mm: replace vma prio_tree with an interval tree

Implement an interval tree as a replacement for the VMA prio_tree.  The
algorithms are similar to lib/interval_tree.c; however that code can't be
directly reused as the interval endpoints are not explicitly stored in the
VMA.  So instead, the common algorithm is moved into a template and the
details (node type, how to get interval endpoints from the node, etc) are
filled in using the C preprocessor.

Once the interval tree functions are available, using them as a
replacement to the VMA prio tree is a relatively simple, mechanical job.

Signed-off-by: Michel Lespinasse <walken@google.com>
Cc: Rik van Riel <riel@redhat.com>
Cc: Hillf Danton <dhillf@gmail.com>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: David Woodhouse <dwmw2@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

25 files changed, 357 insertions, 466 deletions

diff --git a/arch/arm/mm/fault-armv.c b/arch/arm/mm/fault-armv.c
index 7599e2625c7d..2a5907b5c8d2 100644
--- a/arch/arm/mm/fault-armv.c
+++ b/arch/arm/mm/fault-armv.c
@@ -134,7 +134,6 @@ make_coherent(struct address_space *mapping, struct vm_area_struct *vma,
 {
         struct mm_struct *mm = vma->vm_mm;
         struct vm_area_struct *mpnt;
-        struct prio_tree_iter iter;
         unsigned long offset;
         pgoff_t pgoff;
         int aliases = 0;
@@ -147,7 +146,7 @@ make_coherent(struct address_space *mapping, struct vm_area_struct *vma,
          * cache coherency.
          */
         flush_dcache_mmap_lock(mapping);
-        vma_prio_tree_foreach(mpnt, &iter, &mapping->i_mmap, pgoff, pgoff) {
+        vma_interval_tree_foreach(mpnt, &mapping->i_mmap, pgoff, pgoff) {
                 /*
                  * If this VMA is not in our MM, we can ignore it.
                  * Note that we intentionally mask out the VMA
diff --git a/arch/arm/mm/flush.c b/arch/arm/mm/flush.c
index 40ca11ed6e5f..1c8f7f564175 100644
--- a/arch/arm/mm/flush.c
+++ b/arch/arm/mm/flush.c
@@ -196,7 +196,6 @@ static void __flush_dcache_aliases(struct address_space *mapping, struct page *p
 {
         struct mm_struct *mm = current->active_mm;
         struct vm_area_struct *mpnt;
-        struct prio_tree_iter iter;
         pgoff_t pgoff;
 
         /*
@@ -208,7 +207,7 @@ static void __flush_dcache_aliases(struct address_space *mapping, struct page *p
         pgoff = page->index << (PAGE_CACHE_SHIFT - PAGE_SHIFT);
 
         flush_dcache_mmap_lock(mapping);
-        vma_prio_tree_foreach(mpnt, &iter, &mapping->i_mmap, pgoff, pgoff) {
+        vma_interval_tree_foreach(mpnt, &mapping->i_mmap, pgoff, pgoff) {
                 unsigned long offset;
 
                 /*
diff --git a/arch/parisc/kernel/cache.c b/arch/parisc/kernel/cache.c
index 9d181890a7e3..48e16dc20102 100644
--- a/arch/parisc/kernel/cache.c
+++ b/arch/parisc/kernel/cache.c
@@ -276,7 +276,6 @@ void flush_dcache_page(struct page *page)
 {
         struct address_space *mapping = page_mapping(page);
         struct vm_area_struct *mpnt;
-        struct prio_tree_iter iter;
         unsigned long offset;
         unsigned long addr, old_addr = 0;
         pgoff_t pgoff;
@@ -299,7 +298,7 @@ void flush_dcache_page(struct page *page)
          * to flush one address here for them all to become coherent */
 
         flush_dcache_mmap_lock(mapping);
-        vma_prio_tree_foreach(mpnt, &iter, &mapping->i_mmap, pgoff, pgoff) {
+        vma_interval_tree_foreach(mpnt, &mapping->i_mmap, pgoff, pgoff) {
                 offset = (pgoff - mpnt->vm_pgoff) << PAGE_SHIFT;
                 addr = mpnt->vm_start + offset;
 
diff --git a/arch/x86/mm/hugetlbpage.c b/arch/x86/mm/hugetlbpage.c
index b91e48512425..937bff5cdaa7 100644
--- a/arch/x86/mm/hugetlbpage.c
+++ b/arch/x86/mm/hugetlbpage.c
@@ -71,7 +71,6 @@ huge_pmd_share(struct mm_struct *mm, unsigned long addr, pud_t *pud)
         struct address_space *mapping = vma->vm_file->f_mapping;
         pgoff_t idx = ((addr - vma->vm_start) >> PAGE_SHIFT) +
                         vma->vm_pgoff;
-        struct prio_tree_iter iter;
         struct vm_area_struct *svma;
         unsigned long saddr;
         pte_t *spte = NULL;
@@ -81,7 +80,7 @@ huge_pmd_share(struct mm_struct *mm, unsigned long addr, pud_t *pud)
                 return (pte_t *)pmd_alloc(mm, pud, addr);
 
         mutex_lock(&mapping->i_mmap_mutex);
-        vma_prio_tree_foreach(svma, &iter, &mapping->i_mmap, idx, idx) {
+        vma_interval_tree_foreach(svma, &mapping->i_mmap, idx, idx) {
                 if (svma == vma)
                         continue;
 
diff --git a/fs/hugetlbfs/inode.c b/fs/hugetlbfs/inode.c
index 0a0ab8e21b19..c5bc355d8243 100644
--- a/fs/hugetlbfs/inode.c
+++ b/fs/hugetlbfs/inode.c
@@ -397,17 +397,16 @@ static void hugetlbfs_evict_inode(struct inode *inode)
 }
 
 static inline void
-hugetlb_vmtruncate_list(struct prio_tree_root *root, pgoff_t pgoff)
+hugetlb_vmtruncate_list(struct rb_root *root, pgoff_t pgoff)
 {
         struct vm_area_struct *vma;
-        struct prio_tree_iter iter;
 
-        vma_prio_tree_foreach(vma, &iter, root, pgoff, ULONG_MAX) {
+        vma_interval_tree_foreach(vma, root, pgoff, ULONG_MAX) {
                 unsigned long v_offset;
 
                 /*
                  * Can the expression below overflow on 32-bit arches?
-                 * No, because the prio_tree returns us only those vmas
+                 * No, because the interval tree returns us only those vmas
                  * which overlap the truncated area starting at pgoff,
                  * and no vma on a 32-bit arch can span beyond the 4GB.
                  */
@@ -432,7 +431,7 @@ static int hugetlb_vmtruncate(struct inode *inode, loff_t offset)
 
