[PATCH 1/2 v2] tools/tracing/rtla: osnoise_hist: use total duration for average calculation

From: Andreas Ziegler
Date: Tue Jan 03 2023 - 05:34:49 EST


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).

Fixes: 829a6c0b5698 ("rtla/osnoise: Add the hist mode")

Signed-off-by: Andreas Ziegler <br015@xxxxxxxxxx>
---
Changes v1 -> v2:
- add 'Fixes' line (Daniel)

tools/tracing/rtla/src/osnoise_hist.c | 5 ++++-
1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/tools/tracing/rtla/src/osnoise_hist.c b/tools/tracing/rtla/src/osnoise_hist.c
index 5d7ea479ac89..fe34452fc4ec 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)
--
2.34.1