From: Namhyung Kim Date: Tue, 8 Jan 2013 09:39:26 +0000 (+0900) Subject: perf bench: Flush stdout before starting bench suite X-Git-Tag: v3.9-rc1~173^2~13^2~36 X-Git-Url: http://git.openpandora.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=9b494ea2f5638184bc203a30062b32b9a9a05d9e;p=pandora-kernel.git 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 Acked-by: Hitoshi Mitake Cc: Hitoshi Mitake Cc: Ingo Molnar Cc: Paul Mackerras Cc: Peter Zijlstra Link: http://lkml.kernel.org/r/1357637966-8216-1-git-send-email-namhyung@kernel.org Signed-off-by: Arnaldo Carvalho de Melo --- Reading git-diff-tree failed