[PATCH tip/core/rcu 3/3] rcu: Open-code the rcu_cblist_n_lazy_cbs() function

[Paul E. McKenney]

Because the rcu_cblist_n_lazy_cbs() just samples the ->len_lazy counter,
and because the rcu_cblist structure is quite straightforward, it makes
sense to open-code rcu_cblist_n_lazy_cbs(p) as p->len_lazy, cutting out
a level of indirection.  This commit makes this change.

Reported-by: Ingo Molnar <mingo@xxxxxxxxxx>
Signed-off-by: Paul E. McKenney <paulmck@xxxxxxxxxxxxxxxxxx>
Cc: Peter Zijlstra <peterz@xxxxxxxxxxxxx>
Cc: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
Cc: Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxxx>
---
 kernel/rcu/rcu_segcblist.h | 6 ------
 kernel/rcu/tree.c          | 2 +-
 kernel/rcu/tree_plugin.h   | 2 +-
 kernel/rcu/tree_trace.c    | 2 +-
 4 files changed, 3 insertions(+), 9 deletions(-)

diff --git a/kernel/rcu/rcu_segcblist.h b/kernel/rcu/rcu_segcblist.h
index 424a6b230921..6e36e36478cd 100644
--- a/kernel/rcu/rcu_segcblist.h
+++ b/kernel/rcu/rcu_segcblist.h
@@ -22,12 +22,6 @@
 
 #include <linux/rcu_segcblist.h>
 
-/* Return number of lazy callbacks in simple callback list. */
-static inline long rcu_cblist_n_lazy_cbs(struct rcu_cblist *rclp)
-{
-	return rclp->len_lazy;
-}
-
 /*
  * Account for the fact that a previously dequeued callback turned out
  * to be marked as lazy.
diff --git a/kernel/rcu/tree.c b/kernel/rcu/tree.c
index 942d529fccbc..1205c8ad138a 100644
--- a/kernel/rcu/tree.c
+++ b/kernel/rcu/tree.c
@@ -2634,7 +2634,7 @@ static void rcu_adopt_orphan_cbs(struct rcu_state *rsp, unsigned long flags)
 
 	/* Do the accounting first. */
 	rdp->n_cbs_adopted += rsp->orphan_done.len;
-	if (rcu_cblist_n_lazy_cbs(&rsp->orphan_done) != rsp->orphan_done.len)
+	if (rsp->orphan_done.len_lazy != rsp->orphan_done.len)
 		rcu_idle_count_callbacks_posted();
 	rcu_segcblist_insert_count(&rdp->cblist, &rsp->orphan_done);
 
diff --git a/kernel/rcu/tree_plugin.h b/kernel/rcu/tree_plugin.h
index 7ebe357df155..c9a48657512a 100644
--- a/kernel/rcu/tree_plugin.h
+++ b/kernel/rcu/tree_plugin.h
@@ -1935,7 +1935,7 @@ static bool __maybe_unused rcu_nocb_adopt_orphan_cbs(struct rcu_state *rsp,
 						     unsigned long flags)
 {
 	long ql = rsp->orphan_done.len;
-	long qll = rcu_cblist_n_lazy_cbs(&rsp->orphan_done);
+	long qll = rsp->orphan_done.len_lazy;
 
 	/* If this is not a no-CBs CPU, tell the caller to do it the old way. */
 	if (!rcu_is_nocb_cpu(smp_processor_id()))
diff --git a/kernel/rcu/tree_trace.c b/kernel/rcu/tree_trace.c
index b7743aa2965f..6cea17a1ea30 100644
--- a/kernel/rcu/tree_trace.c
+++ b/kernel/rcu/tree_trace.c
@@ -277,7 +277,7 @@ static void print_one_rcu_state(struct seq_file *m, struct rcu_state *rsp)
 		   rsp->n_force_qs, rsp->n_force_qs_ngp,
 		   rsp->n_force_qs - rsp->n_force_qs_ngp,
 		   READ_ONCE(rsp->n_force_qs_lh),
-		   rcu_cblist_n_lazy_cbs(&rsp->orphan_done),
+		   rsp->orphan_done.len_lazy,
 		   rsp->orphan_done.len);
 	for (rnp = &rsp->node[0]; rnp - &rsp->node[0] < rcu_num_nodes; rnp++) {
 		if (rnp->level != level) {
-- 
2.5.2