         i_size_write(inode, offset);
         mutex_lock(&mapping->i_mmap_mutex);
-        if (!prio_tree_empty(&mapping->i_mmap))
+        if (!RB_EMPTY_ROOT(&mapping->i_mmap))
                 hugetlb_vmtruncate_list(&mapping->i_mmap, pgoff);
         mutex_unlock(&mapping->i_mmap_mutex);
         truncate_hugepages(inode, offset);
diff --git a/fs/inode.c b/fs/inode.c
index ac8d904b3f16..b03c71957246 100644
--- a/fs/inode.c
+++ b/fs/inode.c
@@ -348,7 +348,7 @@ void address_space_init_once(struct address_space *mapping)
         mutex_init(&mapping->i_mmap_mutex);
         INIT_LIST_HEAD(&mapping->private_list);
         spin_lock_init(&mapping->private_lock);
-        INIT_RAW_PRIO_TREE_ROOT(&mapping->i_mmap);
+        mapping->i_mmap = RB_ROOT;
         INIT_LIST_HEAD(&mapping->i_mmap_nonlinear);
 }
 EXPORT_SYMBOL(address_space_init_once);
diff --git a/include/linux/fs.h b/include/linux/fs.h
index 5a8a273d5b2f..c617ed024df8 100644
--- a/include/linux/fs.h
+++ b/include/linux/fs.h
@@ -401,7 +401,7 @@ struct inodes_stat_t {
 #include <linux/cache.h>
 #include <linux/list.h>
 #include <linux/radix-tree.h>
-#include <linux/prio_tree.h>
+#include <linux/rbtree.h>
 #include <linux/init.h>
 #include <linux/pid.h>
 #include <linux/bug.h>
@@ -669,7 +669,7 @@ struct address_space {
         struct radix_tree_root  page_tree;      /* radix tree of all pages */
         spinlock_t              tree_lock;      /* and lock protecting it */
         unsigned int            i_mmap_writable;/* count VM_SHARED mappings */
-        struct prio_tree_root   i_mmap;         /* tree of private and shared mappings */
+        struct rb_root          i_mmap;         /* tree of private and shared mappings */
         struct list_head        i_mmap_nonlinear;/*list VM_NONLINEAR mappings */
         struct mutex            i_mmap_mutex;   /* protect tree, count, list */
         /* Protected by tree_lock together with the radix tree */
@@ -741,7 +741,7 @@ int mapping_tagged(struct address_space *mapping, int tag);
  */
 static inline int mapping_mapped(struct address_space *mapping)
 {
-        return  !prio_tree_empty(&mapping->i_mmap) ||
+        return  !RB_EMPTY_ROOT(&mapping->i_mmap) ||
                 !list_empty(&mapping->i_mmap_nonlinear);
 }
 
diff --git a/include/linux/interval_tree_tmpl.h b/include/linux/interval_tree_tmpl.h
new file mode 100644
index 000000000000..c65deda31413
--- /dev/null
+++ b/include/linux/interval_tree_tmpl.h
@@ -0,0 +1,215 @@
+/*
+  Interval Trees
+  (C) 2012  Michel Lespinasse <walken@google.com>
+
+  This program is free software; you can redistribute it and/or modify
+  it under the terms of the GNU General Public License as published by
+  the Free Software Foundation; either version 2 of the License, or
+  (at your option) any later version.
+
+  This program is distributed in the hope that it will be useful,
+  but WITHOUT ANY WARRANTY; without even the implied warranty of
+  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+  GNU General Public License for more details.
+
+  You should have received a copy of the GNU General Public License
+  along with this program; if not, write to the Free Software
+  Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
+
+  include/linux/interval_tree_tmpl.h
+*/
+
+/*
+ * Template for implementing interval trees
+ *
+ * ITSTRUCT:   struct type of the interval tree nodes
+ * ITRB:       name of struct rb_node field within ITSTRUCT
+ * ITTYPE:     type of the interval endpoints
+ * ITSUBTREE:  name of ITTYPE field within ITSTRUCT holding last-in-subtree
+ * ITSTART(n): start endpoint of ITSTRUCT node n
+ * ITLAST(n):  last endpoing of ITSTRUCT node n
+ * ITSTATIC:   'static' or empty
+ * ITPREFIX:   prefix to use for the inline tree definitions
+ */
+
+/* IT(name) -> ITPREFIX_name */
+#define _ITNAME(prefix, name) prefix ## _ ## name
+#define ITNAME(prefix, name) _ITNAME(prefix, name)
+#define IT(name) ITNAME(ITPREFIX, name)
+
+/* Callbacks for augmented rbtree insert and remove */
+
+static inline ITTYPE IT(compute_subtree_last)(ITSTRUCT *node)
+{
+        ITTYPE max = ITLAST(node), subtree_last;
+        if (node->ITRB.rb_left) {
+                subtree_last = rb_entry(node->ITRB.rb_left,
+                                        ITSTRUCT, ITRB)->ITSUBTREE;
+                if (max < subtree_last)
+                        max = subtree_last;
+        }
+        if (node->ITRB.rb_right) {
+                subtree_last = rb_entry(node->ITRB.rb_right,
+                                        ITSTRUCT, ITRB)->ITSUBTREE;
+                if (max < subtree_last)
+                        max = subtree_last;
+        }
+        return max;
+}
+
+static void IT(augment_propagate)(struct rb_node *rb, struct rb_node *stop)
+{
+        while (rb != stop) {
+                ITSTRUCT *node = rb_entry(rb, ITSTRUCT, ITRB);
+                ITTYPE subtree_last = IT(compute_subtree_last)(node);
+                if (node->ITSUBTREE == subtree_last)
+                        break;
+                node->ITSUBTREE = subtree_last;
+                rb = rb_parent(&node->ITRB);
+        }
+}
+
+static void IT(augment_copy)(struct rb_node *rb_old, struct rb_node *rb_new)
+{
+        ITSTRUCT *old = rb_entry(rb_old, ITSTRUCT, ITRB);
+        ITSTRUCT *new = rb_entry(rb_new, ITSTRUCT, ITRB);
+
+        new->ITSUBTREE = old->ITSUBTREE;
+}
+
+static void IT(augment_rotate)(struct rb_node *rb_old, struct rb_node *rb_new)
+{
+        ITSTRUCT *old = rb_entry(rb_old, ITSTRUCT, ITRB);
+        ITSTRUCT *new = rb_entry(rb_new, ITSTRUCT, ITRB);
+
+        new->ITSUBTREE = old->ITSUBTREE;
+        old->ITSUBTREE = IT(compute_subtree_last)(old);
+}
+
+static const struct rb_augment_callbacks IT(augment_callbacks) = {
+        IT(augment_propagate), IT(augment_copy), IT(augment_rotate)
+};
+
+/* Insert / remove interval nodes from the tree */
+
+ITSTATIC void IT(insert)(ITSTRUCT *node, struct rb_root *root)
+{
+        struct rb_node **link = &root->rb_node, *rb_parent = NULL;
+        ITTYPE start = ITSTART(node), last = ITLAST(node);
+        ITSTRUCT *parent;
+
+        while (*link) {
+                rb_parent = *link;
+                parent = rb_entry(rb_parent, ITSTRUCT, ITRB);
+                if (parent->ITSUBTREE < last)
+                        parent->ITSUBTREE = last;
+                if (start < ITSTART(parent))
+                        link = &parent->ITRB.rb_left;
+                else
+                        link = &parent->ITRB.rb_right;
+        }
+
+        node->ITSUBTREE = last;
+        rb_link_node(&node->ITRB, rb_parent, link);
+        rb_insert_augmented(&node->ITRB, root, &IT(augment_callbacks));
+}
+
+ITSTATIC void IT(remove)(ITSTRUCT *node, struct rb_root *root)
+{
+        rb_erase_augmented(&node->ITRB, root, &IT(augment_callbacks));
+}
+
+/*
+ * Iterate over intervals intersecting [start;last]
+ *
+ * Note that a node's interval intersects [start;last] iff:
+ *   Cond1: ITSTART(node) <= last
+ * and
+ *   Cond2: start <= ITLAST(node)
+ */
+
+static ITSTRUCT *IT(subtree_search)(ITSTRUCT *node, ITTYPE start, ITTYPE last)
+{
+        while (true) {
+                /*
+                 * Loop invariant: start <= node->ITSUBTREE
+                 * (Cond2 is satisfied by one of the subtree nodes)
+                 */
+                if (node->ITRB.rb_left) {
+                        ITSTRUCT *left = rb_entry(node->ITRB.rb_left,
+                                                  ITSTRUCT, ITRB);
+                        if (start <= left->ITSUBTREE) {
+                                /*
+                                 * Some nodes in left subtree satisfy Cond2.
+                                 * Iterate to find the leftmost such node N.
+                                 * If it also satisfies Cond1, that's the match
+                                 * we are looking for. Otherwise, there is no
+                                 * matching interval as nodes to the right of N
+                                 * can't satisfy Cond1 either.
+                                 */
+                                node = left;
+                                continue;
+                        }
+                }
+                if (ITSTART(node) <= last) {            /* Cond1 */
+                        if (start <= ITLAST(node))      /* Cond2 */
+                                return node;    /* node is leftmost match */
+                        if (node->ITRB.rb_right) {
+                                node = rb_entry(node->ITRB.rb_right,
+                                                ITSTRUCT, ITRB);
+                                if (start <= node->ITSUBTREE)
+                                        continue;
+                        }
+                }
+                return NULL;    /* No match */
+        }
+}
+
+ITSTATIC ITSTRUCT *IT(iter_first)(struct rb_root *root,
+                                  ITTYPE start, ITTYPE last)
+{
+        ITSTRUCT *node;
+
+        if (!root->rb_node)
+                return NULL;
+        node = rb_entry(root->rb_node, ITSTRUCT, ITRB);
+        if (node->ITSUBTREE < start)
+                return NULL;
+        return IT(subtree_search)(node, start, last);
+}
+
+ITSTATIC ITSTRUCT *IT(iter_next)(ITSTRUCT *node, ITTYPE start, ITTYPE last)
+{
+        struct rb_node *rb = node->ITRB.rb_right, *prev;
+
+        while (true) {
+                /*
+                 * Loop invariants:
+                 *   Cond1: ITSTART(node) <= last
+                 *   rb == node->ITRB.rb_right
+                 *
+                 * First, search right subtree if suitable
+                 */
+                if (rb) {
+                        ITSTRUCT *right = rb_entry(rb, ITSTRUCT, ITRB);
+                        if (start <= right->ITSUBTREE)
+                                return IT(subtree_search)(right, start, last);
+                }
+
+                /* Move up the tree until we come from a node's left child */
+                do {
+                        rb = rb_parent(&node->ITRB);
+                        if (!rb)
+                                return NULL;
+                        prev = &node->ITRB;
+                        node = rb_entry(rb, ITSTRUCT, ITRB);
+                        rb = node->ITRB.rb_right;
+                } while (prev == rb);
+
+                /* Check if the node intersects [start;last] */
+                if (last < ITSTART(node))               /* !Cond1 */
+                        return NULL;
+                else if (start <= ITLAST(node))         /* Cond2 */
+                        return node;
+        }
+}
diff --git a/include/linux/mm.h b/include/linux/mm.h
index 5ddb11b2b4bb..0f671ef09eba 100644
--- a/include/linux/mm.h
+++ b/include/linux/mm.h
@@ -10,7 +10,6 @@
 #include <linux/list.h>
 #include <linux/mmzone.h>
 #include <linux/rbtree.h>
-#include <linux/prio_tree.h>
 #include <linux/atomic.h>
 #include <linux/debug_locks.h>
 #include <linux/mm_types.h>
@@ -1355,22 +1354,27 @@ extern void zone_pcp_reset(struct zone *zone);
 extern atomic_long_t mmap_pages_allocated;
 extern int nommu_shrink_inode_mappings(struct inode *, size_t, size_t);
 
