[PATCH 28/56] perf stat record: Add record command

[Jiri Olsa <jolsa@kernel.org>]

Add 'perf stat record' command support. It creates simple
(header only) perf.data file ATM.

Link: http://lkml.kernel.org/n/tip-0av5yfkwyywwgoiali88w4hi@git.kernel.org
Signed-off-by: Jiri Olsa <jolsa@kernel.org>
---
 tools/perf/Documentation/perf-stat.txt | 12 ++++++
 tools/perf/builtin-stat.c              | 74 +++++++++++++++++++++++++++++++++-
 2 files changed, 84 insertions(+), 2 deletions(-)

diff --git a/tools/perf/Documentation/perf-stat.txt b/tools/perf/Documentation/perf-stat.txt
index 4e074a660826..70eee1c2c444 100644
--- a/tools/perf/Documentation/perf-stat.txt
+++ b/tools/perf/Documentation/perf-stat.txt
@@ -10,6 +10,7 @@ SYNOPSIS
 [verse]
 'perf stat' [-e <EVENT> | --event=EVENT] [-a] <command>
 'perf stat' [-e <EVENT> | --event=EVENT] [-a] -- <command> [<options>]
+'perf stat' [-e <EVENT> | --event=EVENT] [-a] record [-o file] -- <command> [<options>]
 
 DESCRIPTION
 -----------
@@ -22,6 +23,8 @@ OPTIONS
 <command>...::
 	Any command you can specify in a shell.
 
+record::
+	See STAT RECORD.
 
 -e::
 --event=::
@@ -159,6 +162,15 @@ filter out the startup phase of the program, which is often very different.
 
 Print statistics of transactional execution if supported.
 
+STAT RECORD
+-----------
+Stores stat data into perf data file.
+
+-o file::
+--output file::
+Output file name.
+
+
 EXAMPLES
 --------
 
diff --git a/tools/perf/builtin-stat.c b/tools/perf/builtin-stat.c
index abeb15aebd12..a909160bdf8e 100644
--- a/tools/perf/builtin-stat.c
+++ b/tools/perf/builtin-stat.c
@@ -59,6 +59,7 @@
 #include "util/thread.h"
 #include "util/thread_map.h"
 #include "util/counts.h"
+#include "util/session.h"
 
 #include <stdlib.h>
 #include <sys/prctl.h>
@@ -121,6 +122,16 @@ static struct timespec		ref_time;
 static struct cpu_map		*aggr_map;
 static int			(*aggr_get_id)(struct cpu_map *m, int cpu);
 
+struct perf_stat {
+	bool			 record;
+	struct perf_data_file	 file;
+	struct perf_session	*session;
+	u64			 bytes_written;
+};
+
+static struct perf_stat		perf_stat;
+#define STAT_RECORD		perf_stat.record
+
 static volatile int done = 0;
 
 static struct perf_stat_config stat_config = {
@@ -339,6 +350,15 @@ static int __run_perf_stat(int argc, const char **argv)
 		return -1;
 	}
 
+	if (STAT_RECORD) {
+		int err, fd = perf_data_file__fd(&perf_stat.file);
+
+		err = perf_session__write_header(perf_stat.session, evsel_list,
+						 fd, false);
+		if (err < 0)
+			return err;
+	}
+
 	/*
 	 * Enable counters and exec the command:
 	 */
@@ -1130,6 +1150,39 @@ static int add_default_attributes(void)
 	return perf_evlist__add_default_attrs(evsel_list, very_very_detailed_attrs);
 }
 
+static const char * const recort_usage[] = {
+	"perf stat record [<options>]",
+	NULL,
+};
+
+static int __cmd_record(int argc, const char **argv)
+{
+	struct perf_session *session;
+	struct perf_data_file *file = &perf_stat.file;
+	const struct option options[] = {
+	OPT_STRING('o', "output", &perf_stat.file.path, "file", "output file name"),
+	OPT_END()
+	};
+
+	argc = parse_options(argc, argv, options, record_usage,
+			     PARSE_OPT_STOP_AT_NON_OPTION);
+
+	session = perf_session__new(file, false, NULL);
+	if (session == NULL) {
+		pr_err("Perf session creation failed.\n");
+		return -1;
+	}
+
+	/* No pipe support ATM */
+	if (perf_stat.file.is_pipe)
+		return -EINVAL;
+
+	session->evlist   = evsel_list;
+	perf_stat.session = session;
+	perf_stat.record  = true;
+	return argc;
+}
+
 int cmd_stat(int argc, const char **argv, const char *prefix __maybe_unused)
 {
 	bool append_file = false;
@@ -1203,6 +1256,7 @@ int cmd_stat(int argc, const char **argv, const char *prefix __maybe_unused)
 	const char *mode;
 	FILE *output = stderr;
 	unsigned int interval;
+	const char * const stat_subcommands[] = { "record" };
 
 	setlocale(LC_ALL, "");
 
@@ -1210,8 +1264,15 @@ int cmd_stat(int argc, const char **argv, const char *prefix __maybe_unused)
 	if (evsel_list == NULL)
 		return -ENOMEM;
 
-	argc = parse_options(argc, argv, options, stat_usage,
-		PARSE_OPT_STOP_AT_NON_OPTION);
+	argc = parse_options_subcommand(argc, argv, options, stat_subcommands,
+					(const char **) stat_usage,
+					PARSE_OPT_STOP_AT_NON_OPTION);
+
+	if (argc && !strncmp(argv[0], "rec", 3)) {
+		argc = __cmd_record(argc, argv);
+		if (argc < 0)
+			return -1;
+	}
 
 	interval = stat_config.interval;
 
@@ -1382,6 +1443,15 @@ int cmd_stat(int argc, const char **argv, const char *prefix __maybe_unused)
 	if (!forever && status != -1 && !interval)
 		print_counters(NULL, argc, argv);
 
+	if (STAT_RECORD) {
+		int fd = perf_data_file__fd(&perf_stat.file);
+
+		perf_stat.session->header.data_size += perf_stat.bytes_written;
+		perf_session__write_header(perf_stat.session, evsel_list, fd, true);
+
+		perf_session__delete(perf_stat.session);
+	}
+
 	perf_evlist__free_stats(evsel_list);
 out:
 	perf_evlist__delete(evsel_list);
-- 
2.4.3