[tip: sched/core] cpuidle, cpu_pm: Remove RCU fiddling from cpu_pm_{enter,exit}()

[tip-bot2 for Peter Zijlstra]

The following commit has been merged into the sched/core branch of tip:

Commit-ID:     924aed1646bf2859726f7e5dd9265ba14358fbb8
Gitweb:        https://git.kernel.org/tip/924aed1646bf2859726f7e5dd9265ba14358fbb8
Author:        Peter Zijlstra <peterz@xxxxxxxxxxxxx>
AuthorDate:    Thu, 12 Jan 2023 20:43:28 +01:00
Committer:     Ingo Molnar <mingo@xxxxxxxxxx>
CommitterDate: Fri, 13 Jan 2023 11:48:15 +01:00

cpuidle, cpu_pm: Remove RCU fiddling from cpu_pm_{enter,exit}()

All callers should still have RCU enabled.

Signed-off-by: Peter Zijlstra (Intel) <peterz@xxxxxxxxxxxxx>
Signed-off-by: Ingo Molnar <mingo@xxxxxxxxxx>
Tested-by: Tony Lindgren <tony@xxxxxxxxxxx>
Tested-by: Ulf Hansson <ulf.hansson@xxxxxxxxxx>
Reviewed-by: Ulf Hansson <ulf.hansson@xxxxxxxxxx>
Acked-by: Mark Rutland <mark.rutland@xxxxxxx>
Acked-by: Rafael J. Wysocki <rafael.j.wysocki@xxxxxxxxx>
Acked-by: Frederic Weisbecker <frederic@xxxxxxxxxx>
Link: https://lore.kernel.org/r/20230112195540.190860672@xxxxxxxxxxxxx
---
 kernel/cpu_pm.c |  9 ---------
 1 file changed, 9 deletions(-)

diff --git a/kernel/cpu_pm.c b/kernel/cpu_pm.c
index ba4ba71..b0f0d15 100644
--- a/kernel/cpu_pm.c
+++ b/kernel/cpu_pm.c
@@ -30,16 +30,9 @@ static int cpu_pm_notify(enum cpu_pm_event event)
 {
 	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_pm_event event_up, enum cpu_pm_event ev
 	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);
 }