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rcu: Cleanup: balance rcu_irq_enter()/rcu_irq_exit() calls 

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>
Cc: dipankar@in.ibm.com
Cc: mathieu.desnoyers@polymtl.ca
Cc: josh@joshtriplett.org
Cc: dvhltc@us.ibm.com
Cc: niv@us.ibm.com
Cc: peterz@infradead.org
Cc: rostedt@goodmis.org
Cc: Valdis.Kletnieks@vt.edu
Cc: dhowells@redhat.com
LKML-Reference: <12567428891605-git-send-email->
Signed-off-by: Ingo Molnar <mingo@elte.hu>
This commit is contained in:
Lai Jiangshan 2009-10-28 08:14:48 -07:00 committed by Ingo Molnar
parent 2c28e2451d
commit c5e0cb3ddc
1 changed files with 1 additions and 1 deletions
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2
kernel/softirq.c
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@ -302,9 +302,9 @@ void irq_exit(void)
if (!in_interrupt() && local_softirq_pending()) if (!in_interrupt() && local_softirq_pending())
invoke_softirq(); invoke_softirq();
rcu_irq_exit();
#ifdef CONFIG_NO_HZ #ifdef CONFIG_NO_HZ
/* Make sure that timer wheel updates are propagated */ /* Make sure that timer wheel updates are propagated */
rcu_irq_exit();
if (idle_cpu(smp_processor_id()) && !in_interrupt() && !need_resched()) if (idle_cpu(smp_processor_id()) && !in_interrupt() && !need_resched())
tick_nohz_stop_sched_tick(0); tick_nohz_stop_sched_tick(0);
#endif #endif