Messages in this thread |  | | Date | Tue, 08 Jan 2013 22:59:36 +0900 | From | Hitoshi Mitake <> | Subject | Re: [PATCH] perf bench: Flush stdout before starting bench suite |
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At Tue, 8 Jan 2013 18:39:26 +0900, Namhyung Kim wrote: > > 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.
Thanks a lot, I couldn't notice this problem.
Acked-by: Hitoshi Mitake <h.mitake@gmail.com>
> > 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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