[PATCH 3/3] perf: Avoid cpu_hotplug_lock r-r recursion

[Peter Zijlstra]

There are two call-sites where using static_key results in recursing
on the cpu_hotplug_lock.

Signed-off-by: Peter Zijlstra (Intel) <peterz@xxxxxxxxxxxxx>
---
 kernel/events/core.c |    4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

--- a/kernel/events/core.c
+++ b/kernel/events/core.c
@@ -7785,7 +7785,7 @@ static int perf_swevent_init(struct perf
 		if (err)
 			return err;
 
-		static_key_slow_inc(&perf_swevent_enabled[event_id]);
+		static_key_slow_inc_nohp(&perf_swevent_enabled[event_id]);
 		event->destroy = sw_perf_event_destroy;
 	}
 
@@ -9294,7 +9294,7 @@ static void account_event(struct perf_ev
 
 		mutex_lock(&perf_sched_mutex);
 		if (!atomic_read(&perf_sched_count)) {
-			static_branch_enable(&perf_sched_events);
+			static_key_slow_inc_nohp(&perf_sched_events.key);
 			/*
 			 * Guarantee that all CPUs observe they key change and
 			 * call the perf scheduling hooks before proceeding to