The resctrl selftests drop the results from every first test run to avoid (per comment) "inaccurate due to monitoring setup transition phase" data. Previously inaccurate data resulted from workloads needing some time to "settle" and also the measurements themselves to account for earlier measurements to measure across needed timeframe.
commit da50de0a92f3 ("selftests/resctrl: Calculate resctrl FS derived mem bw over sleep(1) only")
ensured that measurements accurately measure just the time frame of interest. The default "fill_buf" benchmark since separated the buffer prepare phase from the benchmark run phase reducing the need for the tests themselves to accommodate the benchmark's "settle" time.
With these enhancements there are no remaining portions needing to "settle" and the first test run can contribute to measurements.
Signed-off-by: Reinette Chatre reinette.chatre@intel.com --- tools/testing/selftests/resctrl/cmt_test.c | 5 ++--- tools/testing/selftests/resctrl/mba_test.c | 6 +++--- tools/testing/selftests/resctrl/mbm_test.c | 10 +++------- 3 files changed, 8 insertions(+), 13 deletions(-)
diff --git a/tools/testing/selftests/resctrl/cmt_test.c b/tools/testing/selftests/resctrl/cmt_test.c index f09d5dfab38c..85cb93d525b8 100644 --- a/tools/testing/selftests/resctrl/cmt_test.c +++ b/tools/testing/selftests/resctrl/cmt_test.c @@ -99,14 +99,13 @@ static int check_results(struct resctrl_val_param *param, size_t span, int no_of }
/* Field 3 is llc occ resc value */ - if (runs > 0) - sum_llc_occu_resc += strtoul(token_array[3], NULL, 0); + sum_llc_occu_resc += strtoul(token_array[3], NULL, 0); runs++; } fclose(fp);
return show_results_info(sum_llc_occu_resc, no_of_bits, span, - MAX_DIFF, MAX_DIFF_PERCENT, runs - 1, true); + MAX_DIFF, MAX_DIFF_PERCENT, runs, true); }
static void cmt_test_cleanup(void) diff --git a/tools/testing/selftests/resctrl/mba_test.c b/tools/testing/selftests/resctrl/mba_test.c index 204b9ac4b108..dddf9bc04cfa 100644 --- a/tools/testing/selftests/resctrl/mba_test.c +++ b/tools/testing/selftests/resctrl/mba_test.c @@ -88,14 +88,14 @@ static bool show_mba_info(unsigned long *bw_imc, unsigned long *bw_resc) * The first run is discarded due to inaccurate value from * phase transition. */ - for (runs = NUM_OF_RUNS * allocation + 1; + for (runs = NUM_OF_RUNS * allocation; runs < NUM_OF_RUNS * allocation + NUM_OF_RUNS ; runs++) { sum_bw_imc += bw_imc[runs]; sum_bw_resc += bw_resc[runs]; }
- avg_bw_imc = sum_bw_imc / (NUM_OF_RUNS - 1); - avg_bw_resc = sum_bw_resc / (NUM_OF_RUNS - 1); + avg_bw_imc = sum_bw_imc / NUM_OF_RUNS; + avg_bw_resc = sum_bw_resc / NUM_OF_RUNS; if (avg_bw_imc < THROTTLE_THRESHOLD || avg_bw_resc < THROTTLE_THRESHOLD) { ksft_print_msg("Bandwidth below threshold (%d MiB). Dropping results from MBA schemata %u.\n", THROTTLE_THRESHOLD, diff --git a/tools/testing/selftests/resctrl/mbm_test.c b/tools/testing/selftests/resctrl/mbm_test.c index 734bfa4f42b3..bbacba4ec195 100644 --- a/tools/testing/selftests/resctrl/mbm_test.c +++ b/tools/testing/selftests/resctrl/mbm_test.c @@ -22,17 +22,13 @@ show_bw_info(unsigned long *bw_imc, unsigned long *bw_resc, size_t span) int runs, ret, avg_diff_per; float avg_diff = 0;
- /* - * Discard the first value which is inaccurate due to monitoring setup - * transition phase. - */ - for (runs = 1; runs < NUM_OF_RUNS ; runs++) { + for (runs = 0; runs < NUM_OF_RUNS ; runs++) { sum_bw_imc += bw_imc[runs]; 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; + avg_bw_resc = sum_bw_resc / NUM_OF_RUNS; avg_diff = (float)labs(avg_bw_resc - avg_bw_imc) / avg_bw_imc; avg_diff_per = (int)(avg_diff * 100);