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Diffstat (limited to 'kernel')
-rw-r--r--kernel/events/core.c29
1 files changed, 14 insertions, 15 deletions
diff --git a/kernel/events/core.c b/kernel/events/core.c
index 64698fbfad9f..92d6999a4f2f 100644
--- a/kernel/events/core.c
+++ b/kernel/events/core.c
@@ -1645,7 +1645,7 @@ out:
static bool is_orphaned_event(struct perf_event *event)
{
- return event->state == PERF_EVENT_STATE_EXIT;
+ return event->state == PERF_EVENT_STATE_DEAD;
}
static inline int pmu_filter_match(struct perf_event *event)
@@ -1732,7 +1732,6 @@ group_sched_out(struct perf_event *group_event,
}
#define DETACH_GROUP 0x01UL
-#define DETACH_STATE 0x02UL
/*
* Cross CPU call to remove a performance event
@@ -1752,8 +1751,6 @@ __perf_remove_from_context(struct perf_event *event,
if (flags & DETACH_GROUP)
perf_group_detach(event);
list_del_event(event, ctx);
- if (flags & DETACH_STATE)
- event->state = PERF_EVENT_STATE_EXIT;
if (!ctx->nr_events && ctx->is_active) {
ctx->is_active = 0;
@@ -3772,22 +3769,24 @@ int perf_event_release_kernel(struct perf_event *event)
ctx = perf_event_ctx_lock(event);
WARN_ON_ONCE(ctx->parent_ctx);
- perf_remove_from_context(event, DETACH_GROUP | DETACH_STATE);
- perf_event_ctx_unlock(event, ctx);
+ perf_remove_from_context(event, DETACH_GROUP);
+ raw_spin_lock_irq(&ctx->lock);
/*
- * At this point we must have event->state == PERF_EVENT_STATE_EXIT,
- * either from the above perf_remove_from_context() or through
- * perf_event_exit_event().
+ * Mark this even as STATE_DEAD, there is no external reference to it
+ * anymore.
*
- * Therefore, anybody acquiring event->child_mutex after the below
- * loop _must_ also see this, most importantly inherit_event() which
- * will avoid placing more children on the list.
+ * Anybody acquiring event->child_mutex after the below loop _must_
+ * also see this, most importantly inherit_event() which will avoid
+ * placing more children on the list.
*
* Thus this guarantees that we will in fact observe and kill _ALL_
* child events.
*/
- WARN_ON_ONCE(event->state != PERF_EVENT_STATE_EXIT);
+ event->state = PERF_EVENT_STATE_DEAD;
+ raw_spin_unlock_irq(&ctx->lock);
+
+ perf_event_ctx_unlock(event, ctx);
again:
mutex_lock(&event->child_mutex);
@@ -4000,7 +3999,7 @@ static bool is_event_hup(struct perf_event *event)
{
bool no_children;
- if (event->state != PERF_EVENT_STATE_EXIT)
+ if (event->state > PERF_EVENT_STATE_EXIT)
return false;
mutex_lock(&event->child_mutex);
@@ -8727,7 +8726,7 @@ perf_event_exit_event(struct perf_event *child_event,
if (parent_event)
perf_group_detach(child_event);
list_del_event(child_event, child_ctx);
- child_event->state = PERF_EVENT_STATE_EXIT; /* see perf_event_release_kernel() */
+ child_event->state = PERF_EVENT_STATE_EXIT; /* is_event_hup() */
raw_spin_unlock_irq(&child_ctx->lock);
/*