[PATCH tip/core/rcu 13/15] rcu: Make rcu_idle_enter() rely on callers disabling irqs

From: Paul E. McKenney
Date: Mon Jul 24 2017 - 17:46:46 EST


From: "Peter Zijlstra (Intel)" <peterz@xxxxxxxxxxxxx>

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@xxxxxxxxxxxxx>
Signed-off-by: Paul E. McKenney <paulmck@xxxxxxxxxxxxxxxxxx>
---
kernel/rcu/tree.c | 5 +----
1 file changed, 1 insertion(+), 4 deletions(-)

diff --git a/kernel/rcu/tree.c b/kernel/rcu/tree.c
index c028eb254704..64b2cb9a8830 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);

--
2.5.2