1 files changed, 130 insertions, 317 deletions

diff --git a/tools/testing/selftests/resctrl/resctrl_val.c b/tools/testing/selftests/resctrl/resctrl_val.c
index 8c275f6b4dd7..7c08e936572d 100644
--- a/tools/testing/selftests/resctrl/resctrl_val.c
+++ b/tools/testing/selftests/resctrl/resctrl_val.c
@@ -12,13 +12,10 @@
 
 #define UNCORE_IMC		"uncore_imc"
 #define READ_FILE_NAME		"events/cas_count_read"
-#define WRITE_FILE_NAME		"events/cas_count_write"
 #define DYN_PMU_PATH		"/sys/bus/event_source/devices"
 #define SCALE			0.00006103515625
 #define MAX_IMCS		20
 #define MAX_TOKENS		5
-#define READ			0
-#define WRITE			1
 
 #define CON_MBM_LOCAL_BYTES_PATH		\
 	"%s/%s/mon_data/mon_L3_%02d/mbm_local_bytes"
@@ -41,85 +38,71 @@ struct imc_counter_config {
 
 static char mbm_total_path[1024];
 static int imcs;
-static struct imc_counter_config imc_counters_config[MAX_IMCS][2];
+static struct imc_counter_config imc_counters_config[MAX_IMCS];
 static const struct resctrl_test *current_test;
 
-void membw_initialize_perf_event_attr(int i, int j)
+static void read_mem_bw_initialize_perf_event_attr(int i)
 {
-	memset(&imc_counters_config[i][j].pe, 0,
+	memset(&imc_counters_config[i].pe, 0,
 	       sizeof(struct perf_event_attr));
-	imc_counters_config[i][j].pe.type = imc_counters_config[i][j].type;
-	imc_counters_config[i][j].pe.size = sizeof(struct perf_event_attr);
-	imc_counters_config[i][j].pe.disabled = 1;
-	imc_counters_config[i][j].pe.inherit = 1;
-	imc_counters_config[i][j].pe.exclude_guest = 0;
-	imc_counters_config[i][j].pe.config =
-		imc_counters_config[i][j].umask << 8 |
-		imc_counters_config[i][j].event;
-	imc_counters_config[i][j].pe.sample_type = PERF_SAMPLE_IDENTIFIER;
-	imc_counters_config[i][j].pe.read_format =
+	imc_counters_config[i].pe.type = imc_counters_config[i].type;
+	imc_counters_config[i].pe.size = sizeof(struct perf_event_attr);
+	imc_counters_config[i].pe.disabled = 1;
+	imc_counters_config[i].pe.inherit = 1;
+	imc_counters_config[i].pe.exclude_guest = 0;
+	imc_counters_config[i].pe.config =
+		imc_counters_config[i].umask << 8 |
+		imc_counters_config[i].event;
+	imc_counters_config[i].pe.sample_type = PERF_SAMPLE_IDENTIFIER;
+	imc_counters_config[i].pe.read_format =
 		PERF_FORMAT_TOTAL_TIME_ENABLED | PERF_FORMAT_TOTAL_TIME_RUNNING;
 }
 
-void membw_ioctl_perf_event_ioc_reset_enable(int i, int j)
+static void read_mem_bw_ioctl_perf_event_ioc_reset_enable(int i)
 {
-	ioctl(imc_counters_config[i][j].fd, PERF_EVENT_IOC_RESET, 0);
-	ioctl(imc_counters_config[i][j].fd, PERF_EVENT_IOC_ENABLE, 0);
+	ioctl(imc_counters_config[i].fd, PERF_EVENT_IOC_RESET, 0);
+	ioctl(imc_counters_config[i].fd, PERF_EVENT_IOC_ENABLE, 0);
 }
 
-void membw_ioctl_perf_event_ioc_disable(int i, int j)
+static void read_mem_bw_ioctl_perf_event_ioc_disable(int i)
 {
-	ioctl(imc_counters_config[i][j].fd, PERF_EVENT_IOC_DISABLE, 0);
+	ioctl(imc_counters_config[i].fd, PERF_EVENT_IOC_DISABLE, 0);
 }
 
