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* [PATCH] perf/core: fix parent pid/tid in task exit events
@ 2020-04-17 18:28 Ian Rogers
  2020-04-17 18:45 ` Peter Zijlstra
  2020-04-22 21:20 ` [tip: perf/urgent] " tip-bot2 for Ian Rogers
  0 siblings, 2 replies; 4+ messages in thread
From: Ian Rogers @ 2020-04-17 18:28 UTC (permalink / raw)
  To: Peter Zijlstra, Ingo Molnar, Arnaldo Carvalho de Melo,
	Mark Rutland, Alexander Shishkin, Jiri Olsa, Namhyung Kim,
	linux-kernel, linux-perf-users
  Cc: Stephane Eranian, KP Singh, Ian Rogers

Current logic yields the child task as the parent.

Before:
$ perf record bash -c "perf list > /dev/null"
$ perf script -D |grep 'FORK\|EXIT'
4387036190981094 0x5a70 [0x30]: PERF_RECORD_FORK(10472:10472):(10470:10470)
4387036606207580 0xf050 [0x30]: PERF_RECORD_EXIT(10472:10472):(10472:10472)
4387036607103839 0x17150 [0x30]: PERF_RECORD_EXIT(10470:10470):(10470:10470)
                                                   ^
  Note the repeated values here -------------------/

After:
383281514043 0x9d8 [0x30]: PERF_RECORD_FORK(2268:2268):(2266:2266)
383442003996 0x2180 [0x30]: PERF_RECORD_EXIT(2268:2268):(2266:2266)
383451297778 0xb70 [0x30]: PERF_RECORD_EXIT(2266:2266):(2265:2265)

Reported-by: KP Singh <kpsingh@google.com>
Signed-off-by: Ian Rogers <irogers@google.com>
---
 kernel/events/core.c | 13 ++++++++++---
 1 file changed, 10 insertions(+), 3 deletions(-)

diff --git a/kernel/events/core.c b/kernel/events/core.c
index bc9b98a9af9a..633b4ae72ed5 100644
--- a/kernel/events/core.c
+++ b/kernel/events/core.c
@@ -7491,10 +7491,17 @@ static void perf_event_task_output(struct perf_event *event,
 		goto out;
 
 	task_event->event_id.pid = perf_event_pid(event, task);
-	task_event->event_id.ppid = perf_event_pid(event, current);
-
 	task_event->event_id.tid = perf_event_tid(event, task);
-	task_event->event_id.ptid = perf_event_tid(event, current);
+
+	if (task_event->event_id.header.type == PERF_RECORD_EXIT) {
+		task_event->event_id.ppid = perf_event_pid(event,
+							task->real_parent);
+		task_event->event_id.ptid = perf_event_pid(event,
+							task->real_parent);
+	} else {  /* PERF_RECORD_FORK */
+		task_event->event_id.ppid = perf_event_pid(event, current);
+		task_event->event_id.ptid = perf_event_tid(event, current);
+	}
 
 	task_event->event_id.time = perf_event_clock(event);
 
-- 
2.26.1.301.g55bc3eb7cb9-goog


^ permalink raw reply	[flat|nested] 4+ messages in thread

* Re: [PATCH] perf/core: fix parent pid/tid in task exit events
  2020-04-17 18:28 [PATCH] perf/core: fix parent pid/tid in task exit events Ian Rogers
@ 2020-04-17 18:45 ` Peter Zijlstra
  2020-04-17 21:31   ` Ian Rogers
  2020-04-22 21:20 ` [tip: perf/urgent] " tip-bot2 for Ian Rogers
  1 sibling, 1 reply; 4+ messages in thread
From: Peter Zijlstra @ 2020-04-17 18:45 UTC (permalink / raw)
  To: Ian Rogers
  Cc: Ingo Molnar, Arnaldo Carvalho de Melo, Mark Rutland,
	Alexander Shishkin, Jiri Olsa, Namhyung Kim, linux-kernel,
	linux-perf-users, Stephane Eranian, KP Singh

