1 files changed, 641 insertions, 0 deletions

diff --git a/tools/testing/selftests/resctrl/resctrl_val.c b/tools/testing/selftests/resctrl/resctrl_val.c
new file mode 100644
index 000000000000..7c08e936572d
--- /dev/null
+++ b/tools/testing/selftests/resctrl/resctrl_val.c
@@ -0,0 +1,641 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Memory bandwidth monitoring and allocation library
+ *
+ * Copyright (C) 2018 Intel Corporation
+ *
+ * Authors:
+ *    Sai Praneeth Prakhya <sai.praneeth.prakhya@intel.com>,
+ *    Fenghua Yu <fenghua.yu@intel.com>
+ */
+#include "resctrl.h"
+
+#define UNCORE_IMC		"uncore_imc"
+#define READ_FILE_NAME		"events/cas_count_read"
+#define DYN_PMU_PATH		"/sys/bus/event_source/devices"
+#define SCALE			0.00006103515625
+#define MAX_IMCS		20
+#define MAX_TOKENS		5
+
+#define CON_MBM_LOCAL_BYTES_PATH		\
+	"%s/%s/mon_data/mon_L3_%02d/mbm_local_bytes"
+
+struct membw_read_format {
+	__u64 value;         /* The value of the event */
+	__u64 time_enabled;  /* if PERF_FORMAT_TOTAL_TIME_ENABLED */
+	__u64 time_running;  /* if PERF_FORMAT_TOTAL_TIME_RUNNING */
+	__u64 id;            /* if PERF_FORMAT_ID */
+};
+
+struct imc_counter_config {
+	__u32 type;
+	__u64 event;
+	__u64 umask;
+	struct perf_event_attr pe;
+	struct membw_read_format return_value;
+	int fd;
+};
+
+static char mbm_total_path[1024];
+static int imcs;
+static struct imc_counter_config imc_counters_config[MAX_IMCS];
+static const struct resctrl_test *current_test;
+
+static void read_mem_bw_initialize_perf_event_attr(int i)
+{
+	memset(&imc_counters_config[i].pe, 0,
+	       sizeof(struct perf_event_attr));
+	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;
+}
+
+static void read_mem_bw_ioctl_perf_event_ioc_reset_enable(int i)
+{
+	ioctl(imc_counters_config[i].fd, PERF_EVENT_IOC_RESET, 0);
+	ioctl(imc_counters_config[i].fd, PERF_EVENT_IOC_ENABLE, 0);
+}
+
+static void read_mem_bw_ioctl_perf_event_ioc_disable(int i)
+{
+	ioctl(imc_counters_config[i].fd, PERF_EVENT_IOC_DISABLE, 0);
+}
+
+/*
+ * get_read_event_and_umask:	Parse config into event and umask
+ * @cas_count_cfg:	Config
+ * @count:		iMC number
+ */
+static void get_read_event_and_umask(char *cas_count_cfg, int count)
+{
+	char *token[MAX_TOKENS];
+	int i = 0;
+
+	token[0] = strtok(cas_count_cfg, "=,");
+
+	for (i = 1; i < MAX_TOKENS; i++)
+		token[i] = strtok(NULL, "=,");
+
+	for (i = 0; i < MAX_TOKENS - 1; i++) {
+		if (!token[i])
+			break;
+		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_read_event(int i, int cpu_no)
+{
+	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].fd == -1) {
+		fprintf(stderr, "Error opening leader %llx\n",
+			imc_counters_config[i].pe.config);
+
+		return -1;
+	}
+
+	return 0;
+}
+
+/* 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];
+	FILE *fp;
+
+	/* Get type of iMC counter */
+	sprintf(imc_counter_type, "%s%s", imc_dir, "type");
+	fp = fopen(imc_counter_type, "r");
+	if (!fp) {
+		ksft_perror("Failed to open iMC counter type file");
+
+		return -1;
+	}
+	if (fscanf(fp, "%u", &imc_counters_config[count].type) <= 0) {
+		ksft_perror("Could not get iMC type");
+		fclose(fp);
+
+		return -1;
+	}
+	fclose(fp);
+
+	/* Get read config */
+	sprintf(imc_counter_cfg, "%s%s", imc_dir, READ_FILE_NAME);
+	fp = fopen(imc_counter_cfg, "r");
+	if (!fp) {
+		ksft_perror("Failed to open iMC config file");
+
+		return -1;
+	}
+	if (fscanf(fp, "%1023s", cas_count_cfg) <= 0) {
+		ksft_perror("Could not get iMC cas count read");
+		fclose(fp);
+
+		return -1;
+	}
+	fclose(fp);
+
+	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'. 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.