 /*
- * get_event_and_umask:	Parse config into event and umask
+ * get_read_event_and_umask:	Parse config into event and umask
  * @cas_count_cfg:	Config
  * @count:		iMC number
- * @op:			Operation (read/write)
  */
-void get_event_and_umask(char *cas_count_cfg, int count, bool op)
+static void get_read_event_and_umask(char *cas_count_cfg, int count)
 {
 	char *token[MAX_TOKENS];
 	int i = 0;
 
-	strcat(cas_count_cfg, ",");
 	token[0] = strtok(cas_count_cfg, "=,");
 
 	for (i = 1; i < MAX_TOKENS; i++)
 		token[i] = strtok(NULL, "=,");
 
-	for (i = 0; i < MAX_TOKENS; i++) {
+	for (i = 0; i < MAX_TOKENS - 1; i++) {
 		if (!token[i])
 			break;
-		if (strcmp(token[i], "event") == 0) {
-			if (op == READ)
-				imc_counters_config[count][READ].event =
-				strtol(token[i + 1], NULL, 16);
-			else
-				imc_counters_config[count][WRITE].event =
-				strtol(token[i + 1], NULL, 16);
-		}
-		if (strcmp(token[i], "umask") == 0) {
-			if (op == READ)
-				imc_counters_config[count][READ].umask =
-				strtol(token[i + 1], NULL, 16);
-			else
-				imc_counters_config[count][WRITE].umask =
-				strtol(token[i + 1], NULL, 16);
-		}
+		if (strcmp(token[i], "event") == 0)
+			imc_counters_config[count].event = strtol(token[i + 1], NULL, 16);
+		if (strcmp(token[i], "umask") == 0)
+			imc_counters_config[count].umask = strtol(token[i + 1], NULL, 16);
 	}
 }
 
-static int open_perf_event(int i, int cpu_no, int j)
+static int open_perf_read_event(int i, int cpu_no)
 {
-	imc_counters_config[i][j].fd =
-		perf_event_open(&imc_counters_config[i][j].pe, -1, cpu_no, -1,
+	imc_counters_config[i].fd =
+		perf_event_open(&imc_counters_config[i].pe, -1, cpu_no, -1,
 				PERF_FLAG_FD_CLOEXEC);
 
-	if (imc_counters_config[i][j].fd == -1) {
+	if (imc_counters_config[i].fd == -1) {
 		fprintf(stderr, "Error opening leader %llx\n",
-			imc_counters_config[i][j].pe.config);
+			imc_counters_config[i].pe.config);
 
 		return -1;
 	}
@@ -127,7 +110,7 @@ static int open_perf_event(int i, int cpu_no, int j)
 	return 0;
 }
 
-/* Get type and config (read and write) of an iMC counter */
+/* Get type and config of an iMC counter's read event. */
 static int read_from_imc_dir(char *imc_dir, int count)
 {
 	char cas_count_cfg[1024], imc_counter_cfg[1024], imc_counter_type[1024];
@@ -141,7 +124,7 @@ static int read_from_imc_dir(char *imc_dir, int count)
 
 		return -1;
 	}
-	if (fscanf(fp, "%u", &imc_counters_config[count][READ].type) <= 0) {
+	if (fscanf(fp, "%u", &imc_counters_config[count].type) <= 0) {
 		ksft_perror("Could not get iMC type");
 		fclose(fp);
 
@@ -149,9 +132,6 @@ static int read_from_imc_dir(char *imc_dir, int count)
 	}
 	fclose(fp);
 
-	imc_counters_config[count][WRITE].type =
-				imc_counters_config[count][READ].type;
-
 	/* Get read config */
 	sprintf(imc_counter_cfg, "%s%s", imc_dir, READ_FILE_NAME);
 	fp = fopen(imc_counter_cfg, "r");
@@ -160,7 +140,7 @@ static int read_from_imc_dir(char *imc_dir, int count)
 
 		return -1;
 	}
-	if (fscanf(fp, "%s", cas_count_cfg) <= 0) {
+	if (fscanf(fp, "%1023s", cas_count_cfg) <= 0) {
 		ksft_perror("Could not get iMC cas count read");
 		fclose(fp);
 