-/* prio_tree.c */
-void vma_prio_tree_add(struct vm_area_struct *, struct vm_area_struct *old);
-void vma_prio_tree_insert(struct vm_area_struct *, struct prio_tree_root *);
-void vma_prio_tree_remove(struct vm_area_struct *, struct prio_tree_root *);
-struct vm_area_struct *vma_prio_tree_next(struct vm_area_struct *vma,
-        struct prio_tree_iter *iter);
-
-#define vma_prio_tree_foreach(vma, iter, root, begin, end)      \
-        for (prio_tree_iter_init(iter, root, begin, end), vma = NULL;   \
-                (vma = vma_prio_tree_next(vma, iter)); )
+/* interval_tree.c */
+void vma_interval_tree_add(struct vm_area_struct *vma,
+                           struct vm_area_struct *old,
+                           struct address_space *mapping);
+void vma_interval_tree_insert(struct vm_area_struct *node,
+                              struct rb_root *root);
+void vma_interval_tree_remove(struct vm_area_struct *node,
+                              struct rb_root *root);
+struct vm_area_struct *vma_interval_tree_iter_first(struct rb_root *root,
+                                unsigned long start, unsigned long last);
+struct vm_area_struct *vma_interval_tree_iter_next(struct vm_area_struct *node,
+                                unsigned long start, unsigned long last);
+
+#define vma_interval_tree_foreach(vma, root, start, last)               \
+        for (vma = vma_interval_tree_iter_first(root, start, last);     \
+             vma; vma = vma_interval_tree_iter_next(vma, start, last))
 
 static inline void vma_nonlinear_insert(struct vm_area_struct *vma,
                                         struct list_head *list)
 {
-        vma->shared.vm_set.parent = NULL;
-        list_add_tail(&vma->shared.vm_set.list, list);
+        list_add_tail(&vma->shared.nonlinear, list);
 }
 
 /* mmap.c */
diff --git a/include/linux/mm_types.h b/include/linux/mm_types.h
index a57a43f5ca7c..31f8a3af7d94 100644
--- a/include/linux/mm_types.h
+++ b/include/linux/mm_types.h
@@ -6,7 +6,6 @@
 #include <linux/threads.h>
 #include <linux/list.h>
 #include <linux/spinlock.h>
-#include <linux/prio_tree.h>
 #include <linux/rbtree.h>
 #include <linux/rwsem.h>
 #include <linux/completion.h>
@@ -240,18 +239,15 @@ struct vm_area_struct {
 
         /*
          * For areas with an address space and backing store,
-         * linkage into the address_space->i_mmap prio tree, or
-         * linkage to the list of like vmas hanging off its node, or
+         * linkage into the address_space->i_mmap interval tree, or
          * linkage of vma in the address_space->i_mmap_nonlinear list.
          */
         union {
                 struct {
-                        struct list_head list;
-                        void *parent;   /* aligns with prio_tree_node parent */
-                        struct vm_area_struct *head;
-                } vm_set;
-
-                struct raw_prio_tree_node prio_tree_node;
+                        struct rb_node rb;
+                        unsigned long rb_subtree_last;
+                } linear;
+                struct list_head nonlinear;
         } shared;
 
