diff mbox series

[6/6] selftests/resctrl: Keep results from first test run

Message ID 772813207becd105d309de43d1ab03e52bbd3091.1724970211.git.reinette.chatre@intel.com
State Superseded
Headers show
Series selftests/resctrl: Support diverse platforms with MBM and MBA tests | expand

Commit Message

Reinette Chatre Aug. 29, 2024, 10:52 p.m. UTC
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 mbox series

Patch

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);