+ */
+static int num_of_imcs(void)
+{
+	char imc_dir[512], *temp;
+	unsigned int count = 0;
+	struct dirent *ep;
+	int ret;
+	DIR *dp;
+
+	dp = opendir(DYN_PMU_PATH);
+	if (dp) {
+		while ((ep = readdir(dp))) {
+			temp = strstr(ep->d_name, UNCORE_IMC);
+			if (!temp)
+				continue;
+
+			/*
+			 * imc counters are named as "uncore_imc_<n>", hence
+			 * increment the pointer to point to <n>. Note that
+			 * sizeof(UNCORE_IMC) would count for null character as
+			 * well and hence the last underscore character in
+			 * uncore_imc'_' need not be counted.
+			 */
+			temp = temp + sizeof(UNCORE_IMC);
+
+			/*
+			 * Some directories under "DYN_PMU_PATH" could have
+			 * names like "uncore_imc_free_running", hence, check if
+			 * first character is a numerical digit or not.
+			 */
+			if (temp[0] >= '0' && temp[0] <= '9') {
+				sprintf(imc_dir, "%s/%s/", DYN_PMU_PATH,
+					ep->d_name);
+				ret = read_from_imc_dir(imc_dir, count);
+				if (ret) {
+					closedir(dp);
+
+					return ret;
+				}
+				count++;
+			}
+		}
+		closedir(dp);
+		if (count == 0) {
+			ksft_print_msg("Unable to find iMC counters\n");
+
+			return -1;
+		}
+	} else {
+		ksft_perror("Unable to open PMU directory");
+
+		return -1;
+	}
+
+	return count;
+}
+
+int initialize_read_mem_bw_imc(void)
+{
+	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++)
+		read_mem_bw_initialize_perf_event_attr(imc);
+
+	return 0;
+}
+
+static void perf_close_imc_read_mem_bw(void)
+{
+	int mc;
+
+	for (mc = 0; mc < imcs; mc++) {
+		if (imc_counters_config[mc].fd != -1)
+			close(imc_counters_config[mc].fd);
+	}
+}
+
+/*
+ * 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_read_mem_bw(int cpu_no)
+{
+	int imc, ret;
+
+	for (imc = 0; imc < imcs; imc++)
+		imc_counters_config[imc].fd = -1;
+
+	for (imc = 0; imc < imcs; imc++) {
+		ret = open_perf_read_event(imc, cpu_no);
+		if (ret)
+			goto close_fds;
+	}
+
+	return 0;
+
+close_fds:
+	perf_close_imc_read_mem_bw();
+	return -1;
+}
+
+/*
+ * 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_read_mem_bw_test(void)
+{
+	int imc;
+
+	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. */
+	for (imc = 0; imc < imcs; imc++)
+		read_mem_bw_ioctl_perf_event_ioc_disable(imc);
+}
+
+/*
+ * get_read_mem_bw_imc - Memory read bandwidth as reported by iMC 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_read_mem_bw_imc(float *bw_imc)
+{
+	float reads = 0, of_mul_read = 1;
+	int imc;
+
+	/*
+	 * 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];
+
+		if (read(r->fd, &r->return_value,
+			 sizeof(struct membw_read_format)) == -1) {
+			ksft_perror("Couldn't get read bandwidth through iMC");
+			return -1;
+		}
+
+		__u64 r_time_enabled = r->return_value.time_enabled;
+		__u64 r_time_running = r->return_value.time_running;
