1 files changed, 432 insertions, 0 deletions
diff --git a/tools/perf/util/intel-tpebs.c b/tools/perf/util/intel-tpebs.c
new file mode 100644
index 000000000000..50a3c3e07160
--- /dev/null
+++ b/tools/perf/util/intel-tpebs.c
@@ -0,0 +1,432 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * intel_tpebs.c: Intel TPEBS support
+ */
+
+
+#include <sys/param.h>
+#include <subcmd/run-command.h>
+#include <thread.h>
+#include "intel-tpebs.h"
+#include <linux/list.h>
+#include <linux/zalloc.h>
+#include <linux/err.h>
+#include "sample.h"
+#include "debug.h"
+#include "evlist.h"
+#include "evsel.h"
+#include "session.h"
+#include "tool.h"
+#include "cpumap.h"
+#include "metricgroup.h"
+#include <sys/stat.h>
+#include <sys/file.h>
+#include <poll.h>
+#include <math.h>
+
+#define PERF_DATA		"-"
+
+bool tpebs_recording;
+static pid_t tpebs_pid = -1;
+static size_t tpebs_event_size;
+static LIST_HEAD(tpebs_results);
+static pthread_t tpebs_reader_thread;
+static struct child_process *tpebs_cmd;
+
+struct tpebs_retire_lat {
+	struct list_head nd;
+	/* Event name */
+	const char *name;
+	/* Event name with the TPEBS modifier R */
+	const char *tpebs_name;
+	/* Count of retire_latency values found in sample data */
+	size_t count;
+	/* Sum of all the retire_latency values in sample data */
+	int sum;
+	/* Average of retire_latency, val = sum / count */
+	double val;
+};
+
+static int get_perf_record_args(const char **record_argv, char buf[],
+				const char *cpumap_buf)
+{
+	struct tpebs_retire_lat *e;
+	int i = 0;
+
+	pr_debug("tpebs: Prepare perf record for retire_latency\n");
+
+	record_argv[i++] = "perf";
+	record_argv[i++] = "record";
+	record_argv[i++] = "-W";
+	record_argv[i++] = "--synth=no";
+	record_argv[i++] = buf;
+
+	if (!cpumap_buf) {
+		pr_err("tpebs: Require cpumap list to run sampling\n");
+		return -ECANCELED;
+	}
+	/* Use -C when cpumap_buf is not "-1" */
+	if (strcmp(cpumap_buf, "-1")) {
+		record_argv[i++] = "-C";
+		record_argv[i++] = cpumap_buf;
+	}
+
+	list_for_each_entry(e, &tpebs_results, nd) {
+		record_argv[i++] = "-e";
+		record_argv[i++] = e->name;
+	}
+
+	record_argv[i++] = "-o";
+	record_argv[i++] = PERF_DATA;
+
+	return 0;
+}
+
+static int prepare_run_command(const char **argv)
+{
+	tpebs_cmd = zalloc(sizeof(struct child_process));
+	if (!tpebs_cmd)
+		return -ENOMEM;
+	tpebs_cmd->argv = argv;
+	tpebs_cmd->out = -1;
+	return 0;
+}
+
+static int start_perf_record(int control_fd[], int ack_fd[],
+				const char *cpumap_buf)
+{
+	const char **record_argv;
+	int ret;
+	char buf[32];
+
+	scnprintf(buf, sizeof(buf), "--control=fd:%d,%d", control_fd[0], ack_fd[1]);
+
+	record_argv = calloc(12 + 2 * tpebs_event_size, sizeof(char *));
+	if (!record_argv)
+		return -ENOMEM;
+
+	ret = get_perf_record_args(record_argv, buf, cpumap_buf);
+	if (ret)
+		goto out;
+
+	ret = prepare_run_command(record_argv);
+	if (ret)
+		goto out;
+	ret = start_command(tpebs_cmd);
+out:
+	free(record_argv);
+	return ret;
+}
+
+static int process_sample_event(const struct perf_tool *tool __maybe_unused,
+				union perf_event *event __maybe_unused,
+				struct perf_sample *sample,
+				struct evsel *evsel,
+				struct machine *machine __maybe_unused)
+{
+	int ret = 0;
+	const char *evname;
+	struct tpebs_retire_lat *t;
+
+	evname = evsel__name(evsel);
+
+	/*
+	 * Need to handle per core results? We are assuming average retire
+	 * latency value will be used. Save the number of samples and the sum of
+	 * retire latency value for each event.