         /*
diff --git a/kernel/events/uprobes.c b/kernel/events/uprobes.c
index 912ef48d28ab..1d9c0a985960 100644
--- a/kernel/events/uprobes.c
+++ b/kernel/events/uprobes.c
@@ -735,7 +735,6 @@ static struct map_info *
 build_map_info(struct address_space *mapping, loff_t offset, bool is_register)
 {
         unsigned long pgoff = offset >> PAGE_SHIFT;
-        struct prio_tree_iter iter;
         struct vm_area_struct *vma;
         struct map_info *curr = NULL;
         struct map_info *prev = NULL;
@@ -744,7 +743,7 @@ build_map_info(struct address_space *mapping, loff_t offset, bool is_register)
 
  again:
         mutex_lock(&mapping->i_mmap_mutex);
-        vma_prio_tree_foreach(vma, &iter, &mapping->i_mmap, pgoff, pgoff) {
+        vma_interval_tree_foreach(vma, &mapping->i_mmap, pgoff, pgoff) {
                 if (!valid_vma(vma, is_register))
                         continue;
 
diff --git a/kernel/fork.c b/kernel/fork.c
index 972762e01024..90dace52715e 100644
--- a/kernel/fork.c
+++ b/kernel/fork.c
@@ -423,7 +423,7 @@ static int dup_mmap(struct mm_struct *mm, struct mm_struct *oldmm)
                                 mapping->i_mmap_writable++;
                         flush_dcache_mmap_lock(mapping);
                         /* insert tmp into the share list, just after mpnt */
-                        vma_prio_tree_add(tmp, mpnt);
+                        vma_interval_tree_add(tmp, mpnt, mapping);
                         flush_dcache_mmap_unlock(mapping);
                         mutex_unlock(&mapping->i_mmap_mutex);
                 }
diff --git a/lib/interval_tree.c b/lib/interval_tree.c
index 6fd540b1e499..77a793e0644b 100644
--- a/lib/interval_tree.c
+++ b/lib/interval_tree.c
@@ -1,159 +1,13 @@
 #include <linux/init.h>
 #include <linux/interval_tree.h>
 
-/* Callbacks for augmented rbtree insert and remove */
-
-static inline unsigned long
-compute_subtree_last(struct interval_tree_node *node)
-{
-        unsigned long max = node->last, subtree_last;
-        if (node->rb.rb_left) {
-                subtree_last = rb_entry(node->rb.rb_left,
-                        struct interval_tree_node, rb)->__subtree_last;
-                if (max < subtree_last)
-                        max = subtree_last;
-        }
-        if (node->rb.rb_right) {
-                subtree_last = rb_entry(node->rb.rb_right,
-                        struct interval_tree_node, rb)->__subtree_last;
-                if (max < subtree_last)
-                        max = subtree_last;
-        }
-        return max;
-}
-
-RB_DECLARE_CALLBACKS(static, augment_callbacks, struct interval_tree_node, rb,
-                     unsigned long, __subtree_last, compute_subtree_last)
-
-/* Insert / remove interval nodes from the tree */
-
-void interval_tree_insert(struct interval_tree_node *node,
-                          struct rb_root *root)
-{
-        struct rb_node **link = &root->rb_node, *rb_parent = NULL;
-        unsigned long start = node->start, last = node->last;
-        struct interval_tree_node *parent;
-
-        while (*link) {
-                rb_parent = *link;
-                parent = rb_entry(rb_parent, struct interval_tree_node, rb);
-                if (parent->__subtree_last < last)
-                        parent->__subtree_last = last;
-                if (start < parent->start)
-                        link = &parent->rb.rb_left;
-                else
-                        link = &parent->rb.rb_right;
-        }
-
-        node->__subtree_last = last;
-        rb_link_node(&node->rb, rb_parent, link);
-        rb_insert_augmented(&node->rb, root, &augment_callbacks);
-}
-
-void interval_tree_remove(struct interval_tree_node *node,
-                          struct rb_root *root)
-{
-        rb_erase_augmented(&node->rb, root, &augment_callbacks);
-}
-
-/*
- * Iterate over intervals intersecting [start;last]
- *
- * Note that a node's interval intersects [start;last] iff:
- *   Cond1: node->start <= last
- * and
- *   Cond2: start <= node->last
- */
-
-static struct interval_tree_node *
-subtree_search(struct interval_tree_node *node,
-               unsigned long start, unsigned long last)
-{
-        while (true) {
-                /*
-                 * Loop invariant: start <= node->__subtree_last
-                 * (Cond2 is satisfied by one of the subtree nodes)
-                 */
-                if (node->rb.rb_left) {
-                        struct interval_tree_node *left =
-                                rb_entry(node->rb.rb_left,
-                                         struct interval_tree_node, rb);
-                        if (start <= left->__subtree_last) {
-                                /*
-                                 * Some nodes in left subtree satisfy Cond2.
-                                 * Iterate to find the leftmost such node N.
-                                 * If it also satisfies Cond1, that's the match
-                                 * we are looking for. Otherwise, there is no
-                                 * matching interval as nodes to the right of N
-                                 * can't satisfy Cond1 either.
-                                 */
-                                node = left;
-                                continue;
-                        }
-                }
-                if (node->start <= last) {              /* Cond1 */
-                        if (start <= node->last)        /* Cond2 */
-                                return node;    /* node is leftmost match */
-                        if (node->rb.rb_right) {
-                                node = rb_entry(node->rb.rb_right,
-                                        struct interval_tree_node, rb);
-                                if (start <= node->__subtree_last)
-                                        continue;
-                        }
-                }
-                return NULL;    /* No match */
-        }
-}
-
-struct interval_tree_node *
-interval_tree_iter_first(struct rb_root *root,
-                         unsigned long start, unsigned long last)
-{
-        struct interval_tree_node *node;
-
-        if (!root->rb_node)
-                return NULL;
-        node = rb_entry(root->rb_node, struct interval_tree_node, rb);
-        if (node->__subtree_last < start)
-                return NULL;
-        return subtree_search(node, start, last);
-}
-
-struct interval_tree_node *
-interval_tree_iter_next(struct interval_tree_node *node,
-                        unsigned long start, unsigned long last)
-{
-        struct rb_node *rb = node->rb.rb_right, *prev;
-
-        while (true) {
-                /*
-                 * Loop invariants:
-                 *   Cond1: node->start <= last
-                 *   rb == node->rb.rb_right
-                 *
-                 * First, search right subtree if suitable
-                 */
-                if (rb) {
-                        struct interval_tree_node *right =
-                                rb_entry(rb, struct interval_tree_node, rb);
-                        if (start <= right->__subtree_last)
-                                return subtree_search(right, start, last);
-                }
-
-                /* Move up the tree until we come from a node's left child */
-                do {
-                        rb = rb_parent(&node->rb);
-                        if (!rb)
-                                return NULL;
-                        prev = &node->rb;
-                        node = rb_entry(rb, struct interval_tree_node, rb);
-                        rb = node->rb.rb_right;
-                } while (prev == rb);
-
-                /* Check if the node intersects [start;last] */
-                if (last < node->start)         /* !Cond1 */
-                        return NULL;
-                else if (start <= node->last)   /* Cond2 */
-                        return node;
-        }
-}
+#define ITSTRUCT   struct interval_tree_node
+#define ITRB       rb
+#define ITTYPE     unsigned long
+#define ITSUBTREE  __subtree_last
+#define ITSTART(n) ((n)->start)
+#define ITLAST(n)  ((n)->last)
+#define ITSTATIC
+#define ITPREFIX   interval_tree
+
+#include <linux/interval_tree_tmpl.h>
diff --git a/lib/prio_tree.c b/lib/prio_tree.c
index 4e0d2edff2b4..bba37148c15e 100644
--- a/lib/prio_tree.c
+++ b/lib/prio_tree.c
@@ -44,27 +44,12 @@
  * The following macros are used for implementing prio_tree for i_mmap
  */
 
