[PATCH v8 06/13] selftests/resctrl: Add MBM test

From: Fenghua Yu
Date: Wed Nov 27 2019 - 20:43:50 EST


MBM (Memory Bandwidth Monitoring) test is the first implemented selftest.
It starts a stressful memory bandwidth benchmark and assigns the
bandwidth pid in a resctrl monitoring group. Read and compare perf IMC
counter and MBM total bytes for the benchmark. The numbers should be
close enough 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 monitoring 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/Makefile | 7 +-
tools/testing/selftests/resctrl/mbm_test.c | 145 ++++++++++++++++++
tools/testing/selftests/resctrl/resctrl.h | 6 +
.../testing/selftests/resctrl/resctrl_tests.c | 132 ++++++++++++++++
tools/testing/selftests/resctrl/resctrl_val.c | 2 +
tools/testing/selftests/resctrl/resctrlfs.c | 77 ++++++++++
6 files changed, 368 insertions(+), 1 deletion(-)
create mode 100644 tools/testing/selftests/resctrl/mbm_test.c
create mode 100644 tools/testing/selftests/resctrl/resctrl_tests.c

diff --git a/tools/testing/selftests/resctrl/Makefile b/tools/testing/selftests/resctrl/Makefile
index 76bbd6d3e4a8..d585cc1948cc 100644
--- a/tools/testing/selftests/resctrl/Makefile
+++ b/tools/testing/selftests/resctrl/Makefile
@@ -3,10 +3,15 @@ CFLAGS = -g -Wall
SRCS=$(wildcard *.c)
OBJS=$(SRCS:.c=.o)

+all: resctrl_tests
+
$(OBJS): $(SRCS)
$(CC) $(CFLAGS) -c $(SRCS)

+resctrl_tests: $(OBJS)
+ $(CC) $(CFLAGS) -o $@ $^
+
.PHONY: clean

clean:
- $(RM) $(OBJS)
+ $(RM) $(OBJS) resctrl_tests
diff --git a/tools/testing/selftests/resctrl/mbm_test.c b/tools/testing/selftests/resctrl/mbm_test.c
new file mode 100644
index 000000000000..4700f7453f81
--- /dev/null
+++ b/tools/testing/selftests/resctrl/mbm_test.c
@@ -0,0 +1,145 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Memory Bandwidth Monitoring (MBM) 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_mbm"
+#define MAX_DIFF 300
+#define NUM_OF_RUNS 5
+
+static void
+show_bw_info(unsigned long *bw_imc, unsigned long *bw_resc, int span)
+{
+ unsigned long avg_bw_imc = 0, avg_bw_resc = 0;
+ unsigned long sum_bw_imc = 0, sum_bw_resc = 0;
+ long avg_diff = 0;
+ int runs;
+
+ /*
+ * Discard the first value which is inaccurate due to monitoring setup
+ * transition phase.
+ */
+ for (runs = 1; 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_diff = avg_bw_resc - avg_bw_imc;
+
+ printf("%sok MBM: diff within %d%%\n",
+ labs(avg_diff) > MAX_DIFF ? "not " : "", MAX_DIFF);
+ tests_run++;
+ printf("# avg_diff: %lu\n", labs(avg_diff));
+ printf("# Span (MB): %d\n", span);
+ printf("# avg_bw_imc: %lu\n", avg_bw_imc);
+ printf("# avg_bw_resc: %lu\n", avg_bw_resc);
+}
+
+static int check_results(int span)
+{
+ unsigned long bw_imc[NUM_OF_RUNS], bw_resc[NUM_OF_RUNS];
+ char temp[1024], *token_array[8];
+ char output[] = RESULT_FILE_NAME;
+ int runs;
+ FILE *fp;
+
+ printf("# Checking for pass/fail\n");
+
+ fp = fopen(output, "r");
+ if (!fp) {
+ perror(output);
+
+ return errno;
+ }
+
+ runs = 0;
+ while (fgets(temp, sizeof(temp), fp)) {
+ char *token = strtok(temp, ":\t");
+ int i = 0;
+
+ while (token) {
+ token_array[i++] = token;
+ token = strtok(NULL, ":\t");
+ }
+
+ bw_resc[runs] = strtoul(token_array[5], NULL, 0);
+ bw_imc[runs] = strtoul(token_array[3], NULL, 0);
+ runs++;
+ }
+
+ show_bw_info(bw_imc, bw_resc, span);
+
+ fclose(fp);
+
+ return 0;
+}
+
+static int mbm_setup(int num, ...)
+{
+ struct resctrl_val_param *p;
+ static int num_of_runs;
+ va_list param;
+ int ret = 0;
+
+ /* Run NUM_OF_RUNS times */
+ if (num_of_runs++ >= NUM_OF_RUNS)
+ return -1;
+
+ va_start(param, num);
+ p = va_arg(param, struct resctrl_val_param *);
+ va_end(param);
+
+ /* Set up shemata with 100% allocation on the first run. */
+ if (num_of_runs == 0)
+ ret = write_schemata(p->ctrlgrp, "100", p->cpu_no,
+ p->resctrl_val);
+
+ return ret;
+}
+
+void mbm_test_cleanup(void)
+{
+ remove(RESULT_FILE_NAME);
+}
+
+int mbm_bw_change(int span, int cpu_no, char *bw_report, char **benchmark_cmd)
+{
+ struct resctrl_val_param param = {
+ .resctrl_val = "mbm",
+ .ctrlgrp = "c1",
+ .mongrp = "m1",
+ .span = span,
+ .cpu_no = cpu_no,
+ .mum_resctrlfs = 1,
+ .filename = RESULT_FILE_NAME,
+ .bw_report = bw_report,
+ .setup = mbm_setup
+ };
+ int ret;
+
+ remove(RESULT_FILE_NAME);
+
+ if (!validate_resctrl_feature_request("mbm"))
+ return -1;
+
+ ret = resctrl_val(benchmark_cmd, &param);
+ if (ret)
+ return ret;
+
+ ret = check_results(span);
+ if (ret)
+ return ret;
+
+ mbm_test_cleanup();
+
+ return 0;
+}
diff --git a/tools/testing/selftests/resctrl/resctrl.h b/tools/testing/selftests/resctrl/resctrl.h
index fb42087c904d..c92bc50c6751 100644
--- a/tools/testing/selftests/resctrl/resctrl.h
+++ b/tools/testing/selftests/resctrl/resctrl.h
@@ -57,7 +57,10 @@ struct resctrl_val_param {
};

