perf record: Add switch-output size option argument (dc0c6127) · Commits · e / devices / android_kernel_fairphone_FP5

tools/perf/Documentation/perf-record.txt

+10 −2

Original line number	Diff line number	Diff line
		@@ -421,9 +421,17 @@ Configure all used events to run in user space.
		--timestamp-filename
		Append timestamp to output file name.

		--switch-output::
		--switch-output[=mode]::
		Generate multiple perf.data files, timestamp prefixed, switching to a new one
		when receiving a SIGUSR2.
		based on 'mode' value:
		"signal" - when receiving a SIGUSR2 (default value) or
		<size> - when reaching the size threshold, size is expected to
		be a number with appended unit character - B/K/M/G

		Note: the precision of the size threshold hugely depends
		on your configuration - the number and size of your ring
		buffers (-m). It is generally more precise for higher sizes
		(like >5M), for lower values expect different sizes.

		A possible use case is to, given an external event, slice the perf.data file
		that gets then processed, possibly via a perf script, to decide if that

tools/perf/builtin-record.c

+53 −14

Original line number	Diff line number	Diff line
		@@ -47,7 +47,9 @@
		#include <linux/time64.h>

		struct switch_output {
		bool enabled;
		bool signal;
		unsigned long size;
		const char *str;
		bool set;
		};
		@@ -72,6 +74,23 @@ struct record {
		unsigned long long samples;
		};

		static volatile int auxtrace_record__snapshot_started;
		static DEFINE_TRIGGER(auxtrace_snapshot_trigger);
		static DEFINE_TRIGGER(switch_output_trigger);

		static bool switch_output_signal(struct record *rec)
		{
		return rec->switch_output.signal &&
		trigger_is_ready(&switch_output_trigger);
		}

		static bool switch_output_size(struct record *rec)
		{
		return rec->switch_output.size &&
		trigger_is_ready(&switch_output_trigger) &&
		(rec->bytes_written >= rec->switch_output.size);
		}

		static int record__write(struct record rec, void bf, size_t size)
		{
		if (perf_data_file__write(rec->session->file, bf, size) < 0) {
		@@ -80,6 +99,10 @@ static int record__write(struct record rec, void bf, size_t size)
		}

		rec->bytes_written += size;

		if (switch_output_size(rec))
		trigger_hit(&switch_output_trigger);

		return 0;
		}

		@@ -199,10 +222,6 @@ static volatile int done;
		static volatile int signr = -1;
		static volatile int child_finished;

		static volatile int auxtrace_record__snapshot_started;
		static DEFINE_TRIGGER(auxtrace_snapshot_trigger);
		static DEFINE_TRIGGER(switch_output_trigger);

		static void sig_handler(int sig)
		{
		if (sig == SIGCHLD)
		@@ -848,11 +867,11 @@ static int __cmd_record(struct record rec, int argc, const char *argv)
		signal(SIGTERM, sig_handler);
		signal(SIGSEGV, sigsegv_handler);

		if (rec->opts.auxtrace_snapshot_mode \|\| rec->switch_output.signal) {
		if (rec->opts.auxtrace_snapshot_mode \|\| rec->switch_output.enabled) {
		signal(SIGUSR2, snapshot_sig_handler);
		if (rec->opts.auxtrace_snapshot_mode)
		trigger_on(&auxtrace_snapshot_trigger);
		if (rec->switch_output.signal)
		if (rec->switch_output.enabled)
		trigger_on(&switch_output_trigger);
		} else {
		signal(SIGUSR2, SIG_IGN);
		@@ -1361,6 +1380,14 @@ static int record__parse_mmap_pages(const struct option *opt,
		static int switch_output_setup(struct record *rec)
		{
		struct switch_output *s = &rec->switch_output;
		static struct parse_tag tags_size[] = {
		{ .tag = 'B', .mult = 1 },
		{ .tag = 'K', .mult = 1 << 10 },
		{ .tag = 'M', .mult = 1 << 20 },
		{ .tag = 'G', .mult = 1 << 30 },
		{ .tag = 0 },
		};
		unsigned long val;

		if (!s->set)
		return 0;
		@@ -1368,10 +1395,22 @@ static int switch_output_setup(struct record *rec)
		if (!strcmp(s->str, "signal")) {
		s->signal = true;
		pr_debug("switch-output with SIGUSR2 signal\n");
		return 0;
		goto enabled;
		}

		val = parse_tag_value(s->str, tags_size);
		if (val != (unsigned long) -1) {
		s->size = val;
		pr_debug("switch-output with %s size threshold\n", s->str);
		goto enabled;
		}

		return -1;

		enabled:
		rec->timestamp_filename = true;
		s->enabled = true;
		return 0;
		}

		static const char * const __record_usage[] = {
		@@ -1542,8 +1581,9 @@ static struct option __record_options[] = {
		OPT_BOOLEAN(0, "timestamp-filename", &record.timestamp_filename,
		"append timestamp to output filename"),
		OPT_STRING_OPTARG_SET(0, "switch-output", &record.switch_output.str,
		&record.switch_output.set, "signal",
		"Switch output when receive SIGUSR2", "signal"),
		&record.switch_output.set, "signal,size",
		"Switch output when receive SIGUSR2 or cross size threshold",
		"signal"),
		OPT_BOOLEAN(0, "dry-run", &dry_run,
		"Parse options then exit"),
		OPT_END()
		@@ -1606,9 +1646,6 @@ int cmd_record(int argc, const char *argv, const char prefix __maybe_unused)
		return -EINVAL;
		}

		if (rec->switch_output.signal)
		rec->timestamp_filename = true;

		if (!rec->itr) {
		rec->itr = auxtrace_record__init(rec->evlist, &err);
		if (err)
		@@ -1657,7 +1694,7 @@ int cmd_record(int argc, const char *argv, const char prefix __maybe_unused)

		if (rec->no_buildid_cache \|\| rec->no_buildid) {
		disable_buildid_cache();
		} else if (rec->switch_output.signal) {
		} else if (rec->switch_output.enabled) {
		/*
		* In 'perf record --switch-output', disable buildid
		* generation by default to reduce data file switching
		@@ -1749,6 +1786,8 @@ int cmd_record(int argc, const char *argv, const char prefix __maybe_unused)

		static void snapshot_sig_handler(int sig __maybe_unused)
		{
		struct record *rec = &record;

		if (trigger_is_ready(&auxtrace_snapshot_trigger)) {
		trigger_hit(&auxtrace_snapshot_trigger);
		auxtrace_record__snapshot_started = 1;
		@@ -1756,6 +1795,6 @@ static void snapshot_sig_handler(int sig __maybe_unused)
		trigger_error(&auxtrace_snapshot_trigger);
		}

		if (trigger_is_ready(&switch_output_trigger))
		if (switch_output_signal(rec))
		trigger_hit(&switch_output_trigger);
		}