Messages in this thread | | | Date | Tue, 1 Oct 2013 13:51:33 -0300 | From | Arnaldo Carvalho de Melo <> | Subject | Re: [PATCH] perf stat: Set child_pid after perf_evlist__prepare_workload() |
| |
Em Mon, Sep 30, 2013 at 07:47:25AM -0600, David Ahern escreveu: > On 9/30/13 3:01 AM, Namhyung Kim wrote: > >From: Namhyung Kim <namhyung.kim@lge.com> > > > >The commit acf2892270dc ("perf stat: Use perf_evlist__prepare/ > >start_workload()") converted to use the function but forgot to update > >child_pid. Fix it. > > > >Cc: David Ahern <dsahern@gmail.com> > >Cc: Stephane Eranian <eranian@google.com> > >Signed-off-by: Namhyung Kim <namhyung@kernel.org> > >--- > > tools/perf/builtin-stat.c | 1 + > > 1 file changed, 1 insertion(+) > > > >diff --git a/tools/perf/builtin-stat.c b/tools/perf/builtin-stat.c > >index f686d5ff594e..5098f144b92d 100644 > >--- a/tools/perf/builtin-stat.c > >+++ b/tools/perf/builtin-stat.c > >@@ -457,6 +457,7 @@ static int __run_perf_stat(int argc, const char **argv) > > perror("failed to prepare workload"); > > return -1; > > } > >+ child_pid = evsel_list->workload.pid; > > } > > > > if (group) > > > > Interesting. I can't find a test case where is matters ... perhaps a > convenience of waitpid taking -1.
Yeah, the interval part initially used the fork return, then after acf2892270dc used the default value of child_pid, -1, which is ok as it waits for any children, but I wonder what would happen in workloads with multiple children.
But for correctness acf2892270dc should have kept the existing semantics, even if using -1 could in the end be ok.
- Arnaldo
| |