@@ -168,34 +148,19 @@ static int read_from_imc_dir(char *imc_dir, int count)
 	}
 	fclose(fp);
 
-	get_event_and_umask(cas_count_cfg, count, READ);
-
-	/* Get write config */
-	sprintf(imc_counter_cfg, "%s%s", imc_dir, WRITE_FILE_NAME);
-	fp = fopen(imc_counter_cfg, "r");
-	if (!fp) {
-		ksft_perror("Failed to open iMC config file");
-
-		return -1;
-	}
-	if  (fscanf(fp, "%s", cas_count_cfg) <= 0) {
-		ksft_perror("Could not get iMC cas count write");
-		fclose(fp);
-
-		return -1;
-	}
-	fclose(fp);
-
-	get_event_and_umask(cas_count_cfg, count, WRITE);
+	get_read_event_and_umask(cas_count_cfg, count);
 
 	return 0;
 }
 
 /*
  * A system can have 'n' number of iMC (Integrated Memory Controller)
- * counters, get that 'n'. For each iMC counter get it's type and config.
- * Also, each counter has two configs, one for read and the other for write.
- * A config again has two parts, event and umask.
+ * counters, get that 'n'. Discover the properties of the available
+ * counters in support of needed performance measurement via perf.
+ * For each iMC counter get it's type and config. Also obtain each
+ * counter's event and umask for the memory read events that will be
+ * measured.
+ *
  * Enumerate all these details into an array of structures.
  *
  * Return: >= 0 on success. < 0 on failure.
@@ -256,55 +221,46 @@ static int num_of_imcs(void)
 	return count;
 }
 
-int initialize_mem_bw_imc(void)
+int initialize_read_mem_bw_imc(void)
 {
-	int imc, j;
+	int imc;
 
 	imcs = num_of_imcs();
 	if (imcs <= 0)
 		return imcs;
 
 	/* Initialize perf_event_attr structures for all iMC's */
-	for (imc = 0; imc < imcs; imc++) {
-		for (j = 0; j < 2; j++)
-			membw_initialize_perf_event_attr(imc, j);
-	}
+	for (imc = 0; imc < imcs; imc++)
+		read_mem_bw_initialize_perf_event_attr(imc);
 
 	return 0;
 }
 
-static void perf_close_imc_mem_bw(void)
+static void perf_close_imc_read_mem_bw(void)
 {
 	int mc;
 
 	for (mc = 0; mc < imcs; mc++) {
-		if (imc_counters_config[mc][READ].fd != -1)
-			close(imc_counters_config[mc][READ].fd);
-		if (imc_counters_config[mc][WRITE].fd != -1)
-			close(imc_counters_config[mc][WRITE].fd);
+		if (imc_counters_config[mc].fd != -1)
+			close(imc_counters_config[mc].fd);
 	}
 }
 
 /*
- * perf_open_imc_mem_bw - Open perf fds for IMCs
+ * perf_open_imc_read_mem_bw - Open perf fds for IMCs
  * @cpu_no: CPU number that the benchmark PID is bound to
  *
  * Return: = 0 on success. < 0 on failure.
  */
-static int perf_open_imc_mem_bw(int cpu_no)
+static int perf_open_imc_read_mem_bw(int cpu_no)
 {
 	int imc, ret;
 
-	for (imc = 0; imc < imcs; imc++) {
-		imc_counters_config[imc][READ].fd = -1;
-		imc_counters_config[imc][WRITE].fd = -1;
-	}
+	for (imc = 0; imc < imcs; imc++)
+		imc_counters_config[imc].fd = -1;
 
 	for (imc = 0; imc < imcs; imc++) {
-		ret = open_perf_event(imc, cpu_no, READ);
-		if (ret)
-			goto close_fds;
-		ret = open_perf_event(imc, cpu_no, WRITE);
+		ret = open_perf_read_event(imc, cpu_no);
 		if (ret)
 			goto close_fds;
 	}
@@ -312,60 +268,52 @@ static int perf_open_imc_mem_bw(int cpu_no)
 	return 0;
 
 close_fds:
-	perf_close_imc_mem_bw();
+	perf_close_imc_read_mem_bw();
 	return -1;
 }
 
