[PATCH tip/core/rcu 30/55] rcu: Eliminate in_irq() checks in rcu_enter_nohz()

[Paul E. McKenney]

The in_irq() check in rcu_enter_nohz() is redundant because if we really
are in an interrupt, the attempt to re-enter dyntick-idle mode will invoke
rcu_needs_cpu() in any case, which will force the check for RCU callbacks.
So this commit removes the check along with the set_need_resched().

Suggested-by: Frederic Weisbecker <fweisbec@xxxxxxxxx>
Signed-off-by: Paul E. McKenney <paulmck@xxxxxxxxxxxxxxxxxx>
---
 kernel/rcutree.c |    7 -------
 1 files changed, 0 insertions(+), 7 deletions(-)

diff --git a/kernel/rcutree.c b/kernel/rcutree.c
index 7e2f297..0c6c30d 100644
--- a/kernel/rcutree.c
+++ b/kernel/rcutree.c
@@ -373,13 +373,6 @@ void rcu_enter_nohz(void)
 	smp_mb__after_atomic_inc();  /* Force ordering with next sojourn. */
 	WARN_ON_ONCE(atomic_read(&rdtp->dynticks) & 0x1);
 	local_irq_restore(flags);
-
-	/* If the interrupt queued a callback, get out of dyntick mode. */
-	if (in_irq() &&
-	    (__get_cpu_var(rcu_sched_data).nxtlist ||
-	     __get_cpu_var(rcu_bh_data).nxtlist ||
-	     rcu_preempt_needs_cpu(smp_processor_id())))
-		set_need_resched();
 }
 
 /*
-- 
1.7.3.2

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