From: Peter Zijlstra (Intel) <peterz@infradead.org>
Date: Wed, 12 Jul 2017 14:59:54 +0000 (-0700)
Subject: rcu: Make rcu_idle_enter() rely on callers disabling irqs
X-Git-Url: https://git.stricted.de/?a=commitdiff_plain;h=3a60799269daff5ed254a9b473a8db6f0f5c6bd9;p=GitHub%2FLineageOS%2Fandroid_kernel_motorola_exynos9610.git

rcu: Make rcu_idle_enter() rely on callers disabling irqs

All callers to rcu_idle_enter() have irqs disabled, so there is no
point in rcu_idle_enter disabling them again.  This commit therefore
replaces the irq disabling with a RCU_LOCKDEP_WARN().

Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
---

diff --git a/kernel/rcu/tree.c b/kernel/rcu/tree.c
index ac2617d857a3..76f88b65961f 100644
--- a/kernel/rcu/tree.c
+++ b/kernel/rcu/tree.c
@@ -843,11 +843,8 @@ static void rcu_eqs_enter(bool user)
  */
 void rcu_idle_enter(void)
 {
-	unsigned long flags;
-
-	local_irq_save(flags);
+	RCU_LOCKDEP_WARN(!irqs_disabled(), "rcu_idle_enter() invoked with irqs enabled!!!");
 	rcu_eqs_enter(false);
-	local_irq_restore(flags);
 }
 EXPORT_SYMBOL_GPL(rcu_idle_enter);