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From: Momchil Velikov <velco@fadata.bg>
To: linux-kernel@vger.kernel.org
Subject: [PATCH] Scalable page cache
Date: 26 Nov 2001 14:31:42 +0200
Hi,
This patch:
- replaces the global page cache hash table with a per mapping
splay tree;
- eliminates the ``pagecache_lock'', instead ``i_shared_lock''
is used so serialize access during insertion/deletion
into/from the tree;
The goals of the patch are to:
- to improve scalability (via the elimination of the global
lock);
- reduce the memory/cache footprint (via to the
``page_hash_table'' elimination);
The patch is against 2.4.16-pre1. Comments are welcome.
Regards,
-velco
diff -Nru a/arch/arm/mm/init.c b/arch/arm/mm/init.c
--- a/arch/arm/mm/init.c Sun Nov 25 16:39:44 2001
+++ b/arch/arm/mm/init.c Sun Nov 25 16:39:44 2001
@@ -103,7 +103,7 @@
* #define PG_skip 10
* #define PageSkip(page) (machine_is_riscpc() && test_bit(PG_skip, &(page)->flags))
* if (PageSkip(page)) {
- * page = page->next_hash;
+ * page = page->left;
* if (page == NULL)
* break;
* }
diff -Nru a/arch/arm/mm/small_page.c b/arch/arm/mm/small_page.c
--- a/arch/arm/mm/small_page.c Sun Nov 25 16:39:44 2001
+++ b/arch/arm/mm/small_page.c Sun Nov 25 16:39:44 2001
@@ -38,15 +38,15 @@
* Theory:
* We "misuse" the Linux memory management system. We use alloc_page
* to allocate a page and then mark it as reserved. The Linux memory
- * management system will then ignore the "offset", "next_hash" and
- * "pprev_hash" entries in the mem_map for this page.
+ * management system will then ignore the "offset", "left" and
+ * "right" entries in the mem_map for this page.
*
* We then use a bitstring in the "offset" field to mark which segments
* of the page are in use, and manipulate this as required during the
* allocation and freeing of these small pages.
*
* We also maintain a queue of pages being used for this purpose using
- * the "next_hash" and "pprev_hash" entries of mem_map;
+ * the "left" and "right" entries of mem_map;
*/
struct order {
@@ -81,20 +81,20 @@
if (page->pprev_hash)
PAGE_BUG(page);
#endif
- page->next_hash = *p;
+ page->left = *p;
if (*p)
- (*p)->pprev_hash = &page->next_hash;
+ (struct page **)(*p)->right = &page->left;
*p = page;
- page->pprev_hash = p;
+ (struct page **)page->right = p;
}
static void remove_page_from_queue(struct page *page)
{
- if (page->pprev_hash) {
- if (page->next_hash)
- page->next_hash->pprev_hash = page->pprev_hash;
- *page->pprev_hash = page->next_hash;
- page->pprev_hash = NULL;
+ if (page->right) {
+ if (page->left)
+ page->left->right = page->right;
+ *(struct page **)page->right = page->left;
+ page->right = NULL;
}
}
diff -Nru a/arch/sparc64/mm/init.c b/arch/sparc64/mm/init.c
--- a/arch/sparc64/mm/init.c Sun Nov 25 16:39:44 2001
+++ b/arch/sparc64/mm/init.c Sun Nov 25 16:39:44 2001
@@ -83,18 +83,18 @@
if (pgd_cache_size > high / 4) {
struct page *page, *page2;
for (page2 = NULL, page = (struct page *)pgd_quicklist; page;) {
- if ((unsigned long)page->pprev_hash == 3) {
+ if ((unsigned long)page->right == 3) {
if (page2)
- page2->next_hash = page->next_hash;
+ page2->left = page->left;
else
- (struct page *)pgd_quicklist = page->next_hash;
- page->next_hash = NULL;
- page->pprev_hash = NULL;
+ (struct page *)pgd_quicklist = page->left;
+ page->left = NULL;
+ page->right = NULL;
pgd_cache_size -= 2;
__free_page(page);
freed++;
if (page2)
- page = page2->next_hash;
+ page = page2->left;
else
page = (struct page *)pgd_quicklist;
if (pgd_cache_size <= low / 4)
@@ -102,7 +102,7 @@
continue;
}
page2 = page;
- page = page->next_hash;
+ page = page->left;
}
}
#endif
diff -Nru a/drivers/block/rd.c b/drivers/block/rd.c
--- a/drivers/block/rd.c Sun Nov 25 16:39:44 2001
+++ b/drivers/block/rd.c Sun Nov 25 16:39:44 2001
@@ -243,7 +243,6 @@
do {
int count;
- struct page ** hash;
struct page * page;
char * src, * dst;
int unlock = 0;
@@ -253,8 +252,7 @@
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;
diff -Nru a/fs/inode.c b/fs/inode.c
--- a/fs/inode.c Sun Nov 25 16:39:44 2001
+++ b/fs/inode.c Sun Nov 25 16:39:44 2001
@@ -110,6 +110,7 @@
sema_init(&inode->i_sem, 1);
sema_init(&inode->i_zombie, 1);
