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| author | Hitoshi Mitake <mitake@dcl.info.waseda.ac.jp> | 2009-11-09 12:31:05 +0900 |
|---|---|---|
| committer | Ingo Molnar <mingo@elte.hu> | 2009-11-09 08:14:30 +0100 |
| commit | 5ff0cfc67f00fe0feaa1da0b2359232ea4aa0ee7 (patch) | |
| tree | f432370dfa63a7a3b63354d670128764eff534a1 /tools/perf/bench | |
| parent | bfde82ef51e3ea6ab8634d0fdbf5adcdd1b429cb (diff) | |
| download | lwn-5ff0cfc67f00fe0feaa1da0b2359232ea4aa0ee7.tar.gz lwn-5ff0cfc67f00fe0feaa1da0b2359232ea4aa0ee7.zip | |
perf bench: Fix bench/sched-pipe.c to wait for child process
Ingo reported this small 'perf bench sched pipe' output problem:
| $ ./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 <mitake@dcl.info.waseda.ac.jp>
Cc: Rusty Russell <rusty@rustcorp.com.au>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Jiri Kosina <jkosina@suse.cz>
LKML-Reference: <1257737465-7546-1-git-send-email-mitake@dcl.info.waseda.ac.jp>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Diffstat (limited to 'tools/perf/bench')
| -rw-r--r-- | 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 3214ed20b1aa..6a29100e9282 100644 --- a/tools/perf/bench/sched-pipe.c +++ b/tools/perf/bench/sched-pipe.c @@ -26,6 +26,7 @@ #include <errno.h> #include <assert.h> #include <sys/time.h> +#include <sys/types.h> #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", |