* [PATCH][RC] radix-tree pagecache for 2.5
@ 2002-04-09 9:47 Christoph Hellwig
2002-04-10 2:32 ` Andrew Morton
0 siblings, 1 reply; 3+ messages in thread
From: Christoph Hellwig @ 2002-04-09 9:47 UTC (permalink / raw)
To: linux-mm, linux-kernel
I think I have a first release candidate of the radix-tree pagecache for
the 2.5 tree. This patch contains the following changes over the last version
- improved OOM handling all over the place (Andrew Morton)
- minor fixes/cleanuos (Andrew Morton, me)
- switch mapping->page_lock to a r/w lock (me)
The patch can be found at:
ftp://ftp.kernel.org/pub/linux/kernel/people/hch/patches/v2.5/2.5.8-pre2/linux-2.5.8-ratcache.patch.gz
ftp://ftp.kernel.org/pub/linux/kernel/people/hch/patches/v2.5/2.5.8-pre2/linux-2.5.8-ratcache.patch.bz2
In addition a BitKeeper tree is available at http://hkernel.bkbits.net.
--
To unsubscribe, send a message with 'unsubscribe linux-mm' in
the body to majordomo@kvack.org. For more info on Linux MM,
see: http://www.linux-mm.org/
^ permalink raw reply [flat|nested] 3+ messages in thread
* Re: [PATCH][RC] radix-tree pagecache for 2.5
2002-04-09 9:47 [PATCH][RC] radix-tree pagecache for 2.5 Christoph Hellwig
@ 2002-04-10 2:32 ` Andrew Morton
2002-04-10 4:07 ` [patch] Velikov/Hellwig radix-tree pagecache Andrew Morton
0 siblings, 1 reply; 3+ messages in thread
From: Andrew Morton @ 2002-04-10 2:32 UTC (permalink / raw)
To: Christoph Hellwig; +Cc: linux-mm, Linus Torvalds
Christoph Hellwig wrote:
>
> I think I have a first release candidate of the radix-tree pagecache for
> the 2.5 tree.
Hi, Christoph.
There are a few places where I believe a write_lock is needed
rather than a read_lock. Places where we hold the lock seemingly
for read, then later on go and modify the tree, or the mapping's
inode lists.
I'll rediff against -pre3, test with the following incremental
patch on the quad and if it survives, pass on to Linus.
I'll add a FIXME at the mempool allocation site too. 512
ratnodes is maybe 300k. We need to justify pinning that
amount of memory... And work out a means of scaling the
pool according to the number of pages in the system...
--- 2.5.8-pre2/mm/vmscan.c~dallocbase-07-new_ratcache_fixes Tue Apr 9 15:39:06 2002
+++ 2.5.8-pre2-akpm/mm/vmscan.c Tue Apr 9 15:39:06 2002
@@ -483,10 +483,10 @@ static int shrink_cache(int nr_pages, zo
* This is the non-racy check for busy page.
*/
if (mapping) {
- read_lock(&mapping->page_lock);
+ write_lock(&mapping->page_lock);
if (is_page_cache_freeable(page))
goto page_freeable;
- read_unlock(&mapping->page_lock);
+ write_unlock(&mapping->page_lock);
}
UnlockPage(page);
page_mapped:
@@ -507,7 +507,7 @@ page_freeable:
* the page is freeable* so not in use by anybody.
*/
if (PageDirty(page)) {
- read_unlock(&mapping->page_lock);
+ write_unlock(&mapping->page_lock);
UnlockPage(page);
continue;
}
@@ -515,12 +515,12 @@ page_freeable:
/* point of no return */
if (likely(!PageSwapCache(page))) {
__remove_inode_page(page);
- read_unlock(&mapping->page_lock);
+ write_unlock(&mapping->page_lock);
} else {
swp_entry_t swap;
swap.val = page->index;
__delete_from_swap_cache(page);
- read_unlock(&mapping->page_lock);
+ write_unlock(&mapping->page_lock);
swap_free(swap);
}
--- 2.5.8-pre2/mm/filemap.c~dallocbase-07-new_ratcache_fixes Tue Apr 9 15:39:06 2002
+++ 2.5.8-pre2-akpm/mm/filemap.c Tue Apr 9 15:39:06 2002
@@ -59,7 +59,7 @@ spinlock_t pagemap_lru_lock __cacheline_
/*
* Remove a page from the page cache and free it. Caller has to make
* sure the page is locked and that nobody else uses it - or that usage
- * is safe.
+ * is safe. The caller must hold a write_lock on the mapping's page_lock.
*/
void __remove_inode_page(struct page *page)
{
@@ -574,6 +574,7 @@ int filemap_fdatawait(struct address_spa
/*
* This adds a page to the page cache, starting out as locked,
* owned by us, but unreferenced, not uptodate and with no errors.
+ * The caller must hold a write_lock on the mapping->page_lock.
*/
static int __add_to_page_cache(struct page *page,
struct address_space *mapping, unsigned long offset)
@@ -874,19 +875,19 @@ struct page * find_or_create_page(struct
if (!page) {
struct page *newpage = alloc_page(gfp_mask);
if (newpage) {
- read_lock(&mapping->page_lock);
+ write_lock(&mapping->page_lock);
page = __find_lock_page(mapping, index);
if (likely(!page)) {
page = newpage;
if (__add_to_page_cache(page, mapping, index)) {
- read_unlock(&mapping->page_lock);
+ write_unlock(&mapping->page_lock);
page_cache_release(page);
page = NULL;
goto out;
}
newpage = NULL;
}
- read_unlock(&mapping->page_lock);
+ write_unlock(&mapping->page_lock);
if (newpage == NULL)
lru_cache_add(page);
else
@@ -1280,13 +1281,13 @@ void do_generic_file_read(struct file *
* Try to find the data in the page cache..
*/
- read_lock(&mapping->page_lock);
+ write_lock(&mapping->page_lock);
page = radix_tree_lookup(&mapping->page_tree, index);
if (!page)
goto no_cached_page;
found_page:
page_cache_get(page);
- read_unlock(&mapping->page_lock);
+ write_unlock(&mapping->page_lock);
if (!Page_Uptodate(page))
goto page_not_up_to_date;
@@ -1380,7 +1381,7 @@ no_cached_page:
* We get here with the page cache lock held.
*/
if (!cached_page) {
- read_unlock(&mapping->page_lock);
+ write_unlock(&mapping->page_lock);
cached_page = page_cache_alloc(mapping);
if (!cached_page) {
desc->error = -ENOMEM;
@@ -1391,7 +1392,7 @@ no_cached_page:
* Somebody may have added the page while we
* dropped the page cache lock. Check for that.
*/
- read_lock(&mapping->page_lock);
+ write_lock(&mapping->page_lock);
page = radix_tree_lookup(&mapping->page_tree, index);
if (page)
goto found_page;
@@ -1401,12 +1402,12 @@ no_cached_page:
* Ok, add the new page to the hash-queues...
*/
if (__add_to_page_cache(cached_page, mapping, index) < 0) {
- read_unlock(&mapping->page_lock);
+ write_unlock(&mapping->page_lock);
desc->error = -ENOMEM;
break;
}
page = cached_page;
- read_unlock(&mapping->page_lock);
+ write_unlock(&mapping->page_lock);
lru_cache_add(page);
cached_page = NULL;
--
To unsubscribe, send a message with 'unsubscribe linux-mm' in
the body to majordomo@kvack.org. For more info on Linux MM,
see: http://www.linux-mm.org/
^ permalink raw reply [flat|nested] 3+ messages in thread
* [patch] Velikov/Hellwig radix-tree pagecache
2002-04-10 2:32 ` Andrew Morton
@ 2002-04-10 4:07 ` Andrew Morton
0 siblings, 0 replies; 3+ messages in thread
From: Andrew Morton @ 2002-04-10 4:07 UTC (permalink / raw)
To: Christoph Hellwig, linux-mm, Linus Torvalds
It was tested for a couple of hours under heavy load, 4 CPU.
It works fine. Here's the rolled-up diff against -pre3.
Before the mempool was added, the VM was getting many, many
0-order allocation failures due to the atomic ratnode
allocations inside swap_out. That monster mempool is
doing its job - drove a 256meg machine a gigabyte into
swap with no ratnode allocation failures at all.
So we do need to trim that pool a bit, and also handle
the case where swap_out fails, and not just keep
pointlessly calling it.
