Messages in this thread | | | Date | Thu, 9 Apr 2015 13:05:19 -0400 | From | Don Zickus <> | Subject | Re: [PATCH] perf tools: Fix ppid for non-main thread |
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On Thu, Apr 09, 2015 at 12:48:27PM -0400, David Ahern wrote: > Commit ca6c41c59b9 sets the ppid based on what is read from the > /proc/pid/status file when synthesizing fork events. This is correct > thing to do for new processes but not threads of a process. Fix > ppid for threads to be the main thread when synthesizing fork events > (ie., assume main thread spawned all sub-threads in a process).
That sounds right. :-) Sorry I should have noticed that a couple of weeks ago.
Acked-by: Don Zickus <dzickus@redhat.com>
> > Reported-by: Arnaldo Carvalho de Melo <arnaldo.melo@gmail.com> > Signed-off-by: David Ahern <david.ahern@oracle.com> > Cc: Don Zickus <dzickus@redhat.com> > --- > tools/perf/util/event.c | 14 ++++++++++++-- > 1 files changed, 12 insertions(+), 2 deletions(-) > > diff --git a/tools/perf/util/event.c b/tools/perf/util/event.c > index 186929a..ff866c4 100644 > --- a/tools/perf/util/event.c > +++ b/tools/perf/util/event.c > @@ -183,8 +183,18 @@ static int perf_event__synthesize_fork(struct perf_tool *tool, > { > memset(&event->fork, 0, sizeof(event->fork) + machine->id_hdr_size); > > - event->fork.ppid = ppid; > - event->fork.ptid = ppid; > + /* > + * for main thread set parent to ppid from status file. For other > + * threads set parent pid to main thread. ie., assume main thread > + * spawns all threads in a process > + */ > + if (tgid == pid) { > + event->fork.ppid = ppid; > + event->fork.ptid = ppid; > + } else { > + event->fork.ppid = tgid; > + event->fork.ptid = tgid; > + } > event->fork.pid = tgid; > event->fork.tid = pid; > event->fork.header.type = PERF_RECORD_FORK; > -- > 1.7.1 >
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