rbtree: avoid generating code twice for the cached versions (tools copy)

As was already noted in rbtree.h, the logic to cache rb_first (or
rb_last) can easily be implemented externally to the core rbtree api.

This commit takes the changes applied to the include/linux/ and lib/
rbtree files in 9f973cb38088 ("lib/rbtree: avoid generating code twice
for the cached versions"), and applies these to the
tools/include/linux/ and tools/lib/ files as well to keep them
synchronized.

Link: http://lkml.kernel.org/r/20190703034812.53002-1-walken@google.com
Signed-off-by: Michel Lespinasse <walken@google.com>
Cc: David Howells <dhowells@redhat.com>
Cc: Davidlohr Bueso <dbueso@suse.de>
Cc: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 12 insertions, 19 deletions

diff --git a/tools/include/linux/rbtree_augmented.h b/tools/include/linux/rbtree_augmented.h
index ddd01006ece5..467a3eefe1d2 100644
--- a/tools/include/linux/rbtree_augmented.h
+++ b/tools/include/linux/rbtree_augmented.h
@@ -32,17 +32,16 @@ struct rb_augment_callbacks {
 	void (*rotate)(struct rb_node *old, struct rb_node *new);
 };
 
-extern void __rb_insert_augmented(struct rb_node *node,
-				  struct rb_root *root,
-				  bool newleft, struct rb_node **leftmost,
+extern void __rb_insert_augmented(struct rb_node *node, struct rb_root *root,
 	void (*augment_rotate)(struct rb_node *old, struct rb_node *new));
+
 /*
  * Fixup the rbtree and update the augmented information when rebalancing.
  *
  * On insertion, the user must update the augmented information on the path
  * leading to the inserted node, then call rb_link_node() as usual and
- * rb_augment_inserted() instead of the usual rb_insert_color() call.
- * If rb_augment_inserted() rebalances the rbtree, it will callback into
+ * rb_insert_augmented() instead of the usual rb_insert_color() call.
+ * If rb_insert_augmented() rebalances the rbtree, it will callback into
  * a user provided function to update the augmented information on the
  * affected subtrees.
  */
@@ -50,7 +49,7 @@ static inline void
 rb_insert_augmented(struct rb_node *node, struct rb_root *root,
 		    const struct rb_augment_callbacks *augment)
 {
-	__rb_insert_augmented(node, root, false, NULL, augment->rotate);
+	__rb_insert_augmented(node, root, augment->rotate);
 }
 
 static inline void
@@ -58,8 +57,9 @@ rb_insert_augmented_cached(struct rb_node *node,
 			   struct rb_root_cached *root, bool newleft,
 			   const struct rb_augment_callbacks *augment)
 {
-	__rb_insert_augmented(node, &root->rb_root,
-			      newleft, &root->rb_leftmost, augment->rotate);
+	if (newleft)
+		root->rb_leftmost = node;
+	rb_insert_augmented(node, &root->rb_root, augment);
 }
 
 #define RB_DECLARE_CALLBACKS(rbstatic, rbname, rbstruct, rbfield,	\
@@ -139,7 +139,6 @@ extern void __rb_erase_color(struct rb_node *parent, struct rb_root *root,
 
 static __always_inline struct rb_node *
 __rb_erase_augmented(struct rb_node *node, struct rb_root *root,
-		     struct rb_node **leftmost,
 		     const struct rb_augment_callbacks *augment)
 {
 	struct rb_node *child = node->rb_right;
@@ -147,9 +146,6 @@ __rb_erase_augmented(struct rb_node *node, struct rb_root *root,
 	struct rb_node *parent, *rebalance;
 	unsigned long pc;
 
-	if (leftmost && node == *leftmost)
-		*leftmost = rb_next(node);
-
 	if (!tmp) {
 		/*
 		 * Case 1: node to erase has no more than 1 child (easy!)
@@ -249,8 +245,7 @@ static __always_inline void
 rb_erase_augmented(struct rb_node *node, struct rb_root *root,
 		   const struct rb_augment_callbacks *augment)
 {
-	struct rb_node *rebalance = __rb_erase_augmented(node, root,
-							 NULL, augment);
+	struct rb_node *rebalance = __rb_erase_augmented(node, root, augment);
 	if (rebalance)
 		__rb_erase_color(rebalance, root, augment->rotate);
 }
@@ -259,11 +254,9 @@ static __always_inline void
 rb_erase_augmented_cached(struct rb_node *node, struct rb_root_cached *root,
 			  const struct rb_augment_callbacks *augment)
 {
-	struct rb_node *rebalance = __rb_erase_augmented(node, &root->rb_root,
-							 &root->rb_leftmost,
-							 augment);
-	if (rebalance)
-		__rb_erase_color(rebalance, &root->rb_root, augment->rotate);
+	if (root->rb_leftmost == node)
+		root->rb_leftmost = rb_next(node);
+	rb_erase_augmented(node, &root->rb_root, augment);
 }
 
 #endif /* _TOOLS_LINUX_RBTREE_AUGMENTED_H */