--- 2.5.8-pre3/drivers/block/rd.c~dallocbase-05-new_ratcache Tue Apr 9 20:35:31 2002
+++ 2.5.8-pre3-akpm/drivers/block/rd.c Tue Apr 9 20:35:31 2002
@@ -156,7 +156,6 @@ static int rd_blkdev_pagecache_IO(int rw
do {
int count;
- struct page ** hash;
struct page * page;
char * src, * dst;
int unlock = 0;
@@ -166,8 +165,7 @@ static int rd_blkdev_pagecache_IO(int rw
count = size;
size -= count;
- hash = page_hash(mapping, index);
- page = __find_get_page(mapping, index, hash);
+ page = find_get_page(mapping, index);
if (!page) {
page = grab_cache_page(mapping, index);
err = -ENOMEM;
--- 2.5.8-pre3/fs/inode.c~dallocbase-05-new_ratcache Tue Apr 9 20:35:31 2002
+++ 2.5.8-pre3-akpm/fs/inode.c Tue Apr 9 20:35:31 2002
@@ -143,6 +143,8 @@ void inode_init_once(struct inode *inode
INIT_LIST_HEAD(&inode->i_dirty_data_buffers);
INIT_LIST_HEAD(&inode->i_devices);
sema_init(&inode->i_sem, 1);
+ INIT_RADIX_TREE(&inode->i_data.page_tree, GFP_ATOMIC);
+ rwlock_init(&inode->i_data.page_lock);
spin_lock_init(&inode->i_data.i_shared_lock);
INIT_LIST_HEAD(&inode->i_data.i_mmap);
INIT_LIST_HEAD(&inode->i_data.i_mmap_shared);
--- 2.5.8-pre3/include/linux/fs.h~dallocbase-05-new_ratcache Tue Apr 9 20:35:31 2002
+++ 2.5.8-pre3-akpm/include/linux/fs.h Tue Apr 9 20:35:31 2002
@@ -21,6 +21,7 @@
#include <linux/cache.h>
#include <linux/stddef.h>
#include <linux/string.h>
+#include <linux/radix-tree.h>
#include <asm/atomic.h>
#include <asm/bitops.h>
@@ -370,6 +371,8 @@ struct address_space_operations {
};
struct address_space {
+ struct radix_tree_root page_tree; /* radix tree of all pages */
+ rwlock_t page_lock; /* and rwlock protecting it */
struct list_head clean_pages; /* list of clean pages */
struct list_head dirty_pages; /* list of dirty pages */
struct list_head locked_pages; /* list of locked pages */
--- 2.5.8-pre3/include/linux/mm.h~dallocbase-05-new_ratcache Tue Apr 9 20:35:31 2002
+++ 2.5.8-pre3-akpm/include/linux/mm.h Tue Apr 9 20:35:31 2002
@@ -149,14 +149,11 @@ typedef struct page {
struct list_head list; /* ->mapping has some page lists. */
struct address_space *mapping; /* The inode (or ...) we belong to. */
unsigned long index; /* Our offset within mapping. */
- struct page *next_hash; /* Next page sharing our hash bucket in
- the pagecache hash table. */
atomic_t count; /* Usage count, see below. */
unsigned long flags; /* atomic flags, some possibly
updated asynchronously */
struct list_head lru; /* Pageout list, eg. active_list;
protected by pagemap_lru_lock !! */
- struct page **pprev_hash; /* Complement to *next_hash. */
struct buffer_head * buffers; /* Buffer maps us to a disk block. */
/*
@@ -236,9 +233,8 @@ typedef struct page {
* using the page->list list_head. These fields are also used for
* freelist managemet (when page->count==0).
*
- * There is also a hash table mapping (mapping,index) to the page
- * in memory if present. The lists for this hash table use the fields
- * page->next_hash and page->pprev_hash.
+ * There is also a per-mapping radix tree mapping index to the page
+ * in memory if present. The tree is rooted at mapping->root.
*
* All process pages can do I/O:
* - inode pages may need to be read from disk,
--- 2.5.8-pre3/include/linux/pagemap.h~dallocbase-05-new_ratcache Tue Apr 9 20:35:31 2002
+++ 2.5.8-pre3-akpm/include/linux/pagemap.h Tue Apr 9 20:35:31 2002
@@ -41,53 +41,39 @@ static inline struct page *page_cache_al
*/
#define page_cache_entry(x) virt_to_page(x)
-extern unsigned int page_hash_bits;
-#define PAGE_HASH_BITS (page_hash_bits)
-#define PAGE_HASH_SIZE (1 << PAGE_HASH_BITS)
-
-extern atomic_t page_cache_size; /* # of pages currently in the hash table */
-extern struct page **page_hash_table;
-
-extern void page_cache_init(unsigned long);
-
-/*
- * We use a power-of-two hash table to avoid a modulus,
- * and get a reasonable hash by knowing roughly how the
- * inode pointer and indexes are distributed (ie, we
- * roughly know which bits are "significant")
- *
- * For the time being it will work for struct address_space too (most of
- * them sitting inside the inodes). We might want to change it later.
- */
-static inline unsigned long _page_hashfn(struct address_space * mapping, unsigned long index)
-{
-#define i (((unsigned long) mapping)/(sizeof(struct inode) & ~ (sizeof(struct inode) - 1)))
-#define s(x) ((x)+((x)>>PAGE_HASH_BITS))
- return s(i+index) & (PAGE_HASH_SIZE-1);
-#undef i
-#undef s
-}
+extern atomic_t page_cache_size; /* # of pages currently in the page cache */
-#define page_hash(mapping,index) (page_hash_table+_page_hashfn(mapping,index))
-
-extern struct page * __find_get_page(struct address_space *mapping,
- unsigned long index, struct page **hash);
-#define find_get_page(mapping, index) \
- __find_get_page(mapping, index, page_hash(mapping, index))
-extern struct page * __find_lock_page (struct address_space * mapping,
- unsigned long index, struct page **hash);
+extern struct page * find_get_page(struct address_space *mapping,
+ unsigned long index);
+extern struct page * find_lock_page(struct address_space *mapping,
+ unsigned long index);
+extern struct page * find_trylock_page(struct address_space *mapping,
+ unsigned long index);
extern struct page * find_or_create_page(struct address_space *mapping,
unsigned long index, unsigned int gfp_mask);
+extern struct page * grab_cache_page(struct address_space *mapping,
+ unsigned long index);
+extern struct page * grab_cache_page_nowait(struct address_space *mapping,
+ unsigned long index);
+
+extern int add_to_page_cache(struct page *page,
+ struct address_space *mapping, unsigned long index);
+extern int add_to_page_cache_unique(struct page *page,
+ struct address_space *mapping, unsigned long index);
+static inline void ___add_to_page_cache(struct page *page,
+ struct address_space *mapping, unsigned long index)
+{
+ list_add(&page->list, &mapping->clean_pages);
+ page->mapping = mapping;
+ page->index = index;
+
+ mapping->nrpages++;
+ atomic_inc(&page_cache_size);
+}
+
extern void FASTCALL(lock_page(struct page *page));
extern void FASTCALL(unlock_page(struct page *page));
-#define find_lock_page(mapping, index) \
- __find_lock_page(mapping, index, page_hash(mapping, index))
-extern struct page *find_trylock_page(struct address_space *, unsigned long);
-
-extern void add_to_page_cache(struct page * page, struct address_space *mapping, unsigned long index);
-extern void add_to_page_cache_locked(struct page * page, struct address_space *mapping, unsigned long index);
-extern int add_to_page_cache_unique(struct page * page, struct address_space *mapping, unsigned long index, struct page **hash);
extern void ___wait_on_page(struct page *);
@@ -99,9 +85,6 @@ static inline void wait_on_page(struct p
extern void wake_up_page(struct page *);
-extern struct page * grab_cache_page (struct address_space *, unsigned long);
-extern struct page * grab_cache_page_nowait (struct address_space *, unsigned long);
-
typedef int filler_t(void *, struct page*);
extern struct page *read_cache_page(struct address_space *, unsigned long,
--- /dev/null Thu Aug 30 13:30:55 2001
+++ 2.5.8-pre3-akpm/include/linux/radix-tree.h Tue Apr 9 20:35:31 2002
@@ -0,0 +1,49 @@
+/*
+ * Copyright (C) 2001 Momchil Velikov
+ * Portions Copyright (C) 2001 Christoph Hellwig
+ *
+ * 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, 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., 675 Mass Ave, Cambridge, MA 02139, USA.
+ */
+#ifndef _LINUX_RADIX_TREE_H
+#define _LINUX_RADIX_TREE_H
+
+struct radix_tree_node;
+
+#define RADIX_TREE_SLOT_RESERVED ((void *)~0UL)
+
+struct radix_tree_root {
+ unsigned int height;
+ int gfp_mask;
+ struct radix_tree_node *rnode;
+};
+
+#define RADIX_TREE_INIT(mask) {0, (mask), NULL}
+
+#define RADIX_TREE(name, mask) \
+ struct radix_tree_root name = RADIX_TREE_INIT(mask)
+
+#define INIT_RADIX_TREE(root, mask) \
+do { \
+ (root)->height = 0; \
+ (root)->gfp_mask = (mask); \
+ (root)->rnode = NULL; \
+} while (0)
+
+extern int radix_tree_reserve(struct radix_tree_root *, unsigned long, void ***);
+extern int radix_tree_insert(struct radix_tree_root *, unsigned long, void *);
+extern void *radix_tree_lookup(struct radix_tree_root *, unsigned long);
+extern int radix_tree_delete(struct radix_tree_root *, unsigned long);
+
+#endif /* _LINUX_RADIX_TREE_H */
--- 2.5.8-pre3/include/linux/swap.h~dallocbase-05-new_ratcache Tue Apr 9 20:35:31 2002
+++ 2.5.8-pre3-akpm/include/linux/swap.h Tue Apr 9 20:35:31 2002
@@ -109,7 +109,7 @@ extern void __remove_inode_page(struct p
struct task_struct;
struct vm_area_struct;
struct sysinfo;
-
+struct address_space;
struct zone_t;
/* linux/mm/swap.c */
@@ -139,6 +139,9 @@ extern void show_swap_cache_info(void);
extern int add_to_swap_cache(struct page *, swp_entry_t);
extern void __delete_from_swap_cache(struct page *page);
extern void delete_from_swap_cache(struct page *page);
+extern int move_to_swap_cache(struct page *page, swp_entry_t entry);
+extern int move_from_swap_cache(struct page *page, unsigned long index,
+ struct address_space *mapping);
extern void free_page_and_swap_cache(struct page *page);
extern struct page * lookup_swap_cache(swp_entry_t);
extern struct page * read_swap_cache_async(swp_entry_t);
--- 2.5.8-pre3/init/main.c~dallocbase-05-new_ratcache Tue Apr 9 20:35:31 2002
+++ 2.5.8-pre3-akpm/init/main.c Tue Apr 9 20:35:31 2002
@@ -69,6 +69,7 @@ extern void sbus_init(void);
extern void sysctl_init(void);
extern void signals_init(void);
+extern void radix_tree_init(void);
extern void free_initmem(void);
#ifdef CONFIG_TC
@@ -392,7 +393,7 @@ asmlinkage void __init start_kernel(void
proc_caches_init();
vfs_caches_init(mempages);
buffer_init(mempages);
- page_cache_init(mempages);
+ radix_tree_init();
#if defined(CONFIG_ARCH_S390)
ccwcache_init();
#endif
--- 2.5.8-pre3/kernel/ksyms.c~dallocbase-05-new_ratcache Tue Apr 9 20:35:31 2002
+++ 2.5.8-pre3-akpm/kernel/ksyms.c Tue Apr 9 20:35:31 2002
@@ -224,8 +224,6 @@ EXPORT_SYMBOL(generic_file_write);
EXPORT_SYMBOL(generic_file_mmap);
EXPORT_SYMBOL(generic_ro_fops);
EXPORT_SYMBOL(generic_buffer_fdatasync);
-EXPORT_SYMBOL(page_hash_bits);
-EXPORT_SYMBOL(page_hash_table);
EXPORT_SYMBOL(file_lock_list);
EXPORT_SYMBOL(locks_init_lock);
EXPORT_SYMBOL(locks_copy_lock);
@@ -266,8 +264,8 @@ EXPORT_SYMBOL(no_llseek);
EXPORT_SYMBOL(__pollwait);
EXPORT_SYMBOL(poll_freewait);
EXPORT_SYMBOL(ROOT_DEV);
-EXPORT_SYMBOL(__find_get_page);
-EXPORT_SYMBOL(__find_lock_page);
+EXPORT_SYMBOL(find_get_page);
+EXPORT_SYMBOL(find_lock_page);
EXPORT_SYMBOL(grab_cache_page);
EXPORT_SYMBOL(grab_cache_page_nowait);
EXPORT_SYMBOL(read_cache_page);
--- 2.5.8-pre3/lib/Makefile~dallocbase-05-new_ratcache Tue Apr 9 20:35:31 2002
+++ 2.5.8-pre3-akpm/lib/Makefile Tue Apr 9 20:35:31 2002
@@ -8,9 +8,11 @@
L_TARGET := lib.a
-export-objs := cmdline.o dec_and_lock.o rwsem-spinlock.o rwsem.o crc32.o rbtree.o
+export-objs := cmdline.o dec_and_lock.o rwsem-spinlock.o rwsem.o \
+ crc32.o rbtree.o radix-tree.o
-obj-y := errno.o ctype.o string.o vsprintf.o brlock.o cmdline.o bust_spinlocks.o rbtree.o
+obj-y := errno.o ctype.o string.o vsprintf.o brlock.o cmdline.o \
+ bust_spinlocks.o rbtree.o radix-tree.o
obj-$(CONFIG_RWSEM_GENERIC_SPINLOCK) += rwsem-spinlock.o
obj-$(CONFIG_RWSEM_XCHGADD_ALGORITHM) += rwsem.o
--- /dev/null Thu Aug 30 13:30:55 2001
+++ 2.5.8-pre3-akpm/lib/radix-tree.c Tue Apr 9 20:35:31 2002
@@ -0,0 +1,296 @@
+/*
+ * Copyright (C) 2001 Momchil Velikov
+ * Portions Copyright (C) 2001 Christoph Hellwig
+ *
+ * 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, 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., 675 Mass Ave, Cambridge, MA 02139, USA.