 /*
- * do_mem_bw_test - Perform memory bandwidth test
+ * do_imc_read_mem_bw_test - Perform memory bandwidth test
  *
  * Runs memory bandwidth test over one second period. Also, handles starting
  * and stopping of the IMC perf counters around the test.
  */
-static void do_imc_mem_bw_test(void)
+static void do_imc_read_mem_bw_test(void)
 {
 	int imc;
 
-	for (imc = 0; imc < imcs; imc++) {
-		membw_ioctl_perf_event_ioc_reset_enable(imc, READ);
-		membw_ioctl_perf_event_ioc_reset_enable(imc, WRITE);
-	}
+	for (imc = 0; imc < imcs; imc++)
+		read_mem_bw_ioctl_perf_event_ioc_reset_enable(imc);
 
 	sleep(1);
 
-	/* Stop counters after a second to get results (both read and write) */
-	for (imc = 0; imc < imcs; imc++) {
-		membw_ioctl_perf_event_ioc_disable(imc, READ);
-		membw_ioctl_perf_event_ioc_disable(imc, WRITE);
-	}
+	/* Stop counters after a second to get results. */
+	for (imc = 0; imc < imcs; imc++)
+		read_mem_bw_ioctl_perf_event_ioc_disable(imc);
 }
 
 /*
- * get_mem_bw_imc - Memory bandwidth as reported by iMC counters
- * @bw_report: Bandwidth report type (reads, writes)
+ * get_read_mem_bw_imc - Memory read bandwidth as reported by iMC counters
  *
- * Memory bandwidth utilized by a process on a socket can be calculated
- * using iMC counters. Perf events are used to read these counters.
+ * Memory read bandwidth utilized by a process on a socket can be calculated
+ * using iMC counters' read events. Perf events are used to read these
+ * counters.
  *
  * Return: = 0 on success. < 0 on failure.
  */
-static int get_mem_bw_imc(const char *bw_report, float *bw_imc)
+static int get_read_mem_bw_imc(float *bw_imc)
 {
-	float reads, writes, of_mul_read, of_mul_write;
+	float reads = 0, of_mul_read = 1;
 	int imc;
 
-	/* Start all iMC counters to log values (both read and write) */
-	reads = 0, writes = 0, of_mul_read = 1, of_mul_write = 1;
-
 	/*
-	 * Get results which are stored in struct type imc_counter_config
+	 * Log read event values from all iMC counters into
+	 * struct imc_counter_config.
 	 * Take overflow into consideration before calculating total bandwidth.
 	 */
 	for (imc = 0; imc < imcs; imc++) {
 		struct imc_counter_config *r =
-			&imc_counters_config[imc][READ];
-		struct imc_counter_config *w =
-			&imc_counters_config[imc][WRITE];
+			&imc_counters_config[imc];
 
 		if (read(r->fd, &r->return_value,
 			 sizeof(struct membw_read_format)) == -1) {
@@ -373,12 +321,6 @@ static int get_mem_bw_imc(const char *bw_report, float *bw_imc)
 			return -1;
 		}
 
-		if (read(w->fd, &w->return_value,
-			 sizeof(struct membw_read_format)) == -1) {
-			ksft_perror("Couldn't get write bandwidth through iMC");
-			return -1;
-		}
-
 		__u64 r_time_enabled = r->return_value.time_enabled;
 		__u64 r_time_running = r->return_value.time_running;
 
@@ -386,27 +328,10 @@ static int get_mem_bw_imc(const char *bw_report, float *bw_imc)
 			of_mul_read = (float)r_time_enabled /
 					(float)r_time_running;
 
-		__u64 w_time_enabled = w->return_value.time_enabled;
-		__u64 w_time_running = w->return_value.time_running;
-
-		if (w_time_enabled != w_time_running)
-			of_mul_write = (float)w_time_enabled /
-					(float)w_time_running;
 		reads += r->return_value.value * of_mul_read * SCALE;
-		writes += w->return_value.value * of_mul_write * SCALE;
 	}
 
