[PATCH 6/6] rbtree: remove prior augmented rbtree implementation

From: Michel Lespinasse
Date: Fri Jul 20 2012 - 08:31:49 EST


convert arch/x86/mm/pat_rbtree.c to the proposed augmented rbtree api
and remove the old augmented rbtree implementation.

timings:
lpa36 ~168 / 282 cycles
lph71 ~168 / 271 cycles
lpk18 ~ 72 / 122 cycles

text data bss dec hex filename
2969 0 0 2969 b99 lib/rbtree.o

0000000000000450 l F .text 0000000000000006 dummy_rotate
00000000000001d0 g F .text 0000000000000272 __rb_erase_color
0000000000000480 g F .text 000000000000001e rb_last
0000000000000510 g F .text 0000000000000047 rb_next
0000000000000000 g F .text 00000000000001cd rb_insert_augmented
00000000000005b0 g F .text 0000000000000165 rb_insert_color
0000000000000560 g F .text 0000000000000047 rb_prev
0000000000000720 g F .text 0000000000000332 rb_erase
0000000000000460 g F .text 000000000000001e rb_first
00000000000004a0 g F .text 000000000000006e rb_replace_node

Signed-off-by: Michel Lespinasse <walken@xxxxxxxxxx>
---
arch/x86/mm/pat_rbtree.c | 52 +++++++++++++++++++++------------
include/linux/rbtree.h | 8 -----
lib/rbtree.c | 71 ----------------------------------------------
3 files changed, 33 insertions(+), 98 deletions(-)

diff --git a/arch/x86/mm/pat_rbtree.c b/arch/x86/mm/pat_rbtree.c
index 8acaddd..fad1d58 100644
--- a/arch/x86/mm/pat_rbtree.c
+++ b/arch/x86/mm/pat_rbtree.c
@@ -13,6 +13,7 @@
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/rbtree.h>
+#include <linux/rbtree_internal.h>
#include <linux/sched.h>
#include <linux/gfp.h>

@@ -54,27 +55,40 @@ static u64 get_subtree_max_end(struct rb_node *node)
return ret;
}

-/* Update 'subtree_max_end' for a node, based on node and its children */
-static void memtype_rb_augment_cb(struct rb_node *node, void *__unused)
+static u64 compute_subtree_max_end(struct memtype *data)
{
- struct memtype *data;
- u64 max_end, child_max_end;
-
- if (!node)
- return;
+ u64 max_end = data->end, child_max_end;

- data = container_of(node, struct memtype, rb);
- max_end = data->end;
-
- child_max_end = get_subtree_max_end(node->rb_right);
+ child_max_end = get_subtree_max_end(data->rb.rb_right);
if (child_max_end > max_end)
max_end = child_max_end;

- child_max_end = get_subtree_max_end(node->rb_left);
+ child_max_end = get_subtree_max_end(data->rb.rb_left);
if (child_max_end > max_end)
max_end = child_max_end;

- data->subtree_max_end = max_end;
+ return max_end;
+}
+
+/* Update 'subtree_max_end' after tree rotation. old and new are the
+ * former and current subtree roots */
+static void memtype_rb_rotate_cb(struct rb_node *old, struct rb_node *new)
+{
+ struct memtype *old_data = container_of(old, struct memtype, rb);
+ struct memtype *new_data = container_of(new, struct memtype, rb);
+
+ new_data->subtree_max_end = old_data->subtree_max_end;
+ old_data->subtree_max_end = compute_subtree_max_end(old_data);
+}
+
+/* Update 'subtree_max_end' for node and its parents */
+static void memtype_rb_propagate_cb(struct rb_node *node)
+{
+ while (node) {
+ struct memtype *data = container_of(node, struct memtype, rb);
+ data->subtree_max_end = compute_subtree_max_end(data);
+ node = rb_parent(&data->rb);
+ }
}

/* Find the first (lowest start addr) overlapping range from rb tree */
@@ -179,15 +193,17 @@ static void memtype_rb_insert(struct rb_root *root, struct memtype *newdata)
struct memtype *data = container_of(*node, struct memtype, rb);

parent = *node;
+ if (data->subtree_max_end < newdata->end)
+ data->subtree_max_end = newdata->end;
if (newdata->start <= data->start)
node = &((*node)->rb_left);
else if (newdata->start > data->start)
node = &((*node)->rb_right);
}

