Messages in this thread Patch in this message |  | | From | Namhyung Kim <> | Subject | [PATCH] perf bench: Flush stdout before starting bench suite | Date | Tue, 8 Jan 2013 18:39:26 +0900 |
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From: Namhyung Kim <namhyung.kim@lge.com>
perf bench prints header message for bench suite before starting the benchmark. However if the stdout is redirected to a file and bench suite forks child processes this (and possibly other debugging messages too) will be repeated multiple times.
$ perf bench sched messaging # Running sched/messaging benchmark... # 20 sender and receiver processes per group # 10 groups == 400 processes run
Total time: 0.100 [sec]
$ perf bench sched messaging > result.txt $ wc -l result.txt 391
In this file, there were so many "Running sched/messaging benchmark..." lines. This was because stdout is converted to fully-buffered due to the redirection and inherited child processes. Other lines are printed after reaping all those tasks.
So fix it by flushing stdout before starting bench suites.
Cc: Hitoshi Mitake <mitake@dcl.info.waseda.ac.jp> Signed-off-by: Namhyung Kim <namhyung@kernel.org> --- tools/perf/builtin-bench.c | 2 ++ 1 file changed, 2 insertions(+)
diff --git a/tools/perf/builtin-bench.c b/tools/perf/builtin-bench.c index cae9a5fd2ecf..afd1255a632f 100644 --- a/tools/perf/builtin-bench.c +++ b/tools/perf/builtin-bench.c @@ -159,6 +159,7 @@ static void all_suite(struct bench_subsys *subsys) /* FROM HERE */ printf("# Running %s/%s benchmark...\n", subsys->name, suites[i].name); + fflush(stdout); argv[1] = suites[i].name; suites[i].fn(1, argv, NULL); @@ -225,6 +226,7 @@ int cmd_bench(int argc, const char **argv, const char *prefix __maybe_unused) printf("# Running %s/%s benchmark...\n", subsystems[i].name, subsystems[i].suites[j].name); + fflush(stdout); status = subsystems[i].suites[j].fn(argc - 1, argv + 1, prefix); goto end; -- 1.7.11.7
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