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rcu: Remove unnecessary spinlock in rcu_boot_init_percpu_data() 

Since rcu_boot_init_percpu_data() is only called at boot time,
there is no data race and spinlock is not needed.

Signed-off-by: Lihao Liang <lianglihao@huawei.com>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
This commit is contained in:
Lihao Liang 2017-11-22 19:00:55 +00:00 committed by Paul E. McKenney
parent 7928b2cbe5
commit 398953e62c
1 changed files with 0 additions and 4 deletions
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4
kernel/rcu/tree.c
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@ -3636,12 +3636,9 @@ static void rcu_init_new_rnp(struct rcu_node *rnp_leaf)
static void __init
rcu_boot_init_percpu_data(int cpu, struct rcu_state *rsp)
{
unsigned long flags;
struct rcu_data *rdp = per_cpu_ptr(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_rcu_node(rnp, flags);
rdp->grpmask = leaf_node_cpu_bit(rdp->mynode, cpu);
rdp->dynticks = &per_cpu(rcu_dynticks, cpu);
WARN_ON_ONCE(rdp->dynticks->dynticks_nesting != 1);
@ -3649,7 +3646,6 @@ rcu_boot_init_percpu_data(int cpu, struct rcu_state *rsp)
rdp->cpu = cpu;
rdp->rsp = rsp;
rcu_boot_init_nocb_percpu_data(rdp);
raw_spin_unlock_irqrestore_rcu_node(rnp, flags);
}
/*