[PATCH tip/core/rcu 12/13] rcu: Move wakeup out from under rnp->lock

[Paul E. McKenney]

From: Peter Zijlstra <pet...@infradead.org>

This patch removes a potential deadlock hazard by moving the
wake_up_process() in rcu_spawn_gp_kthread() out from under rnp->lock.

Signed-off-by: Peter Zijlstra <pet...@infradead.org>
Signed-off-by: Paul E. McKenney <paul...@linux.vnet.ibm.com>
---
 kernel/rcu/tree.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/kernel/rcu/tree.c b/kernel/rcu/tree.c
index 40940b0d0310..87b604d0b0d2 100644
--- a/kernel/rcu/tree.c
+++ b/kernel/rcu/tree.c
@@ -4319,8 +4319,8 @@ static int __init rcu_spawn_gp_kthread(void)
                        sp.sched_priority = kthread_prio;
                        sched_setscheduler_nocheck(t, SCHED_FIFO, &sp);
                }
-               wake_up_process(t);
                raw_spin_unlock_irqrestore(&rnp->lock, flags);
+               wake_up_process(t);
        }
        rcu_spawn_nocb_kthreads();
        rcu_spawn_boost_kthreads();
-- 
2.5.2

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