[PATCH] rcu: remove lock acquirement when very eary boot

[Lai Jiangshan <laijs@cn.fujitsu.com>]

cleanup: remove lock acquirement when very eary boot

Signed-off-by: Lai Jiangshan <laijs@cn.fujitsu.com>
---
diff --git a/kernel/rcutree.c b/kernel/rcutree.c
index 112edb5..e6014e1 100644
--- a/kernel/rcutree.c
+++ b/kernel/rcutree.c
@@ -1646,13 +1646,10 @@ EXPORT_SYMBOL_GPL(rcu_barrier_sched);
 static void __init
 rcu_boot_init_percpu_data(int cpu, struct rcu_state *rsp)
 {
-	unsigned long flags;
 	int i;
 	struct rcu_data *rdp = rsp->rda[cpu];
-	struct rcu_node *rnp = rcu_get_root(rsp);
 
 	/* Set up local state, ensuring consistent view of global state. */
-	raw_spin_lock_irqsave(&rnp->lock, flags);
 	rdp->grpmask = 1UL << (cpu - rdp->mynode->grplo);
 	rdp->nxtlist = NULL;
 	for (i = 0; i < RCU_NEXT_SIZE; i++)
@@ -1662,7 +1659,6 @@ rcu_boot_init_percpu_data(int cpu, struct rcu_state *rsp)
 	rdp->dynticks = &per_cpu(rcu_dynticks, cpu);
 #endif /* #ifdef CONFIG_NO_HZ */
 	rdp->cpu = cpu;
-	raw_spin_unlock_irqrestore(&rnp->lock, flags);
 }
 
 /*