From: H. Peter Anvin on
Hi Linus,

The following changes since commit 980019d74e4b2428362b36a0506519d6d9460800:
Linus Torvalds (1):
Merge git://git.kernel.org/.../gregkh/staging-2.6

are available in the git repository at:

git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip.git x86-fixes-for-linus

Darrick J. Wong (1):
x86, Calgary: Limit the max PHB number to 256

Peter Zijlstra (1):
rbtree: Undo augmented trees performance damage and regression

arch/x86/kernel/pci-calgary_64.c | 4 +-
arch/x86/mm/pat_rbtree.c | 34 ++---------
include/linux/rbtree.h | 13 +++-
lib/rbtree.c | 116 +++++++++++++++++++++++--------------
4 files changed, 88 insertions(+), 79 deletions(-)

diff --git a/arch/x86/kernel/pci-calgary_64.c b/arch/x86/kernel/pci-calgary_64.c
index 0b96b55..078d4ec 100644
--- a/arch/x86/kernel/pci-calgary_64.c
+++ b/arch/x86/kernel/pci-calgary_64.c
@@ -110,7 +110,7 @@ int use_calgary __read_mostly = 0;
* x3950 (PCIE): 8 chassis, 32 PHBs per chassis = 256
* x3950 (PCIX): 8 chassis, 16 PHBs per chassis = 128
*/
-#define MAX_PHB_BUS_NUM 384
+#define MAX_PHB_BUS_NUM 256

#define PHBS_PER_CALGARY 4

@@ -1056,8 +1056,6 @@ static int __init calgary_init_one(struct pci_dev *dev)
struct iommu_table *tbl;
int ret;

- BUG_ON(dev->bus->number >= MAX_PHB_BUS_NUM);
-
bbar = busno_to_bbar(dev->bus->number);
ret = calgary_setup_tar(dev, bbar);
if (ret)
diff --git a/arch/x86/mm/pat_rbtree.c b/arch/x86/mm/pat_rbtree.c
index f20eeec..8acaddd 100644
--- a/arch/x86/mm/pat_rbtree.c
+++ b/arch/x86/mm/pat_rbtree.c
@@ -34,8 +34,7 @@
* memtype_lock protects the rbtree.
*/

-static void memtype_rb_augment_cb(struct rb_node *node);
-static struct rb_root memtype_rbroot = RB_AUGMENT_ROOT(&memtype_rb_augment_cb);
+static struct rb_root memtype_rbroot = RB_ROOT;

static int is_node_overlap(struct memtype *node, u64 start, u64 end)
{
@@ -56,7 +55,7 @@ static u64 get_subtree_max_end(struct rb_node *node)
}

/* Update 'subtree_max_end' for a node, based on node and its children */
-static void update_node_max_end(struct rb_node *node)
+static void memtype_rb_augment_cb(struct rb_node *node, void *__unused)
{
struct memtype *data;
u64 max_end, child_max_end;
@@ -78,25 +77,6 @@ static void update_node_max_end(struct rb_node *node)
data->subtree_max_end = max_end;
}

-/* Update 'subtree_max_end' for a node and all its ancestors */
-static void update_path_max_end(struct rb_node *node)
-{
- u64 old_max_end, new_max_end;
-
- while (node) {
- struct memtype *data = container_of(node, struct memtype, rb);
-
- old_max_end = data->subtree_max_end;
- update_node_max_end(node);
- new_max_end = data->subtree_max_end;
-
- if (new_max_end == old_max_end)
- break;
-
- node = rb_parent(node);
- }
-}
-
/* Find the first (lowest start addr) overlapping range from rb tree */
static struct memtype *memtype_rb_lowest_match(struct rb_root *root,
u64 start, u64 end)
@@ -190,12 +170,6 @@ failure:
return -EBUSY;
}

-static void memtype_rb_augment_cb(struct rb_node *node)
-{
- if (node)
- update_path_max_end(node);
-}
-
static void memtype_rb_insert(struct rb_root *root, struct memtype *newdata)
{
struct rb_node **node = &(root->rb_node);
@@ -213,6 +187,7 @@ static void memtype_rb_insert(struct rb_root *root, struct memtype *newdata)

rb_link_node(&newdata->rb, parent, node);
rb_insert_color(&newdata->rb, root);
+ rb_augment_insert(&newdata->rb, memtype_rb_augment_cb, NULL);
}

int rbt_memtype_check_insert(struct memtype *new, unsigned long *ret_type)
@@ -234,13 +209,16 @@ 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);
out:
return data;
}
diff --git a/include/linux/rbtree.h b/include/linux/rbtree.h
index fe1872e..7066acb 100644
--- a/include/linux/rbtree.h
+++ b/include/linux/rbtree.h
@@ -110,7 +110,6 @@ struct rb_node
struct rb_root
{
struct rb_node *rb_node;
- void (*augment_cb)(struct rb_node *node);
};


@@ -130,9 +129,7 @@ static inline void rb_set_color(struct rb_node *rb, int color)
rb->rb_parent_color = (rb->rb_parent_color & ~1) | color;
}

-#define RB_ROOT (struct rb_root) { NULL, NULL, }
-#define RB_AUGMENT_ROOT(x) (struct rb_root) { NULL, x}
-
+#define RB_ROOT (struct rb_root) { NULL, }
#define rb_entry(ptr, type, member) container_of(ptr, type, member)

#define RB_EMPTY_ROOT(root) ((root)->rb_node == NULL)
@@ -142,6 +139,14 @@ static inline void rb_set_color(struct rb_node *rb, int color)
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 15e10b1..4693f79 100644
--- a/lib/rbtree.c
+++ b/lib/rbtree.c
@@ -44,11 +44,6 @@ 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)
@@ -72,20 +67,12 @@ 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);
@@ -240,15 +227,12 @@ 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
@@ -263,10 +247,8 @@ 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;
@@ -277,24 +259,6 @@ 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;
}

@@ -303,19 +267,15 @@ 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;
-
- if (root->augment_cb)
- root->augment_cb(parent);
-
- } else {
- root->rb_node = child;
}
+ else
+ root->rb_node = child;

color:
if (color == RB_BLACK)
@@ -323,6 +283,74 @@ 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);
+}
+
+/*
+ * 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;
+}
+
+/*
+ * 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);
+}
+
/*
* This function returns the first node (in sort order) of the tree.
*/
--
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