path: root/tools/perf/builtin-record.c

/*
 * builtin-record.c
 *
 * Builtin record command: Record the profile of a workload
 * (or a CPU, or a PID) into the perf.data output file - for
 * later analysis via perf report.
 */
#include "builtin.h"

#include "perf.h"

#include "util/build-id.h"
#include "util/util.h"
#include "util/parse-options.h"
#include "util/parse-events.h"

#include "util/callchain.h"
#include "util/cgroup.h"
#include "util/header.h"
#include "util/event.h"
#include "util/evlist.h"
#include "util/evsel.h"
#include "util/debug.h"
#include "util/session.h"
#include "util/tool.h"
#include "util/symbol.h"
#include "util/cpumap.h"
#include "util/thread_map.h"
#include "util/data.h"

#include <unistd.h>
#include <sched.h>
#include <sys/mman.h>


struct record {
	struct perf_tool	tool;
	struct record_opts	opts;
	u64			bytes_written;
	struct perf_data_file	file;
	struct perf_evlist	*evlist;
	struct perf_session	*session;
	const char		*progname;
	int			realtime_prio;
	bool			no_buildid;
	bool			no_buildid_cache;
	long			samples;
};

static int record__write(struct record *rec, void *bf, size_t size)
{
	if (perf_data_file__write(rec->session->file, bf, size) < 0) {
		pr_err("failed to write perf data, error: %m\n");
		return -1;
	}

	rec->bytes_written += size;
	return 0;
}

static int process_synthesized_event(struct perf_tool *tool,
				     union perf_event *event,
				     struct perf_sample *sample __maybe_unused,
				     struct machine *machine __maybe_unused)
{
	struct record *rec = container_of(tool, struct record, tool);
	return record__write(rec, event, event->header.size);
}

static int record__mmap_read(struct record *rec, int idx)
{
	struct perf_mmap *md = &rec->evlist->mmap[idx];
	unsigned int head = perf_mmap__read_head(md);
	unsigned int old = md->prev;
	unsigned char *data = md->base + page_size;
	unsigned long size;
	void *buf;
	int rc = 0;

	if (old == head)
		return 0;

	rec->samples++;

	size = head - old;

	if ((old & md->mask) + size != (head & md->mask)) {
		buf = &data[old & md->mask];
		size = md->mask + 1 - (old & md->mask);
		old += size;

		if (record__write(rec, buf, size) < 0) {
			rc = -1;
			goto out;
		}
	}

	buf = &data[old & md->mask];
	size = head - old;
	old += size;

	if (record__write(rec, buf, size) < 0) {
		rc = -1;
		goto out;
	}

	md->prev = old;
	perf_evlist__mmap_consume(rec->evlist, idx);
out:
	return rc;
}

static volatile int done = 0;
static volatile int signr = -1;
static volatile int child_finished = 0;

static void sig_handler(int sig)
{
	if (sig == SIGCHLD)
		child_finished = 1;
	else
		signr = sig;

	done = 1;
}

static void record__sig_exit(void)
{
	if (signr == -1)
		return;

	signal(signr, SIG_DFL);
	raise(signr);
}

static int record__open(struct record *rec)
{
	char msg[512];
	struct perf_evsel *pos;
	struct perf_evlist *evlist = rec->evlist;
	struct perf_session *session = rec->session;
	struct record_opts *opts = &rec->opts;
	int rc = 0;

	perf_evlist__config(evlist, opts);

	evlist__for_each(evlist, pos) {
try_again:
		if (perf_evsel__open(pos, evlist->cpus, evlist->threads) < 0) {
			if (perf_evsel__fallback(pos, errno, msg, sizeof(msg))) {
				if (verbose)
					ui__warning("%s\n", msg);
				goto try_again;
			}

			rc = -errno;
			perf_evsel__open_strerror(pos, &opts->target,
						  errno, msg, sizeof(msg));
			ui__error("%s\n", msg);
			goto out;
		}
	}

	if (perf_evlist__apply_filters(evlist)) {
		error("failed to set filter with %d (%s)\n", errno,
			strerror_r(errno, msg, sizeof(msg)));
		rc = -1;
		goto out;
	}

	if (perf_evlist__mmap(evlist, opts->mmap_pages, false) < 0) {
		if (errno == EPERM) {
			pr_err("Permission error mapping pages.\n"
			       "Consider increasing "
			       "/proc/sys/kernel/perf_event_mlock_kb,\n"
			       "or try again with a smaller value of -m/--mmap_pages.\n"
			       "(current value: %u)\n", opts->mmap_pages);
			rc = -errno;
		} else {
			pr_err("failed to mmap with %d (%s)\n", errno,
				strerror_r(errno, msg, sizeof(msg)));
			rc = -errno;
		}
		goto out;
	}

	session->evlist = evlist;
	perf_session__set_id_hdr_size(session);
out:
	return rc;
}

static int process_sample_event(struct perf_tool *tool,
				union perf_event *event,
				struct perf_sample *sample,
				struct perf_evsel *evsel,
				struct machine *machine)
{
	struct record *rec = container_of(tool, struct record, tool);

	rec->samples++;

	return build_id__mark_dso_hit(tool, event, sample, evsel, machine);
}</