1 files changed, 287 insertions, 0 deletions
diff --git a/tools/perf/util/record.c b/tools/perf/util/record.c
new file mode 100644
index 000000000..07e4b96a6
--- /dev/null
+++ b/tools/perf/util/record.c
@@ -0,0 +1,287 @@
+// SPDX-License-Identifier: GPL-2.0
+#include "debug.h"
+#include "evlist.h"
+#include "evsel.h"
+#include "evsel_config.h"
+#include "parse-events.h"
+#include <errno.h>
+#include <limits.h>
+#include <stdlib.h>
+#include <api/fs/fs.h>
+#include <subcmd/parse-options.h>
+#include <perf/cpumap.h>
+#include "cloexec.h"
+#include "util/perf_api_probe.h"
+#include "record.h"
+#include "../perf-sys.h"
+#include "topdown.h"
+
+/*
+ * evsel__config_leader_sampling() uses special rules for leader sampling.
+ * However, if the leader is an AUX area event, then assume the event to sample
+ * is the next event.
+ */
+static struct evsel *evsel__read_sampler(struct evsel *evsel, struct evlist *evlist)
+{
+	struct evsel *leader = evsel->leader;
+
+	if (evsel__is_aux_event(leader) || arch_topdown_sample_read(leader)) {
+		evlist__for_each_entry(evlist, evsel) {
+			if (evsel->leader == leader && evsel != evsel->leader)
+				return evsel;
+		}
+	}
+
+	return leader;
+}
+
+static u64 evsel__config_term_mask(struct evsel *evsel)
+{
+	struct evsel_config_term *term;
+	struct list_head *config_terms = &evsel->config_terms;
+	u64 term_types = 0;
+
+	list_for_each_entry(term, config_terms, list) {
+		term_types |= 1 << term->type;
+	}
+	return term_types;
+}
+
+static void evsel__config_leader_sampling(struct evsel *evsel, struct evlist *evlist)
+{
+	struct perf_event_attr *attr = &evsel->core.attr;
+	struct evsel *leader = evsel->leader;
+	struct evsel *read_sampler;
+	u64 term_types, freq_mask;
+
+	if (!leader->sample_read)
+		return;
+
+	read_sampler = evsel__read_sampler(evsel, evlist);
+
+	if (evsel == read_sampler)
+		return;
+
+	term_types = evsel__config_term_mask(evsel);
+	/*
+	 * Disable sampling for all group members except those with explicit
+	 * config terms or the leader. In the case of an AUX area event, the 2nd
+	 * event in the group is the one that 'leads' the sampling.
+	 */
+	freq_mask = (1 << EVSEL__CONFIG_TERM_FREQ) | (1 << EVSEL__CONFIG_TERM_PERIOD);
+	if ((term_types & freq_mask) == 0) {
+		attr->freq           = 0;
+		attr->sample_freq    = 0;
+		attr->sample_period  = 0;
+	}
+	if ((term_types & (1 << EVSEL__CONFIG_TERM_OVERWRITE)) == 0)
+		attr->write_backward = 0;
+
+	/*
+	 * We don't get a sample for slave events, we make them when delivering
+	 * the group leader sample. Set the slave event to follow the master
+	 * sample_type to ease up reporting.
+	 * An AUX area event also has sample_type requirements, so also include
+	 * the sample type bits from the leader's sample_type to cover that
+	 * case.
+	 */
+	attr->sample_type = read_sampler->core.attr.sample_type |
+			    leader->core.attr.sample_type;
+}
+
+void perf_evlist__config(struct evlist *evlist, struct record_opts *opts,
+			 struct callchain_param *callchain)
+{
+	struct evsel *evsel;
+	bool use_sample_identifier = false;
+	bool use_comm_exec;
+	bool sample_id = opts->sample_id;
+
+	/*
+	 * Set the evsel leader links before we configure attributes,
+	 * since some might depend on this info.
+	 */
+	if (opts->group)
+		perf_evlist__set_leader(evlist);
+
+	if (evlist->core.cpus->map[0] < 0)
+		opts->no_inherit = true;
+
+	use_comm_exec = perf_can_comm_exec();
+
+	evlist__for_each_entry(evlist, evsel) {
+		evsel__config(evsel, opts, callchain);
+		if (evsel->tracking && use_comm_exec)
+			evsel->core.attr.comm_exec = 1;
+	}
+
+	/* Configure leader sampling here now that the sample type is known */
+	evlist__for_each_entry(evlist, evsel)
+		evsel__config_leader_sampling(evsel, evlist);
+
+	if (opts->full_auxtrace) {
+		/*
+		 * Need to be able to synthesize and parse selected events with
+		 * arbitrary sample types, which requires always being able to
+		 * match the id.