+ */
+
+#include <linux/errno.h>
+#include <linux/init.h>
+#include <linux/kernel.h>
+#include <linux/mempool.h>
+#include <linux/module.h>
+#include <linux/radix-tree.h>
+#include <linux/slab.h>
+
+/*
+ * Radix tree node definition.
+ */
+#define RADIX_TREE_MAP_SHIFT 7
+#define RADIX_TREE_MAP_SIZE (1UL << RADIX_TREE_MAP_SHIFT)
+#define RADIX_TREE_MAP_MASK (RADIX_TREE_MAP_SIZE-1)
+
+struct radix_tree_node {
+ unsigned int count;
+ void *slots[RADIX_TREE_MAP_SIZE];
+};
+
+struct radix_tree_path {
+ struct radix_tree_node *node, **slot;
+};
+
+#define RADIX_TREE_INDEX_BITS (8 /* CHAR_BIT */ * sizeof(unsigned long))
+
+/*
+ * Radix tree node cache.
+ */
+static kmem_cache_t *radix_tree_node_cachep;
+static mempool_t *radix_tree_node_pool;
+
+#define radix_tree_node_alloc(root) \
+ mempool_alloc(radix_tree_node_pool, (root)->gfp_mask)
+#define radix_tree_node_free(node) \
+ mempool_free((node), radix_tree_node_pool);
+
+
+/*
+ * Return the maximum key which can be store into a
+ * radix tree with height HEIGHT.
+ */
+static inline unsigned long radix_tree_maxindex(unsigned int height)
+{
+ unsigned int tmp = height * RADIX_TREE_MAP_SHIFT;
+ unsigned long index = (~0UL >> (RADIX_TREE_INDEX_BITS - tmp - 1)) >> 1;
+
+ if (tmp >= RADIX_TREE_INDEX_BITS)
+ index = ~0UL;
+ return index;
+}
+
+
+/*
+ * Extend a radix tree so it can store key @index.
+ */
+static int radix_tree_extend(struct radix_tree_root *root, unsigned long index)
+{
+ struct radix_tree_node *node;
+ unsigned int height;
+
+ /* Figure out what the height should be. */
+ height = root->height + 1;
+ while (index > radix_tree_maxindex(height))
+ height++;
+
+ if (root->rnode) {
+ do {
+ if (!(node = radix_tree_node_alloc(root)))
+ return -ENOMEM;
+
+ /* Increase the height. */
+ node->slots[0] = root->rnode;
+ if (root->rnode)
+ node->count = 1;
+ root->rnode = node;
+ root->height++;
+ } while (height > root->height);
+ } else
+ root->height = height;
+
+ return 0;
+}
+
+
+/**
+ * radix_tree_reserve - reserve space in a radix tree
+ * @root: radix tree root
+ * @index: index key
+ * @pslot: pointer to reserved slot
+ *
+ * Reserve a slot in a radix tree for the key @index.
+ */
+int radix_tree_reserve(struct radix_tree_root *root, unsigned long index, void ***pslot)
+{
+ struct radix_tree_node *node = NULL, *tmp, **slot;
+ unsigned int height, shift;
+ int error;
+
+ /* Make sure the tree is high enough. */
+ if (index > radix_tree_maxindex(root->height)) {
+ error = radix_tree_extend(root, index);
+ if (error)
+ return error;
+ }
+
+ slot = &root->rnode;
+ height = root->height;
+ shift = (height-1) * RADIX_TREE_MAP_SHIFT;
+
+ while (height > 0) {
+ if (*slot == NULL) {
+ /* Have to add a child node. */
+ if (!(tmp = radix_tree_node_alloc(root)))
+ return -ENOMEM;
+ *slot = tmp;
+ if (node)
+ node->count++;
+ }
+
+ /* Go a level down. */
+ node = *slot;
+ slot = (struct radix_tree_node **)
+ (node->slots + ((index >> shift) & RADIX_TREE_MAP_MASK));
+ shift -= RADIX_TREE_MAP_SHIFT;
+ height--;
+ }
+
+ if (*slot != NULL)
+ return -EEXIST;
+ if (node)
+ node->count++;
+
+ *pslot = (void **)slot;
+ **pslot = RADIX_TREE_SLOT_RESERVED;
+ return 0;
+}
+
+EXPORT_SYMBOL(radix_tree_reserve);
+
+
+/**
+ * radix_tree_insert - insert into a radix tree
+ * @root: radix tree root
+ * @index: index key
+ * @item: item to insert
+ *
+ * Insert an item into the radix tree at position @index.
+ */
+int radix_tree_insert(struct radix_tree_root *root, unsigned long index, void *item)
+{
+ void **slot;
+ int error;
+
+ error = radix_tree_reserve(root, index, &slot);
+ if (!error)
+ *slot = item;
+ return error;
+}
+
+EXPORT_SYMBOL(radix_tree_insert);
+
+
+/**
+ * radix_tree_lookup - perform lookup operation on a radix tree
+ * @root: radix tree root
+ * @index: index key
+ *
+ * Lookup them item at the position @index in the radix tree @root.
+ */
+void *radix_tree_lookup(struct radix_tree_root *root, unsigned long index)
+{
+ unsigned int height, shift;
+ struct radix_tree_node **slot;
+
+ height = root->height;
+ if (index > radix_tree_maxindex(height))
+ return NULL;
+
+ shift = (height-1) * RADIX_TREE_MAP_SHIFT;
+ slot = &root->rnode;
+
+ while (height > 0) {
+ if (*slot == NULL)
+ return NULL;
+
+ slot = (struct radix_tree_node **)
+ ((*slot)->slots + ((index >> shift) & RADIX_TREE_MAP_MASK));
+ shift -= RADIX_TREE_MAP_SHIFT;
+ height--;
+ }
+
+ return (void *) *slot;
+}
+
+EXPORT_SYMBOL(radix_tree_lookup);
+
+
+/**
+ * radix_tree_delete - delete an item from a radix tree
+ * @root: radix tree root
+ * @index: index key
+ *
+ * Remove the item at @index from the radix tree rooted at @root.
+ */
+int radix_tree_delete(struct radix_tree_root *root, unsigned long index)
+{
+ struct radix_tree_path path[RADIX_TREE_INDEX_BITS/RADIX_TREE_MAP_SHIFT + 2], *pathp = path;
+ unsigned int height, shift;
+
+ height = root->height;
+ if (index > radix_tree_maxindex(height))
+ return -ENOENT;
+
+ shift = (height-1) * RADIX_TREE_MAP_SHIFT;
+ pathp->node = NULL;
+ pathp->slot = &root->rnode;
+
+ while (height > 0) {
+ if (*pathp->slot == NULL)
+ return -ENOENT;
+
+ pathp[1].node = *pathp[0].slot;
+ pathp[1].slot = (struct radix_tree_node **)
+ (pathp[1].node->slots + ((index >> shift) & RADIX_TREE_MAP_MASK));
+ pathp++;
+ shift -= RADIX_TREE_MAP_SHIFT;
+ height--;
+ }
+
+ if (*pathp[0].slot == NULL)
+ return -ENOENT;
+
+ *pathp[0].slot = NULL;
+ while (pathp[0].node && --pathp[0].node->count == 0) {
+ pathp--;
+ *pathp[0].slot = NULL;
+ radix_tree_node_free(pathp[1].node);
+ }
+
+ return 0;
+}
+
+EXPORT_SYMBOL(radix_tree_delete);
+
+static void radix_tree_node_ctor(void *node, kmem_cache_t *cachep, unsigned long flags)
+{
+ memset(node, 0, sizeof(struct radix_tree_node));
+}
+
+static void *radix_tree_node_pool_alloc(int gfp_mask, void *data)
+{
+ return kmem_cache_alloc(radix_tree_node_cachep, gfp_mask);
+}
+
+static void radix_tree_node_pool_free(void *node, void *data)
+{
+ kmem_cache_free(radix_tree_node_cachep, node);
+}
+
+/*
+ * FIXME! 512 nodes is 200-300k of memory. This needs to be
+ * scaled by the amount of available memory, and hopefully
+ * reduced also.
