On Thu, Dec 09, 2021 at 03:51:37PM -0300, Arnaldo Carvalho de Melo wrote:

Em Sun, Nov 28, 2021 at 04:34:05PM +0100, Jiri Olsa escreveu:

quoted

On Fri, Nov 19, 2021 at 08:14:08AM +0200, Sohaib Mohamed wrote:

quoted

The output of Perf bench gets buffered when I pipe it to a file or to
tee, in such a way that I can see it only at the end.

E.g.
$ perf bench internals synthesize -t
< output comes out fine after each test run >

$ perf bench internals synthesize -t | tee file.txt
< output comes out only at the end of all tests >

This patch resolves this issue for 'bench' and 'test' subcommands.

I can reproduce this for bench, but not for test subcommand
other that that it makes sense to me

I reproduced it, see my comment to Sohaib's message, its not at the end,
its when the buffer fills up.

From the "it makes sense to me" I'm deriving an Acked-by you, ok?

ok, yes

Acked-by: Jiri Olsa <redacted>

jirka

- Arnaldo
 

quoted

jirka

quoted

See, also:
$ perf bench mem all | tee file.txt
$ perf bench sched all | tee file.txt
$ perf bench internals all -t | tee file.txt
$ perf bench internals all | tee file.txt

Suggested-by: Riccardo Mancini <redacted>
Signed-off-by: Sohaib Mohamed <redacted>
---
v1 -> v2:
- Use setvbuf(), instead of sprinkling fflush() calls and missing some places.

v1: https://lore.kernel.org/linux-perf-users/20211112215313.108823-1-sohaib.amhmd@gmail.com/ (local)
---
 tools/perf/builtin-bench.c      | 5 +++--
 tools/perf/tests/builtin-test.c | 3 +++
 2 files changed, 6 insertions(+), 2 deletions(-)

diff --git a/tools/perf/builtin-bench.c b/tools/perf/builtin-bench.c
index d0895162c2ba..d291f3a8af5f 100644
--- a/tools/perf/builtin-bench.c
+++ b/tools/perf/builtin-bench.c

@@ -226,7 +226,6 @@ static void run_collection(struct collection *coll)
 		if (!bench->fn)
 			break;
 		printf("# Running %s/%s benchmark...\n", coll->name, bench->name);
-		fflush(stdout);

 		argv[1] = bench->name;
 		run_bench(coll->name, bench->name, bench->fn, 1, argv);

@@ -247,6 +246,9 @@ int cmd_bench(int argc, const char **argv)
 	struct collection *coll;
 	int ret = 0;

+	/* Unbuffered output */
+	setvbuf(stdout, NULL, _IONBF, 0);
+
 	if (argc < 2) {
 		/* No collection specified. */
 		print_usage();

@@ -300,7 +302,6 @@ int cmd_bench(int argc, const char **argv)

 			if (bench_format == BENCH_FORMAT_DEFAULT)
 				printf("# Running '%s/%s' benchmark:\n", coll->name, bench->name);
-			fflush(stdout);
 			ret = run_bench(coll->name, bench->name, bench->fn, argc-1, argv+1);
 			goto end;
 		}

diff --git a/tools/perf/tests/builtin-test.c b/tools/perf/tests/builtin-test.c
index 8cb5a1c3489e..d92ae4efd2e6 100644
--- a/tools/perf/tests/builtin-test.c
+++ b/tools/perf/tests/builtin-test.c

@@ -606,6 +606,9 @@ int cmd_test(int argc, const char **argv)
         if (ret < 0)
                 return ret;

+	/* Unbuffered output */
+	setvbuf(stdout, NULL, _IONBF, 0);
+
 	argc = parse_options_subcommand(argc, argv, test_options, test_subcommands, test_usage, 0);
 	if (argc >= 1 && !strcmp(argv[0], "list"))
 		return perf_test__list(argc - 1, argv + 1);
--

2.25.1

-- 

- Arnaldo