On Thu, Jan 03, 2019 at 03:40:45PM +0800, Jin Yao wrote: > We hit a perf stat issue by using following script. > > #!/bin/bash > > sleep 1000 & > exec perf stat -a -e cycles -I1000 -- sleep 5 > > Since "perf stat" is launched by exec, so the "sleep 1000" would be > the child process of "perf stat". The wait4() will not return because > it's waiting for the child process "sleep 1000" to be end. So perf > stat doesn't return even 5s passed. > > This patch lets the perf stat return when the specified child process > is end (in this case, specified child process is "sleep 5"). > > Signed-off-by: Jin Yao <[email protected]>
Reviewed-by: Jiri Olsa <[email protected]> thanks, jirka > --- > tools/perf/builtin-stat.c | 3 ++- > 1 file changed, 2 insertions(+), 1 deletion(-) > > diff --git a/tools/perf/builtin-stat.c b/tools/perf/builtin-stat.c > index 1410d66..63a3afc 100644 > --- a/tools/perf/builtin-stat.c > +++ b/tools/perf/builtin-stat.c > @@ -561,7 +561,8 @@ static int __run_perf_stat(int argc, const char **argv, > int run_idx) > break; > } > } > - wait4(child_pid, &status, 0, &stat_config.ru_data); > + if (child_pid != -1) > + wait4(child_pid, &status, 0, &stat_config.ru_data); > > if (workload_exec_errno) { > const char *emsg = str_error_r(workload_exec_errno, > msg, sizeof(msg)); > -- > 2.7.4 >
