summaryrefslogtreecommitdiffstats
diff options
context:
space:
mode:
-rw-r--r--include/linux/perf_event.h1
-rw-r--r--kernel/events/core.c10
2 files changed, 10 insertions, 1 deletions
diff --git a/include/linux/perf_event.h b/include/linux/perf_event.h
index f0a1036b1911..893a0d07986f 100644
--- a/include/linux/perf_event.h
+++ b/include/linux/perf_event.h
@@ -269,6 +269,7 @@ struct pmu {
* enum perf_event_active_state - the states of a event
*/
enum perf_event_active_state {
+ PERF_EVENT_STATE_EXIT = -3,
PERF_EVENT_STATE_ERROR = -2,
PERF_EVENT_STATE_OFF = -1,
PERF_EVENT_STATE_INACTIVE = 0,
diff --git a/kernel/events/core.c b/kernel/events/core.c
index 4575dd6e59ea..d8cb4d21a346 100644
--- a/kernel/events/core.c
+++ b/kernel/events/core.c
@@ -3600,7 +3600,8 @@ perf_read_hw(struct perf_event *event, char __user *buf, size_t count)
* error state (i.e. because it was pinned but it couldn't be
* scheduled on to the CPU at some point).
*/
- if (event->state == PERF_EVENT_STATE_ERROR)
+ if ((event->state == PERF_EVENT_STATE_ERROR) ||
+ (event->state == PERF_EVENT_STATE_EXIT))
return 0;
if (count < event->read_size)
@@ -3630,6 +3631,10 @@ static unsigned int perf_poll(struct file *file, poll_table *wait)
unsigned int events = POLLHUP;
poll_wait(file, &event->waitq, wait);
+
+ if (event->state == PERF_EVENT_STATE_EXIT)
+ return events;
+
/*
* Pin the event->rb by taking event->mmap_mutex; otherwise
* perf_event_set_output() can swizzle our rb and make us miss wakeups.
@@ -7588,6 +7593,9 @@ __perf_event_exit_task(struct perf_event *child_event,
if (child_event->parent) {
sync_child_event(child_event, child);
free_event(child_event);
+ } else {
+ child_event->state = PERF_EVENT_STATE_EXIT;
+ perf_event_wakeup(child_event);
}
}