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H A Dbuiltin-bench.cdiff 9b494ea2f5638184bc203a30062b32b9a9a05d9e Tue Jan 08 10:39:26 CET 2013 Namhyung Kim <namhyung.kim@lge.com> 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>