On Fri, Apr 17, 2020 at 11:28:42AM -0700, Ian Rogers wrote:
> Current logic yields the child task as the parent.
> 
> Before:
> $ perf record bash -c "perf list > /dev/null"
> $ perf script -D |grep 'FORK\|EXIT'
> 4387036190981094 0x5a70 [0x30]: PERF_RECORD_FORK(10472:10472):(10470:10470)
> 4387036606207580 0xf050 [0x30]: PERF_RECORD_EXIT(10472:10472):(10472:10472)
> 4387036607103839 0x17150 [0x30]: PERF_RECORD_EXIT(10470:10470):(10470:10470)
>                                                    ^
>   Note the repeated values here -------------------/
> 
> After:
> 383281514043 0x9d8 [0x30]: PERF_RECORD_FORK(2268:2268):(2266:2266)
> 383442003996 0x2180 [0x30]: PERF_RECORD_EXIT(2268:2268):(2266:2266)
> 383451297778 0xb70 [0x30]: PERF_RECORD_EXIT(2266:2266):(2265:2265)
> 

Fixes: .... ?

> Reported-by: KP Singh <kpsingh@google.com>
> Signed-off-by: Ian Rogers <irogers@google.com>

^ permalink raw reply	[flat|nested] 4+ messages in thread

* Re: [PATCH] perf/core: fix parent pid/tid in task exit events
  2020-04-17 18:45 ` Peter Zijlstra
@ 2020-04-17 21:31   ` Ian Rogers
  0 siblings, 0 replies; 4+ messages in thread
From: Ian Rogers @ 2020-04-17 21:31 UTC (permalink / raw)
  To: Peter Zijlstra
  Cc: Ingo Molnar, Arnaldo Carvalho de Melo, Mark Rutland,
	Alexander Shishkin, Jiri Olsa, Namhyung Kim, LKML,
	linux-perf-users, Stephane Eranian, KP Singh

On Fri, Apr 17, 2020 at 11:45 AM Peter Zijlstra <peterz@infradead.org> wrote:
>
> On Fri, Apr 17, 2020 at 11:28:42AM -0700, Ian Rogers wrote:
> > Current logic yields the child task as the parent.
> >
> > Before:
> > $ perf record bash -c "perf list > /dev/null"
> > $ perf script -D |grep 'FORK\|EXIT'
> > 4387036190981094 0x5a70 [0x30]: PERF_RECORD_FORK(10472:10472):(10470:10470)
> > 4387036606207580 0xf050 [0x30]: PERF_RECORD_EXIT(10472:10472):(10472:10472)
> > 4387036607103839 0x17150 [0x30]: PERF_RECORD_EXIT(10470:10470):(10470:10470)
> >                                                    ^
> >   Note the repeated values here -------------------/
> >
> > After:
> > 383281514043 0x9d8 [0x30]: PERF_RECORD_FORK(2268:2268):(2266:2266)
> > 383442003996 0x2180 [0x30]: PERF_RECORD_EXIT(2268:2268):(2266:2266)
> > 383451297778 0xb70 [0x30]: PERF_RECORD_EXIT(2266:2266):(2265:2265)
> >
>
> Fixes: .... ?

Fixes:  94d5d1b2d891 ("perf_counter: Report the cloning task as parent
on perf_counter_fork()")

Sorry, re-sending as plain-text was disabled on the message and so it
bounced on lkml. Took some digging to find the original commit :-)

Thanks,
Ian

>
> > Reported-by: KP Singh <kpsingh@google.com>
> > Signed-off-by: Ian Rogers <irogers@google.com>

