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mm: replace vma prio_tree with an interval tree

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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>
This commit is contained in:
Michel Lespinasse 2012-10-08 16:31:25 -07:00 committed by Linus Torvalds
parent fff3fd8a12
commit 6b2dbba8b6
25 changed files with 355 additions and 464 deletions
repo.diff.show_diff_stats Download patch file Download diff file Expand all files Collapse all files

3
arch/arm/mm/fault-armv.c
View file

@ -134,7 +134,6 @@ make_coherent(struct address_space *mapping, struct vm_area_struct *vma,
{ {
struct mm_struct *mm = vma->vm_mm; struct mm_struct *mm = vma->vm_mm;
struct vm_area_struct *mpnt; struct vm_area_struct *mpnt;
struct prio_tree_iter iter;
unsigned long offset; unsigned long offset;
pgoff_t pgoff; pgoff_t pgoff;
int aliases = 0; int aliases = 0;
@ -147,7 +146,7 @@ make_coherent(struct address_space *mapping, struct vm_area_struct *vma,
* cache coherency. * cache coherency.
*/ */
flush_dcache_mmap_lock(mapping); 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. * If this VMA is not in our MM, we can ignore it.
* Note that we intentionally mask out the VMA * Note that we intentionally mask out the VMA

3
arch/arm/mm/flush.c
View file

@ -196,7 +196,6 @@ static void __flush_dcache_aliases(struct address_space *mapping, struct page *p
{ {
struct mm_struct *mm = current->active_mm; struct mm_struct *mm = current->active_mm;
struct vm_area_struct *mpnt; struct vm_area_struct *mpnt;
struct prio_tree_iter iter;
pgoff_t pgoff; 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); pgoff = page->index << (PAGE_CACHE_SHIFT - PAGE_SHIFT);
flush_dcache_mmap_lock(mapping); 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; unsigned long offset;
/* /*

3
arch/parisc/kernel/cache.c
View file

@ -276,7 +276,6 @@ void flush_dcache_page(struct page *page)
{ {
struct address_space *mapping = page_mapping(page); struct address_space *mapping = page_mapping(page);
struct vm_area_struct *mpnt; struct vm_area_struct *mpnt;
struct prio_tree_iter iter;
unsigned long offset; unsigned long offset;
unsigned long addr, old_addr = 0; unsigned long addr, old_addr = 0;
pgoff_t pgoff; 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 */ * to flush one address here for them all to become coherent */
flush_dcache_mmap_lock(mapping); 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; offset = (pgoff - mpnt->vm_pgoff) << PAGE_SHIFT;
addr = mpnt->vm_start + offset; addr = mpnt->vm_start + offset;

3
arch/x86/mm/hugetlbpage.c
View file

@ -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; struct address_space *mapping = vma->vm_file->f_mapping;
pgoff_t idx = ((addr - vma->vm_start) >> PAGE_SHIFT) + pgoff_t idx = ((addr - vma->vm_start) >> PAGE_SHIFT) +
vma->vm_pgoff; vma->vm_pgoff;
struct prio_tree_iter iter;
struct vm_area_struct *svma; struct vm_area_struct *svma;
unsigned long saddr; unsigned long saddr;
pte_t *spte = NULL; 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); return (pte_t *)pmd_alloc(mm, pud, addr);
mutex_lock(&mapping->i_mmap_mutex); 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) if (svma == vma)
continue; continue;

9
fs/hugetlbfs/inode.c
View file

@ -397,17 +397,16 @@ static void hugetlbfs_evict_inode(struct inode *inode)
} }
static inline void 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 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; unsigned long v_offset;
/* /*
* Can the expression below overflow on 32-bit arches? * 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, * which overlap the truncated area starting at pgoff,
* and no vma on a 32-bit arch can span beyond the 4GB. * 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); i_size_write(inode, offset);
mutex_lock(&mapping->i_mmap_mutex); 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); hugetlb_vmtruncate_list(&mapping->i_mmap, pgoff);
mutex_unlock(&mapping->i_mmap_mutex); mutex_unlock(&mapping->i_mmap_mutex);
truncate_hugepages(inode, offset); truncate_hugepages(inode, offset);

