diff mbox series

[V4,14/15] selftests/resctrl: Keep results from first test run

Message ID b229f0d6d1b66413ec6da0be8195a5c25b99089b.1729804024.git.reinette.chatre@intel.com
State Accepted
Commit 295b898426d8fb5b79672d1dae358ca8070f2196
Headers show
Series selftests/resctrl: Support diverse platforms with MBM and MBA tests | expand

Commit Message

Reinette Chatre Oct. 24, 2024, 9:18 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>
Reviewed-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
---
Changes since V2:
- Separate patch addresses Ilpo's observation about magic number in
  adjacent code.
- Add Ilpo's Reviewed-by tag.

Changes since V1:
- Remove comment about needing results from first run removed.
- Fix existing incorrect spacing while changing line.
---
 tools/testing/selftests/resctrl/cmt_test.c |  5 ++---
 tools/testing/selftests/resctrl/mba_test.c | 10 +++-------
 tools/testing/selftests/resctrl/mbm_test.c | 10 +++-------
 3 files changed, 8 insertions(+), 17 deletions(-)
diff mbox series

Patch

diff --git a/tools/testing/selftests/resctrl/cmt_test.c b/tools/testing/selftests/resctrl/cmt_test.c
index 4c3cf2c25a38..3bbf3042fb06 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 5b4f0aa7a3a4..4e6645b172e3 100644
--- a/tools/testing/selftests/resctrl/mba_test.c
+++ b/tools/testing/selftests/resctrl/mba_test.c
@@ -86,18 +86,14 @@  static bool show_mba_info(unsigned long *bw_imc, unsigned long *bw_resc)
 		int avg_diff_per;
 		float avg_diff;
 
-		/*
-		 * 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 4224f8ce3538..315b2ef3b3bc 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);