Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754008AbZKIDbK (ORCPT ); Sun, 8 Nov 2009 22:31:10 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1753948AbZKIDbJ (ORCPT ); Sun, 8 Nov 2009 22:31:09 -0500 Received: from ns.dcl.info.waseda.ac.jp ([133.9.216.194]:60134 "EHLO ns.dcl.info.waseda.ac.jp" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753877AbZKIDbI (ORCPT ); Sun, 8 Nov 2009 22:31:08 -0500 From: Hitoshi Mitake To: Ingo Molnar Cc: linux-kernel@vger.kernel.org, Hitoshi Mitake , Rusty Russell , Peter Zijlstra , Paul Mackerras , Mike Galbraith , Arnaldo Carvalho de Melo , Frederic Weisbecker , Jiri Kosina Subject: [PATCH] perf bench: Fix bench/sched-pipe.c to wait child process Date: Mon, 9 Nov 2009 12:31:05 +0900 Message-Id: <1257737465-7546-1-git-send-email-mitake@dcl.info.waseda.ac.jp> X-Mailer: git-send-email 1.6.5.2 In-Reply-To: <20091109.121836.719610044276873093.mitake@dcl.info.waseda.ac.jp> References: <20091109.121836.719610044276873093.mitake@dcl.info.waseda.ac.jp> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2120 Lines: 76 Fixed bench/sched-pipe.c to avoid the below case notified by Ingo Molnar, --- $ ./perf bench sched pipe (executing 1000000 pipe operations between two tasks) Total time:4.898 sec $ 4.898586 usecs/op 204140 ops/sec the shell prompt came back before the usecs/op and ops/sec line was printed. Process teardown race, lack of wait() or so? --- This caused by lack of calling waitpid() by parent process, so I added it. Signed-off-by: Hitoshi Mitake Cc: Rusty Russell Cc: Peter Zijlstra Cc: Paul Mackerras Cc: Mike Galbraith Cc: Arnaldo Carvalho de Melo Cc: Frederic Weisbecker Cc: Jiri Kosina --- tools/perf/bench/sched-pipe.c | 10 +++++++--- 1 files changed, 7 insertions(+), 3 deletions(-) diff --git a/tools/perf/bench/sched-pipe.c b/tools/perf/bench/sched-pipe.c index 3214ed2..6a29100 100644 --- a/tools/perf/bench/sched-pipe.c +++ b/tools/perf/bench/sched-pipe.c @@ -26,6 +26,7 @@ #include #include #include +#include #define LOOPS_DEFAULT 1000000 static int loops = LOOPS_DEFAULT; @@ -58,8 +59,8 @@ int bench_sched_pipe(int argc, const char **argv, * discarding returned value of read(), write() * causes error in building environment for perf */ - int ret; - pid_t pid; + int ret, wait_stat; + pid_t pid, retpid; argc = parse_options(argc, argv, options, bench_sched_pipe_usage, 0); @@ -87,8 +88,11 @@ int bench_sched_pipe(int argc, const char **argv, gettimeofday(&stop, NULL); timersub(&stop, &start, &diff); - if (pid) + if (pid) { + retpid = waitpid(pid, &wait_stat, 0); + assert((retpid == pid) && WIFEXITED(wait_stat)); return 0; + } if (simple) printf("%lu.%03lu\n", -- 1.6.5.2 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/