+ */
+void __init radix_tree_init(void)
+{
+ radix_tree_node_cachep = kmem_cache_create("radix_tree_node",
+ sizeof(struct radix_tree_node), 0,
+ SLAB_HWCACHE_ALIGN, radix_tree_node_ctor, NULL);
+ if (!radix_tree_node_cachep)
+ panic ("Failed to create radix_tree_node cache\n");
+ radix_tree_node_pool = mempool_create(512, radix_tree_node_pool_alloc,
+ radix_tree_node_pool_free, NULL);
+ if (!radix_tree_node_pool)
+ panic ("Failed to create radix_tree_node pool\n");
+}
--- 2.5.8-pre3/mm/filemap.c~dallocbase-05-new_ratcache Tue Apr 9 20:35:31 2002
+++ 2.5.8-pre3-akpm/mm/filemap.c Tue Apr 9 20:35:43 2002
@@ -46,89 +46,46 @@
*/
atomic_t page_cache_size = ATOMIC_INIT(0);
-unsigned int page_hash_bits;
-struct page **page_hash_table;
-spinlock_t pagecache_lock __cacheline_aligned_in_smp = SPIN_LOCK_UNLOCKED;
/*
- * NOTE: to avoid deadlocking you must never acquire the pagemap_lru_lock
- * with the pagecache_lock held.
- *
- * Ordering:
- * swap_lock ->
- * pagemap_lru_lock ->
- * pagecache_lock
+ * Lock ordering:
+ * pagemap_lru_lock ==> page_lock ==> i_shared_lock
*/
spinlock_t pagemap_lru_lock __cacheline_aligned_in_smp = SPIN_LOCK_UNLOCKED;
#define CLUSTER_PAGES (1 << page_cluster)
#define CLUSTER_OFFSET(x) (((x) >> page_cluster) << page_cluster)
-static void FASTCALL(add_page_to_hash_queue(struct page * page, struct page **p));
-static void add_page_to_hash_queue(struct page * page, struct page **p)
-{
- struct page *next = *p;
-
- *p = page;
- page->next_hash = next;
- page->pprev_hash = p;
- if (next)
- next->pprev_hash = &page->next_hash;
- if (page->buffers)
- PAGE_BUG(page);
- atomic_inc(&page_cache_size);
-}
-
-static inline void add_page_to_inode_queue(struct address_space *mapping, struct page * page)
+/*
+ * Remove a page from the page cache and free it. Caller has to make
+ * sure the page is locked and that nobody else uses it - or that usage
+ * is safe. The caller must hold a write_lock on the mapping's page_lock.
+ */
+void __remove_inode_page(struct page *page)
{
- struct list_head *head = &mapping->clean_pages;
-
- mapping->nrpages++;
- list_add(&page->list, head);
- page->mapping = mapping;
-}
+ struct address_space *mapping = page->mapping;
-static inline void remove_page_from_inode_queue(struct page * page)
-{
- struct address_space * mapping = page->mapping;
+ if (unlikely(PageDirty(page)))
+ BUG();
- mapping->nrpages--;
+ radix_tree_delete(&page->mapping->page_tree, page->index);
list_del(&page->list);
page->mapping = NULL;
-}
-
-static inline void remove_page_from_hash_queue(struct page * page)
-{
- struct page *next = page->next_hash;
- struct page **pprev = page->pprev_hash;
- if (next)
- next->pprev_hash = pprev;
- *pprev = next;
- page->pprev_hash = NULL;
+ mapping->nrpages--;
atomic_dec(&page_cache_size);
}
-/*
- * Remove a page from the page cache and free it. Caller has to make
- * sure the page is locked and that nobody else uses it - or that usage
- * is safe.
- */
-void __remove_inode_page(struct page *page)
-{
- if (PageDirty(page)) BUG();
- remove_page_from_inode_queue(page);
- remove_page_from_hash_queue(page);
-}
-
void remove_inode_page(struct page *page)
{
- if (!PageLocked(page))
+ struct address_space *mapping = page->mapping;
+
+ if (unlikely(!PageLocked(page)))
PAGE_BUG(page);
- spin_lock(&pagecache_lock);
+ write_lock(&mapping->page_lock);
__remove_inode_page(page);
- spin_unlock(&pagecache_lock);
+ write_unlock(&mapping->page_lock);
}
static inline int sync_page(struct page *page)
@@ -149,10 +106,10 @@ void set_page_dirty(struct page *page)
struct address_space *mapping = page->mapping;
if (mapping) {
- spin_lock(&pagecache_lock);
+ write_lock(&mapping->page_lock);
list_del(&page->list);
list_add(&page->list, &mapping->dirty_pages);
- spin_unlock(&pagecache_lock);
+ write_unlock(&mapping->page_lock);
if (mapping->host)
mark_inode_dirty_pages(mapping->host);
@@ -172,11 +129,12 @@ void invalidate_inode_pages(struct inode
{
struct list_head *head, *curr;
struct page * page;
+ struct address_space *mapping = inode->i_mapping;
- head = &inode->i_mapping->clean_pages;
+ head = &mapping->clean_pages;
spin_lock(&pagemap_lru_lock);
- spin_lock(&pagecache_lock);
+ write_lock(&mapping->page_lock);
curr = head->next;
while (curr != head) {
@@ -207,7 +165,7 @@ unlock:
continue;
}
- spin_unlock(&pagecache_lock);
+ write_unlock(&mapping->page_lock);
spin_unlock(&pagemap_lru_lock);
}
@@ -246,8 +204,8 @@ static void truncate_complete_page(struc
page_cache_release(page);
}
-static int FASTCALL(truncate_list_pages(struct list_head *, unsigned long, unsigned *));
-static int truncate_list_pages(struct list_head *head, unsigned long start, unsigned *partial)
+static int truncate_list_pages(struct address_space *mapping,
+ struct list_head *head, unsigned long start, unsigned *partial)
{
struct list_head *curr;
struct page * page;
@@ -276,7 +234,7 @@ static int truncate_list_pages(struct li
/* Restart on this page */
list_add(head, curr);
- spin_unlock(&pagecache_lock);
+ write_unlock(&mapping->page_lock);
unlocked = 1;
if (!failed) {
@@ -297,7 +255,7 @@ static int truncate_list_pages(struct li
schedule();
}
- spin_lock(&pagecache_lock);
+ write_lock(&mapping->page_lock);
goto restart;
}
curr = curr->prev;
@@ -321,24 +279,28 @@ void truncate_inode_pages(struct address
unsigned partial = lstart & (PAGE_CACHE_SIZE - 1);
int unlocked;
- spin_lock(&pagecache_lock);
+ write_lock(&mapping->page_lock);
do {
- unlocked = truncate_list_pages(&mapping->clean_pages, start, &partial);
- unlocked |= truncate_list_pages(&mapping->dirty_pages, start, &partial);
- unlocked |= truncate_list_pages(&mapping->locked_pages, start, &partial);
+ unlocked = truncate_list_pages(mapping,
+ &mapping->clean_pages, start, &partial);
+ unlocked |= truncate_list_pages(mapping,
+ &mapping->dirty_pages, start, &partial);
+ unlocked |= truncate_list_pages(mapping,
+ &mapping->locked_pages, start, &partial);
} while (unlocked);
/* Traversed all three lists without dropping the lock */
- spin_unlock(&pagecache_lock);
+ write_unlock(&mapping->page_lock);
}
-static inline int invalidate_this_page2(struct page * page,
+static inline int invalidate_this_page2(struct address_space * mapping,
+ struct page * page,
struct list_head * curr,
struct list_head * head)
{
int unlocked = 1;
/*
- * The page is locked and we hold the pagecache_lock as well
+ * The page is locked and we hold the mapping lock as well
* so both page_count(page) and page->buffers stays constant here.