2
fs/inode.c
View file

@ -348,7 +348,7 @@ void address_space_init_once(struct address_space *mapping)
mutex_init(&mapping->i_mmap_mutex); mutex_init(&mapping->i_mmap_mutex);
INIT_LIST_HEAD(&mapping->private_list); INIT_LIST_HEAD(&mapping->private_list);
spin_lock_init(&mapping->private_lock); 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); INIT_LIST_HEAD(&mapping->i_mmap_nonlinear);
} }
EXPORT_SYMBOL(address_space_init_once); EXPORT_SYMBOL(address_space_init_once);

6
include/linux/fs.h
View file

@ -401,7 +401,7 @@ struct inodes_stat_t {
#include <linux/cache.h> #include <linux/cache.h>
#include <linux/list.h> #include <linux/list.h>
#include <linux/radix-tree.h> #include <linux/radix-tree.h>
#include <linux/prio_tree.h> #include <linux/rbtree.h>
#include <linux/init.h> #include <linux/init.h>
#include <linux/pid.h> #include <linux/pid.h>
#include <linux/bug.h> #include <linux/bug.h>
@ -669,7 +669,7 @@ struct address_space {
struct radix_tree_root page_tree; /* radix tree of all pages */ struct radix_tree_root page_tree; /* radix tree of all pages */
spinlock_t tree_lock; /* and lock protecting it */ spinlock_t tree_lock; /* and lock protecting it */
unsigned int i_mmap_writable;/* count VM_SHARED mappings */ 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 list_head i_mmap_nonlinear;/*list VM_NONLINEAR mappings */
struct mutex i_mmap_mutex; /* protect tree, count, list */ struct mutex i_mmap_mutex; /* protect tree, count, list */
/* Protected by tree_lock together with the radix tree */ /* 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) 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); !list_empty(&mapping->i_mmap_nonlinear);
} }

215
include/linux/interval_tree_tmpl.h Normal file
View file

@ -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;
}
}

28
include/linux/mm.h
View file

@ -10,7 +10,6 @@
#include <linux/list.h> #include <linux/list.h>
#include <linux/mmzone.h> #include <linux/mmzone.h>
#include <linux/rbtree.h> #include <linux/rbtree.h>
#include <linux/prio_tree.h>
#include <linux/atomic.h> #include <linux/atomic.h>
#include <linux/debug_locks.h> #include <linux/debug_locks.h>
#include <linux/mm_types.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 atomic_long_t mmap_pages_allocated;
extern int nommu_shrink_inode_mappings(struct inode *, size_t, size_t); extern int nommu_shrink_inode_mappings(struct inode *, size_t, size_t);
/* prio_tree.c */ /* interval_tree.c */
void vma_prio_tree_add(struct vm_area_struct *, struct vm_area_struct *old); void vma_interval_tree_add(struct vm_area_struct *vma,
void vma_prio_tree_insert(struct vm_area_struct *, struct prio_tree_root *); struct vm_area_struct *old,
void vma_prio_tree_remove(struct vm_area_struct *, struct prio_tree_root *); struct address_space *mapping);
struct vm_area_struct *vma_prio_tree_next(struct vm_area_struct *vma, void vma_interval_tree_insert(struct vm_area_struct *node,
struct prio_tree_iter *iter); 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_prio_tree_foreach(vma, iter, root, begin, end) \ #define vma_interval_tree_foreach(vma, root, start, last) \
for (prio_tree_iter_init(iter, root, begin, end), vma = NULL; \ for (vma = vma_interval_tree_iter_first(root, start, last); \
(vma = vma_prio_tree_next(vma, iter)); ) vma; vma = vma_interval_tree_iter_next(vma, start, last))
static inline void vma_nonlinear_insert(struct vm_area_struct *vma, static inline void vma_nonlinear_insert(struct vm_area_struct *vma,
struct list_head *list) struct list_head *list)
{ {
vma->shared.vm_set.parent = NULL; list_add_tail(&vma->shared.nonlinear, list);
list_add_tail(&vma->shared.vm_set.list, list);
} }
/* mmap.c */ /* mmap.c */