^ permalink raw reply	[flat|nested] 4+ messages in thread

* [tip: perf/urgent] perf/core: fix parent pid/tid in task exit events
  2020-04-17 18:28 [PATCH] perf/core: fix parent pid/tid in task exit events Ian Rogers
  2020-04-17 18:45 ` Peter Zijlstra
@ 2020-04-22 21:20 ` tip-bot2 for Ian Rogers
  1 sibling, 0 replies; 4+ messages in thread
From: tip-bot2 for Ian Rogers @ 2020-04-22 21:20 UTC (permalink / raw)
  To: linux-tip-commits; +Cc: KP Singh, Ian Rogers, Peter Zijlstra (Intel), x86, LKML

The following commit has been merged into the perf/urgent branch of tip:

Commit-ID:     f3bed55e850926614b9898fe982f66d2541a36a5
Gitweb:        https://git.kernel.org/tip/f3bed55e850926614b9898fe982f66d2541a36a5
Author:        Ian Rogers <irogers@google.com>
AuthorDate:    Fri, 17 Apr 2020 11:28:42 -07:00
Committer:     Peter Zijlstra <peterz@infradead.org>
CommitterDate: Wed, 22 Apr 2020 23:10:14 +02:00

perf/core: fix parent pid/tid in task exit events

Current logic yields the child task as the parent.

Before:
$ perf record bash -c "perf list > /dev/null"
$ perf script -D |grep 'FORK\|EXIT'
4387036190981094 0x5a70 [0x30]: PERF_RECORD_FORK(10472:10472):(10470:10470)
4387036606207580 0xf050 [0x30]: PERF_RECORD_EXIT(10472:10472):(10472:10472)
4387036607103839 0x17150 [0x30]: PERF_RECORD_EXIT(10470:10470):(10470:10470)
                                                   ^
  Note the repeated values here -------------------/

After:
383281514043 0x9d8 [0x30]: PERF_RECORD_FORK(2268:2268):(2266:2266)
383442003996 0x2180 [0x30]: PERF_RECORD_EXIT(2268:2268):(2266:2266)
383451297778 0xb70 [0x30]: PERF_RECORD_EXIT(2266:2266):(2265:2265)

Fixes: 94d5d1b2d891 ("perf_counter: Report the cloning task as parent on perf_counter_fork()")
Reported-by: KP Singh <kpsingh@google.com>
Signed-off-by: Ian Rogers <irogers@google.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lkml.kernel.org/r/20200417182842.12522-1-irogers@google.com
---
 kernel/events/core.c | 13 ++++++++++---
 1 file changed, 10 insertions(+), 3 deletions(-)

diff --git a/kernel/events/core.c b/kernel/events/core.c
index bc9b98a..633b4ae 100644
--- a/kernel/events/core.c
+++ b/kernel/events/core.c
@@ -7491,10 +7491,17 @@ static void perf_event_task_output(struct perf_event *event,
 		goto out;
 
 	task_event->event_id.pid = perf_event_pid(event, task);
-	task_event->event_id.ppid = perf_event_pid(event, current);
-
 	task_event->event_id.tid = perf_event_tid(event, task);
-	task_event->event_id.ptid = perf_event_tid(event, current);
+
+	if (task_event->event_id.header.type == PERF_RECORD_EXIT) {
+		task_event->event_id.ppid = perf_event_pid(event,
+							task->real_parent);
+		task_event->event_id.ptid = perf_event_pid(event,
+							task->real_parent);
+	} else {  /* PERF_RECORD_FORK */
+		task_event->event_id.ppid = perf_event_pid(event, current);
+		task_event->event_id.ptid = perf_event_tid(event, current);
+	}
 
 	task_event->event_id.time = perf_event_clock(event);
 

^ permalink raw reply	[flat|nested] 4+ messages in thread

end of thread, other threads:[~2020-04-22 21:20 UTC | newest]

Thread overview: 4+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2020-04-17 18:28 [PATCH] perf/core: fix parent pid/tid in task exit events Ian Rogers
2020-04-17 18:45 ` Peter Zijlstra
2020-04-17 21:31   ` Ian Rogers
2020-04-22 21:20 ` [tip: perf/urgent] " tip-bot2 for Ian Rogers

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