[v3,14/51] cpuidle,cpu_pm: Remove RCU fiddling from cpu_pm_{enter,exit}()

Commit Message

Peter Zijlstra Jan. 12, 2023, 7:43 p.m. UTC

All callers should still have RCU enabled.

Signed-off-by: Peter Zijlstra (Intel) <[e-mail]>
Reviewed-by: Ulf Hansson <[e-mail]>
Acked-by: Mark Rutland <[e-mail]>
Acked-by: Rafael J. Wysocki <[e-mail]>
Acked-by: Frederic Weisbecker <[e-mail]>
Tested-by: Tony Lindgren <[e-mail]>
Tested-by: Ulf Hansson <[e-mail]>
---
 kernel/cpu_pm.c |    9 ---------
 1 file changed, 9 deletions(-)

Patch

--- a/kernel/cpu_pm.c
+++ b/kernel/cpu_pm.c
@@ -30,16 +30,9 @@  static int cpu_pm_notify(enum cpu_pm_eve
 {
 	int ret;
 
-	/*
-	 * This introduces a RCU read critical section, which could be
-	 * disfunctional in cpu idle. Copy RCU_NONIDLE code to let RCU know
-	 * this.
-	 */
-	ct_irq_enter_irqson();
 	rcu_read_lock();
 	ret = raw_notifier_call_chain(&cpu_pm_notifier.chain, event, NULL);
 	rcu_read_unlock();
-	ct_irq_exit_irqson();
 
 	return notifier_to_errno(ret);
 }
@@ -49,11 +42,9 @@  static int cpu_pm_notify_robust(enum cpu
 	unsigned long flags;
 	int ret;
 
-	ct_irq_enter_irqson();
 	raw_spin_lock_irqsave(&cpu_pm_notifier.lock, flags);
 	ret = raw_notifier_call_chain_robust(&cpu_pm_notifier.chain, event_up, event_down, NULL);
 	raw_spin_unlock_irqrestore(&cpu_pm_notifier.lock, flags);
-	ct_irq_exit_irqson();
 
 	return notifier_to_errno(ret);
 }