pid_t bm_pid, ppid;
+int tests_run;

+bool check_resctrlfs_support(void);
+int filter_dmesg(void);
int remount_resctrlfs(bool mum_resctrlfs);
int get_resource_id(int cpu_no, int *resource_id);
int umount_resctrlfs(void);
@@ -75,5 +78,8 @@ int perf_event_open(struct perf_event_attr *hw_event, pid_t pid, int cpu,
int run_fill_buf(unsigned long span, int malloc_and_init_memory, int memflush,
int op, char *resctrl_va);
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);

#endif /* RESCTRL_H */
diff --git a/tools/testing/selftests/resctrl/resctrl_tests.c b/tools/testing/selftests/resctrl/resctrl_tests.c
new file mode 100644
index 000000000000..496c8030fe43
--- /dev/null
+++ b/tools/testing/selftests/resctrl/resctrl_tests.c
@@ -0,0 +1,132 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Resctrl tests
+ *
+ * Copyright (C) 2018 Intel Corporation
+ *
+ * Authors:
+ * Sai Praneeth Prakhya <sai.praneeth.prakhya@xxxxxxxxx>,
+ * Fenghua Yu <fenghua.yu@xxxxxxxxx>
+ */
+#include "resctrl.h"
+
+#define BENCHMARK_ARGS 64
+#define BENCHMARK_ARG_SIZE 64
+
+static void cmd_help(void)
+{
+ printf("usage: resctrl_tests [-h] [-b \"benchmark_cmd [options]\"] [-t test list]\n");
+ printf("\t-b benchmark_cmd [options]: run specified benchmark\n");
+ printf("\t default benchmark is builtin fill_buf\n");
+ printf("\t-t test list: run tests specified in the test list, ");
+ printf("e.g. -t mbm,mba\n");
+ printf("\t-h: help\n");
+}
+
+void tests_cleanup(void)
+{
+ mbm_test_cleanup();
+}
+
+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;
+ int ben_count;
+
+ for (i = 0; i < argc; i++) {
+ if (strcmp(argv[i], "-b") == 0) {
+ ben_ind = i + 1;
+ ben_count = argc - ben_ind;
+ argc_new = ben_ind - 1;
+ has_ben = true;
+ break;
+ }
+ }
+
+ while ((c = getopt(argc_new, argv, "ht:b:")) != -1) {
+ char *token;
+
+ switch (c) {
+ case 't':
+ token = strtok(optarg, ",");
+
+ mbm_test = false;
+ while (token) {
+ if (!strcmp(token, "mbm")) {
+ mbm_test = true;
+ } else {
+ printf("invalid argument\n");
+
+ return -1;
+ }
+ token = strtok(NULL, ":\t");
+ }
+ break;
+ case 'p':
+ cpu_no = atoi(optarg);
+ break;
+ case 'h':
+ cmd_help();
+
+ return 0;
+ default:
+ printf("invalid argument\n");
+
+ return -1;
+ }
+ }
+
+ printf("TAP version 13\n");
+
+ /*
+ * Typically we need root privileges, because:
+ * 1. We write to resctrl FS
+ * 2. We execute perf commands
+ */
+ if (geteuid() != 0)
+ printf("# WARNING: not running as root, tests may fail.\n");
+
+ if (has_ben) {
+ /* Extract benchmark command from command line. */
+ for (i = ben_ind; i < argc; i++) {
+ benchmark_cmd[i - ben_ind] = benchmark_cmd_area[i];
+ sprintf(benchmark_cmd[i - ben_ind], "%s", argv[i]);
+ }
+ benchmark_cmd[ben_count] = NULL;
+ } else {
+ /* If no benchmark is given by "-b" argument, use fill_buf. */
+ for (i = 0; i < 6; i++)
+ benchmark_cmd[i] = benchmark_cmd_area[i];
+
+ strcpy(benchmark_cmd[0], "fill_buf");
+ sprintf(benchmark_cmd[1], "%d", span);
+ strcpy(benchmark_cmd[2], "1");
+ strcpy(benchmark_cmd[3], "1");
+ strcpy(benchmark_cmd[4], "0");
+ strcpy(benchmark_cmd[5], "");
+ benchmark_cmd[6] = NULL;
+ }
+
+ sprintf(bw_report, "reads");
+ sprintf(bm_type, "fill_buf");
+
+ check_resctrlfs_support();
+ filter_dmesg();
+
+ if (mbm_test) {
+ printf("# Starting MBM BW change ...\n");
+ if (!has_ben)
+ sprintf(benchmark_cmd[5], "%s", "mba");
+ res = mbm_bw_change(span, cpu_no, bw_report, benchmark_cmd);
+ printf("%sok MBM: bw change\n", res ? "not " : "");
+ mbm_test_cleanup();
+ tests_run++;
+ }
+
+ printf("1..%d\n", tests_run);
+
+ return 0;
+}
diff --git a/tools/testing/selftests/resctrl/resctrl_val.c b/tools/testing/selftests/resctrl/resctrl_val.c
index 0d1bd03ec4be..4f7bd5a4d86e 100644
--- a/tools/testing/selftests/resctrl/resctrl_val.c
+++ b/tools/testing/selftests/resctrl/resctrl_val.c
@@ -435,6 +435,8 @@ pid_t bm_pid, ppid;
static void ctrlc_handler(int signum, siginfo_t *info, void *ptr)
{
kill(bm_pid, SIGKILL);
+ umount_resctrlfs();
+ tests_cleanup();
printf("Ending\n\n");

