[PATCH 2/4] selftests/resctrl: Don't hard code divisor in MBM results

From: Ilpo Järvinen
Date: Wed Feb 08 2023 - 04:40:49 EST


From: Fenghua Yu <fenghua.yu@xxxxxxxxx>

Presently, while calculating MBM results, the divisor is hard coded as 4.
It's hard coded to 4 because "NUM_OF_RUNS" is defined as 5 and the test
does not count first result and hence 4. So, instead of hard coding the
value to 4, change it to NUM_OF_RUNS - 1.

Signed-off-by: Fenghua Yu <fenghua.yu@xxxxxxxxx>
---
tools/testing/selftests/resctrl/mbm_test.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/tools/testing/selftests/resctrl/mbm_test.c b/tools/testing/selftests/resctrl/mbm_test.c
index 8392e5c55ed0..4f85cbbfd037 100644
--- a/tools/testing/selftests/resctrl/mbm_test.c
+++ b/tools/testing/selftests/resctrl/mbm_test.c
@@ -31,8 +31,8 @@ show_bw_info(unsigned long *bw_imc, unsigned long *bw_resc, int span)
sum_bw_resc += bw_resc[runs];
}

- avg_bw_imc = sum_bw_imc / 4;
- avg_bw_resc = sum_bw_resc / 4;
+ avg_bw_imc = sum_bw_imc / (NUM_OF_RUNS - 1);
+ avg_bw_resc = sum_bw_resc / (NUM_OF_RUNS - 1);
avg_diff = (float)labs(avg_bw_resc - avg_bw_imc) / avg_bw_imc;
avg_diff_per = (int)(avg_diff * 100);

--
2.30.2