculation of total duration by summing (duration * count).
Link: https://lkml.kernel.org/r/20230103103400.275566-2-br015@xxxxxxxxxx
Fixes: 829a6c0b5698 ("rtla/osnoise: Add the hist mode")
Signed-off-by: Andreas Ziegler <br015@xxxxxxxxxx>
Acked-by: Daniel Bristot de Oliveira <bristot@xxxxxxxxxx>
Signed-off-by: Steven Rostedt (Google) <rostedt@xxxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
diff --git a/tools/tracing/rtla/src/osnoise_hist.c b/tools/tracing/rtla/src/osnoise_hist.c
index 5d7ea479ac89f..fe34452fc4ec0 100644
--- a/tools/tracing/rtla/src/osnoise_hist.c
+++ b/tools/tracing/rtla/src/osnoise_hist.c
@@ -121,6 +121,7 @@ static void osnoise_hist_update_multiple(struct osnoise_tool *tool, int cpu,
{
struct osnoise_hist_params *params = tool->params;
struct osnoise_hist_data *data = tool->data;
+ unsigned long long total_duration;
int entries = data->entries;
int bucket;
int *hist;
@@ -131,10 +132,12 @@ static void osnoise_hist_update_multiple(struct osnoise_tool *tool, int cpu,
if (data->bucket_size)
bucket = duration / data->bucket_size;
+ total_duration = duration * count;
+
hist = data->hist[cpu].samples;
data->hist[cpu].count += count;
update_min(&data->hist[cpu].min_sample, &duration);
- update_sum(&data->hist[cpu].sum_sample, &duration);
+ update_sum(&data->hist[cpu].sum_sample, &total_duration);
update_max(&data->hist[cpu].max_sample, &duration);
if (bucket < entries)
