[RFC PATCH v3 14/18] lib/plist.c: remove requeue function

[Lian Wang <lianux.mm@gmail.com>]

From: Kairui Song <kasong@tencent.com>

Now the last user of plist requeue is gone, this function can be
removed.

Signed-off-by: Kairui Song <kasong@tencent.com>
Signed-off-by: Lian Wang <lianux.mm@gmail.com>
---
 include/linux/plist.h |  2 --
 lib/plist.c           | 64 -------------------------------------------
 2 files changed, 66 deletions(-)

diff --git a/include/linux/plist.h b/include/linux/plist.h
index 16cf4355b5c1..73d359c1a053 100644
--- a/include/linux/plist.h
+++ b/include/linux/plist.h
@@ -132,8 +132,6 @@ static inline void plist_node_init(struct plist_node *node, int prio)
 extern void plist_add(struct plist_node *node, struct plist_head *head);
 extern void plist_del(struct plist_node *node, struct plist_head *head);
 
-extern void plist_requeue(struct plist_node *node, struct plist_head *head);
-
 /**
  * plist_for_each - iterate over the plist
  * @pos:	the type * to use as a loop counter
diff --git a/lib/plist.c b/lib/plist.c
index a5bef38add43..b05ae7ffea87 100644
--- a/lib/plist.c
+++ b/lib/plist.c
@@ -142,58 +142,6 @@ void plist_del(struct plist_node *node, struct plist_head *head)
 	plist_check_head(head);
 }
 
-/**
- * plist_requeue - Requeue @node at end of same-prio entries.
- *
- * This is essentially an optimized plist_del() followed by
- * plist_add().  It moves an entry already in the plist to
- * after any other same-priority entries.
- *
- * @node:	&struct plist_node pointer - entry to be moved
- * @head:	&struct plist_head pointer - list head
- */
-void plist_requeue(struct plist_node *node, struct plist_head *head)
-{
-	struct plist_node *iter;
-	struct list_head *node_next = &head->node_list;
-
-	plist_check_head(head);
-	BUG_ON(plist_head_empty(head));
-	BUG_ON(plist_node_empty(node));
-
-	if (node == plist_last(head))
-		return;
-
-	iter = plist_next(node);
-
-	if (node->prio != iter->prio)
-		return;
-
-	plist_del(node, head);
-
-	/*
-	 * After plist_del(), iter is the replacement of the node.  If the node
-	 * was on prio_list, take shortcut to find node_next instead of looping.
-	 */
-	if (!list_empty(&iter->prio_list)) {
-		iter = list_entry(iter->prio_list.next, struct plist_node,
-				  prio_list);
-		node_next = &iter->node_list;
-		goto queue;
-	}
-
-	plist_for_each_continue(iter, head) {
-		if (node->prio != iter->prio) {
-			node_next = &iter->node_list;
-			break;
-		}
-	}
-queue:
-	list_add_tail(&node->node_list, node_next);
-
-	plist_check_head(head);
-}
-
 #ifdef CONFIG_DEBUG_PLIST
 #include <linux/sched.h>
 #include <linux/sched/clock.h>
@@ -231,14 +179,6 @@ static void __init plist_test_check(int nr_expect)
 	BUG_ON(prio_pos->prio_list.next != &first->prio_list);
 }
 
-static void __init plist_test_requeue(struct plist_node *node)
-{
-	plist_requeue(node, &test_head);
-
-	if (node != plist_last(&test_head))
-		BUG_ON(node->prio == plist_next(node)->prio);
-}
-
 static int  __init plist_test(void)
 {
 	int nr_expect = 0, i, loop;
@@ -262,10 +202,6 @@ static int  __init plist_test(void)
 			nr_expect--;
 		}
 		plist_test_check(nr_expect);
-		if (!plist_node_empty(test_node + i)) {
-			plist_test_requeue(test_node + i);
-			plist_test_check(nr_expect);
-		}
 	}
 
 	for (i = 0; i < ARRAY_SIZE(test_node); i++) {