+
+		if (r_time_enabled != r_time_running)
+			of_mul_read = (float)r_time_enabled /
+					(float)r_time_running;
+
+		reads += r->return_value.value * of_mul_read * SCALE;
+	}
+
+	*bw_imc = reads;
+	return 0;
+}
+
+/*
+ * initialize_mem_bw_resctrl:	Appropriately populate "mbm_total_path"
+ * @param:	Parameters passed to resctrl_val()
+ * @domain_id:	Domain ID (cache ID; for MB, L3 cache ID)
+ */
+void initialize_mem_bw_resctrl(const struct resctrl_val_param *param,
+			       int domain_id)
+{
+	sprintf(mbm_total_path, CON_MBM_LOCAL_BYTES_PATH, RESCTRL_PATH,
+		param->ctrlgrp, domain_id);
+}
+
+/*
+ * Open file to read MBM local bytes from resctrl FS
+ */
+static FILE *open_mem_bw_resctrl(const char *mbm_bw_file)
+{
+	FILE *fp;
+
+	fp = fopen(mbm_bw_file, "r");
+	if (!fp)
+		ksft_perror("Failed to open total memory bandwidth file");
+
+	return fp;
+}
+
+/*
+ * Get MBM Local bytes as reported by resctrl FS
+ */
+static int get_mem_bw_resctrl(FILE *fp, unsigned long *mbm_total)
+{
+	if (fscanf(fp, "%lu\n", mbm_total) <= 0) {
+		ksft_perror("Could not get MBM local bytes");
+		return -1;
+	}
+	return 0;
+}
+
+static pid_t bm_pid;
+
+void ctrlc_handler(int signum, siginfo_t *info, void *ptr)
+{
+	/* Only kill child after bm_pid is set after fork() */
+	if (bm_pid)
+		kill(bm_pid, SIGKILL);
+	umount_resctrlfs();
+	if (current_test && current_test->cleanup)
+		current_test->cleanup();
+	ksft_print_msg("Ending\n\n");
+
+	exit(EXIT_SUCCESS);
+}
+
+/*
+ * Register CTRL-C handler for parent, as it has to kill
+ * child process before exiting.
+ */
+int signal_handler_register(const struct resctrl_test *test)
+{
+	struct sigaction sigact = {};
+	int ret = 0;
+
+	bm_pid = 0;
+
+	current_test = test;
+	sigact.sa_sigaction = ctrlc_handler;
+	sigemptyset(&sigact.sa_mask);
+	sigact.sa_flags = SA_SIGINFO;
+	if (sigaction(SIGINT, &sigact, NULL) ||
+	    sigaction(SIGTERM, &sigact, NULL) ||
+	    sigaction(SIGHUP, &sigact, NULL)) {
+		ksft_perror("sigaction");
+		ret = -1;
+	}
+	return ret;
+}
+
+/*
+ * Reset signal handler to SIG_DFL.
+ * Non-Value return because the caller should keep
+ * the error code of other path even if sigaction fails.
+ */
+void signal_handler_unregister(void)
+{
+	struct sigaction sigact = {};
+
+	current_test = NULL;
+	sigact.sa_handler = SIG_DFL;
+	sigemptyset(&sigact.sa_mask);
+	if (sigaction(SIGINT, &sigact, NULL) ||
+	    sigaction(SIGTERM, &sigact, NULL) ||
+	    sigaction(SIGHUP, &sigact, NULL)) {
+		ksft_perror("sigaction");
+	}
+}
+
+/*
+ * print_results_bw:	the memory bandwidth results are stored in a file
+ * @filename:		file that stores the results
+ * @bm_pid:		child pid that runs benchmark
+ * @bw_imc:		perf imc counter value
+ * @bw_resc:		memory bandwidth value
+ *
+ * Return:		0 on success, < 0 on error.
