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authorIan Rogers <irogers@google.com>2020-04-17 11:28:42 -0700
committerPeter Zijlstra <peterz@infradead.org>2020-04-22 23:10:14 +0200
commitf3bed55e850926614b9898fe982f66d2541a36a5 (patch)
tree8b294cbdc7a76ba82f640582e85ff7921e85274b /kernel
parent5b16ef2e43ffa1be596652d992235b1cbb244935 (diff)
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.c13
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);