*/
if (page_count(page) == 1 + !!page->buffers) {
@@ -347,7 +309,7 @@ static inline int invalidate_this_page2(
list_add_tail(head, curr);
page_cache_get(page);
- spin_unlock(&pagecache_lock);
+ write_unlock(&mapping->page_lock);
truncate_complete_page(page);
} else {
if (page->buffers) {
@@ -356,7 +318,7 @@ static inline int invalidate_this_page2(
list_add_tail(head, curr);
page_cache_get(page);
- spin_unlock(&pagecache_lock);
+ write_unlock(&mapping->page_lock);
block_invalidate_page(page);
} else
unlocked = 0;
@@ -368,8 +330,8 @@ static inline int invalidate_this_page2(
return unlocked;
}
-static int FASTCALL(invalidate_list_pages2(struct list_head *));
-static int invalidate_list_pages2(struct list_head *head)
+static int invalidate_list_pages2(struct address_space * mapping,
+ struct list_head * head)
{
struct list_head *curr;
struct page * page;
@@ -383,7 +345,7 @@ static int invalidate_list_pages2(struct
if (!TryLockPage(page)) {
int __unlocked;
- __unlocked = invalidate_this_page2(page, curr, head);
+ __unlocked = invalidate_this_page2(mapping, page, curr, head);
UnlockPage(page);
unlocked |= __unlocked;
if (!__unlocked) {
@@ -396,7 +358,7 @@ static int invalidate_list_pages2(struct
list_add(head, curr);
page_cache_get(page);
- spin_unlock(&pagecache_lock);
+ write_unlock(&mapping->page_lock);
unlocked = 1;
wait_on_page(page);
}
@@ -407,7 +369,7 @@ static int invalidate_list_pages2(struct
schedule();
}
- spin_lock(&pagecache_lock);
+ write_lock(&mapping->page_lock);
goto restart;
}
return unlocked;
@@ -422,41 +384,27 @@ void invalidate_inode_pages2(struct addr
{
int unlocked;
- spin_lock(&pagecache_lock);
+ write_lock(&mapping->page_lock);
do {
- unlocked = invalidate_list_pages2(&mapping->clean_pages);
- unlocked |= invalidate_list_pages2(&mapping->dirty_pages);
- unlocked |= invalidate_list_pages2(&mapping->locked_pages);
+ unlocked = invalidate_list_pages2(mapping,
+ &mapping->clean_pages);
+ unlocked |= invalidate_list_pages2(mapping,
+ &mapping->dirty_pages);
+ unlocked |= invalidate_list_pages2(mapping,
+ &mapping->locked_pages);
} while (unlocked);
- spin_unlock(&pagecache_lock);
+ write_unlock(&mapping->page_lock);
}
-static inline struct page * __find_page_nolock(struct address_space *mapping, unsigned long offset, struct page *page)
-{
- goto inside;
-
- for (;;) {
- page = page->next_hash;
-inside:
- if (!page)
- goto not_found;
- if (page->mapping != mapping)
- continue;
- if (page->index == offset)
- break;
- }
-
-not_found:
- return page;
-}
-
-static int do_buffer_fdatasync(struct list_head *head, unsigned long start, unsigned long end, int (*fn)(struct page *))
+static int do_buffer_fdatasync(struct address_space *mapping,
+ struct list_head *head, unsigned long start,
+ unsigned long end, int (*fn)(struct page *))
{
struct list_head *curr;
struct page *page;
int retval = 0;
- spin_lock(&pagecache_lock);
+ write_lock(&mapping->page_lock);
curr = head->next;
while (curr != head) {
page = list_entry(curr, struct page, list);
@@ -469,7 +417,7 @@ static int do_buffer_fdatasync(struct li
continue;
page_cache_get(page);
- spin_unlock(&pagecache_lock);
+ write_unlock(&mapping->page_lock);
lock_page(page);
/* The buffers could have been free'd while we waited for the page lock */
@@ -477,11 +425,11 @@ static int do_buffer_fdatasync(struct li
retval |= fn(page);
UnlockPage(page);
- spin_lock(&pagecache_lock);
+ write_lock(&mapping->page_lock);
curr = page->list.next;
page_cache_release(page);
}
- spin_unlock(&pagecache_lock);
+ write_unlock(&mapping->page_lock);
return retval;
}
@@ -492,17 +440,24 @@ static int do_buffer_fdatasync(struct li
*/
int generic_buffer_fdatasync(struct inode *inode, unsigned long start_idx, unsigned long end_idx)
{
+ struct address_space *mapping = inode->i_mapping;
int retval;
/* writeout dirty buffers on pages from both clean and dirty lists */
- retval = do_buffer_fdatasync(&inode->i_mapping->dirty_pages, start_idx, end_idx, writeout_one_page);
- retval |= do_buffer_fdatasync(&inode->i_mapping->clean_pages, start_idx, end_idx, writeout_one_page);
- retval |= do_buffer_fdatasync(&inode->i_mapping->locked_pages, start_idx, end_idx, writeout_one_page);
+ retval = do_buffer_fdatasync(mapping, &mapping->dirty_pages,
+ start_idx, end_idx, writeout_one_page);
+ retval |= do_buffer_fdatasync(mapping, &mapping->clean_pages,
+ start_idx, end_idx, writeout_one_page);
+ retval |= do_buffer_fdatasync(mapping, &mapping->locked_pages,
+ start_idx, end_idx, writeout_one_page);
/* now wait for locked buffers on pages from both clean and dirty lists */
- retval |= do_buffer_fdatasync(&inode->i_mapping->dirty_pages, start_idx, end_idx, waitfor_one_page);
- retval |= do_buffer_fdatasync(&inode->i_mapping->clean_pages, start_idx, end_idx, waitfor_one_page);
- retval |= do_buffer_fdatasync(&inode->i_mapping->locked_pages, start_idx, end_idx, waitfor_one_page);
+ retval |= do_buffer_fdatasync(mapping, &mapping->dirty_pages,
+ start_idx, end_idx, waitfor_one_page);
+ retval |= do_buffer_fdatasync(mapping, &mapping->clean_pages,
+ start_idx, end_idx, waitfor_one_page);
+ retval |= do_buffer_fdatasync(mapping, &mapping->locked_pages,
+ start_idx, end_idx, waitfor_one_page);
return retval;
}
@@ -548,7 +503,7 @@ int filemap_fdatasync(struct address_spa
int ret = 0;
int (*writepage)(struct page *) = mapping->a_ops->writepage;
- spin_lock(&pagecache_lock);
+ write_lock(&mapping->page_lock);
while (!list_empty(&mapping->dirty_pages)) {
struct page *page = list_entry(mapping->dirty_pages.prev, struct page, list);
@@ -560,7 +515,7 @@ int filemap_fdatasync(struct address_spa
continue;
page_cache_get(page);
- spin_unlock(&pagecache_lock);
+ write_unlock(&mapping->page_lock);
lock_page(page);
@@ -574,9 +529,9 @@ int filemap_fdatasync(struct address_spa
UnlockPage(page);
page_cache_release(page);
- spin_lock(&pagecache_lock);
+ write_lock(&mapping->page_lock);
}
- spin_unlock(&pagecache_lock);
+ write_unlock(&mapping->page_lock);
return ret;
}
@@ -591,7 +546,7 @@ int filemap_fdatawait(struct address_spa
{
int ret = 0;
- spin_lock(&pagecache_lock);
+ write_lock(&mapping->page_lock);
while (!list_empty(&mapping->locked_pages)) {
struct page *page = list_entry(mapping->locked_pages.next, struct page, list);
@@ -603,86 +558,69 @@ int filemap_fdatawait(struct address_spa
continue;
page_cache_get(page);
- spin_unlock(&pagecache_lock);
+ write_unlock(&mapping->page_lock);
___wait_on_page(page);
if (PageError(page))
ret = -EIO;
page_cache_release(page);
- spin_lock(&pagecache_lock);
+ write_lock(&mapping->page_lock);
}
- spin_unlock(&pagecache_lock);
+ write_unlock(&mapping->page_lock);
return ret;
}
/*
- * Add a page to the inode page cache.
- *
- * The caller must have locked the page and
- * set all the page flags correctly..
- */
-void add_to_page_cache_locked(struct page * page, struct address_space *mapping, unsigned long index)
-{
- if (!PageLocked(page))
- BUG();
-
- page->index = index;
- page_cache_get(page);
- spin_lock(&pagecache_lock);
- add_page_to_inode_queue(mapping, page);
- add_page_to_hash_queue(page, page_hash(mapping, index));
- spin_unlock(&pagecache_lock);
-
- lru_cache_add(page);
-}
-
-/*
* This adds a page to the page cache, starting out as locked,
* owned by us, but unreferenced, not uptodate and with no errors.
+ * The caller must hold a write_lock on the mapping->page_lock.
*/
-static inline void __add_to_page_cache(struct page * page,
- struct address_space *mapping, unsigned long offset,
- struct page **hash)
+static int __add_to_page_cache(struct page *page,
+ struct address_space *mapping, unsigned long offset)
{
unsigned long flags;
+ page_cache_get(page);
+ if (radix_tree_insert(&mapping->page_tree, offset, page) < 0)
+ goto nomem;
flags = page->flags & ~(1 << PG_uptodate | 1 << PG_error | 1 << PG_dirty | 1 << PG_referenced | 1 << PG_arch_1 | 1 << PG_checked);
page->flags = flags | (1 << PG_locked);
- page_cache_get(page);
- page->index = offset;
- add_page_to_inode_queue(mapping, page);
- add_page_to_hash_queue(page, hash);
+ ___add_to_page_cache(page, mapping, offset);
+ return 0;
+ nomem:
+ page_cache_release(page);
+ return -ENOMEM;
}
-void add_to_page_cache(struct page * page, struct address_space * mapping, unsigned long offset)
+int add_to_page_cache(struct page *page,
+ struct address_space *mapping, unsigned long offset)
{
- spin_lock(&pagecache_lock);
- __add_to_page_cache(page, mapping, offset, page_hash(mapping, offset));
- spin_unlock(&pagecache_lock);
+ write_lock(&mapping->page_lock);
+ if (__add_to_page_cache(page, mapping, offset) < 0)
+ goto nomem;
+ write_unlock(&mapping->page_lock);
lru_cache_add(page);
+ return 0;
+nomem:
+ write_unlock(&mapping->page_lock);
+ return -ENOMEM;
}
-int add_to_page_cache_unique(struct page * page,
- struct address_space *mapping, unsigned long offset,
- struct page **hash)
+int add_to_page_cache_unique(struct page *page,
+ struct address_space *mapping, unsigned long offset)
{
- int err;
struct page *alias;
+ int error = -EEXIST;
- spin_lock(&pagecache_lock);
- alias = __find_page_nolock(mapping, offset, *hash);
-
- err = 1;
- if (!alias) {
- __add_to_page_cache(page,mapping,offset,hash);
- err = 0;
- }
+ write_lock(&mapping->page_lock);
+ if (!(alias = radix_tree_lookup(&mapping->page_tree, offset)))
+ error = __add_to_page_cache(page, mapping, offset);
+ write_unlock(&mapping->page_lock);
- spin_unlock(&pagecache_lock);
- if (!err)
+ if (!error)
lru_cache_add(page);
- return err;
+ return error;
}
/*
@@ -693,12 +631,12 @@ static int FASTCALL(page_cache_read(stru
static int page_cache_read(struct file * file, unsigned long offset)
{
struct address_space *mapping = file->f_dentry->d_inode->i_mapping;
- struct page **hash = page_hash(mapping, offset);
struct page *page;
+ int error;
- spin_lock(&pagecache_lock);
- page = __find_page_nolock(mapping, offset, *hash);
- spin_unlock(&pagecache_lock);
+ read_lock(&mapping->page_lock);
+ page = radix_tree_lookup(&mapping->page_tree, offset);
+ read_unlock(&mapping->page_lock);
if (page)
return 0;
@@ -706,17 +644,20 @@ static int page_cache_read(struct file *
if (!page)
return -ENOMEM;
- if (!add_to_page_cache_unique(page, mapping, offset, hash)) {
- int error = mapping->a_ops->readpage(file, page);
+ error = add_to_page_cache_unique(page, mapping, offset);
+ if (!error) {
+ error = mapping->a_ops->readpage(file, page);
page_cache_release(page);
return error;
}
+
/*
* We arrive here in the unlikely event that someone
- * raced with us and added our page to the cache first.
