[PATCH] rcu: Remove the unnecessary separate function, rcu_preempt_do_callback()

[Byungchul Park]

rcu_preemptp_do_callback() was introduced in commit 09223371dea(rcu:
Use softirq to address performance regression), where it had to be
distinguished between in the case CONFIG_TREE_PREEMPT_RCU is set and
it's not.

Now that the code was cleaned up so that rcu_preemt_do_callback() is
only called in rcu_kthread_do_work() in the same file, tree_plugin.h,
we don't have to keep the separate function anymore. Remove it for a
better readability.

Signed-off-by: Byungchul Park <byungchul.park@xxxxxxx>
---
 kernel/rcu/tree.h        |  1 -
 kernel/rcu/tree_plugin.h | 11 +----------
 2 files changed, 1 insertion(+), 11 deletions(-)

diff --git a/kernel/rcu/tree.h b/kernel/rcu/tree.h
index 478b79e..4172833 100644
--- a/kernel/rcu/tree.h
+++ b/kernel/rcu/tree.h
@@ -439,7 +439,6 @@ struct rcu_state {
 static void invoke_rcu_callbacks_kthread(void);
 static bool rcu_is_callbacks_kthread(void);
 #ifdef CONFIG_RCU_BOOST
-static void rcu_preempt_do_callbacks(void);
 static int rcu_spawn_one_boost_kthread(struct rcu_state *rsp,
 						 struct rcu_node *rnp);
 #endif /* #ifdef CONFIG_RCU_BOOST */
diff --git a/kernel/rcu/tree_plugin.h b/kernel/rcu/tree_plugin.h
index 26d7a31..1070a04 100644
--- a/kernel/rcu/tree_plugin.h
+++ b/kernel/rcu/tree_plugin.h
@@ -686,15 +686,6 @@ static void rcu_preempt_check_callbacks(void)
 		t->rcu_read_unlock_special.b.need_qs = true;
 }
 
-#ifdef CONFIG_RCU_BOOST
-
-static void rcu_preempt_do_callbacks(void)
-{
-	rcu_do_batch(rcu_state_p, this_cpu_ptr(rcu_data_p));
-}
-
-#endif /* #ifdef CONFIG_RCU_BOOST */
-
 /**
  * call_rcu() - Queue an RCU callback for invocation after a grace period.
  * @head: structure to be used for queueing the RCU updates.
@@ -1170,7 +1161,7 @@ static void rcu_kthread_do_work(void)
 {
 	rcu_do_batch(&rcu_sched_state, this_cpu_ptr(&rcu_sched_data));
 	rcu_do_batch(&rcu_bh_state, this_cpu_ptr(&rcu_bh_data));
-	rcu_preempt_do_callbacks();
+	rcu_do_batch(rcu_state_p, this_cpu_ptr(rcu_data_p));
 }
 
 static void rcu_cpu_kthread_setup(unsigned int cpu)
-- 
1.9.1