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| author | Ian Rogers <irogers@google.com> | 2020-04-17 11:28:42 -0700 |
|---|---|---|
| committer | Peter Zijlstra <peterz@infradead.org> | 2020-04-22 23:10:14 +0200 |
| commit | f3bed55e850926614b9898fe982f66d2541a36a5 (patch) | |
| tree | 8b294cbdc7a76ba82f640582e85ff7921e85274b /kernel | |
| parent | 5b16ef2e43ffa1be596652d992235b1cbb244935 (diff) | |
| download | linux-f3bed55e850926614b9898fe982f66d2541a36a5.tar.gz linux-f3bed55e850926614b9898fe982f66d2541a36a5.tar.bz2 linux-f3bed55e850926614b9898fe982f66d2541a36a5.zip | |
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
Diffstat (limited to 'kernel')
| -rw-r--r-- | kernel/events/core.c | 13 |
1 files 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); |