[PATCH v8 07/13] selftests/resctrl: Add MBA test

From: Fenghua Yu
Date: Wed Nov 27 2019 - 20:43:33 EST


MBA (Memory Bandwidth Allocation) test starts a stressful memory
bandwidth benchmark and allocates memory bandwidth from 100% down
to 10% for the benchmark process. For each allocation, compare
perf IMC counter and mbm total bytes from resctrl. The difference
between the two values should be within a threshold to pass the test.

Default benchmark is built-in fill_buf. But users can specify their
own benchmark by option "-b".

We can add memory bandwidth allocation for multiple processes in the
future.

Signed-off-by: Sai Praneeth Prakhya <sai.praneeth.prakhya@xxxxxxxxx>,
Signed-off-by: Babu Moger <babu.moger@xxxxxxx>
Signed-off-by: Fenghua Yu <fenghua.yu@xxxxxxxxx>
---
tools/testing/selftests/resctrl/mba_test.c | 171 ++++++++++++++++++
tools/testing/selftests/resctrl/resctrl.h | 2 +
.../testing/selftests/resctrl/resctrl_tests.c | 16 +-
3 files changed, 188 insertions(+), 1 deletion(-)
create mode 100644 tools/testing/selftests/resctrl/mba_test.c

diff --git a/tools/testing/selftests/resctrl/mba_test.c b/tools/testing/selftests/resctrl/mba_test.c
new file mode 100644
index 000000000000..7bf8eaa6204b
--- /dev/null
+++ b/tools/testing/selftests/resctrl/mba_test.c
@@ -0,0 +1,171 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Memory Bandwidth Allocation (MBA) test
+ *
+ * Copyright (C) 2018 Intel Corporation
+ *
+ * Authors:
+ * Sai Praneeth Prakhya <sai.praneeth.prakhya@xxxxxxxxx>,
+ * Fenghua Yu <fenghua.yu@xxxxxxxxx>
+ */
+#include "resctrl.h"
+
+#define RESULT_FILE_NAME "result_mba"
+#define NUM_OF_RUNS 5
+#define MAX_DIFF 300
+#define ALLOCATION_MAX 100
+#define ALLOCATION_MIN 10
+#define ALLOCATION_STEP 10
+
+/*
+ * Change schemata percentage from 100 to 10%. Write schemata to specified
+ * con_mon grp, mon_grp in resctrl FS.
+ * For each allocation, run 5 times in order to get average values.
+ */
+static int mba_setup(int num, ...)
+{
+ static int runs_per_allocation, allocation = 100;
+ struct resctrl_val_param *p;
+ char allocation_str[64];
+ va_list param;
+
+ va_start(param, num);
+ p = va_arg(param, struct resctrl_val_param *);
+ va_end(param);
+
+ if (runs_per_allocation >= NUM_OF_RUNS)
+ runs_per_allocation = 0;
+
+ /* Only set up schemata once every NUM_OF_RUNS of allocations */
+ if (runs_per_allocation++ != 0)
+ return 0;
+
+ if (allocation < ALLOCATION_MIN || allocation > ALLOCATION_MAX)
+ return -1;
+
+ sprintf(allocation_str, "%d", allocation);
+
+ write_schemata(p->ctrlgrp, allocation_str, p->cpu_no, p->resctrl_val);
+ allocation -= ALLOCATION_STEP;
+
+ return 0;
+}
+
+static void show_mba_info(unsigned long *bw_imc, unsigned long *bw_resc)
+{
+ int allocation, runs;
+ bool failed = false;
+
+ printf("# Results are displayed in (MB)\n");
+ /* Memory bandwidth from 100% down to 10% */
+ for (allocation = 0; allocation < ALLOCATION_MAX / ALLOCATION_STEP;
+ allocation++) {
+ unsigned long avg_bw_imc, avg_bw_resc;
+ unsigned long sum_bw_imc = 0, sum_bw_resc = 0;
+ unsigned long avg_diff;
+
+ /*
+ * The first run is discarded due to inaccurate value from
+ * phase transition.
+ */
+ for (runs = NUM_OF_RUNS * allocation + 1;
+ 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_diff = labs((long)(avg_bw_resc - avg_bw_imc));
+
+ printf("%sok MBA schemata percentage %u smaller than %d %%\n",
+ avg_diff > MAX_DIFF ? "not " : "",
+ ALLOCATION_MAX - ALLOCATION_STEP * allocation,
+ MAX_DIFF);
+ tests_run++;
+ printf("# avg_diff: %lu\n", avg_diff);
+ printf("# avg_bw_imc: %lu\n", avg_bw_imc);
+ printf("# avg_bw_resc: %lu\n", avg_bw_resc);
+ if (avg_diff > MAX_DIFF)
+ failed = true;
+ }
+
+ printf("%sok schemata change using MBA%s\n", failed ? "not " : "",
+ failed ? " # at least one test failed" : "");
+ tests_run++;
+}
+
+static int check_results(void)
+{
+ char *token_array[8], output[] = RESULT_FILE_NAME, temp[512];
+ unsigned long bw_imc[1024], bw_resc[1024];
+ int runs;
+ FILE *fp;
+
+ fp = fopen(output, "r");
+ if (!fp) {
+ perror(output);
+
+ return errno;
+ }
+
+ runs = 0;
+ while (fgets(temp, sizeof(temp), fp)) {
+ char *token = strtok(temp, ":\t");
+ int fields = 0;
+
+ while (token) {
+ token_array[fields++] = token;
+ token = strtok(NULL, ":\t");
+ }
+
+ /* Field 3 is perf imc value */
+ bw_imc[runs] = strtoul(token_array[3], NULL, 0);
+ /* Field 5 is resctrl value */
+ bw_resc[runs] = strtoul(token_array[5], NULL, 0);
+ runs++;
+ }
+
+ fclose(fp);
+
+ show_mba_info(bw_imc, bw_resc);
+
+ return 0;
+}
+
+void mba_test_cleanup(void)
+{
+ remove(RESULT_FILE_NAME);
+}
+
+int mba_schemata_change(int cpu_no, char *bw_report, char **benchmark_cmd)
+{
+ struct resctrl_val_param param = {
+ .resctrl_val = "mba",
+ .ctrlgrp = "c1",
+ .mongrp = "m1",
+ .cpu_no = cpu_no,
+ .mum_resctrlfs = 1,
+ .filename = RESULT_FILE_NAME,
+ .bw_report = bw_report,
+ .setup = mba_setup
+ };
+ int ret;
+
+ remove(RESULT_FILE_NAME);
+
+ if (!validate_resctrl_feature_request("mba"))
+ return -1;
+
+ ret = resctrl_val(benchmark_cmd, &param);
+ if (ret)
+ return ret;
+
+ ret = check_results();
+ if (ret)
+ return ret;
+
+ mba_test_cleanup();
+
+ return 0;
+}
diff --git a/tools/testing/selftests/resctrl/resctrl.h b/tools/testing/selftests/resctrl/resctrl.h
index c92bc50c6751..a6196ab6b59f 100644
--- a/tools/testing/selftests/resctrl/resctrl.h
+++ b/tools/testing/selftests/resctrl/resctrl.h
@@ -81,5 +81,7 @@ int resctrl_val(char **benchmark_cmd, struct resctrl_val_param *param);
int mbm_bw_change(int span, int cpu_no, char *bw_report, char **benchmark_cmd);
void tests_cleanup(void);
void mbm_test_cleanup(void);
+int mba_schemata_change(int cpu_no, char *bw_report, char **benchmark_cmd);
+void mba_test_cleanup(void);