+	 */
+	list_for_each_entry(t, &tpebs_results, nd) {
+		if (!strcmp(evname, t->name)) {
+			t->count += 1;
+			t->sum += sample->retire_lat;
+			t->val = (double) t->sum / t->count;
+			break;
+		}
+	}
+
+	return ret;
+}
+
+static int process_feature_event(struct perf_session *session,
+				 union perf_event *event)
+{
+	if (event->feat.feat_id < HEADER_LAST_FEATURE)
+		return perf_event__process_feature(session, event);
+	return 0;
+}
+
+static void *__sample_reader(void *arg)
+{
+	struct child_process *child = arg;
+	struct perf_session *session;
+	struct perf_data data = {
+		.mode = PERF_DATA_MODE_READ,
+		.path = PERF_DATA,
+		.file.fd = child->out,
+	};
+	struct perf_tool tool;
+
+	perf_tool__init(&tool, /*ordered_events=*/false);
+	tool.sample = process_sample_event;
+	tool.feature = process_feature_event;
+	tool.attr = perf_event__process_attr;
+
+	session = perf_session__new(&data, &tool);
+	if (IS_ERR(session))
+		return NULL;
+	perf_session__process_events(session);
+	perf_session__delete(session);
+
+	return NULL;
+}
+
+/*
+ * tpebs_stop - stop the sample data read thread and the perf record process.
+ */
+static int tpebs_stop(void)
+{
+	int ret = 0;
+
+	/* Like tpebs_start, we should only run tpebs_end once. */
+	if (tpebs_pid != -1) {
+		kill(tpebs_cmd->pid, SIGTERM);
+		tpebs_pid = -1;
+		pthread_join(tpebs_reader_thread, NULL);
+		close(tpebs_cmd->out);
+		ret = finish_command(tpebs_cmd);
+		if (ret == -ERR_RUN_COMMAND_WAITPID_SIGNAL)
+			ret = 0;
+	}
+	return ret;
+}
+
+/*
+ * tpebs_start - start tpebs execution.
+ * @evsel_list: retire_latency evsels in this list will be selected and sampled
+ * to get the average retire_latency value.
+ *
+ * This function will be called from evlist level later when evlist__open() is
+ * called consistently.
+ */
+int tpebs_start(struct evlist *evsel_list)
+{
+	int ret = 0;
+	struct evsel *evsel;
+	char cpumap_buf[50];
+
+	/*
+	 * We should only run tpebs_start when tpebs_recording is enabled.
+	 * And we should only run it once with all the required events.
+	 */
+	if (tpebs_pid != -1 || !tpebs_recording)
+		return 0;
+
+	cpu_map__snprint(evsel_list->core.user_requested_cpus, cpumap_buf, sizeof(cpumap_buf));
+	/*
+	 * Prepare perf record for sampling event retire_latency before fork and
+	 * prepare workload
+	 */
+	evlist__for_each_entry(evsel_list, evsel) {
+		int i;
+		char *name;
+		struct tpebs_retire_lat *new;
+
+		if (!evsel->retire_lat)
+			continue;
+
+		pr_debug("tpebs: Retire_latency of event %s is required\n", evsel->name);
+		for (i = strlen(evsel->name) - 1; i > 0; i--) {
+			if (evsel->name[i] == 'R')
+				break;
+		}
+		if (i <= 0 || evsel->name[i] != 'R') {
+			ret = -1;
+			goto err;
+		}
+
+		name = strdup(evsel->name);
+		if (!name) {
+			ret = -ENOMEM;
+			goto err;
+		}
+		name[i] = 'p';
+
+		new = zalloc(sizeof(*new));
+		if (!new) {
+			ret = -1;
+			zfree(name);
+			goto err;
+		}
+		new->name = name;
+		new->tpebs_name = evsel->name;
+		list_add_tail(&new->nd, &tpebs_results);
+		tpebs_event_size += 1;
+	}
+
+	if (tpebs_event_size > 0) {
+		struct pollfd pollfd = { .events = POLLIN, };
+		int control_fd[2], ack_fd[2], len;
+		char ack_buf[8];
+
+		/*Create control and ack fd for --control*/
+		if (pipe(control_fd) < 0) {
+			pr_err("tpebs: Failed to create control fifo");
+			ret = -1;
+			goto out;
+		}
+		if (pipe(ack_fd) < 0) {
+			pr_err("tpebs: Failed to create control fifo");
+			ret = -1;
+			goto out;
+		}
+
+		ret = start_perf_record(control_fd, ack_fd, cpumap_buf);
+		if (ret)
+			goto out;
+		tpebs_pid = tpebs_cmd->pid;
+		if (pthread_create(&tpebs_reader_thread, NULL, __sample_reader, tpebs_cmd)) {
+			kill(tpebs_cmd->pid, SIGTERM);
+			close(tpebs_cmd->out);
+			pr_err("Could not create thread to process sample data.\n");
+			ret = -1;
+			goto out;
+		}
+		/* Wait for perf record initialization.*/
+		len = strlen(EVLIST_CTL_CMD_ENABLE_TAG);
+		ret = write(control_fd[1], EVLIST_CTL_CMD_ENABLE_TAG, len);
+		if (ret != len) {
+			pr_err("perf record control write control message failed\n");
+			goto out;
+		}
+
+		/* wait for an ack */
+		pollfd.fd = ack_fd[0];
+
+		/*
+		 * We need this poll to ensure the ack_fd PIPE will not hang
+		 * when perf record failed for any reason. The timeout value
+		 * 3000ms is an empirical selection.