-	if (strcmp(bw_report, "reads") == 0) {
-		*bw_imc = reads;
-		return 0;
-	}
-
-	if (strcmp(bw_report, "writes") == 0) {
-		*bw_imc = writes;
-		return 0;
-	}
-
-	*bw_imc = reads + writes;
+	*bw_imc = reads;
 	return 0;
 }
 
@@ -448,7 +373,7 @@ static int get_mem_bw_resctrl(FILE *fp, unsigned long *mbm_total)
 	return 0;
 }
 
-static pid_t bm_pid, ppid;
+static pid_t bm_pid;
 
 void ctrlc_handler(int signum, siginfo_t *info, void *ptr)
 {
@@ -506,13 +431,6 @@ void signal_handler_unregister(void)
 	}
 }
 
-static void parent_exit(pid_t ppid)
-{
-	kill(ppid, SIGKILL);
-	umount_resctrlfs();
-	exit(EXIT_FAILURE);
-}
-
 /*
  * print_results_bw:	the memory bandwidth results are stored in a file
  * @filename:		file that stores the results
@@ -552,35 +470,31 @@ static int print_results_bw(char *filename, pid_t bm_pid, float bw_imc,
 }
 
 /*
- * measure_mem_bw - Measures memory bandwidth numbers while benchmark runs
+ * measure_read_mem_bw - Measures read memory bandwidth numbers while benchmark runs
  * @uparams:		User supplied parameters
  * @param:		Parameters passed to resctrl_val()
  * @bm_pid:		PID that runs the benchmark
- * @bw_report:		Bandwidth report type (reads, writes)
  *
  * Measure memory bandwidth from resctrl and from another source which is
  * perf imc value or could be something else if perf imc event is not
  * available. Compare the two values to validate resctrl value. It takes
  * 1 sec to measure the data.
+ * resctrl does not distinguish between read and write operations so
+ * its data includes all memory operations.
  */
-int measure_mem_bw(const struct user_params *uparams,
-		   struct resctrl_val_param *param, pid_t bm_pid,
-		   const char *bw_report)
+int measure_read_mem_bw(const struct user_params *uparams,
+			struct resctrl_val_param *param, pid_t bm_pid)
 {
 	unsigned long bw_resc, bw_resc_start, bw_resc_end;
 	FILE *mem_bw_fp;
 	float bw_imc;
 	int ret;
 
-	bw_report = get_bw_report_type(bw_report);
-	if (!bw_report)
-		return -1;
-
 	mem_bw_fp = open_mem_bw_resctrl(mbm_total_path);
 	if (!mem_bw_fp)
 		return -1;
 
-	ret = perf_open_imc_mem_bw(uparams->cpu);
+	ret = perf_open_imc_read_mem_bw(uparams->cpu);
 	if (ret < 0)
 		goto close_fp;
 
@@ -590,17 +504,17 @@ int measure_mem_bw(const struct user_params *uparams,
 
 	rewind(mem_bw_fp);
 
-	do_imc_mem_bw_test();
+	do_imc_read_mem_bw_test();
 
 	ret = get_mem_bw_resctrl(mem_bw_fp, &bw_resc_end);
 	if (ret < 0)
 		goto close_imc;
 
-	ret = get_mem_bw_imc(bw_report, &bw_imc);
+	ret = get_read_mem_bw_imc(&bw_imc);
 	if (ret < 0)
 		goto close_imc;
 
-	perf_close_imc_mem_bw();
+	perf_close_imc_read_mem_bw();
 	fclose(mem_bw_fp);
 
 	bw_resc = (bw_resc_end - bw_resc_start) / MB;
@@ -608,87 +522,30 @@ int measure_mem_bw(const struct user_params *uparams,
 	return print_results_bw(param->filename, bm_pid, bw_imc, bw_resc);
 
 close_imc:
-	perf_close_imc_mem_bw();
+	perf_close_imc_read_mem_bw();
 close_fp:
 	fclose(mem_bw_fp);
 	return ret;
 }
 