spin_lock_init(&inode->i_data.i_shared_lock);
+ inode->i_data.root = 0;
}
}
diff -Nru a/include/linux/fs.h b/include/linux/fs.h
--- a/include/linux/fs.h Sun Nov 25 16:39:44 2001
+++ b/include/linux/fs.h Sun Nov 25 16:39:44 2001
@@ -403,6 +403,7 @@
struct vm_area_struct *i_mmap; /* list of private mappings */
struct vm_area_struct *i_mmap_shared; /* list of shared mappings */
spinlock_t i_shared_lock; /* and spinlock protecting it */
+ struct page *root;
int gfp_mask; /* how to allocate the pages */
};
diff -Nru a/include/linux/mm.h b/include/linux/mm.h
--- a/include/linux/mm.h Sun Nov 25 16:39:44 2001
+++ b/include/linux/mm.h Sun Nov 25 16:39:44 2001
@@ -152,15 +152,14 @@
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. */
+ struct page *left; /* Left child in the mapping tree */
+ struct page *right; /* Right child in the mapping tree */
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 !! */
wait_queue_head_t wait; /* Page locked? Stand in line... */
- struct page **pprev_hash; /* Complement to *next_hash. */
struct buffer_head * buffers; /* Buffer maps us to a disk block. */
void *virtual; /* Kernel virtual address (NULL if
not kmapped, ie. highmem) */
@@ -228,9 +227,9 @@
* 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 splay tree mapping (index) to the page
+ * in memory if present. The tree uses the fields page->left and
+ * page->right.
*
* All process pages can do I/O:
* - inode pages may need to be read from disk,
diff -Nru a/include/linux/pagemap.h b/include/linux/pagemap.h
--- a/include/linux/pagemap.h Sun Nov 25 16:39:44 2001
+++ b/include/linux/pagemap.h Sun Nov 25 16:39:44 2001
@@ -41,53 +41,26 @@
*/
#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
-}
-
-#define page_hash(mapping,index) (page_hash_table+_page_hashfn(mapping,index))
+extern atomic_t page_cache_size; /* # of pages currently in the page cache */
extern struct page * __find_get_page(struct address_space *mapping,
- unsigned long index, struct page **hash);
+ unsigned long index);
#define find_get_page(mapping, index) \
- __find_get_page(mapping, index, page_hash(mapping, index))
+ __find_get_page(mapping, index)
extern struct page * __find_lock_page (struct address_space * mapping,
- unsigned long index, struct page **hash);
+ unsigned long index);
extern struct page * find_or_create_page(struct address_space *mapping,
unsigned long index, unsigned int gfp_mask);
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))
+ __find_lock_page(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 int add_to_page_cache_unique(struct page * page, struct address_space *mapping, unsigned long index);
extern void ___wait_on_page(struct page *);
diff -Nru a/init/main.c b/init/main.c
--- a/init/main.c Sun Nov 25 16:39:44 2001
+++ b/init/main.c Sun Nov 25 16:39:44 2001
@@ -597,7 +597,6 @@
proc_caches_init();
vfs_caches_init(mempages);
buffer_init(mempages);
- page_cache_init(mempages);
#if defined(CONFIG_ARCH_S390)
ccwcache_init();
#endif
diff -Nru a/kernel/ksyms.c b/kernel/ksyms.c
--- a/kernel/ksyms.c Sun Nov 25 16:39:44 2001
+++ b/kernel/ksyms.c Sun Nov 25 16:39:44 2001
@@ -215,8 +215,6 @@
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);
diff -Nru a/mm/Makefile b/mm/Makefile
--- a/mm/Makefile Sun Nov 25 16:39:44 2001
+++ b/mm/Makefile Sun Nov 25 16:39:44 2001
@@ -14,7 +14,7 @@
obj-y := memory.o mmap.o filemap.o mprotect.o mlock.o mremap.o \
vmalloc.o slab.o bootmem.o swap.o vmscan.o page_io.o \
page_alloc.o swap_state.o swapfile.o numa.o oom_kill.o \
- shmem.o
+ shmem.o page_splay.o
obj-$(CONFIG_HIGHMEM) += highmem.o
diff -Nru a/mm/filemap.c b/mm/filemap.c
--- a/mm/filemap.c Sun Nov 25 16:39:44 2001
+++ b/mm/filemap.c Sun Nov 25 16:39:44 2001
@@ -31,6 +31,8 @@
#include <linux/highmem.h>
+#include "page_splay.h"
+
/*
* Shared mappings implemented 30.11.1994. It's not fully working yet,
* though.
@@ -44,8 +46,6 @@
*/
atomic_t page_cache_size = ATOMIC_INIT(0);
-unsigned int page_hash_bits;
-struct page **page_hash_table;
int vm_max_readahead = 31;
int vm_min_readahead = 3;
@@ -53,35 +53,20 @@
EXPORT_SYMBOL(vm_min_readahead);
-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.
+ * with the mapping lock held.
