[PATCH 15/36] cpuidle,cpu_pm: Remove RCU fiddling from cpu_pm_{enter,exit}()

Peter Zijlstra peterz at infradead.org
Wed Jun 8 07:27:38 PDT 2022


All callers should still have RCU enabled.

Signed-off-by: Peter Zijlstra (Intel) <peterz at infradead.org>
---
 kernel/cpu_pm.c |    9 ---------
 1 file changed, 9 deletions(-)

--- 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.
-	 */
-	rcu_irq_enter_irqson();
 	rcu_read_lock();
 	ret = raw_notifier_call_chain(&cpu_pm_notifier.chain, event, NULL);
 	rcu_read_unlock();
-	rcu_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;
 
-	rcu_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);
-	rcu_irq_exit_irqson();
 
 	return notifier_to_errno(ret);
 }





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