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-rw-r--r--kernel/events/core.c52
1 files changed, 43 insertions, 9 deletions
diff --git a/kernel/events/core.c b/kernel/events/core.c
index 72d06e302e99..534e01e7bc36 100644
--- a/kernel/events/core.c
+++ b/kernel/events/core.c
@@ -2009,8 +2009,8 @@ event_sched_out(struct perf_event *event,
event->pmu->del(event, 0);
event->oncpu = -1;
- if (event->pending_disable) {
- event->pending_disable = 0;
+ if (READ_ONCE(event->pending_disable) >= 0) {
+ WRITE_ONCE(event->pending_disable, -1);
state = PERF_EVENT_STATE_OFF;
}
perf_event_set_state(event, state);
@@ -2198,7 +2198,8 @@ EXPORT_SYMBOL_GPL(perf_event_disable);
void perf_event_disable_inatomic(struct perf_event *event)
{
- event->pending_disable = 1;
+ WRITE_ONCE(event->pending_disable, smp_processor_id());
+ /* can fail, see perf_pending_event_disable() */
irq_work_queue(&event->pending);
}
@@ -5810,10 +5811,45 @@ void perf_event_wakeup(struct perf_event *event)
}
}
+static void perf_pending_event_disable(struct perf_event *event)
+{
+ int cpu = READ_ONCE(event->pending_disable);
+
+ if (cpu < 0)
+ return;
+
+ if (cpu == smp_processor_id()) {
+ WRITE_ONCE(event->pending_disable, -1);
+ perf_event_disable_local(event);
+ return;
+ }
+
+ /*
+ * CPU-A CPU-B
+ *
+ * perf_event_disable_inatomic()
+ * @pending_disable = CPU-A;
+ * irq_work_queue();
+ *
+ * sched-out
+ * @pending_disable = -1;
+ *
+ * sched-in
+ * perf_event_disable_inatomic()
+ * @pending_disable = CPU-B;
+ * irq_work_queue(); // FAILS
+ *
+ * irq_work_run()
+ * perf_pending_event()
+ *
+ * But the event runs on CPU-B and wants disabling there.
+ */
+ irq_work_queue_on(&event->pending, cpu);
+}
+
static void perf_pending_event(struct irq_work *entry)
{
- struct perf_event *event = container_of(entry,
- struct perf_event, pending);
+ struct perf_event *event = container_of(entry, struct perf_event, pending);
int rctx;
rctx = perf_swevent_get_recursion_context();
@@ -5822,10 +5858,7 @@ static void perf_pending_event(struct irq_work *entry)
* and we won't recurse 'further'.
*/
- if (event->pending_disable) {
- event->pending_disable = 0;
- perf_event_disable_local(event);
- }
+ perf_pending_event_disable(event);
if (event->pending_wakeup) {
event->pending_wakeup = 0;
@@ -10236,6 +10269,7 @@ perf_event_alloc(struct perf_event_attr *attr, int cpu,
init_waitqueue_head(&event->waitq);
+ event->pending_disable = -1;
init_irq_work(&event->pending, perf_pending_event);
mutex_init(&event->mmap_mutex);