14
include/linux/mm_types.h
View file

@ -6,7 +6,6 @@
#include <linux/threads.h> #include <linux/threads.h>
#include <linux/list.h> #include <linux/list.h>
#include <linux/spinlock.h> #include <linux/spinlock.h>
#include <linux/prio_tree.h>
#include <linux/rbtree.h> #include <linux/rbtree.h>
#include <linux/rwsem.h> #include <linux/rwsem.h>
#include <linux/completion.h> #include <linux/completion.h>
@ -240,18 +239,15 @@ struct vm_area_struct {
/* /*
* For areas with an address space and backing store, * For areas with an address space and backing store,
* linkage into the address_space->i_mmap prio tree, or * linkage into the address_space->i_mmap interval tree, or
* linkage to the list of like vmas hanging off its node, or
* linkage of vma in the address_space->i_mmap_nonlinear list. * linkage of vma in the address_space->i_mmap_nonlinear list.
*/ */
union { union {
struct { struct {
struct list_head list; struct rb_node rb;
void *parent; /* aligns with prio_tree_node parent */ unsigned long rb_subtree_last;
struct vm_area_struct *head; } linear;
} vm_set; struct list_head nonlinear;
struct raw_prio_tree_node prio_tree_node;
} shared; } shared;
/* /*

3
kernel/events/uprobes.c
View file

@ -735,7 +735,6 @@ static struct map_info *
build_map_info(struct address_space *mapping, loff_t offset, bool is_register) build_map_info(struct address_space *mapping, loff_t offset, bool is_register)
{ {
unsigned long pgoff = offset >> PAGE_SHIFT; unsigned long pgoff = offset >> PAGE_SHIFT;
struct prio_tree_iter iter;
struct vm_area_struct *vma; struct vm_area_struct *vma;
struct map_info *curr = NULL; struct map_info *curr = NULL;
struct map_info *prev = NULL; struct map_info *prev = NULL;
@ -744,7 +743,7 @@ build_map_info(struct address_space *mapping, loff_t offset, bool is_register)
again: again:
mutex_lock(&mapping->i_mmap_mutex); 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)) if (!valid_vma(vma, is_register))
continue; continue;

2
kernel/fork.c
View file

@ -423,7 +423,7 @@ static int dup_mmap(struct mm_struct *mm, struct mm_struct *oldmm)
mapping->i_mmap_writable++; mapping->i_mmap_writable++;
flush_dcache_mmap_lock(mapping); flush_dcache_mmap_lock(mapping);
/* insert tmp into the share list, just after mpnt */ /* 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); flush_dcache_mmap_unlock(mapping);
mutex_unlock(&mapping->i_mmap_mutex); mutex_unlock(&mapping->i_mmap_mutex);
} }

164
lib/interval_tree.c
View file

@ -1,159 +1,13 @@
#include <linux/init.h> #include <linux/init.h>
#include <linux/interval_tree.h> #include <linux/interval_tree.h>
/* Callbacks for augmented rbtree insert and remove */ #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
static inline unsigned long #include <linux/interval_tree_tmpl.h>
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;
}
}

15
lib/prio_tree.c
View file

@ -44,27 +44,12 @@
* The following macros are used for implementing prio_tree for i_mmap * 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, static void get_index(const struct prio_tree_root *root,
const struct prio_tree_node *node, const struct prio_tree_node *node,
unsigned long *radix, unsigned long *heap) 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; *radix = node->start;
*heap = node->last; *heap = node->last;
}
} }
static unsigned long index_bits_to_maxindex[BITS_PER_LONG]; static unsigned long index_bits_to_maxindex[BITS_PER_LONG];

4
mm/Makefile
View file

@ -14,9 +14,9 @@ endif
obj-y := filemap.o mempool.o oom_kill.o fadvise.o \ obj-y := filemap.o mempool.o oom_kill.o fadvise.o \
maccess.o page_alloc.o page-writeback.o \ maccess.o page_alloc.o page-writeback.o \
readahead.o swap.o truncate.o vmscan.o shmem.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 \ 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 obj-y += init-mm.o

3
mm/filemap_xip.c
View file

@ -167,7 +167,6 @@ __xip_unmap (struct address_space * mapping,
{ {
struct vm_area_struct *vma; struct vm_area_struct *vma;
struct mm_struct *mm; struct mm_struct *mm;
struct prio_tree_iter iter;
unsigned long address; unsigned long address;
pte_t *pte; pte_t *pte;
pte_t pteval; pte_t pteval;
@ -184,7 +183,7 @@ __xip_unmap (struct address_space * mapping,
retry: retry:
mutex_lock(&mapping->i_mmap_mutex); 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; mm = vma->vm_mm;
address = vma->vm_start + address = vma->vm_start +
((pgoff - vma->vm_pgoff) << PAGE_SHIFT); ((pgoff - vma->vm_pgoff) << PAGE_SHIFT);

