[PATCH tip/core/rcu 1/2] rcu: cleanup: balance rcu_irq_enter()/rcu_irq_exit() calls

Paul E. McKenney
2009-10-28T15:16:52Z

From: Lai Jiangshan <laijs@cn.fujitsu.com>

Currently, rcu_irq_exit() is invoked only for CONFIG_NO_HZ, while
rcu_irq_enter() is invoked unconditionally. This patch moves
rcu_irq_exit() out from under CONFIG_NO_HZ so that the calls are
balanced.

This patch has no effect on the behavior of the kernel because
both rcu_irq_enter() and rcu_irq_exit() are empty for !CONFIG_NO_HZ,
but the code is easier to understand if the calls are obviously
balanced in all cases.

Signed-off-by: Lai Jiangshan <laijs@cn.fujitsu.com>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
---
kernel/softirq.c | 2 +-
1 files changed, 1 insertions(+), 1 deletions(-)

diff --git a/kernel/softirq.c b/kernel/softirq.c
index f8749e5..21939d9 100644
--- a/kernel/softirq.c
+++ b/kernel/softirq.c
@@ -302,9 +302,9 @@ void irq_exit(void)
if (!in_interrupt() && local_softirq_pending())
invoke_softirq();

+ rcu_irq_exit();
#ifdef CONFIG_NO_HZ
/* Make sure that timer wheel updates are propagated */
- rcu_irq_exit();
if (idle_cpu(smp_processor_id()) && !in_interrupt() && !need_resched())
tick_nohz_stop_sched_tick(0);
#endif
--
1.5.2.5