Donate to e Foundation | Murena handsets with /e/OS | Own a part of Murena! Learn more

Commit 56f3bae7 authored by Jim Cromie's avatar Jim Cromie Committed by Arnaldo Carvalho de Melo
Browse files

perf stat: Add --log-fd <N> option to redirect stderr elsewhere 

This perf stat option emulates valgrind's --log-fd option, allowing the
user to send perf results elsewhere, and leaving stderr for use by the
program under test.  This complements --output file option, and is
mutually exclusive with it.

   3>results  perf stat --log-fd 3          -- $cmd
   3>>results perf stat --log-fd 3 --append -- $cmd

The perl distro's make test.valgrind target uses valgrind's --log-fd
option, I've adapted it to invoke perf also, and tested this patch
there.

Link: http://lkml.kernel.org/r/1315437244-3788-2-git-send-email-jim.cromie@gmail.com


Signed-off-by: default avatarArnaldo Carvalho de Melo <acme@redhat.com>
Signed-off-by: default avatarJim Cromie <jim.cromie@gmail.com>
Signed-off-by: default avatarArnaldo Carvalho de Melo <acme@redhat.com>
parent dcc101d1

tools/perf/Documentation/perf-stat.txt

+10 −1
Original line number Diff line number Diff line
@@ -95,12 +95,21 @@ corresponding events, i.e., they always refer to events defined earlier on the c 
line.



-o file::

-output file::

--output file::

Print the output into the designated file.



--append::

Append to the output file designated with the -o option. Ignored if -o is not specified.



--log-fd::



Log output to fd, instead of stderr.  Complementary to --output, and mutually exclusive

with it.  --append may be used here.  Examples:

     3>results  perf stat --log-fd 3          -- $cmd

     3>>results perf stat --log-fd 3 --append -- $cmd







EXAMPLES

--------

tools/perf/builtin-stat.c

+14 −0
Original line number Diff line number Diff line
@@ -196,6 +196,7 @@ static bool csv_output = false; 
static bool			group				= false;

static const char		*output_name			= NULL;

static FILE			*output				= NULL;

static int			output_fd;



static volatile int done = 0;
@@ -1080,6 +1081,8 @@ static const struct option options[] = { 
	OPT_STRING('o', "output", &output_name, "file",

		    "output file name"),

	OPT_BOOLEAN(0, "append", &append_file, "append to the output file"),

	OPT_INTEGER(0, "log-fd", &output_fd,

		    "log output to fd, instead of stderr"),

	OPT_END()

};
@@ -1166,6 +1169,10 @@ int cmd_stat(int argc, const char **argv, const char *prefix __used) 
	if (output_name && strcmp(output_name, "-"))

		output = NULL;



	if (output_name && output_fd) {

		fprintf(stderr, "cannot use both --output and --log-fd\n");

		usage_with_options(stat_usage, options);

	}

	if (!output) {

		struct timespec tm;

		mode = append_file ? "a" : "w";
@@ -1177,6 +1184,13 @@ int cmd_stat(int argc, const char **argv, const char *prefix __used) 
		}

		clock_gettime(CLOCK_REALTIME, &tm);

		fprintf(output, "# started on %s\n", ctime(&tm.tv_sec));

	} else if (output_fd != 2) {

		mode = append_file ? "a" : "w";

		output = fdopen(output_fd, mode);

		if (!output) {

			perror("Failed opening logfd");

			return -errno;

		}

	}



	if (csv_sep)