#endif /* RESCTRL_H */
diff --git a/tools/testing/selftests/resctrl/resctrl_tests.c b/tools/testing/selftests/resctrl/resctrl_tests.c
index 496c8030fe43..0ed953a97db2 100644
--- a/tools/testing/selftests/resctrl/resctrl_tests.c
+++ b/tools/testing/selftests/resctrl/resctrl_tests.c
@@ -26,6 +26,7 @@ static void cmd_help(void)
void tests_cleanup(void)
{
mbm_test_cleanup();
+ mba_test_cleanup();
}

int main(int argc, char **argv)
@@ -33,7 +34,7 @@ int main(int argc, char **argv)
int res, c, cpu_no = 1, span = 250, argc_new = argc, i, ben_ind;
char *benchmark_cmd[BENCHMARK_ARGS], bw_report[64], bm_type[64];
char benchmark_cmd_area[BENCHMARK_ARGS][BENCHMARK_ARG_SIZE];
- bool has_ben = false, mbm_test = true;
+ bool has_ben = false, mbm_test = true, mba_test = true;
int ben_count;

for (i = 0; i < argc; i++) {
@@ -54,9 +55,12 @@ int main(int argc, char **argv)
token = strtok(optarg, ",");

mbm_test = false;
+ mba_test = false;
while (token) {
if (!strcmp(token, "mbm")) {
mbm_test = true;
+ } else if (!strcmp(token, "mba")) {
+ mba_test = true;
} else {
printf("invalid argument\n");

@@ -126,6 +130,16 @@ int main(int argc, char **argv)
tests_run++;
}

+ if (mba_test) {
+ printf("# Starting MBA Schemata change ...\n");
+ if (!has_ben)
+ sprintf(benchmark_cmd[1], "%d", span);
+ res = mba_schemata_change(cpu_no, bw_report, benchmark_cmd);
+ printf("%sok MBA: schemata change\n", res ? "not " : "");
+ mba_test_cleanup();
+ tests_run++;
+ }
+
printf("1..%d\n", tests_run);

return 0;
--
2.19.1