 /*
- * run_benchmark - Run a specified benchmark or fill_buf (default benchmark)
- *		   in specified signal. Direct benchmark stdio to /dev/null.
- * @signum:	signal number
- * @info:	signal info
- * @ucontext:	user context in signal handling
- */
-static void run_benchmark(int signum, siginfo_t *info, void *ucontext)
-{
-	int operation, ret, memflush;
-	char **benchmark_cmd;
-	size_t span;
-	bool once;
-	FILE *fp;
-
-	benchmark_cmd = info->si_ptr;
-
-	/*
-	 * Direct stdio of child to /dev/null, so that only parent writes to
-	 * stdio (console)
-	 */
-	fp = freopen("/dev/null", "w", stdout);
-	if (!fp) {
-		ksft_perror("Unable to direct benchmark status to /dev/null");
-		parent_exit(ppid);
-	}
-
-	if (strcmp(benchmark_cmd[0], "fill_buf") == 0) {
-		/* Execute default fill_buf benchmark */
-		span = strtoul(benchmark_cmd[1], NULL, 10);
-		memflush =  atoi(benchmark_cmd[2]);
-		operation = atoi(benchmark_cmd[3]);
-		if (!strcmp(benchmark_cmd[4], "true")) {
-			once = true;
-		} else if (!strcmp(benchmark_cmd[4], "false")) {
-			once = false;
-		} else {
-			ksft_print_msg("Invalid once parameter\n");
-			parent_exit(ppid);
-		}
-
-		if (run_fill_buf(span, memflush, operation, once))
-			fprintf(stderr, "Error in running fill buffer\n");
-	} else {
-		/* Execute specified benchmark */
-		ret = execvp(benchmark_cmd[0], benchmark_cmd);
-		if (ret)
-			ksft_perror("execvp");
-	}
-
-	fclose(stdout);
-	ksft_print_msg("Unable to run specified benchmark\n");
-	parent_exit(ppid);
-}
-
-/*
  * resctrl_val:	execute benchmark and measure memory bandwidth on
  *			the benchmark
  * @test:		test information structure
  * @uparams:		user supplied parameters
- * @benchmark_cmd:	benchmark command and its arguments
  * @param:		parameters passed to resctrl_val()
  *
  * Return:		0 when the test was run, < 0 on error.
  */
 int resctrl_val(const struct resctrl_test *test,
 		const struct user_params *uparams,
-		const char * const *benchmark_cmd,
 		struct resctrl_val_param *param)
 {
-	struct sigaction sigact;
-	int ret = 0, pipefd[2];
-	char pipe_message = 0;
-	union sigval value;
+	unsigned char *buf = NULL;
+	cpu_set_t old_affinity;
 	int domain_id;
+	int ret = 0;
+	pid_t ppid;
 
 	if (strcmp(param->filename, "") == 0)
 		sprintf(param->filename, "stdio");
@@ -699,111 +556,65 @@ int resctrl_val(const struct resctrl_test *test,
 		return ret;
 	}
 
-	/*
-	 * If benchmark wasn't successfully started by child, then child should
-	 * kill parent, so save parent's pid
-	 */
 	ppid = getpid();
 
-	if (pipe(pipefd)) {
-		ksft_perror("Unable to create pipe");
+	/* Taskset test to specified CPU. */
+	ret = taskset_benchmark(ppid, uparams->cpu, &old_affinity);
+	if (ret)
+		return ret;
 
-		return -1;
+	/* Write test to specified control & monitoring group in resctrl FS. */
+	ret = write_bm_pid_to_resctrl(ppid, param->ctrlgrp, param->mongrp);
+	if (ret)
+		goto reset_affinity;
+
+	if (param->init) {
+		ret = param->init(param, domain_id);
+		if (ret)
+			goto reset_affinity;
 	}
 
 	/*
-	 * Fork to start benchmark, save child's pid so that it can be killed
-	 * when needed
+	 * If not running user provided benchmark, run the default
+	 * "fill_buf". First phase of "fill_buf" is to prepare the
+	 * buffer that the benchmark will operate on. No measurements
+	 * are needed during this phase and prepared memory will be
+	 * passed to next part of benchmark via copy-on-write thus
+	 * no impact on the benchmark that relies on reading from
+	 * memory only.
 	 */
+	if (param->fill_buf) {
+		buf = alloc_buffer(param->fill_buf->buf_size,
+				   param->fill_buf->memflush);
+		if (!buf) {
+			ret = -ENOMEM;
+			goto reset_affinity;
+		}
+	}
+
 	fflush(stdout);
 	bm_pid = fork();
 	if (bm_pid == -1) {
+		ret = -errno;
 		ksft_perror("Unable to fork");
-
-		return -1;
+		goto free_buf;
 	}
 