-#define RADIX_INDEX(vma)  ((vma)->vm_pgoff)
-#define VMA_SIZE(vma)     (((vma)->vm_end - (vma)->vm_start) >> PAGE_SHIFT)
-/* avoid overflow */
-#define HEAP_INDEX(vma)   ((vma)->vm_pgoff + (VMA_SIZE(vma) - 1))
-
-
 static void get_index(const struct prio_tree_root *root,
     const struct prio_tree_node *node,
     unsigned long *radix, unsigned long *heap)
 {
-        if (root->raw) {
-                struct vm_area_struct *vma = prio_tree_entry(
-                    node, struct vm_area_struct, shared.prio_tree_node);
-
-                *radix = RADIX_INDEX(vma);
-                *heap = HEAP_INDEX(vma);
-        }
-        else {
-                *radix = node->start;
-                *heap = node->last;
-        }
+        *radix = node->start;
+        *heap = node->last;
 }
 
 static unsigned long index_bits_to_maxindex[BITS_PER_LONG];
diff --git a/mm/Makefile b/mm/Makefile
index 92753e2d82da..6b025f80af34 100644
--- a/mm/Makefile
+++ b/mm/Makefile
@@ -14,9 +14,9 @@ endif
 obj-y                   := filemap.o mempool.o oom_kill.o fadvise.o \
                            maccess.o page_alloc.o page-writeback.o \
                            readahead.o swap.o truncate.o vmscan.o shmem.o \
-                           prio_tree.o util.o mmzone.o vmstat.o backing-dev.o \
+                           util.o mmzone.o vmstat.o backing-dev.o \
                            mm_init.o mmu_context.o percpu.o slab_common.o \
-                           compaction.o $(mmu-y)
+                           compaction.o interval_tree.o $(mmu-y)
 
 obj-y += init-mm.o
 
diff --git a/mm/filemap_xip.c b/mm/filemap_xip.c
index 91750227a191..a52daee11d3f 100644
--- a/mm/filemap_xip.c
+++ b/mm/filemap_xip.c
@@ -167,7 +167,6 @@ __xip_unmap (struct address_space * mapping,
 {
         struct vm_area_struct *vma;
         struct mm_struct *mm;
-        struct prio_tree_iter iter;
         unsigned long address;
         pte_t *pte;
         pte_t pteval;
@@ -184,7 +183,7 @@ __xip_unmap (struct address_space * mapping,
 
 retry:
         mutex_lock(&mapping->i_mmap_mutex);
-        vma_prio_tree_foreach(vma, &iter, &mapping->i_mmap, pgoff, pgoff) {
+        vma_interval_tree_foreach(vma, &mapping->i_mmap, pgoff, pgoff) {
                 mm = vma->vm_mm;
                 address = vma->vm_start +
                         ((pgoff - vma->vm_pgoff) << PAGE_SHIFT);
diff --git a/mm/fremap.c b/mm/fremap.c
index 3d731a498788..3899a86851ce 100644
--- a/mm/fremap.c
+++ b/mm/fremap.c
@@ -214,7 +214,7 @@ SYSCALL_DEFINE5(remap_file_pages, unsigned long, start, unsigned long, size,
                 mutex_lock(&mapping->i_mmap_mutex);
                 flush_dcache_mmap_lock(mapping);
                 vma->vm_flags |= VM_NONLINEAR;
-                vma_prio_tree_remove(vma, &mapping->i_mmap);
+                vma_interval_tree_remove(vma, &mapping->i_mmap);
                 vma_nonlinear_insert(vma, &mapping->i_mmap_nonlinear);
                 flush_dcache_mmap_unlock(mapping);
                 mutex_unlock(&mapping->i_mmap_mutex);
diff --git a/mm/hugetlb.c b/mm/hugetlb.c
index f1bb534254f6..c9b40e3a9936 100644
--- a/mm/hugetlb.c
+++ b/mm/hugetlb.c
@@ -2474,7 +2474,6 @@ static int unmap_ref_private(struct mm_struct *mm, struct vm_area_struct *vma,
         struct hstate *h = hstate_vma(vma);
         struct vm_area_struct *iter_vma;
         struct address_space *mapping;
-        struct prio_tree_iter iter;
         pgoff_t pgoff;
 
         /*
@@ -2491,7 +2490,7 @@ static int unmap_ref_private(struct mm_struct *mm, struct vm_area_struct *vma,
          * __unmap_hugepage_range() is called as the lock is already held
          */
         mutex_lock(&mapping->i_mmap_mutex);
-        vma_prio_tree_foreach(iter_vma, &iter, &mapping->i_mmap, pgoff, pgoff) {
+        vma_interval_tree_foreach(iter_vma, &mapping->i_mmap, pgoff, pgoff) {
                 /* Do not unmap the current VMA */
                 if (iter_vma == vma)
                         continue;
diff --git a/mm/interval_tree.c b/mm/interval_tree.c
new file mode 100644
index 000000000000..7dc565660e56
--- /dev/null
+++ b/mm/interval_tree.c
@@ -0,0 +1,61 @@
+/*
+ * mm/interval_tree.c - interval tree for mapping->i_mmap
+ *
+ * Copyright (C) 2012, Michel Lespinasse <walken@google.com>
+ *
+ * This file is released under the GPL v2.
+ */
+
+#include <linux/mm.h>
+#include <linux/fs.h>
+
+#define ITSTRUCT   struct vm_area_struct
+#define ITRB       shared.linear.rb
+#define ITTYPE     unsigned long
+#define ITSUBTREE  shared.linear.rb_subtree_last
+#define ITSTART(n) ((n)->vm_pgoff)
+#define ITLAST(n)  ((n)->vm_pgoff + \
+                    (((n)->vm_end - (n)->vm_start) >> PAGE_SHIFT) - 1)
+#define ITSTATIC
+#define ITPREFIX   vma_interval_tree
+
+#include <linux/interval_tree_tmpl.h>
+
+/* Insert old immediately after vma in the interval tree */
+void vma_interval_tree_add(struct vm_area_struct *vma,
+                           struct vm_area_struct *old,
+                           struct address_space *mapping)
+{
+        struct rb_node **link;
+        struct vm_area_struct *parent;
+        unsigned long last;
+
+        if (unlikely(vma->vm_flags & VM_NONLINEAR)) {
+                list_add(&vma->shared.nonlinear, &old->shared.nonlinear);
+                return;
+        }
+
+        last = ITLAST(vma);
+
+        if (!old->shared.linear.rb.rb_right) {
+                parent = old;
+                link = &old->shared.linear.rb.rb_right;
+        } else {
+                parent = rb_entry(old->shared.linear.rb.rb_right,
+                                  struct vm_area_struct, shared.linear.rb);
+                if (parent->shared.linear.rb_subtree_last < last)
+                        parent->shared.linear.rb_subtree_last = last;
+                while (parent->shared.linear.rb.rb_left) {
+                        parent = rb_entry(parent->shared.linear.rb.rb_left,
+                                struct vm_area_struct, shared.linear.rb);
+                        if (parent->shared.linear.rb_subtree_last < last)
+                                parent->shared.linear.rb_subtree_last = last;
+                }
+                link = &parent->shared.linear.rb.rb_left;
+        }
+
+        vma->shared.linear.rb_subtree_last = last;
+        rb_link_node(&vma->shared.linear.rb, &parent->shared.linear.rb, link);
+        rb_insert_augmented(&vma->shared.linear.rb, &mapping->i_mmap,
+                            &vma_interval_tree_augment_callbacks);
+}
diff --git a/mm/memory-failure.c b/mm/memory-failure.c
index a6e2141a6610..c38a6257d082 100644
--- a/mm/memory-failure.c
+++ b/mm/memory-failure.c
@@ -431,7 +431,6 @@ static void collect_procs_file(struct page *page, struct list_head *to_kill,
 {
         struct vm_area_struct *vma;
         struct task_struct *tsk;
-        struct prio_tree_iter iter;
         struct address_space *mapping = page->mapping;
 
         mutex_lock(&mapping->i_mmap_mutex);
@@ -442,7 +441,7 @@ static void collect_procs_file(struct page *page, struct list_head *to_kill,
                 if (!task_early_kill(tsk))
                         continue;
 