+		 */
+		if (!poll(&pollfd, 1, 3000)) {
+			pr_err("tpebs failed: perf record ack timeout\n");
+			ret = -1;
+			goto out;
+		}
+
+		if (!(pollfd.revents & POLLIN)) {
+			pr_err("tpebs failed: did not received an ack\n");
+			ret = -1;
+			goto out;
+		}
+
+		ret = read(ack_fd[0], ack_buf, sizeof(ack_buf));
+		if (ret > 0)
+			ret = strcmp(ack_buf, EVLIST_CTL_CMD_ACK_TAG);
+		else {
+			pr_err("tpebs: perf record control ack failed\n");
+			goto out;
+		}
+out:
+		close(control_fd[0]);
+		close(control_fd[1]);
+		close(ack_fd[0]);
+		close(ack_fd[1]);
+	}
+err:
+	if (ret)
+		tpebs_delete();
+	return ret;
+}
+
+
+int tpebs_set_evsel(struct evsel *evsel, int cpu_map_idx, int thread)
+{
+	__u64 val;
+	bool found = false;
+	struct tpebs_retire_lat *t;
+	struct perf_counts_values *count;
+
+	/* Non reitre_latency evsel should never enter this function. */
+	if (!evsel__is_retire_lat(evsel))
+		return -1;
+
+	/*
+	 * Need to stop the forked record to ensure get sampled data from the
+	 * PIPE to process and get non-zero retire_lat value for hybrid.
+	 */
+	tpebs_stop();
+	count = perf_counts(evsel->counts, cpu_map_idx, thread);
+
+	list_for_each_entry(t, &tpebs_results, nd) {
+		if (t->tpebs_name == evsel->name ||
+		    (evsel->metric_id && !strcmp(t->tpebs_name, evsel->metric_id))) {
+			found = true;
+			break;
+		}
+	}
+
+	/* Set ena and run to non-zero */
+	count->ena = count->run = 1;
+	count->lost = 0;
+
+	if (!found) {
+		/*
+		 * Set default value or 0 when retire_latency for this event is
+		 * not found from sampling data (record_tpebs not set or 0
+		 * sample recorded).
+		 */
+		count->val = 0;
+		return 0;
+	}
+
+	/*
+	 * Only set retire_latency value to the first CPU and thread.
+	 */
+	if (cpu_map_idx == 0 && thread == 0)
+		val = rint(t->val);
+	else
+		val = 0;
+
+	count->val = val;
+	return 0;
+}
+
+static void tpebs_retire_lat__delete(struct tpebs_retire_lat *r)
+{
+	zfree(&r->name);
+	free(r);
+}
+
+
+/*
+ * tpebs_delete - delete tpebs related data and stop the created thread and
+ * process by calling tpebs_stop().
+ *
+ * This function is called from evlist_delete() and also from builtin-stat
+ * stat_handle_error(). If tpebs_start() is called from places other then perf
+ * stat, need to ensure tpebs_delete() is also called to safely free mem and
+ * close the data read thread and the forked perf record process.
+ *
+ * This function is also called in evsel__close() to be symmetric with
+ * tpebs_start() being called in evsel__open(). We will update this call site
+ * when move tpebs_start() to evlist level.
+ */
+void tpebs_delete(void)
+{
+	struct tpebs_retire_lat *r, *rtmp;
+
+	if (tpebs_pid == -1)
+		return;
+
+	tpebs_stop();
+
+	list_for_each_entry_safe(r, rtmp, &tpebs_results, nd) {
+		list_del_init(&r->nd);
+		tpebs_retire_lat__delete(r);
+	}
+
+	if (tpebs_cmd) {
+		free(tpebs_cmd);
+		tpebs_cmd = NULL;
+	}
+}