2
mm/fremap.c
View file

@ -214,7 +214,7 @@ SYSCALL_DEFINE5(remap_file_pages, unsigned long, start, unsigned long, size,
mutex_lock(&mapping->i_mmap_mutex); mutex_lock(&mapping->i_mmap_mutex);
flush_dcache_mmap_lock(mapping); flush_dcache_mmap_lock(mapping);
vma->vm_flags |= VM_NONLINEAR; 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); vma_nonlinear_insert(vma, &mapping->i_mmap_nonlinear);
flush_dcache_mmap_unlock(mapping); flush_dcache_mmap_unlock(mapping);
mutex_unlock(&mapping->i_mmap_mutex); mutex_unlock(&mapping->i_mmap_mutex);

3
mm/hugetlb.c
View file

@ -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 hstate *h = hstate_vma(vma);
struct vm_area_struct *iter_vma; struct vm_area_struct *iter_vma;
struct address_space *mapping; struct address_space *mapping;
struct prio_tree_iter iter;
pgoff_t pgoff; 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 * __unmap_hugepage_range() is called as the lock is already held
*/ */
mutex_lock(&mapping->i_mmap_mutex); 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 */ /* Do not unmap the current VMA */
if (iter_vma == vma) if (iter_vma == vma)
continue; continue;

61
mm/interval_tree.c Normal file
View file

@ -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);
}

3
mm/memory-failure.c
View file

@ -431,7 +431,6 @@ static void collect_procs_file(struct page *page, struct list_head *to_kill,
{ {
struct vm_area_struct *vma; struct vm_area_struct *vma;
struct task_struct *tsk; struct task_struct *tsk;
struct prio_tree_iter iter;
struct address_space *mapping = page->mapping; struct address_space *mapping = page->mapping;
mutex_lock(&mapping->i_mmap_mutex); 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)) if (!task_early_kill(tsk))
continue; continue;
vma_prio_tree_foreach(vma, &iter, &mapping->i_mmap, pgoff, vma_interval_tree_foreach(vma, &mapping->i_mmap, pgoff,
pgoff) { pgoff) {
/* /*
* Send early kill signal to tasks where a vma covers * Send early kill signal to tasks where a vma covers

9
mm/memory.c
View file

@ -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); 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 zap_details *details)
{ {
struct vm_area_struct *vma; struct vm_area_struct *vma;
struct prio_tree_iter iter;
pgoff_t vba, vea, zba, zea; 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) { details->first_index, details->last_index) {
vba = vma->vm_pgoff; 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 * across *all* the pages in each nonlinear VMA, not just the pages
* whose virtual address lies outside the file truncation point. * 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; details->nonlinear_vma = vma;
unmap_mapping_range_vma(vma, vma->vm_start, vma->vm_end, details); 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); 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); unmap_mapping_range_tree(&mapping->i_mmap, &details);
if (unlikely(!list_empty(&mapping->i_mmap_nonlinear))) if (unlikely(!list_empty(&mapping->i_mmap_nonlinear)))
unmap_mapping_range_list(&mapping->i_mmap_nonlinear, &details); unmap_mapping_range_list(&mapping->i_mmap_nonlinear, &details);