+		 */
+		use_sample_identifier = perf_can_sample_identifier();
+		sample_id = true;
+	} else if (evlist->core.nr_entries > 1) {
+		struct evsel *first = evlist__first(evlist);
+
+		evlist__for_each_entry(evlist, evsel) {
+			if (evsel->core.attr.sample_type == first->core.attr.sample_type)
+				continue;
+			use_sample_identifier = perf_can_sample_identifier();
+			break;
+		}
+		sample_id = true;
+	}
+
+	if (sample_id) {
+		evlist__for_each_entry(evlist, evsel)
+			evsel__set_sample_id(evsel, use_sample_identifier);
+	}
+
+	perf_evlist__set_id_pos(evlist);
+}
+
+static int get_max_rate(unsigned int *rate)
+{
+	return sysctl__read_int("kernel/perf_event_max_sample_rate", (int *)rate);
+}
+
+static int record_opts__config_freq(struct record_opts *opts)
+{
+	bool user_freq = opts->user_freq != UINT_MAX;
+	unsigned int max_rate;
+
+	if (opts->user_interval != ULLONG_MAX)
+		opts->default_interval = opts->user_interval;
+	if (user_freq)
+		opts->freq = opts->user_freq;
+
+	/*
+	 * User specified count overrides default frequency.
+	 */
+	if (opts->default_interval)
+		opts->freq = 0;
+	else if (opts->freq) {
+		opts->default_interval = opts->freq;
+	} else {
+		pr_err("frequency and count are zero, aborting\n");
+		return -1;
+	}
+
+	if (get_max_rate(&max_rate))
+		return 0;
+
+	/*
+	 * User specified frequency is over current maximum.
+	 */
+	if (user_freq && (max_rate < opts->freq)) {
+		if (opts->strict_freq) {
+			pr_err("error: Maximum frequency rate (%'u Hz) exceeded.\n"
+			       "       Please use -F freq option with a lower value or consider\n"
+			       "       tweaking /proc/sys/kernel/perf_event_max_sample_rate.\n",
+			       max_rate);
+			return -1;
+		} else {
+			pr_warning("warning: Maximum frequency rate (%'u Hz) exceeded, throttling from %'u Hz to %'u Hz.\n"
+				   "         The limit can be raised via /proc/sys/kernel/perf_event_max_sample_rate.\n"
+				   "         The kernel will lower it when perf's interrupts take too long.\n"
+				   "         Use --strict-freq to disable this throttling, refusing to record.\n",
+				   max_rate, opts->freq, max_rate);
+
+			opts->freq = max_rate;
+		}
+	}
+
+	/*
+	 * Default frequency is over current maximum.
+	 */
+	if (max_rate < opts->freq) {
+		pr_warning("Lowering default frequency rate to %u.\n"
+			   "Please consider tweaking "
+			   "/proc/sys/kernel/perf_event_max_sample_rate.\n",
+			   max_rate);
+		opts->freq = max_rate;
+	}
+
+	return 0;
+}
+
+int record_opts__config(struct record_opts *opts)
+{
+	return record_opts__config_freq(opts);
+}
+
+bool perf_evlist__can_select_event(struct evlist *evlist, const char *str)
+{
+	struct evlist *temp_evlist;
+	struct evsel *evsel;
+	int err, fd, cpu;
+	bool ret = false;
+	pid_t pid = -1;
+
+	temp_evlist = evlist__new();
+	if (!temp_evlist)
+		return false;
+
+	err = parse_events(temp_evlist, str, NULL);
+	if (err)
+		goto out_delete;
+
+	evsel = evlist__last(temp_evlist);
+
+	if (!evlist || perf_cpu_map__empty(evlist->core.cpus)) {
+		struct perf_cpu_map *cpus = perf_cpu_map__new(NULL);
+
+		cpu =  cpus ? cpus->map[0] : 0;
+		perf_cpu_map__put(cpus);
+	} else {
+		cpu = evlist->core.cpus->map[0];
+	}
+
+	while (1) {
+		fd = sys_perf_event_open(&evsel->core.attr, pid, cpu, -1,
+					 perf_event_open_cloexec_flag());
+		if (fd < 0) {
+			if (pid == -1 && errno == EACCES) {
+				pid = 0;
+				continue;
+			}
+			goto out_delete;
+		}
+		break;
+	}
+	close(fd);
+	ret = true;
+
+out_delete:
+	evlist__delete(temp_evlist);
+	return ret;
+}
+
+int record__parse_freq(const struct option *opt, const char *str, int unset __maybe_unused)
+{
+	unsigned int freq;
+	struct record_opts *opts = opt->value;
+
+	if (!str)
+		return -EINVAL;
+
+	if (strcasecmp(str, "max") == 0) {
+		if (get_max_rate(&freq)) {
+			pr_err("couldn't read /proc/sys/kernel/perf_event_max_sample_rate\n");
+			return -1;
+		}
+		pr_info("info: Using a maximum frequency rate of %'d Hz\n", freq);
+	} else {
+		freq = atoi(str);
+	}
+
+	opts->user_freq = freq;
+	return 0;
+}