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authorPallipadi, Venkatesh <venkatesh.pallipadi@intel.com>2010-02-10 15:23:44 -0800
committerH. Peter Anvin <hpa@zytor.com>2010-02-18 15:40:56 -0800
commit17d9ddc72fb8bba0d4f67868c9c612e472a594a9 (patch)
tree51c5e50f91eb060e346c129aa7403624934966d8 /lib/rbtree.c
parent724e6d3fe8003c3f60bf404bf22e4e331327c596 (diff)
downloadlinux-2.6.34-ux500-17d9ddc72fb8bba0d4f67868c9c612e472a594a9.tar.gz
rbtree: Add support for augmented rbtrees
Add support for augmented rbtrees in core rbtree code. This will be used in subsequent patches, in x86 PAT code, which needs interval trees to efficiently keep track of PAT ranges. Signed-off-by: Venkatesh Pallipadi <venkatesh.pallipadi@intel.com> LKML-Reference: <20100210232343.GA11465@linux-os.sc.intel.com> Signed-off-by: Suresh Siddha <suresh.b.siddha@intel.com> Signed-off-by: H. Peter Anvin <hpa@zytor.com>
Diffstat (limited to 'lib/rbtree.c')
-rw-r--r--lib/rbtree.c48
1 files changed, 44 insertions, 4 deletions
diff --git a/lib/rbtree.c b/lib/rbtree.c
index e2aa3be2985..15e10b1afdd 100644
--- a/lib/rbtree.c
+++ b/lib/rbtree.c
@@ -44,6 +44,11 @@ static void __rb_rotate_left(struct rb_node *node, struct rb_root *root)
else
root->rb_node = right;
rb_set_parent(node, right);
+
+ if (root->augment_cb) {
+ root->augment_cb(node);
+ root->augment_cb(right);
+ }
}
static void __rb_rotate_right(struct rb_node *node, struct rb_root *root)
@@ -67,12 +72,20 @@ static void __rb_rotate_right(struct rb_node *node, struct rb_root *root)
else
root->rb_node = left;
rb_set_parent(node, left);
+
+ if (root->augment_cb) {
+ root->augment_cb(node);
+ root->augment_cb(left);
+ }
}
void rb_insert_color(struct rb_node *node, struct rb_root *root)
{
struct rb_node *parent, *gparent;
+ if (root->augment_cb)
+ root->augment_cb(node);
+
while ((parent = rb_parent(node)) && rb_is_red(parent))
{
gparent = rb_parent(parent);
@@ -227,12 +240,15 @@ void rb_erase(struct rb_node *node, struct rb_root *root)
else
{
struct rb_node *old = node, *left;
+ int old_parent_cb = 0;
+ int successor_parent_cb = 0;
node = node->rb_right;
while ((left = node->rb_left) != NULL)
node = left;
if (rb_parent(old)) {
+ old_parent_cb = 1;
if (rb_parent(old)->rb_left == old)
rb_parent(old)->rb_left = node;
else
@@ -247,8 +263,10 @@ void rb_erase(struct rb_node *node, struct rb_root *root)
if (parent == old) {
parent = node;
} else {
+ successor_parent_cb = 1;
if (child)
rb_set_parent(child, parent);
+
parent->rb_left = child;
node->rb_right = old->rb_right;
@@ -259,6 +277,24 @@ void rb_erase(struct rb_node *node, struct rb_root *root)
node->rb_left = old->rb_left;
rb_set_parent(old->rb_left, node);
+ if (root->augment_cb) {
+ /*
+ * Here, three different nodes can have new children.
+ * The parent of the successor node that was selected
+ * to replace the node to be erased.
+ * The node that is getting erased and is now replaced
+ * by its successor.
+ * The parent of the node getting erased-replaced.
+ */
+ if (successor_parent_cb)
+ root->augment_cb(parent);
+
+ root->augment_cb(node);
+
+ if (old_parent_cb)
+ root->augment_cb(rb_parent(old));
+ }
+
goto color;
}
@@ -267,15 +303,19 @@ void rb_erase(struct rb_node *node, struct rb_root *root)
if (child)
rb_set_parent(child, parent);
- if (parent)
- {
+
+ if (parent) {
if (parent->rb_left == node)
parent->rb_left = child;
else
parent->rb_right = child;
- }
- else
+
+ if (root->augment_cb)
+ root->augment_cb(parent);
+
+ } else {
root->rb_node = child;
+ }
color:
if (color == RB_BLACK)