rcu: Replace this_cpu_ptr() with __this_cpu_read()

Because __this_cpu_read() can be lighter weight than equivalent uses of
this_cpu_ptr(), this commit replaces the latter with the former.

Signed-off-by: Paul E. McKenney <paulmck@linux.ibm.com>

diff --git a/kernel/rcu/tree_plugin.h b/kernel/rcu/tree_plugin.h
index 618956c..0bb1c15 100644 (file)
--- a/kernel/rcu/tree_plugin.h
+++ b/kernel/rcu/tree_plugin.h
@@ -597,7 +597,7 @@ rcu_preempt_deferred_qs_irqrestore(struct task_struct *t, unsigned long flags)
  */
 static bool rcu_preempt_need_deferred_qs(struct task_struct *t)
 {
-       return (this_cpu_ptr(&rcu_data)->deferred_qs ||
+       return (__this_cpu_read(rcu_data.deferred_qs) ||
                READ_ONCE(t->rcu_read_unlock_special.s)) &&
               t->rcu_read_lock_nesting <= 0;
 }