+ newdata->subtree_max_end = newdata->end;
rb_link_node(&newdata->rb, parent, node);
- rb_insert_color(&newdata->rb, root);
- rb_augment_insert(&newdata->rb, memtype_rb_augment_cb, NULL);
+ rb_insert_augmented(&newdata->rb, root, memtype_rb_rotate_cb);
}

int rbt_memtype_check_insert(struct memtype *new, unsigned long *ret_type)
@@ -209,16 +225,14 @@ int rbt_memtype_check_insert(struct memtype *new, unsigned long *ret_type)

struct memtype *rbt_memtype_erase(u64 start, u64 end)
{
- struct rb_node *deepest;
struct memtype *data;

data = memtype_rb_exact_match(&memtype_rbroot, start, end);
if (!data)
goto out;

- deepest = rb_augment_erase_begin(&data->rb);
- rb_erase(&data->rb, &memtype_rbroot);
- rb_augment_erase_end(deepest, memtype_rb_augment_cb, NULL);
+ rb_erase_augmented(&data->rb, &memtype_rbroot,
+ memtype_rb_propagate_cb, memtype_rb_rotate_cb);
out:
return data;
}
diff --git a/include/linux/rbtree.h b/include/linux/rbtree.h
index bf836a2..487f00b 100644
--- a/include/linux/rbtree.h
+++ b/include/linux/rbtree.h
@@ -61,14 +61,6 @@ struct rb_root {
extern void rb_insert_color(struct rb_node *, struct rb_root *);
extern void rb_erase(struct rb_node *, struct rb_root *);

-typedef void (*rb_augment_f)(struct rb_node *node, void *data);
-
-extern void rb_augment_insert(struct rb_node *node,
- rb_augment_f func, void *data);
-extern struct rb_node *rb_augment_erase_begin(struct rb_node *node);
-extern void rb_augment_erase_end(struct rb_node *node,
- rb_augment_f func, void *data);
-
/* Find logical next and previous nodes in a tree */
extern struct rb_node *rb_next(const struct rb_node *);
extern struct rb_node *rb_prev(const struct rb_node *);
diff --git a/lib/rbtree.c b/lib/rbtree.c
index 7ea3e4c..8f40f9d 100644
--- a/lib/rbtree.c
+++ b/lib/rbtree.c
@@ -364,77 +364,6 @@ void rb_erase(struct rb_node *node, struct rb_root *root)
}
EXPORT_SYMBOL(rb_erase);

-static void rb_augment_path(struct rb_node *node, rb_augment_f func, void *data)
-{
- struct rb_node *parent;
-
-up:
- func(node, data);
- parent = rb_parent(node);
- if (!parent)
- return;
-
- if (node == parent->rb_left && parent->rb_right)
- func(parent->rb_right, data);
- else if (parent->rb_left)
- func(parent->rb_left, data);
-
- node = parent;
- goto up;
-}
-
-/*
- * after inserting @node into the tree, update the tree to account for
- * both the new entry and any damage done by rebalance
- */
-void rb_augment_insert(struct rb_node *node, rb_augment_f func, void *data)
-{
- if (node->rb_left)
- node = node->rb_left;
- else if (node->rb_right)
- node = node->rb_right;
-
- rb_augment_path(node, func, data);
-}
-EXPORT_SYMBOL(rb_augment_insert);
-
-/*
- * before removing the node, find the deepest node on the rebalance path
- * that will still be there after @node gets removed
- */
-struct rb_node *rb_augment_erase_begin(struct rb_node *node)
-{
- struct rb_node *deepest;
-
- if (!node->rb_right && !node->rb_left)
- deepest = rb_parent(node);
- else if (!node->rb_right)
- deepest = node->rb_left;
- else if (!node->rb_left)
- deepest = node->rb_right;
- else {
- deepest = rb_next(node);
- if (deepest->rb_right)
- deepest = deepest->rb_right;
- else if (rb_parent(deepest) != node)
- deepest = rb_parent(deepest);
- }
-
- return deepest;
-}
-EXPORT_SYMBOL(rb_augment_erase_begin);
-
-/*
- * after removal, update the tree to account for the removed entry
- * and any rebalance damage.
- */
-void rb_augment_erase_end(struct rb_node *node, rb_augment_f func, void *data)
-{
- if (node)
- rb_augment_path(node, func, data);
-}
-EXPORT_SYMBOL(rb_augment_erase_end);
-
/*
* This function returns the first node (in sort order) of the tree.
*/
--
1.7.7.3

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