+ * raced with us and added our page to the cache first
+ * or we are out of memory for radix-tree nodes.
*/
page_cache_release(page);
- return 0;
+ return error == -EEXIST ? 0 : error;
}
/*
@@ -842,8 +783,7 @@ void lock_page(struct page *page)
* a rather lightweight function, finding and getting a reference to a
* hashed page atomically.
*/
-struct page * __find_get_page(struct address_space *mapping,
- unsigned long offset, struct page **hash)
+struct page * find_get_page(struct address_space *mapping, unsigned long offset)
{
struct page *page;
@@ -851,11 +791,11 @@ struct page * __find_get_page(struct add
* We scan the hash list read-only. Addition to and removal from
* the hash-list needs a held write-lock.
*/
- spin_lock(&pagecache_lock);
- page = __find_page_nolock(mapping, offset, *hash);
+ read_lock(&mapping->page_lock);
+ page = radix_tree_lookup(&mapping->page_tree, offset);
if (page)
page_cache_get(page);
- spin_unlock(&pagecache_lock);
+ read_unlock(&mapping->page_lock);
return page;
}
@@ -865,15 +805,12 @@ struct page * __find_get_page(struct add
struct page *find_trylock_page(struct address_space *mapping, unsigned long offset)
{
struct page *page;
- struct page **hash = page_hash(mapping, offset);
- spin_lock(&pagecache_lock);
- page = __find_page_nolock(mapping, offset, *hash);
- if (page) {
- if (TryLockPage(page))
- page = NULL;
- }
- spin_unlock(&pagecache_lock);
+ read_lock(&mapping->page_lock);
+ page = radix_tree_lookup(&mapping->page_tree, offset);
+ if (page && TryLockPage(page))
+ page = NULL;
+ read_unlock(&mapping->page_lock);
return page;
}
@@ -882,9 +819,8 @@ struct page *find_trylock_page(struct ad
* will return with it held (but it may be dropped
* during blocking operations..
*/
-static struct page * FASTCALL(__find_lock_page_helper(struct address_space *, unsigned long, struct page *));
-static struct page * __find_lock_page_helper(struct address_space *mapping,
- unsigned long offset, struct page *hash)
+static struct page *__find_lock_page(struct address_space *mapping,
+ unsigned long offset)
{
struct page *page;
@@ -893,13 +829,13 @@ static struct page * __find_lock_page_he
* the hash-list needs a held write-lock.
*/
repeat:
- page = __find_page_nolock(mapping, offset, hash);
+ page = radix_tree_lookup(&mapping->page_tree, offset);
if (page) {
page_cache_get(page);
if (TryLockPage(page)) {
- spin_unlock(&pagecache_lock);
+ read_unlock(&mapping->page_lock);
lock_page(page);
- spin_lock(&pagecache_lock);
+ read_lock(&mapping->page_lock);
/* Has the page been re-allocated while we slept? */
if (page->mapping != mapping || page->index != offset) {
@@ -916,46 +852,50 @@ repeat:
* Same as the above, but lock the page too, verifying that
* it's still valid once we own it.
*/
-struct page * __find_lock_page (struct address_space *mapping,
- unsigned long offset, struct page **hash)
+struct page * find_lock_page(struct address_space *mapping, unsigned long offset)
{
struct page *page;
- spin_lock(&pagecache_lock);
- page = __find_lock_page_helper(mapping, offset, *hash);
- spin_unlock(&pagecache_lock);
+ read_lock(&mapping->page_lock);
+ page = __find_lock_page(mapping, offset);
+ read_unlock(&mapping->page_lock);
+
return page;
}
/*
* Same as above, but create the page if required..
*/
-struct page * find_or_create_page(struct address_space *mapping, unsigned long index, unsigned int gfp_mask)
+struct page * find_or_create_page(struct address_space *mapping,
+ unsigned long index, unsigned int gfp_mask)
{
struct page *page;
- struct page **hash = page_hash(mapping, index);
- spin_lock(&pagecache_lock);
- page = __find_lock_page_helper(mapping, index, *hash);
- spin_unlock(&pagecache_lock);
+ page = find_lock_page(mapping, index);
if (!page) {
struct page *newpage = alloc_page(gfp_mask);
if (newpage) {
- spin_lock(&pagecache_lock);
- page = __find_lock_page_helper(mapping, index, *hash);
+ write_lock(&mapping->page_lock);
+ page = __find_lock_page(mapping, index);
if (likely(!page)) {
page = newpage;
- __add_to_page_cache(page, mapping, index, hash);
+ if (__add_to_page_cache(page, mapping, index)) {
+ write_unlock(&mapping->page_lock);
+ page_cache_release(page);
+ page = NULL;
+ goto out;
+ }
newpage = NULL;
}
- spin_unlock(&pagecache_lock);
+ write_unlock(&mapping->page_lock);
if (newpage == NULL)
lru_cache_add(page);
else
page_cache_release(newpage);
}
}
- return page;
+out:
+ return page;
}
/*
@@ -975,10 +915,9 @@ struct page *grab_cache_page(struct addr
*/
struct page *grab_cache_page_nowait(struct address_space *mapping, unsigned long index)
{
- struct page *page, **hash;
+ struct page *page;
- hash = page_hash(mapping, index);
- page = __find_get_page(mapping, index, hash);
+ page = find_get_page(mapping, index);
if ( page ) {
if ( !TryLockPage(page) ) {
@@ -1000,11 +939,14 @@ struct page *grab_cache_page_nowait(stru
}
page = page_cache_alloc(mapping);
- if ( unlikely(!page) )
+ if (unlikely(!page))
return NULL; /* Failed to allocate a page */
- if ( unlikely(add_to_page_cache_unique(page, mapping, index, hash)) ) {
- /* Someone else grabbed the page already. */
+ if (unlikely(add_to_page_cache_unique(page, mapping, index))) {
+ /*
+ * Someone else grabbed the page already, or
+ * failed to allocate a radix-tree node
+ */
page_cache_release(page);
return NULL;
}
@@ -1319,7 +1261,7 @@ void do_generic_file_read(struct file *
}
for (;;) {
- struct page *page, **hash;
+ struct page *page;
unsigned long end_index, nr, ret;
end_index = inode->i_size >> PAGE_CACHE_SHIFT;
@@ -1338,15 +1280,14 @@ void do_generic_file_read(struct file *
/*
* Try to find the data in the page cache..
*/
- hash = page_hash(mapping, index);
- spin_lock(&pagecache_lock);
- page = __find_page_nolock(mapping, index, *hash);
+ write_lock(&mapping->page_lock);
+ page = radix_tree_lookup(&mapping->page_tree, index);
if (!page)
goto no_cached_page;
found_page:
page_cache_get(page);
- spin_unlock(&pagecache_lock);
+ write_unlock(&mapping->page_lock);
if (!Page_Uptodate(page))
goto page_not_up_to_date;
@@ -1440,7 +1381,7 @@ no_cached_page:
* We get here with the page cache lock held.
*/
if (!cached_page) {
- spin_unlock(&pagecache_lock);
+ write_unlock(&mapping->page_lock);
cached_page = page_cache_alloc(mapping);
if (!cached_page) {
desc->error = -ENOMEM;
@@ -1451,8 +1392,8 @@ no_cached_page:
* Somebody may have added the page while we
* dropped the page cache lock. Check for that.
*/
- spin_lock(&pagecache_lock);
- page = __find_page_nolock(mapping, index, *hash);
+ write_lock(&mapping->page_lock);
+ page = radix_tree_lookup(&mapping->page_tree, index);
if (page)
goto found_page;
}
@@ -1460,9 +1401,13 @@ no_cached_page:
/*
* Ok, add the new page to the hash-queues...
*/
+ if (__add_to_page_cache(cached_page, mapping, index) < 0) {
+ write_unlock(&mapping->page_lock);
+ desc->error = -ENOMEM;
+ break;
+ }
page = cached_page;
- __add_to_page_cache(page, mapping, index, hash);
- spin_unlock(&pagecache_lock);
+ write_unlock(&mapping->page_lock);
lru_cache_add(page);
cached_page = NULL;
@@ -1902,7 +1847,7 @@ struct page * filemap_nopage(struct vm_a
struct file *file = area->vm_file;
struct address_space *mapping = file->f_dentry->d_inode->i_mapping;
struct inode *inode = mapping->host;
- struct page *page, **hash;
+ struct page *page;
unsigned long size, pgoff, endoff;
pgoff = ((address - area->vm_start) >> PAGE_CACHE_SHIFT) + area->vm_pgoff;
@@ -1924,9 +1869,8 @@ retry_all:
/*
* Do we have something in the page cache already?