-                vma_prio_tree_foreach(vma, &iter, &mapping->i_mmap, pgoff,
+                vma_interval_tree_foreach(vma, &mapping->i_mmap, pgoff,
                                       pgoff) {
                         /*
                          * Send early kill signal to tasks where a vma covers
diff --git a/mm/memory.c b/mm/memory.c
index e09c04813186..d205e4381a34 100644
--- a/mm/memory.c
+++ b/mm/memory.c
@@ -2801,14 +2801,13 @@ static void unmap_mapping_range_vma(struct vm_area_struct *vma,
         zap_page_range_single(vma, start_addr, end_addr - start_addr, details);
 }
 
-static inline void unmap_mapping_range_tree(struct prio_tree_root *root,
+static inline void unmap_mapping_range_tree(struct rb_root *root,
                                             struct zap_details *details)
 {
         struct vm_area_struct *vma;
-        struct prio_tree_iter iter;
         pgoff_t vba, vea, zba, zea;
 
-        vma_prio_tree_foreach(vma, &iter, root,
+        vma_interval_tree_foreach(vma, root,
                         details->first_index, details->last_index) {
 
                 vba = vma->vm_pgoff;
@@ -2839,7 +2838,7 @@ static inline void unmap_mapping_range_list(struct list_head *head,
          * across *all* the pages in each nonlinear VMA, not just the pages
          * whose virtual address lies outside the file truncation point.
          */
-        list_for_each_entry(vma, head, shared.vm_set.list) {
+        list_for_each_entry(vma, head, shared.nonlinear) {
                 details->nonlinear_vma = vma;
                 unmap_mapping_range_vma(vma, vma->vm_start, vma->vm_end, details);
         }
@@ -2883,7 +2882,7 @@ void unmap_mapping_range(struct address_space *mapping,
 
 
         mutex_lock(&mapping->i_mmap_mutex);
-        if (unlikely(!prio_tree_empty(&mapping->i_mmap)))
+        if (unlikely(!RB_EMPTY_ROOT(&mapping->i_mmap)))
                 unmap_mapping_range_tree(&mapping->i_mmap, &details);
         if (unlikely(!list_empty(&mapping->i_mmap_nonlinear)))
                 unmap_mapping_range_list(&mapping->i_mmap_nonlinear, &details);
diff --git a/mm/mmap.c b/mm/mmap.c
index e3c365ff1b6a..5ac533f88e99 100644
--- a/mm/mmap.c
+++ b/mm/mmap.c
@@ -199,14 +199,14 @@ static void __remove_shared_vm_struct(struct vm_area_struct *vma,
 
         flush_dcache_mmap_lock(mapping);
         if (unlikely(vma->vm_flags & VM_NONLINEAR))
-                list_del_init(&vma->shared.vm_set.list);
+                list_del_init(&vma->shared.nonlinear);
         else
-                vma_prio_tree_remove(vma, &mapping->i_mmap);
+                vma_interval_tree_remove(vma, &mapping->i_mmap);
         flush_dcache_mmap_unlock(mapping);
 }
 
 /*
- * Unlink a file-based vm structure from its prio_tree, to hide
+ * Unlink a file-based vm structure from its interval tree, to hide
  * vma from rmap and vmtruncate before freeing its page tables.
  */
 void unlink_file_vma(struct vm_area_struct *vma)
@@ -411,7 +411,7 @@ static void __vma_link_file(struct vm_area_struct *vma)
                 if (unlikely(vma->vm_flags & VM_NONLINEAR))
                         vma_nonlinear_insert(vma, &mapping->i_mmap_nonlinear);
                 else
-                        vma_prio_tree_insert(vma, &mapping->i_mmap);
+                        vma_interval_tree_insert(vma, &mapping->i_mmap);
                 flush_dcache_mmap_unlock(mapping);
         }
 }
@@ -449,7 +449,7 @@ static void vma_link(struct mm_struct *mm, struct vm_area_struct *vma,
 
 /*
  * Helper for vma_adjust() in the split_vma insert case: insert a vma into the
- * mm's list and rbtree.  It has already been inserted into the prio_tree.
+ * mm's list and rbtree.  It has already been inserted into the interval tree.
  */
 static void __insert_vm_struct(struct mm_struct *mm, struct vm_area_struct *vma)
 {
@@ -491,7 +491,7 @@ int vma_adjust(struct vm_area_struct *vma, unsigned long start,
         struct vm_area_struct *next = vma->vm_next;
         struct vm_area_struct *importer = NULL;
         struct address_space *mapping = NULL;
-        struct prio_tree_root *root = NULL;
+        struct rb_root *root = NULL;
         struct anon_vma *anon_vma = NULL;
         struct file *file = vma->vm_file;
         long adjust_next = 0;
@@ -554,7 +554,7 @@ again:			remove_next = 1 + (end > next->vm_end);
                 mutex_lock(&mapping->i_mmap_mutex);
                 if (insert) {
                         /*
-                         * Put into prio_tree now, so instantiated pages
+                         * Put into interval tree now, so instantiated pages
                          * are visible to arm/parisc __flush_dcache_page
                          * throughout; but we cannot insert into address
                          * space until vma start or end is updated.
@@ -582,9 +582,9 @@ again:			remove_next = 1 + (end > next->vm_end);
 
         if (root) {
                 flush_dcache_mmap_lock(mapping);
-                vma_prio_tree_remove(vma, root);
+                vma_interval_tree_remove(vma, root);
                 if (adjust_next)
-                        vma_prio_tree_remove(next, root);
+                        vma_interval_tree_remove(next, root);
         }
 
         vma->vm_start = start;
@@ -597,8 +597,8 @@ again:			remove_next = 1 + (end > next->vm_end);
 
         if (root) {
                 if (adjust_next)
-                        vma_prio_tree_insert(next, root);
-                vma_prio_tree_insert(vma, root);
+                        vma_interval_tree_insert(next, root);
+                vma_interval_tree_insert(vma, root);
                 flush_dcache_mmap_unlock(mapping);
         }
 
diff --git a/mm/nommu.c b/mm/nommu.c
index 12e84e69dd06..45131b41bcdb 100644
--- a/mm/nommu.c
+++ b/mm/nommu.c
@@ -698,7 +698,7 @@ static void add_vma_to_mm(struct mm_struct *mm, struct vm_area_struct *vma)
 
                 mutex_lock(&mapping->i_mmap_mutex);
                 flush_dcache_mmap_lock(mapping);
-                vma_prio_tree_insert(vma, &mapping->i_mmap);
+                vma_interval_tree_insert(vma, &mapping->i_mmap);
                 flush_dcache_mmap_unlock(mapping);
                 mutex_unlock(&mapping->i_mmap_mutex);
         }
@@ -764,7 +764,7 @@ static void delete_vma_from_mm(struct vm_area_struct *vma)
 
                 mutex_lock(&mapping->i_mmap_mutex);
                 flush_dcache_mmap_lock(mapping);
-                vma_prio_tree_remove(vma, &mapping->i_mmap);
+                vma_interval_tree_remove(vma, &mapping->i_mmap);
                 flush_dcache_mmap_unlock(mapping);
                 mutex_unlock(&mapping->i_mmap_mutex);
         }
@@ -2044,7 +2044,6 @@ int nommu_shrink_inode_mappings(struct inode *inode, size_t size,
                                 size_t newsize)
 {
         struct vm_area_struct *vma;
-        struct prio_tree_iter iter;
         struct vm_region *region;
         pgoff_t low, high;
         size_t r_size, r_top;
@@ -2056,8 +2055,7 @@ int nommu_shrink_inode_mappings(struct inode *inode, size_t size,
         mutex_lock(&inode->i_mapping->i_mmap_mutex);
 
