plist: Shrink struct plist_head

[thirdparty/linux.git] / lib / plist.c

diff --git a/lib/plist.c b/lib/plist.c
index 1471988d9190db351355faa35a21ab10f85c262a..8c614d0e6c356962a4623116c86c28a7b9430b15 100644 (file)
--- a/lib/plist.c
+++ b/lib/plist.c
@@ -59,7 +59,8 @@ static void plist_check_head(struct plist_head *head)
                WARN_ON_SMP(!raw_spin_is_locked(head->rawlock));
        if (head->spinlock)
                WARN_ON_SMP(!spin_is_locked(head->spinlock));
-       plist_check_list(&head->prio_list);
+       if (!plist_head_empty(head))
+               plist_check_list(&plist_first(head)->prio_list);
        plist_check_list(&head->node_list);
 }
 
@@ -75,25 +76,33 @@ static void plist_check_head(struct plist_head *head)
  */
 void plist_add(struct plist_node *node, struct plist_head *head)
 {
-       struct plist_node *iter;
+       struct plist_node *first, *iter, *prev = NULL;
+       struct list_head *node_next = &head->node_list;
 
        plist_check_head(head);
        WARN_ON(!plist_node_empty(node));
+       WARN_ON(!list_empty(&node->prio_list));
 
-       list_for_each_entry(iter, &head->prio_list, plist.prio_list) {
-               if (node->prio < iter->prio)
-                       goto lt_prio;
-               else if (node->prio == iter->prio) {
-                       iter = list_entry(iter->plist.prio_list.next,
-                                       struct plist_node, plist.prio_list);
-                       goto eq_prio;
+       if (plist_head_empty(head))
+               goto ins_node;
+
+       first = iter = plist_first(head);
+
+       do {
+               if (node->prio < iter->prio) {
+                       node_next = &iter->node_list;
+                       break;
                }
-       }
 
-lt_prio:
-       list_add_tail(&node->plist.prio_list, &iter->plist.prio_list);
-eq_prio:
-       list_add_tail(&node->plist.node_list, &iter->plist.node_list);
+               prev = iter;
+               iter = list_entry(iter->prio_list.next,
+                               struct plist_node, prio_list);
+       } while (iter != first);
+
+       if (!prev || prev->prio != node->prio)
+               list_add_tail(&node->prio_list, &iter->prio_list);
+ins_node:
+       list_add_tail(&node->node_list, node_next);
 
        plist_check_head(head);
 }
@@ -108,14 +117,21 @@ void plist_del(struct plist_node *node, struct plist_head *head)
 {
        plist_check_head(head);
 
-       if (!list_empty(&node->plist.prio_list)) {
-               struct plist_node *next = plist_first(&node->plist);
+       if (!list_empty(&node->prio_list)) {
+               if (node->node_list.next != &head->node_list) {
+                       struct plist_node *next;
+
+                       next = list_entry(node->node_list.next,
+                                       struct plist_node, node_list);
 
-               list_move_tail(&next->plist.prio_list, &node->plist.prio_list);
-               list_del_init(&node->plist.prio_list);
+                       /* add the next plist_node into prio_list */
+                       if (list_empty(&next->prio_list))
+                               list_add(&next->prio_list, &node->prio_list);
+               }
+               list_del_init(&node->prio_list);
        }
 
-       list_del_init(&node->plist.node_list);
+       list_del_init(&node->node_list);
 
        plist_check_head(head);
 }