*/
- hash = page_hash(mapping, pgoff);
retry_find:
- page = __find_get_page(mapping, pgoff, hash);
+ page = find_get_page(mapping, pgoff);
if (!page)
goto no_cached_page;
@@ -2418,20 +2362,25 @@ struct page *__read_cache_page(struct ad
int (*filler)(void *,struct page*),
void *data)
{
- struct page **hash = page_hash(mapping, index);
struct page *page, *cached_page = NULL;
int err;
repeat:
- page = __find_get_page(mapping, index, hash);
+ page = find_get_page(mapping, index);
if (!page) {
if (!cached_page) {
cached_page = page_cache_alloc(mapping);
if (!cached_page)
return ERR_PTR(-ENOMEM);
}
- page = cached_page;
- if (add_to_page_cache_unique(page, mapping, index, hash))
+ err = add_to_page_cache_unique(cached_page, mapping, index);
+ if (err == -EEXIST)
goto repeat;
+ if (err < 0) {
+ /* Presumably ENOMEM for radix tree node */
+ page_cache_release(cached_page);
+ return ERR_PTR(err);
+ }
+ page = cached_page;
cached_page = NULL;
err = filler(data, page);
if (err < 0) {
@@ -2486,19 +2435,23 @@ retry:
static inline struct page * __grab_cache_page(struct address_space *mapping,
unsigned long index, struct page **cached_page)
{
- struct page *page, **hash = page_hash(mapping, index);
+ int err;
+ struct page *page;
repeat:
- page = __find_lock_page(mapping, index, hash);
+ page = find_lock_page(mapping, index);
if (!page) {
if (!*cached_page) {
*cached_page = page_cache_alloc(mapping);
if (!*cached_page)
return NULL;
}
- page = *cached_page;
- if (add_to_page_cache_unique(page, mapping, index, hash))
+ err = add_to_page_cache_unique(*cached_page, mapping, index);
+ if (err == -EEXIST)
goto repeat;
- *cached_page = NULL;
+ if (err == 0) {
+ page = *cached_page;
+ *cached_page = NULL;
+ }
}
return page;
}
@@ -2772,30 +2725,3 @@ o_direct:
status = generic_osync_inode(inode, OSYNC_METADATA);
goto out_status;
}
-
-void __init page_cache_init(unsigned long mempages)
-{
- unsigned long htable_size, order;
-
- htable_size = mempages;
- htable_size *= sizeof(struct page *);
- for(order = 0; (PAGE_SIZE << order) < htable_size; order++)
- ;
-
- do {
- unsigned long tmp = (PAGE_SIZE << order) / sizeof(struct page *);
-
- page_hash_bits = 0;
- while((tmp >>= 1UL) != 0UL)
- page_hash_bits++;
-
- page_hash_table = (struct page **)
- __get_free_pages(GFP_ATOMIC, order);
- } while(page_hash_table == NULL && --order > 0);
-
- printk("Page-cache hash table entries: %d (order: %ld, %ld bytes)\n",
- (1 << page_hash_bits), order, (PAGE_SIZE << order));
- if (!page_hash_table)
- panic("Failed to allocate page hash table\n");
- memset((void *)page_hash_table, 0, PAGE_HASH_SIZE * sizeof(struct page *));
-}
--- 2.5.8-pre3/mm/mincore.c~dallocbase-05-new_ratcache Tue Apr 9 20:35:31 2002
+++ 2.5.8-pre3-akpm/mm/mincore.c Tue Apr 9 20:35:31 2002
@@ -27,9 +27,9 @@ static unsigned char mincore_page(struct
{
unsigned char present = 0;
struct address_space * as = vma->vm_file->f_dentry->d_inode->i_mapping;
- struct page * page, ** hash = page_hash(as, pgoff);
+ struct page * page;
- page = __find_get_page(as, pgoff, hash);
+ page = find_get_page(as, pgoff);
if (page) {
present = Page_Uptodate(page);
page_cache_release(page);
--- 2.5.8-pre3/mm/shmem.c~dallocbase-05-new_ratcache Tue Apr 9 20:35:31 2002
+++ 2.5.8-pre3-akpm/mm/shmem.c Tue Apr 9 20:35:31 2002
@@ -370,9 +370,10 @@ static int shmem_unuse_inode (struct shm
swp_entry_t *ptr;
unsigned long idx;
int offset;
-
- idx = 0;
+
spin_lock (&info->lock);
+repeat:
+ idx = 0;
offset = shmem_clear_swp (entry, info->i_direct, SHMEM_NR_DIRECT);
if (offset >= 0)
goto found;
@@ -389,13 +390,16 @@ static int shmem_unuse_inode (struct shm
spin_unlock (&info->lock);
return 0;
found:
- delete_from_swap_cache(page);
- add_to_page_cache(page, info->vfs_inode.i_mapping, offset + idx);
- SetPageDirty(page);
- SetPageUptodate(page);
- info->swapped--;
- spin_unlock(&info->lock);
- return 1;
+ if (!move_from_swap_cache (page, offset+idx, info->vfs_inode.i_mapping)) {
+ info->swapped--;
+ SetPageUptodate (page);
+ spin_unlock (&info->lock);
+ return 1;
+ }
+
+ /* Yield for kswapd, and try again */
+ yield();
+ goto repeat;
}
/*
@@ -425,6 +429,7 @@ void shmem_unuse(swp_entry_t entry, stru
*/
static int shmem_writepage(struct page * page)
{
+ int err;
struct shmem_inode_info *info;
swp_entry_t *entry, swap;
struct address_space *mapping;
@@ -442,7 +447,6 @@ static int shmem_writepage(struct page *
info = SHMEM_I(inode);
if (info->locked)
return fail_writepage(page);
-getswap:
swap = get_swap_page();
if (!swap.val)
return fail_writepage(page);
@@ -455,29 +459,20 @@ getswap:
if (entry->val)
BUG();
- /* Remove it from the page cache */
- remove_inode_page(page);
- page_cache_release(page);
-
- /* Add it to the swap cache */
- if (add_to_swap_cache(page, swap) != 0) {
- /*
- * Raced with "speculative" read_swap_cache_async.
- * Add page back to page cache, unref swap, try again.
- */
- add_to_page_cache_locked(page, mapping, index);
+ err = move_to_swap_cache(page, swap);
+ if (!err) {
+ *entry = swap;
+ info->swapped++;
spin_unlock(&info->lock);
- swap_free(swap);
- goto getswap;
+ SetPageUptodate(page);
+ set_page_dirty(page);
+ UnlockPage(page);
+ return 0;
}
- *entry = swap;
- info->swapped++;
spin_unlock(&info->lock);
- SetPageUptodate(page);
- set_page_dirty(page);
- UnlockPage(page);
- return 0;
+ swap_free(swap);
+ return fail_writepage(page);
}
/*
@@ -493,10 +488,11 @@ getswap:
*/
static struct page * shmem_getpage_locked(struct shmem_inode_info *info, struct inode * inode, unsigned long idx)
{
- struct address_space * mapping = inode->i_mapping;
+ struct address_space *mapping = inode->i_mapping;
struct shmem_sb_info *sbinfo;
- struct page * page;
+ struct page *page;
swp_entry_t *entry;
+ int error;
repeat:
page = find_lock_page(mapping, idx);
@@ -524,8 +520,6 @@ repeat:
shmem_recalc_inode(inode);
if (entry->val) {
- unsigned long flags;
-
/* Look it up and read it in.. */
page = find_get_page(&swapper_space, entry->val);
if (!page) {
@@ -550,16 +544,18 @@ repeat:
goto repeat;
}
- /* We have to this with page locked to prevent races */
+ /* We have to do this with page locked to prevent races */
if (TryLockPage(page))
goto wait_retry;
+ error = move_from_swap_cache(page, idx, mapping);
+ if (error < 0) {
+ UnlockPage(page);
+ return ERR_PTR(error);
+ }
+
swap_free(*entry);
*entry = (swp_entry_t) {0};
- delete_from_swap_cache(page);
- flags = page->flags & ~((1 << PG_uptodate) | (1 << PG_error) | (1 << PG_referenced) | (1 << PG_arch_1));
- page->flags = flags | (1 << PG_dirty);
- add_to_page_cache_locked(page, mapping, idx);
info->swapped--;
spin_unlock (&info->lock);
} else {
@@ -581,9 +577,13 @@ repeat:
page = page_cache_alloc(mapping);
if (!page)
return ERR_PTR(-ENOMEM);
+ error = add_to_page_cache(page, mapping, idx);
+ if (error < 0) {
+ page_cache_release(page);
+ return ERR_PTR(-ENOMEM);
+ }
clear_highpage(page);
inode->i_blocks += BLOCKS_PER_PAGE;
- add_to_page_cache (page, mapping, idx);
}
/* We have the page */
--- 2.5.8-pre3/mm/swapfile.c~dallocbase-05-new_ratcache Tue Apr 9 20:35:31 2002
+++ 2.5.8-pre3-akpm/mm/swapfile.c Tue Apr 9 20:35:31 2002
@@ -239,10 +239,10 @@ static int exclusive_swap_page(struct pa
/* Is the only swap cache user the cache itself? */
if (p->swap_map[SWP_OFFSET(entry)] == 1) {
/* Recheck the page count with the pagecache lock held.. */
- spin_lock(&pagecache_lock);
+ read_lock(&swapper_space.page_lock);
if (page_count(page) - !!page->buffers == 2)
retval = 1;
- spin_unlock(&pagecache_lock);
+ read_unlock(&swapper_space.page_lock);
}
swap_info_put(p);
}
@@ -307,13 +307,13 @@ int remove_exclusive_swap_page(struct pa
retval = 0;
if (p->swap_map[SWP_OFFSET(entry)] == 1) {
/* Recheck the page count with the pagecache lock held.. */
- spin_lock(&pagecache_lock);
+ read_lock(&swapper_space.page_lock);
if (page_count(page) - !!page->buffers == 2) {
__delete_from_swap_cache(page);
SetPageDirty(page);
retval = 1;
}
- spin_unlock(&pagecache_lock);
+ read_unlock(&swapper_space.page_lock);
}
swap_info_put(p);
--- 2.5.8-pre3/mm/swap_state.c~dallocbase-05-new_ratcache Tue Apr 9 20:35:31 2002