         /* search for VMAs that fall within the dead zone */
-        vma_prio_tree_foreach(vma, &iter, &inode->i_mapping->i_mmap,
-                              low, high) {
+        vma_interval_tree_foreach(vma, &inode->i_mapping->i_mmap, low, high) {
                 /* found one - only interested if it's shared out of the page
                  * cache */
                 if (vma->vm_flags & VM_SHARED) {
@@ -2073,8 +2071,8 @@ int nommu_shrink_inode_mappings(struct inode *inode, size_t size,
          * we don't check for any regions that start beyond the EOF as there
          * shouldn't be any
          */
-        vma_prio_tree_foreach(vma, &iter, &inode->i_mapping->i_mmap,
-                              0, ULONG_MAX) {
+        vma_interval_tree_foreach(vma, &inode->i_mapping->i_mmap,
+                                  0, ULONG_MAX) {
                 if (!(vma->vm_flags & VM_SHARED))
                         continue;
 
diff --git a/mm/prio_tree.c b/mm/prio_tree.c
deleted file mode 100644
index 799dcfd7cd8c..000000000000
--- a/mm/prio_tree.c
+++ /dev/null
@@ -1,208 +0,0 @@
-/*
- * mm/prio_tree.c - priority search tree for mapping->i_mmap
- *
- * Copyright (C) 2004, Rajesh Venkatasubramanian <vrajesh@umich.edu>
- *
- * This file is released under the GPL v2.
- *
- * Based on the radix priority search tree proposed by Edward M. McCreight
- * SIAM Journal of Computing, vol. 14, no.2, pages 257-276, May 1985
- *
- * 02Feb2004    Initial version
- */
-
-#include <linux/mm.h>
-#include <linux/prio_tree.h>
-#include <linux/prefetch.h>
-
-/*
- * See lib/prio_tree.c for details on the general radix priority search tree
- * code.
- */
-
-/*
- * The following #defines are mirrored from lib/prio_tree.c. They're only used
- * for debugging, and should be removed (along with the debugging code using
- * them) when switching also VMAs to the regular prio_tree code.
- */
-
-#define RADIX_INDEX(vma)  ((vma)->vm_pgoff)
-#define VMA_SIZE(vma)     (((vma)->vm_end - (vma)->vm_start) >> PAGE_SHIFT)
-/* avoid overflow */
-#define HEAP_INDEX(vma)   ((vma)->vm_pgoff + (VMA_SIZE(vma) - 1))
-
-/*
- * Radix priority search tree for address_space->i_mmap
- *
- * For each vma that map a unique set of file pages i.e., unique [radix_index,
- * heap_index] value, we have a corresponding priority search tree node. If
- * multiple vmas have identical [radix_index, heap_index] value, then one of
- * them is used as a tree node and others are stored in a vm_set list. The tree
- * node points to the first vma (head) of the list using vm_set.head.
- *
- * prio_tree_root
- *      |
- *      A       vm_set.head
- *     / \      /
- *    L   R -> H-I-J-K-M-N-O-P-Q-S
- *    ^   ^    <-- vm_set.list -->
- *  tree nodes
- *
- * We need some way to identify whether a vma is a tree node, head of a vm_set
- * list, or just a member of a vm_set list. We cannot use vm_flags to store
- * such information. The reason is, in the above figure, it is possible that
- * vm_flags' of R and H are covered by the different mmap_sems. When R is
- * removed under R->mmap_sem, H replaces R as a tree node. Since we do not hold
- * H->mmap_sem, we cannot use H->vm_flags for marking that H is a tree node now.
- * That's why some trick involving shared.vm_set.parent is used for identifying
- * tree nodes and list head nodes.
- *
- * vma radix priority search tree node rules:
- *
- * vma->shared.vm_set.parent != NULL    ==> a tree node
- *      vma->shared.vm_set.head != NULL ==> list of others mapping same range
- *      vma->shared.vm_set.head == NULL ==> no others map the same range
- *
- * vma->shared.vm_set.parent == NULL
- *      vma->shared.vm_set.head != NULL ==> list head of vmas mapping same range
- *      vma->shared.vm_set.head == NULL ==> a list node
- */
-
-/*
- * Add a new vma known to map the same set of pages as the old vma:
- * useful for fork's dup_mmap as well as vma_prio_tree_insert below.
- * Note that it just happens to work correctly on i_mmap_nonlinear too.
- */
-void vma_prio_tree_add(struct vm_area_struct *vma, struct vm_area_struct *old)
-{
-        /* Leave these BUG_ONs till prio_tree patch stabilizes */
-        BUG_ON(RADIX_INDEX(vma) != RADIX_INDEX(old));
-        BUG_ON(HEAP_INDEX(vma) != HEAP_INDEX(old));
-
-        vma->shared.vm_set.head = NULL;
-        vma->shared.vm_set.parent = NULL;
-
-        if (!old->shared.vm_set.parent)
-                list_add(&vma->shared.vm_set.list,
-                                &old->shared.vm_set.list);
-        else if (old->shared.vm_set.head)
-                list_add_tail(&vma->shared.vm_set.list,
-                                &old->shared.vm_set.head->shared.vm_set.list);
-        else {
-                INIT_LIST_HEAD(&vma->shared.vm_set.list);
-                vma->shared.vm_set.head = old;
-                old->shared.vm_set.head = vma;
-        }
-}
-
-void vma_prio_tree_insert(struct vm_area_struct *vma,
-                          struct prio_tree_root *root)
-{
-        struct prio_tree_node *ptr;
-        struct vm_area_struct *old;
-
-        vma->shared.vm_set.head = NULL;
-
-        ptr = raw_prio_tree_insert(root, &vma->shared.prio_tree_node);
-        if (ptr != (struct prio_tree_node *) &vma->shared.prio_tree_node) {
-                old = prio_tree_entry(ptr, struct vm_area_struct,
-                                        shared.prio_tree_node);
-                vma_prio_tree_add(vma, old);
-        }
-}
-
-void vma_prio_tree_remove(struct vm_area_struct *vma,
-                          struct prio_tree_root *root)
-{
-        struct vm_area_struct *node, *head, *new_head;
-
-        if (!vma->shared.vm_set.head) {
-                if (!vma->shared.vm_set.parent)
-                        list_del_init(&vma->shared.vm_set.list);
-                else
-                        raw_prio_tree_remove(root, &vma->shared.prio_tree_node);
-        } else {
-                /* Leave this BUG_ON till prio_tree patch stabilizes */
-                BUG_ON(vma->shared.vm_set.head->shared.vm_set.head != vma);
-                if (vma->shared.vm_set.parent) {
-                        head = vma->shared.vm_set.head;
-                        if (!list_empty(&head->shared.vm_set.list)) {
-                                new_head = list_entry(
-                                        head->shared.vm_set.list.next,
-                                        struct vm_area_struct,
-                                        shared.vm_set.list);
-                                list_del_init(&head->shared.vm_set.list);
-                        } else
-                                new_head = NULL;
-
-                        raw_prio_tree_replace(root, &vma->shared.prio_tree_node,
-                                        &head->shared.prio_tree_node);
-                        head->shared.vm_set.head = new_head;
-                        if (new_head)
-                                new_head->shared.vm_set.head = head;
-
-                } else {
-                        node = vma->shared.vm_set.head;
-                        if (!list_empty(&vma->shared.vm_set.list)) {
-                                new_head = list_entry(
-                                        vma->shared.vm_set.list.next,
-                                        struct vm_area_struct,
-                                        shared.vm_set.list);
-                                list_del_init(&vma->shared.vm_set.list);
-                                node->shared.vm_set.head = new_head;
-                                new_head->shared.vm_set.head = node;
-                        } else
-                                node->shared.vm_set.head = NULL;
-                }
-        }
-}
-
-/*
- * Helper function to enumerate vmas that map a given file page or a set of
- * contiguous file pages. The function returns vmas that at least map a single
- * page in the given range of contiguous file pages.
- */
-struct vm_area_struct *vma_prio_tree_next(struct vm_area_struct *vma,
-                                        struct prio_tree_iter *iter)
-{
-        struct prio_tree_node *ptr;
-        struct vm_area_struct *next;
-
-        if (!vma) {
-                /*
-                 * First call is with NULL vma
-                 */
-                ptr = prio_tree_next(iter);
-                if (ptr) {
-                        next = prio_tree_entry(ptr, struct vm_area_struct,
-                                                shared.prio_tree_node);
-                        prefetch(next->shared.vm_set.head);
-                        return next;
-                } else
-                        return NULL;
-        }
-
-        if (vma->shared.vm_set.parent) {
-                if (vma->shared.vm_set.head) {
-                        next = vma->shared.vm_set.head;
-                        prefetch(next->shared.vm_set.list.next);
-                        return next;
-                }
-        } else {
-                next = list_entry(vma->shared.vm_set.list.next,
-                                struct vm_area_struct, shared.vm_set.list);
-                if (!next->shared.vm_set.head) {
-                        prefetch(next->shared.vm_set.list.next);
-                        return next;
-                }
-        }
-
-        ptr = prio_tree_next(iter);
-        if (ptr) {
-                next = prio_tree_entry(ptr, struct vm_area_struct,
-                                        shared.prio_tree_node);
-                prefetch(next->shared.vm_set.head);
-                return next;
-        } else
-                return NULL;
-}
diff --git a/mm/rmap.c b/mm/rmap.c
index 0f3b7cda2a24..7b5b51d25fc5 100644
--- a/mm/rmap.c
+++ b/mm/rmap.c
@@ -820,7 +820,6 @@ static int page_referenced_file(struct page *page,
         struct address_space *mapping = page->mapping;
         pgoff_t pgoff = page->index << (PAGE_CACHE_SHIFT - PAGE_SHIFT);
         struct vm_area_struct *vma;
-        struct prio_tree_iter iter;
         int referenced = 0;
 