+ */
+static int print_results_bw(char *filename, pid_t bm_pid, float bw_imc,
+			    unsigned long bw_resc)
+{
+	unsigned long diff = fabs(bw_imc - bw_resc);
+	FILE *fp;
+
+	if (strcmp(filename, "stdio") == 0 || strcmp(filename, "stderr") == 0) {
+		printf("Pid: %d \t Mem_BW_iMC: %f \t ", (int)bm_pid, bw_imc);
+		printf("Mem_BW_resc: %lu \t Difference: %lu\n", bw_resc, diff);
+	} else {
+		fp = fopen(filename, "a");
+		if (!fp) {
+			ksft_perror("Cannot open results file");
+
+			return -1;
+		}
+		if (fprintf(fp, "Pid: %d \t Mem_BW_iMC: %f \t Mem_BW_resc: %lu \t Difference: %lu\n",
+			    (int)bm_pid, bw_imc, bw_resc, diff) <= 0) {
+			ksft_print_msg("Could not log results\n");
+			fclose(fp);
+
+			return -1;
+		}
+		fclose(fp);
+	}
+
+	return 0;
+}
+
+/*
+ * 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
+ *
+ * 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_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;
+
+	mem_bw_fp = open_mem_bw_resctrl(mbm_total_path);
+	if (!mem_bw_fp)
+		return -1;
+
+	ret = perf_open_imc_read_mem_bw(uparams->cpu);
+	if (ret < 0)
+		goto close_fp;
+
+	ret = get_mem_bw_resctrl(mem_bw_fp, &bw_resc_start);
+	if (ret < 0)
+		goto close_imc;
+
+	rewind(mem_bw_fp);
+
+	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_read_mem_bw_imc(&bw_imc);
+	if (ret < 0)
+		goto close_imc;
+
+	perf_close_imc_read_mem_bw();
+	fclose(mem_bw_fp);
+
+	bw_resc = (bw_resc_end - bw_resc_start) / MB;
+
+	return print_results_bw(param->filename, bm_pid, bw_imc, bw_resc);
+
+close_imc:
+	perf_close_imc_read_mem_bw();
+close_fp:
+	fclose(mem_bw_fp);
+	return ret;
+}
+
+/*
+ * resctrl_val:	execute benchmark and measure memory bandwidth on
+ *			the benchmark
+ * @test:		test information structure
+ * @uparams:		user supplied parameters
+ * @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,
+		struct resctrl_val_param *param)
+{
+	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");
+
+	ret = get_domain_id(test->resource, uparams->cpu, &domain_id);
+	if (ret < 0) {
+		ksft_print_msg("Could not get domain ID\n");
+		return ret;
+	}
+
+	ppid = getpid();
+
+	/* Taskset test to specified CPU. */
+	ret = taskset_benchmark(ppid, uparams->cpu, &old_affinity);
+	if (ret)
+		return ret;
+
+	/* 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;
+	}
+
+	/*
+	 * 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");
+		goto free_buf;
+	}
+
+	/*
+	 * What needs to be measured runs in separate process until
+	 * terminated.
+	 */
+	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);
+	}
+
+	ksft_print_msg("Benchmark PID: %d\n", (int)bm_pid);
+
+	/* Give benchmark enough time to fully run. */
+	sleep(1);
+
+	/* Test runs until the callback setup() tells the test to stop. */
+	while (1) {
+		ret = param->setup(test, uparams, param);
+		if (ret == END_OF_TESTS) {
+			ret = 0;
+			break;
+		}
+		if (ret < 0)
+			break;
+
+		ret = param->measure(uparams, param, bm_pid);
+		if (ret)
+			break;
+	}
+
+	kill(bm_pid, SIGKILL);
+free_buf:
+	free(buf);
+reset_affinity:
+	taskset_restore(ppid, &old_affinity);
+	return ret;
+}