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Commit 3c1cb7e3 authored by Wang Nan's avatar Wang Nan Committed by Arnaldo Carvalho de Melo
Browse files

perf record: Split output into multiple files via '--switch-output' 



Allow 'perf record' to split its output into multiple files.

For example:

  # ~/perf record -a --timestamp-filename --switch-output &
  [1] 10763
  # kill -s SIGUSR2 10763
  [ perf record: dump data: Woken up 1 times ]
  # [ perf record: Dump perf.data.2015122622314468 ]

  # kill -s SIGUSR2 10763
  [ perf record: dump data: Woken up 1 times ]
  # [ perf record: Dump perf.data.2015122622314762 ]

  # kill -s SIGUSR2 10763
  [ perf record: dump data: Woken up 1 times ]
  #[ perf record: Dump perf.data.2015122622315171 ]

  # fg
  perf record -a --timestamp-filename --switch-output
  ^C[ perf record: Woken up 1 times to write data ]
  [ perf record: Dump perf.data.2015122622315513 ]
  [ perf record: Captured and wrote 0.014 MB perf.data.<timestamp> (296 samples) ]

  # ls -l
  total 920
  -rw------- 1 root root 797692 Dec 26 22:31 perf.data.2015122622314468
  -rw------- 1 root root  59960 Dec 26 22:31 perf.data.2015122622314762
  -rw------- 1 root root  59912 Dec 26 22:31 perf.data.2015122622315171
  -rw------- 1 root root  19220 Dec 26 22:31 perf.data.2015122622315513

Signed-off-by: default avatarWang Nan <wangnan0@huawei.com>
Tested-by: default avatarArnaldo Carvalho de Melo <acme@redhat.com>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Zefan Li <lizefan@huawei.com>
Cc: pi3orama@163.com
Link: http://lkml.kernel.org/r/1461178794-40467-4-git-send-email-wangnan0@huawei.com


Signed-off-by: default avatarHe Kuang <hekuang@huawei.com>
[ Added man page entry, used the re-synthesize patch in this series as a fixup ]
Signed-off-by: default avatarArnaldo Carvalho de Melo <acme@redhat.com>
parent 5f9cf599

tools/perf/Documentation/perf-record.txt

+8 −0
Original line number Diff line number Diff line
@@ -347,6 +347,14 @@ Configure all used events to run in kernel space. 
--all-user::

Configure all used events to run in user space.



--switch-output::

Generate multiple perf.data files, timestamp prefixed, switching to a new one

when receiving a SIGUSR2.



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

particular perf.data snapshot should be kept or not.



SEE ALSO

--------

linkperf:perf-stat[1], linkperf:perf-list[1]

tools/perf/builtin-record.c

+38 −2
Original line number Diff line number Diff line
@@ -58,6 +58,7 @@ struct record { 
	bool			no_buildid_cache_set;

	bool			buildid_all;

	bool			timestamp_filename;

	bool			switch_output;

	unsigned long long	samples;

};
@@ -130,6 +131,7 @@ 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)

{
@@ -498,6 +500,8 @@ record__finish_output(struct record *rec) 
	return;

}



static int record__synthesize(struct record *rec);



static int

record__switch_output(struct record *rec, bool at_exit)

{
@@ -526,6 +530,11 @@ record__switch_output(struct record *rec, bool at_exit) 
	if (!quiet)

		fprintf(stderr, "[ perf record: Dump %s.%s ]\n",

			file->path, timestamp);



	/* Output tracking events */

	if (!at_exit)

		record__synthesize(rec);



	return fd;

}
@@ -650,9 +659,12 @@ static int __cmd_record(struct record *rec, int argc, const char **argv) 
	signal(SIGINT, sig_handler);

	signal(SIGTERM, sig_handler);



	if (rec->opts.auxtrace_snapshot_mode) {

	if (rec->opts.auxtrace_snapshot_mode || rec->switch_output) {

		signal(SIGUSR2, snapshot_sig_handler);

		if (rec->opts.auxtrace_snapshot_mode)

			trigger_on(&auxtrace_snapshot_trigger);

		if (rec->switch_output)

			trigger_on(&switch_output_trigger);

	} else {

		signal(SIGUSR2, SIG_IGN);

	}
@@ -782,11 +794,13 @@ static int __cmd_record(struct record *rec, int argc, const char **argv) 
	}



	trigger_ready(&auxtrace_snapshot_trigger);

	trigger_ready(&switch_output_trigger);

	for (;;) {

		unsigned long long hits = rec->samples;



		if (record__mmap_read_all(rec) < 0) {

			trigger_error(&auxtrace_snapshot_trigger);

			trigger_error(&switch_output_trigger);

			err = -1;

			goto out_child;

		}
@@ -802,6 +816,22 @@ static int __cmd_record(struct record *rec, int argc, const char **argv) 
			}

		}



		if (trigger_is_hit(&switch_output_trigger)) {

			trigger_ready(&switch_output_trigger);



			if (!quiet)

				fprintf(stderr, "[ perf record: dump data: Woken up %ld times ]\n",

					waking);

			waking = 0;

			fd = record__switch_output(rec, false);

			if (fd < 0) {

				pr_err("Failed to switch to new file\n");

				trigger_error(&switch_output_trigger);

				err = fd;

				goto out_child;

			}

		}



		if (hits == rec->samples) {

			if (done || draining)

				break;
@@ -830,6 +860,7 @@ static int __cmd_record(struct record *rec, int argc, const char **argv) 
		}

	}

	trigger_off(&auxtrace_snapshot_trigger);

	trigger_off(&switch_output_trigger);



	if (forks && workload_exec_errno) {

		char msg[STRERR_BUFSIZE];
@@ -1263,6 +1294,8 @@ struct option __record_options[] = { 
		    "Record build-id of all DSOs regardless of hits"),

	OPT_BOOLEAN(0, "timestamp-filename", &record.timestamp_filename,

		    "append timestamp to output filename"),

	OPT_BOOLEAN(0, "switch-output", &record.switch_output,

		    "Switch output when receive SIGUSR2"),

	OPT_END()

};
@@ -1417,4 +1450,7 @@ static void snapshot_sig_handler(int sig __maybe_unused) 
		if (auxtrace_record__snapshot_start(record.itr))

			trigger_error(&auxtrace_snapshot_trigger);

	}



	if (trigger_is_ready(&switch_output_trigger))

		trigger_hit(&switch_output_trigger);

}