22
mm/mmap.c
View file

@ -199,14 +199,14 @@ static void __remove_shared_vm_struct(struct vm_area_struct *vma,
flush_dcache_mmap_lock(mapping); flush_dcache_mmap_lock(mapping);
if (unlikely(vma->vm_flags & VM_NONLINEAR)) if (unlikely(vma->vm_flags & VM_NONLINEAR))
list_del_init(&vma->shared.vm_set.list); list_del_init(&vma->shared.nonlinear);
else else
vma_prio_tree_remove(vma, &mapping->i_mmap); vma_interval_tree_remove(vma, &mapping->i_mmap);
flush_dcache_mmap_unlock(mapping); 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. * vma from rmap and vmtruncate before freeing its page tables.
*/ */
void unlink_file_vma(struct vm_area_struct *vma) 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)) if (unlikely(vma->vm_flags & VM_NONLINEAR))
vma_nonlinear_insert(vma, &mapping->i_mmap_nonlinear); vma_nonlinear_insert(vma, &mapping->i_mmap_nonlinear);
else else
vma_prio_tree_insert(vma, &mapping->i_mmap); vma_interval_tree_insert(vma, &mapping->i_mmap);
flush_dcache_mmap_unlock(mapping); 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 * 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) 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 *next = vma->vm_next;
struct vm_area_struct *importer = NULL; struct vm_area_struct *importer = NULL;
struct address_space *mapping = NULL; struct address_space *mapping = NULL;
struct prio_tree_root *root = NULL; struct rb_root *root = NULL;
struct anon_vma *anon_vma = NULL; struct anon_vma *anon_vma = NULL;
struct file *file = vma->vm_file; struct file *file = vma->vm_file;
long adjust_next = 0; long adjust_next = 0;
@ -554,7 +554,7 @@ again: remove_next = 1 + (end > next->vm_end);
mutex_lock(&mapping->i_mmap_mutex); mutex_lock(&mapping->i_mmap_mutex);
if (insert) { 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 * are visible to arm/parisc __flush_dcache_page
* throughout; but we cannot insert into address * throughout; but we cannot insert into address
* space until vma start or end is updated. * space until vma start or end is updated.
@ -582,9 +582,9 @@ again: remove_next = 1 + (end > next->vm_end);
if (root) { if (root) {
flush_dcache_mmap_lock(mapping); flush_dcache_mmap_lock(mapping);
vma_prio_tree_remove(vma, root); vma_interval_tree_remove(vma, root);
if (adjust_next) if (adjust_next)
vma_prio_tree_remove(next, root); vma_interval_tree_remove(next, root);
} }
vma->vm_start = start; vma->vm_start = start;
@ -597,8 +597,8 @@ again: remove_next = 1 + (end > next->vm_end);
if (root) { if (root) {
if (adjust_next) if (adjust_next)
vma_prio_tree_insert(next, root); vma_interval_tree_insert(next, root);
vma_prio_tree_insert(vma, root); vma_interval_tree_insert(vma, root);
flush_dcache_mmap_unlock(mapping); flush_dcache_mmap_unlock(mapping);
} }

10
mm/nommu.c
View file

@ -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); mutex_lock(&mapping->i_mmap_mutex);
flush_dcache_mmap_lock(mapping); 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); flush_dcache_mmap_unlock(mapping);
mutex_unlock(&mapping->i_mmap_mutex); 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); mutex_lock(&mapping->i_mmap_mutex);
flush_dcache_mmap_lock(mapping); 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); flush_dcache_mmap_unlock(mapping);
mutex_unlock(&mapping->i_mmap_mutex); mutex_unlock(&mapping->i_mmap_mutex);
} }
@ -2044,7 +2044,6 @@ int nommu_shrink_inode_mappings(struct inode *inode, size_t size,
size_t newsize) size_t newsize)
{ {
struct vm_area_struct *vma; struct vm_area_struct *vma;
struct prio_tree_iter iter;
struct vm_region *region; struct vm_region *region;
pgoff_t low, high; pgoff_t low, high;
size_t r_size, r_top; 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); mutex_lock(&inode->i_mapping->i_mmap_mutex);
/* search for VMAs that fall within the dead zone */ /* search for VMAs that fall within the dead zone */
vma_prio_tree_foreach(vma, &iter, &inode->i_mapping->i_mmap, vma_interval_tree_foreach(vma, &inode->i_mapping->i_mmap, low, high) {
low, high) {
/* found one - only interested if it's shared out of the page /* found one - only interested if it's shared out of the page
* cache */ * cache */
if (vma->vm_flags & VM_SHARED) { if (vma->vm_flags & VM_SHARED) {
@ -2073,7 +2071,7 @@ 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 * we don't check for any regions that start beyond the EOF as there
* shouldn't be any * shouldn't be any
*/ */
vma_prio_tree_foreach(vma, &iter, &inode->i_mapping->i_mmap, vma_interval_tree_foreach(vma, &inode->i_mapping->i_mmap,
0, ULONG_MAX) { 0, ULONG_MAX) {
if (!(vma->vm_flags & VM_SHARED)) if (!(vma->vm_flags & VM_SHARED))
continue; continue;