-	if (bm_pid == 0) {
-		/*
-		 * Mask all signals except SIGUSR1, parent uses SIGUSR1 to
-		 * start benchmark
-		 */
-		sigfillset(&sigact.sa_mask);
-		sigdelset(&sigact.sa_mask, SIGUSR1);
-
-		sigact.sa_sigaction = run_benchmark;
-		sigact.sa_flags = SA_SIGINFO;
-
-		/* Register for "SIGUSR1" signal from parent */
-		if (sigaction(SIGUSR1, &sigact, NULL)) {
-			ksft_perror("Can't register child for signal");
-			parent_exit(ppid);
-		}
-
-		/* Tell parent that child is ready */
-		close(pipefd[0]);
-		pipe_message = 1;
-		if (write(pipefd[1], &pipe_message, sizeof(pipe_message)) <
-		    sizeof(pipe_message)) {
-			ksft_perror("Failed signaling parent process");
-			close(pipefd[1]);
-			return -1;
-		}
-		close(pipefd[1]);
-
-		/* Suspend child until delivery of "SIGUSR1" from parent */
-		sigsuspend(&sigact.sa_mask);
-
-		ksft_perror("Child is done");
-		parent_exit(ppid);
-	}
-
-	ksft_print_msg("Benchmark PID: %d\n", (int)bm_pid);
-
 	/*
-	 * The cast removes constness but nothing mutates benchmark_cmd within
-	 * the context of this process. At the receiving process, it becomes
-	 * argv, which is mutable, on exec() but that's after fork() so it
-	 * doesn't matter for the process running the tests.
+	 * What needs to be measured runs in separate process until
+	 * terminated.
 	 */
-	value.sival_ptr = (void *)benchmark_cmd;
-
-	/* Taskset benchmark to specified cpu */
-	ret = taskset_benchmark(bm_pid, uparams->cpu, NULL);
-	if (ret)
-		goto out;
-
-	/* Write benchmark to specified control&monitoring grp in resctrl FS */
-	ret = write_bm_pid_to_resctrl(bm_pid, param->ctrlgrp, param->mongrp);
-	if (ret)
-		goto out;
-
-	if (param->init) {
-		ret = param->init(param, domain_id);
-		if (ret)
-			goto out;
-	}
-
-	/* Parent waits for child to be ready. */
-	close(pipefd[1]);
-	while (pipe_message != 1) {
-		if (read(pipefd[0], &pipe_message, sizeof(pipe_message)) <
-		    sizeof(pipe_message)) {
-			ksft_perror("Failed reading message from child process");
-			close(pipefd[0]);
-			goto out;
-		}
+	if (bm_pid == 0) {
+		if (param->fill_buf)
+			fill_cache_read(buf, param->fill_buf->buf_size, false);
+		else if (uparams->benchmark_cmd[0])
+			execvp(uparams->benchmark_cmd[0], (char **)uparams->benchmark_cmd);
+		exit(EXIT_SUCCESS);
 	}
-	close(pipefd[0]);
 
-	/* Signal child to start benchmark */
-	if (sigqueue(bm_pid, SIGUSR1, value) == -1) {
-		ksft_perror("sigqueue SIGUSR1 to child");
-		ret = -1;
-		goto out;
-	}
+	ksft_print_msg("Benchmark PID: %d\n", (int)bm_pid);
 
-	/* Give benchmark enough time to fully run */
+	/* Give benchmark enough time to fully run. */
 	sleep(1);
 
 	/* Test runs until the callback setup() tells the test to stop. */
@@ -821,8 +632,10 @@ int resctrl_val(const struct resctrl_test *test,
 			break;
 	}
 
-out:
 	kill(bm_pid, SIGKILL);
-
+free_buf:
+	free(buf);
+reset_affinity:
+	taskset_restore(ppid, &old_affinity);
 	return ret;
 }