[PATCH 17/22] selftests/resctrl: Pass the real number of tests to show_cache_info()

From: Ilpo Järvinen
Date: Wed Apr 12 2023 - 09:25:01 EST


Some results include warm-up tests which are discarded before passing
the sum to show_cache_info(). Currently, show_cache_info() handles this
by subtracting -1 from number of tests in divisor. It is a trappy
construct to have sum and number of tests parameters to disagree like
this.

A more logical place for subtracting the skipped tests is where the sum
is calculated so move it there. Pass the correct number of tests to
show_cache_info() soit can use directly as the divisor for calculating
the average.

Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@xxxxxxxxxxxxxxx>
---
tools/testing/selftests/resctrl/cache.c | 2 +-
tools/testing/selftests/resctrl/cat_test.c | 2 +-
tools/testing/selftests/resctrl/cmt_test.c | 2 +-
3 files changed, 3 insertions(+), 3 deletions(-)

diff --git a/tools/testing/selftests/resctrl/cache.c b/tools/testing/selftests/resctrl/cache.c
index 5e59c239961c..835d5a892524 100644
--- a/tools/testing/selftests/resctrl/cache.c
+++ b/tools/testing/selftests/resctrl/cache.c
@@ -312,7 +312,7 @@ int show_cache_info(unsigned long sum_llc_val, int no_of_bits,
long avg_diff = 0;
int ret;

- avg_llc_val = sum_llc_val / (num_of_runs - 1);
+ avg_llc_val = sum_llc_val / num_of_runs;
avg_diff = (long)abs(cache_span - avg_llc_val);
diff_percent = ((float)cache_span - avg_llc_val) / cache_span * 100;

diff --git a/tools/testing/selftests/resctrl/cat_test.c b/tools/testing/selftests/resctrl/cat_test.c
index 2b5333ad13bb..edcc340744d7 100644
--- a/tools/testing/selftests/resctrl/cat_test.c
+++ b/tools/testing/selftests/resctrl/cat_test.c
@@ -81,7 +81,7 @@ static int check_results(struct resctrl_val_param *param)
no_of_bits = count_consecutive_bits(param->mask, NULL);

return show_cache_info(sum_llc_perf_miss, no_of_bits, param->span / 64,
- MAX_DIFF, MAX_DIFF_PERCENT, NUM_OF_RUNS,
+ MAX_DIFF, MAX_DIFF_PERCENT, runs - 1,
get_vendor() == ARCH_INTEL, false);
}

diff --git a/tools/testing/selftests/resctrl/cmt_test.c b/tools/testing/selftests/resctrl/cmt_test.c
index 15e824ada9b5..70c656581686 100644
--- a/tools/testing/selftests/resctrl/cmt_test.c
+++ b/tools/testing/selftests/resctrl/cmt_test.c
@@ -63,7 +63,7 @@ static int check_results(struct resctrl_val_param *param, int no_of_bits)
fclose(fp);

return show_cache_info(sum_llc_occu_resc, no_of_bits, param->span,
- MAX_DIFF, MAX_DIFF_PERCENT, NUM_OF_RUNS,
+ MAX_DIFF, MAX_DIFF_PERCENT, runs - 1,
true, true);
}

--
2.30.2