+++ 2.5.8-pre3-akpm/mm/swap_state.c Tue Apr 9 20:35:31 2002
@@ -37,11 +37,13 @@ static struct address_space_operations s
};
struct address_space swapper_space = {
- LIST_HEAD_INIT(swapper_space.clean_pages),
- LIST_HEAD_INIT(swapper_space.dirty_pages),
- LIST_HEAD_INIT(swapper_space.locked_pages),
- 0, /* nrpages */
- &swap_aops,
+ page_tree: RADIX_TREE_INIT(GFP_ATOMIC),
+ page_lock: RW_LOCK_UNLOCKED,
+ clean_pages: LIST_HEAD_INIT(swapper_space.clean_pages),
+ dirty_pages: LIST_HEAD_INIT(swapper_space.dirty_pages),
+ locked_pages: LIST_HEAD_INIT(swapper_space.locked_pages),
+ a_ops: &swap_aops,
+ i_shared_lock: SPIN_LOCK_UNLOCKED,
};
#ifdef SWAP_CACHE_INFO
@@ -69,17 +71,21 @@ void show_swap_cache_info(void)
int add_to_swap_cache(struct page *page, swp_entry_t entry)
{
+ int error;
+
if (page->mapping)
BUG();
if (!swap_duplicate(entry)) {
INC_CACHE_INFO(noent_race);
return -ENOENT;
}
- if (add_to_page_cache_unique(page, &swapper_space, entry.val,
- page_hash(&swapper_space, entry.val)) != 0) {
+
+ error = add_to_page_cache_unique(page, &swapper_space, entry.val);
+ if (error != 0) {
swap_free(entry);
- INC_CACHE_INFO(exist_race);
- return -EEXIST;
+ if (error == -EEXIST)
+ INC_CACHE_INFO(exist_race);
+ return error;
}
if (!PageLocked(page))
BUG();
@@ -121,14 +127,96 @@ void delete_from_swap_cache(struct page
entry.val = page->index;
- spin_lock(&pagecache_lock);
+ write_lock(&swapper_space.page_lock);
__delete_from_swap_cache(page);
- spin_unlock(&pagecache_lock);
+ write_unlock(&swapper_space.page_lock);
swap_free(entry);
page_cache_release(page);
}
+int move_to_swap_cache(struct page *page, swp_entry_t entry)
+{
+ struct address_space *mapping = page->mapping;
+ void **pslot;
+ int err;
+
+ if (!mapping)
+ BUG();
+
+ if (!swap_duplicate(entry)) {
+ INC_CACHE_INFO(noent_race);
+ return -ENOENT;
+ }
+
+ write_lock(&swapper_space.page_lock);
+ write_lock(&mapping->page_lock);
+
+ err = radix_tree_reserve(&swapper_space.page_tree, entry.val, &pslot);
+ if (!err) {
+ /* Remove it from the page cache */
+ __remove_inode_page (page);
+
+ /* Add it to the swap cache */
+ *pslot = page;
+ page->flags = ((page->flags & ~(1 << PG_uptodate | 1 << PG_error
+ | 1 << PG_dirty | 1 << PG_referenced
+ | 1 << PG_arch_1 | 1 << PG_checked))
+ | (1 << PG_locked));
+ ___add_to_page_cache(page, &swapper_space, entry.val);
+ }
+
+ write_unlock(&mapping->page_lock);
+ write_unlock(&swapper_space.page_lock);
+
+ if (!err) {
+ INC_CACHE_INFO(add_total);
+ return 0;
+ }
+
+ swap_free(entry);
+
+ if (err == -EEXIST)
+ INC_CACHE_INFO(exist_race);
+
+ return err;
+}
+
+int move_from_swap_cache(struct page *page, unsigned long index,
+ struct address_space *mapping)
+{
+ void **pslot;
+ int err;
+
+ if (!PageLocked(page))
+ BUG();
+
+ write_lock(&swapper_space.page_lock);
+ write_lock(&mapping->page_lock);
+
+ err = radix_tree_reserve(&mapping->page_tree, index, &pslot);
+ if (!err) {
+ swp_entry_t entry;
+
+ block_flushpage(page, 0);
+ entry.val = page->index;
+ __delete_from_swap_cache(page);
+ swap_free(entry);
+
+ *pslot = page;
+ page->flags &= ~(1 << PG_uptodate | 1 << PG_error |
+ 1 << PG_referenced | 1 << PG_arch_1 |
+ 1 << PG_checked);
+ page->flags |= (1 << PG_dirty);
+ ___add_to_page_cache(page, mapping, index);
+ }
+
+ write_unlock(&mapping->page_lock);
+ write_unlock(&swapper_space.page_lock);
+
+ return err;
+}
+
/*
* Perform a free_page(), also freeing any swap cache associated with
* this page if it is the last user of the page. Can not do a lock_page,
@@ -213,6 +301,7 @@ struct page * read_swap_cache_async(swp_
* swap cache: added by a racing read_swap_cache_async,
* or by try_to_swap_out (or shmem_writepage) re-using
* the just freed swap entry for an existing page.
+ * May fail (-ENOMEM) if radix-tree node allocation failed.
*/
err = add_to_swap_cache(new_page, entry);
if (!err) {
@@ -222,7 +311,7 @@ struct page * read_swap_cache_async(swp_
rw_swap_page(READ, new_page);
return new_page;
}
- } while (err != -ENOENT);
+ } while (err != -ENOENT && err != -ENOMEM);
if (new_page)
page_cache_release(new_page);
--- 2.5.8-pre3/mm/vmscan.c~dallocbase-05-new_ratcache Tue Apr 9 20:35:31 2002
+++ 2.5.8-pre3-akpm/mm/vmscan.c Tue Apr 9 20:35:43 2002
@@ -138,10 +138,16 @@ drop_pte:
* (adding to the page cache will clear the dirty
* and uptodate bits, so we need to do it again)
*/
- if (add_to_swap_cache(page, entry) == 0) {
+ switch (add_to_swap_cache(page, entry)) {
+ case 0: /* Success */
SetPageUptodate(page);
set_page_dirty(page);
goto set_swap_pte;
+ case -ENOMEM: /* radix-tree allocation */
+ swap_free(entry);
+ goto preserve;
+ default: /* ENOENT: raced */
+ break;
}
/* Raced with "speculative" read_swap_cache_async */
swap_free(entry);
@@ -341,6 +347,7 @@ static int FASTCALL(shrink_cache(int nr_
static int shrink_cache(int nr_pages, zone_t * classzone, unsigned int gfp_mask, int priority)
{
struct list_head * entry;
+ struct address_space *mapping;
int max_scan = nr_inactive_pages / priority;
int max_mapped = nr_pages << (9 - priority);
@@ -395,7 +402,9 @@ static int shrink_cache(int nr_pages, zo
continue;
}
- if (PageDirty(page) && is_page_cache_freeable(page) && page->mapping) {
+ mapping = page->mapping;
+
+ if (PageDirty(page) && is_page_cache_freeable(page) && mapping) {
/*
* It is not critical here to write it only if
* the page is unmapped beause any direct writer
@@ -406,7 +415,7 @@ static int shrink_cache(int nr_pages, zo
*/
int (*writepage)(struct page *);
- writepage = page->mapping->a_ops->writepage;
+ writepage = mapping->a_ops->writepage;
if ((gfp_mask & __GFP_FS) && writepage) {
ClearPageDirty(page);
SetPageLaunder(page);
@@ -433,7 +442,7 @@ static int shrink_cache(int nr_pages, zo
page_cache_get(page);
if (try_to_release_page(page, gfp_mask)) {
- if (!page->mapping) {
+ if (!mapping) {
/*
* We must not allow an anon page
* with no buffers to be visible on
@@ -470,33 +479,35 @@ static int shrink_cache(int nr_pages, zo
}
}
- spin_lock(&pagecache_lock);
-
/*
- * this is the non-racy check for busy page.
+ * This is the non-racy check for busy page.
*/
- if (!page->mapping || !is_page_cache_freeable(page)) {
- spin_unlock(&pagecache_lock);
- UnlockPage(page);
+ if (mapping) {
+ write_lock(&mapping->page_lock);
+ if (is_page_cache_freeable(page))
+ goto page_freeable;
+ write_unlock(&mapping->page_lock);
+ }
+ UnlockPage(page);
page_mapped:
- if (--max_mapped >= 0)
- continue;
+ if (--max_mapped >= 0)
+ continue;
- /*
- * Alert! We've found too many mapped pages on the
- * inactive list, so we start swapping out now!
- */
- spin_unlock(&pagemap_lru_lock);
- swap_out(priority, gfp_mask, classzone);
- return nr_pages;
- }
+ /*
+ * Alert! We've found too many mapped pages on the
+ * inactive list, so we start swapping out now!
+ */
+ spin_unlock(&pagemap_lru_lock);
+ swap_out(priority, gfp_mask, classzone);
+ return nr_pages;
+page_freeable:
/*
* It is critical to check PageDirty _after_ we made sure
* the page is freeable* so not in use by anybody.
*/
if (PageDirty(page)) {
- spin_unlock(&pagecache_lock);
+ write_unlock(&mapping->page_lock);
UnlockPage(page);
continue;
}
@@ -504,12 +515,12 @@ page_mapped:
/* point of no return */
if (likely(!PageSwapCache(page))) {
__remove_inode_page(page);
- spin_unlock(&pagecache_lock);
+ write_unlock(&mapping->page_lock);
} else {
swp_entry_t swap;
swap.val = page->index;
__delete_from_swap_cache(page);
- spin_unlock(&pagecache_lock);
+ write_unlock(&mapping->page_lock);
swap_free(swap);
}
-
--
To unsubscribe, send a message with 'unsubscribe linux-mm' in
the body to majordomo@kvack.org. For more info on Linux MM,
see: http://www.linux-mm.org/
^ permalink raw reply [flat|nested] 3+ messages in thread
end of thread, other threads:[~2002-04-10 4:07 UTC | newest]
Thread overview: 3+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2002-04-09 9:47 [PATCH][RC] radix-tree pagecache for 2.5 Christoph Hellwig
2002-04-10 2:32 ` Andrew Morton
2002-04-10 4:07 ` [patch] Velikov/Hellwig radix-tree pagecache Andrew Morton
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox