tools/tracing/rtla: osnoise_hist: use total duration for average calculation

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@umbiko.net
Fixes: 829a6c0b5698 ("rtla/osnoise: Add the hist mode")

Signed-off-by: Andreas Ziegler <br015@umbiko.net>
Acked-by: Daniel Bristot de Oliveira <bristot@kernel.org>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>

diff --git a/tools/tracing/rtla/src/osnoise_hist.c b/tools/tracing/rtla/src/osnoise_hist.c
index 5d7ea47..fe34452 100644 (file)
--- 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)