exit(EXIT_SUCCESS);
diff --git a/tools/testing/selftests/resctrl/resctrlfs.c b/tools/testing/selftests/resctrl/resctrlfs.c
index 1b125f9d8e5d..07c8394b427f 100644
--- a/tools/testing/selftests/resctrl/resctrlfs.c
+++ b/tools/testing/selftests/resctrl/resctrlfs.c
@@ -388,6 +388,41 @@ int write_schemata(char *ctrlgrp, char *schemata, int cpu_no, char *resctrl_val)
return ret;
}

+bool check_resctrlfs_support(void)
+{
+ FILE *inf = fopen("/proc/filesystems", "r");
+ DIR *dp;
+ char *res;
+ bool ret = false;
+
+ if (!inf)
+ return false;
+
+ res = fgrep(inf, "nodev\tresctrl\n");
+
+ if (res) {
+ ret = true;
+ free(res);
+ }
+
+ fclose(inf);
+
+ printf("%sok kernel supports resctrl filesystem\n", ret ? "" : "not ");
+ tests_run++;
+
+ dp = opendir(RESCTRL_PATH);
+ printf("%sok resctrl mountpoint \"%s\" exists\n",
+ dp ? "" : "not ", RESCTRL_PATH);
+ if (dp)
+ closedir(dp);
+ tests_run++;
+
+ printf("# resctrl filesystem %s mounted\n",
+ find_resctrl_mount(NULL) ? "not" : "is");
+
+ return ret;
+}
+
char *fgrep(FILE *inf, const char *str)
{
char line[256];
@@ -433,6 +468,48 @@ bool validate_resctrl_feature_request(char *resctrl_val)
return found;
}

+int filter_dmesg(void)
+{
+ char line[1024];
+ FILE *fp;
+ int pipefds[2];
+ pid_t pid;
+ int ret;
+
+ ret = pipe(pipefds);
+ if (ret) {
+ perror("pipe");
+ return ret;
+ }
+ pid = fork();
+ if (pid == 0) {
+ close(pipefds[0]);
+ dup2(pipefds[1], STDOUT_FILENO);
+ execlp("dmesg", "dmesg", NULL);
+ perror("executing dmesg");
+ exit(1);
+ }
+ close(pipefds[1]);
+ fp = fdopen(pipefds[0], "r");
+ if (!fp) {
+ perror("fdopen(pipe)");
+ kill(pid, SIGTERM);
+
+ return -1;
+ }
+
+ while (fgets(line, 1024, fp)) {
+ if (strstr(line, "intel_rdt:"))
+ printf("# dmesg: %s", line);
+ if (strstr(line, "resctrl:"))
+ printf("# dmesg: %s", line);
+ }
+ fclose(fp);
+ waitpid(pid, NULL, 0);
+
+ return 0;
+}
+
int validate_bw_report_request(char *bw_report)
{
if (strcmp(bw_report, "reads") == 0)
--
2.19.1