Messages in this thread Patch in this message | | | Date | Fri, 25 Jan 2013 03:32:56 -0800 | From | tip-bot for Namhyung Kim <> | Subject | [tip:perf/core] perf bench: Flush stdout before starting bench suite |
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Commit-ID: 9b494ea2f5638184bc203a30062b32b9a9a05d9e Gitweb: http://git.kernel.org/tip/9b494ea2f5638184bc203a30062b32b9a9a05d9e Author: Namhyung Kim <namhyung.kim@lge.com> AuthorDate: Tue, 8 Jan 2013 18:39:26 +0900 Committer: Arnaldo Carvalho de Melo <acme@redhat.com> CommitDate: Thu, 24 Jan 2013 16:40:19 -0300
perf bench: Flush stdout before starting bench suite
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.
Signed-off-by: Namhyung Kim <namhyung@kernel.org> Acked-by: Hitoshi Mitake <h.mitake@gmail.com> Cc: Hitoshi Mitake <mitake@dcl.info.waseda.ac.jp> Cc: Ingo Molnar <mingo@kernel.org> Cc: Paul Mackerras <paulus@samba.org> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Link: http://lkml.kernel.org/r/1357637966-8216-1-git-send-email-namhyung@kernel.org Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com> --- 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 cae9a5f..afd1255 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;
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