208
mm/prio_tree.c
View file

@ -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;
}

18
mm/rmap.c
View file

@ -820,7 +820,6 @@ static int page_referenced_file(struct page *page,
struct address_space *mapping = page->mapping; struct address_space *mapping = page->mapping;
pgoff_t pgoff = page->index << (PAGE_CACHE_SHIFT - PAGE_SHIFT); pgoff_t pgoff = page->index << (PAGE_CACHE_SHIFT - PAGE_SHIFT);
struct vm_area_struct *vma; struct vm_area_struct *vma;
struct prio_tree_iter iter;
int referenced = 0; int referenced = 0;
/* /*
@ -846,7 +845,7 @@ static int page_referenced_file(struct page *page,
*/ */
mapcount = page_mapcount(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); unsigned long address = vma_address(page, vma);
if (address == -EFAULT) if (address == -EFAULT)
continue; 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); pgoff_t pgoff = page->index << (PAGE_CACHE_SHIFT - PAGE_SHIFT);
struct vm_area_struct *vma; struct vm_area_struct *vma;
struct prio_tree_iter iter;
int ret = 0; int ret = 0;
BUG_ON(PageAnon(page)); BUG_ON(PageAnon(page));
mutex_lock(&mapping->i_mmap_mutex); 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) { if (vma->vm_flags & VM_SHARED) {
unsigned long address = vma_address(page, vma); unsigned long address = vma_address(page, vma);
if (address == -EFAULT) 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; struct address_space *mapping = page->mapping;
pgoff_t pgoff = page->index << (PAGE_CACHE_SHIFT - PAGE_SHIFT); pgoff_t pgoff = page->index << (PAGE_CACHE_SHIFT - PAGE_SHIFT);
struct vm_area_struct *vma; struct vm_area_struct *vma;
struct prio_tree_iter iter;
int ret = SWAP_AGAIN; int ret = SWAP_AGAIN;
unsigned long cursor; unsigned long cursor;
unsigned long max_nl_cursor = 0; 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; unsigned int mapcount;
mutex_lock(&mapping->i_mmap_mutex); 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); unsigned long address = vma_address(page, vma);
if (address == -EFAULT) if (address == -EFAULT)
continue; continue;
@ -1576,7 +1573,7 @@ static int try_to_unmap_file(struct page *page, enum ttu_flags flags)
goto out; goto out;
list_for_each_entry(vma, &mapping->i_mmap_nonlinear, list_for_each_entry(vma, &mapping->i_mmap_nonlinear,
shared.vm_set.list) { shared.nonlinear) {
cursor = (unsigned long) vma->vm_private_data; cursor = (unsigned long) vma->vm_private_data;
if (cursor > max_nl_cursor) if (cursor > max_nl_cursor)
max_nl_cursor = cursor; max_nl_cursor = cursor;
@ -1608,7 +1605,7 @@ static int try_to_unmap_file(struct page *page, enum ttu_flags flags)
do { do {
list_for_each_entry(vma, &mapping->i_mmap_nonlinear, list_for_each_entry(vma, &mapping->i_mmap_nonlinear,
shared.vm_set.list) { shared.nonlinear) {
cursor = (unsigned long) vma->vm_private_data; cursor = (unsigned long) vma->vm_private_data;
while ( cursor < max_nl_cursor && while ( cursor < max_nl_cursor &&
cursor < vma->vm_end - vma->vm_start) { 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 * in locked vmas). Reset cursor on all unreserved nonlinear
* vmas, now forgetting on which ones it had fallen behind. * 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; vma->vm_private_data = NULL;
out: out:
mutex_unlock(&mapping->i_mmap_mutex); 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; struct address_space *mapping = page->mapping;
pgoff_t pgoff = page->index << (PAGE_CACHE_SHIFT - PAGE_SHIFT); pgoff_t pgoff = page->index << (PAGE_CACHE_SHIFT - PAGE_SHIFT);
struct vm_area_struct *vma; struct vm_area_struct *vma;
struct prio_tree_iter iter;
int ret = SWAP_AGAIN; int ret = SWAP_AGAIN;
if (!mapping) if (!mapping)
return ret; return ret;
mutex_lock(&mapping->i_mmap_mutex); 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); unsigned long address = vma_address(page, vma);
if (address == -EFAULT) if (address == -EFAULT)
continue; continue;