         /*
@@ -846,7 +845,7 @@ static int page_referenced_file(struct page *page,
          */
         mapcount = page_mapcount(page);
 
-        vma_prio_tree_foreach(vma, &iter, &mapping->i_mmap, pgoff, pgoff) {
+        vma_interval_tree_foreach(vma, &mapping->i_mmap, pgoff, pgoff) {
                 unsigned long address = vma_address(page, vma);
                 if (address == -EFAULT)
                         continue;
@@ -945,13 +944,12 @@ static int page_mkclean_file(struct address_space *mapping, struct page *page)
 {
         pgoff_t pgoff = page->index << (PAGE_CACHE_SHIFT - PAGE_SHIFT);
         struct vm_area_struct *vma;
-        struct prio_tree_iter iter;
         int ret = 0;
 
         BUG_ON(PageAnon(page));
 
         mutex_lock(&mapping->i_mmap_mutex);
-        vma_prio_tree_foreach(vma, &iter, &mapping->i_mmap, pgoff, pgoff) {
+        vma_interval_tree_foreach(vma, &mapping->i_mmap, pgoff, pgoff) {
                 if (vma->vm_flags & VM_SHARED) {
                         unsigned long address = vma_address(page, vma);
                         if (address == -EFAULT)
@@ -1547,7 +1545,6 @@ static int try_to_unmap_file(struct page *page, enum ttu_flags flags)
         struct address_space *mapping = page->mapping;
         pgoff_t pgoff = page->index << (PAGE_CACHE_SHIFT - PAGE_SHIFT);
         struct vm_area_struct *vma;
-        struct prio_tree_iter iter;
         int ret = SWAP_AGAIN;
         unsigned long cursor;
         unsigned long max_nl_cursor = 0;
@@ -1555,7 +1552,7 @@ static int try_to_unmap_file(struct page *page, enum ttu_flags flags)
         unsigned int mapcount;
 
         mutex_lock(&mapping->i_mmap_mutex);
-        vma_prio_tree_foreach(vma, &iter, &mapping->i_mmap, pgoff, pgoff) {
+        vma_interval_tree_foreach(vma, &mapping->i_mmap, pgoff, pgoff) {
                 unsigned long address = vma_address(page, vma);
                 if (address == -EFAULT)
                         continue;
@@ -1576,7 +1573,7 @@ static int try_to_unmap_file(struct page *page, enum ttu_flags flags)
                 goto out;
 
         list_for_each_entry(vma, &mapping->i_mmap_nonlinear,
-                                                shared.vm_set.list) {
+                                                        shared.nonlinear) {
                 cursor = (unsigned long) vma->vm_private_data;
                 if (cursor > max_nl_cursor)
                         max_nl_cursor = cursor;
@@ -1608,7 +1605,7 @@ static int try_to_unmap_file(struct page *page, enum ttu_flags flags)
 
         do {
                 list_for_each_entry(vma, &mapping->i_mmap_nonlinear,
-                                                shared.vm_set.list) {
+                                                        shared.nonlinear) {
                         cursor = (unsigned long) vma->vm_private_data;
                         while ( cursor < max_nl_cursor &&
                                 cursor < vma->vm_end - vma->vm_start) {
@@ -1631,7 +1628,7 @@ static int try_to_unmap_file(struct page *page, enum ttu_flags flags)
          * in locked vmas).  Reset cursor on all unreserved nonlinear
          * vmas, now forgetting on which ones it had fallen behind.
          */
-        list_for_each_entry(vma, &mapping->i_mmap_nonlinear, shared.vm_set.list)
+        list_for_each_entry(vma, &mapping->i_mmap_nonlinear, shared.nonlinear)
                 vma->vm_private_data = NULL;
 out:
         mutex_unlock(&mapping->i_mmap_mutex);
@@ -1748,13 +1745,12 @@ static int rmap_walk_file(struct page *page, int (*rmap_one)(struct page *,
         struct address_space *mapping = page->mapping;
         pgoff_t pgoff = page->index << (PAGE_CACHE_SHIFT - PAGE_SHIFT);
         struct vm_area_struct *vma;
-        struct prio_tree_iter iter;
         int ret = SWAP_AGAIN;
 
         if (!mapping)
                 return ret;
         mutex_lock(&mapping->i_mmap_mutex);
-        vma_prio_tree_foreach(vma, &iter, &mapping->i_mmap, pgoff, pgoff) {
+        vma_interval_tree_foreach(vma, &mapping->i_mmap, pgoff, pgoff) {
                 unsigned long address = vma_address(page, vma);
                 if (address == -EFAULT)
                         continue;