1 files changed, 13 insertions, 12 deletions

diff --git a/kernel/time/tick-sched.c b/kernel/time/tick-sched.c
index 266c242dc354..c76aefe764b0 100644
--- a/kernel/time/tick-sched.c
+++ b/kernel/time/tick-sched.c
@@ -453,18 +453,22 @@ out:
  *
  * When the next event is more than a tick into the future, stop the idle tick
  * Called when we start the idle loop.
- * This also enters into RCU extended quiescent state so that this CPU doesn't
- * need anymore to be part of any global grace period completion. This way
- * the tick can be stopped safely as we don't need to report quiescent states.
+ *
+ * If no use of RCU is made in the idle loop between
+ * tick_nohz_idle_enter() and tick_nohz_idle_exit() calls, then
+ * tick_nohz_idle_enter_norcu() should be called instead and the arch
+ * doesn't need to call rcu_idle_enter() and rcu_idle_exit() explicitly.
+ *
+ * Otherwise the arch is responsible of calling:
+ *
+ * - rcu_idle_enter() after its last use of RCU before the CPU is put
+ *  to sleep.
+ * - rcu_idle_exit() before the first use of RCU after the CPU is woken up.
  */
-void tick_nohz_idle_enter(void)
+void __tick_nohz_idle_enter(void)
 {
         struct tick_sched *ts;
 
-        WARN_ON_ONCE(irqs_disabled());
-
-        local_irq_disable();
-
         ts = &__get_cpu_var(tick_cpu_sched);
         /*
          * set ts->inidle unconditionally. even if the system did not
@@ -473,9 +477,6 @@ void tick_nohz_idle_enter(void)
          */
         ts->inidle = 1;
         tick_nohz_stop_sched_tick(ts);
-        rcu_idle_enter();
-
-        local_irq_enable();
 }
 
 /**
@@ -551,7 +552,7 @@ void tick_nohz_idle_exit(void)
         ktime_t now;
 
         local_irq_disable();
-        rcu_idle_exit();
+
         if (ts->idle_active || (ts->inidle && ts->tick_stopped))
                 now = ktime_get();