rcu: Remove old memory barriers from rcu_process_callbacks()

Second step of partitioning of commit e59fb3120b.

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

diff --git a/kernel/rcutree.c b/kernel/rcutree.c
index 3731141..011bf6f 100644 (file)
--- a/kernel/rcutree.c
+++ b/kernel/rcutree.c
@@ -1460,25 +1460,11 @@ __rcu_process_callbacks(struct rcu_state *rsp, struct rcu_data *rdp)
  */
 static void rcu_process_callbacks(void)
 {
-       /*
-        * Memory references from any prior RCU read-side critical sections
-        * executed by the interrupted code must be seen before any RCU
-        * grace-period manipulations below.
-        */
-       smp_mb(); /* See above block comment. */
-
        __rcu_process_callbacks(&rcu_sched_state,
                                &__get_cpu_var(rcu_sched_data));
        __rcu_process_callbacks(&rcu_bh_state, &__get_cpu_var(rcu_bh_data));
        rcu_preempt_process_callbacks();
 
-       /*
-        * Memory references from any later RCU read-side critical sections
-        * executed by the interrupted code must be seen after any RCU
-        * grace-period manipulations above.
-        */
-       smp_mb(); /* See above block comment. */
-
        /* If we are last CPU on way to dyntick-idle mode, accelerate it. */
        rcu_needs_cpu_flush();
 }