*
* Ordering:
* swap_lock ->
* pagemap_lru_lock ->
- * pagecache_lock
+ * mapping 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)
{
@@ -101,18 +86,6 @@
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;
- 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
@@ -121,18 +94,20 @@
void __remove_inode_page(struct page *page)
{
if (PageDirty(page)) BUG();
+ page_splay_tree_delete (&page->mapping->root, page->index);
remove_page_from_inode_queue(page);
- remove_page_from_hash_queue(page);
+ atomic_dec(&page_cache_size);
}
void remove_inode_page(struct page *page)
{
+ struct address_space *mapping = page->mapping;
if (!PageLocked(page))
PAGE_BUG(page);
- spin_lock(&pagecache_lock);
+ spin_lock(&mapping->i_shared_lock);
__remove_inode_page(page);
- spin_unlock(&pagecache_lock);
+ spin_unlock(&mapping->i_shared_lock);
}
static inline int sync_page(struct page *page)
@@ -153,10 +128,10 @@
struct address_space *mapping = page->mapping;
if (mapping) {
- spin_lock(&pagecache_lock);
+ spin_lock(&mapping->i_shared_lock);
list_del(&page->list);
list_add(&page->list, &mapping->dirty_pages);
- spin_unlock(&pagecache_lock);
+ spin_unlock(&mapping->i_shared_lock);
if (mapping->host)
mark_inode_dirty_pages(mapping->host);
@@ -176,11 +151,12 @@
{
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);
+ spin_lock(&mapping->i_shared_lock);
curr = head->next;
while (curr != head) {
@@ -211,7 +187,7 @@
continue;
}
- spin_unlock(&pagecache_lock);
+ spin_unlock(&mapping->i_shared_lock);
spin_unlock(&pagemap_lru_lock);
}
@@ -250,8 +226,9 @@
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 FASTCALL(truncate_list_pages(struct address_space *, struct list_head *, unsigned long, unsigned *));
+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;
@@ -280,7 +257,7 @@
/* Restart on this page */
list_add(head, curr);
- spin_unlock(&pagecache_lock);
+ spin_unlock(&mapping->i_shared_lock);
unlocked = 1;
if (!failed) {
@@ -301,7 +278,7 @@
schedule();
}
- spin_lock(&pagecache_lock);
+ spin_lock(&mapping->i_shared_lock);
goto restart;
}
curr = curr->prev;
@@ -325,24 +302,25 @@
unsigned partial = lstart & (PAGE_CACHE_SIZE - 1);
int unlocked;
- spin_lock(&pagecache_lock);
+ spin_lock(&mapping->i_shared_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);
+ spin_unlock(&mapping->i_shared_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) {
@@ -351,7 +329,7 @@
list_add_tail(head, curr);
page_cache_get(page);
- spin_unlock(&pagecache_lock);
+ spin_unlock(&mapping->i_shared_lock);
truncate_complete_page(page);
} else {
if (page->buffers) {
@@ -360,7 +338,7 @@
list_add_tail(head, curr);
page_cache_get(page);
- spin_unlock(&pagecache_lock);
+ spin_unlock(&mapping->i_shared_lock);
block_invalidate_page(page);
} else
unlocked = 0;
@@ -372,8 +350,8 @@
return unlocked;
}
-static int FASTCALL(invalidate_list_pages2(struct list_head *));
-static int invalidate_list_pages2(struct list_head *head)
+static int FASTCALL(invalidate_list_pages2(struct address_space *mapping, struct list_head *));
+static int invalidate_list_pages2(struct address_space *mapping, struct list_head *head)
{
struct list_head *curr;
struct page * page;
@@ -387,7 +365,7 @@
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) {
@@ -400,7 +378,7 @@
list_add(head, curr);
page_cache_get(page);
- spin_unlock(&pagecache_lock);
+ spin_unlock(&mapping->i_shared_lock);
unlocked = 1;
wait_on_page(page);
}
@@ -411,7 +389,7 @@
schedule();
}
- spin_lock(&pagecache_lock);
+ spin_lock(&mapping->i_shared_lock);
goto restart;
}
return unlocked;
@@ -426,32 +404,13 @@
{
int unlocked;
- spin_lock(&pagecache_lock);
+ spin_lock(&mapping->i_shared_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);
-}
-
-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;
+ spin_unlock(&mapping->i_shared_lock);
}
/*
@@ -489,13 +448,14 @@
return error;
}
-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);
+ spin_lock(&mapping->i_shared_lock);
curr = head->next;
while (curr != head) {
page = list_entry(curr, struct page, list);
@@ -508,7 +468,7 @@
continue;
page_cache_get(page);
- spin_unlock(&pagecache_lock);
+ spin_unlock(&mapping->i_shared_lock);
lock_page(page);
/* The buffers could have been free'd while we waited for the page lock */
@@ -516,11 +476,11 @@
retval |= fn(page);
UnlockPage(page);
- spin_lock(&pagecache_lock);
+ spin_lock(&mapping->i_shared_lock);
curr = page->list.next;
page_cache_release(page);
}
- spin_unlock(&pagecache_lock);
+ spin_unlock(&mapping->i_shared_lock);
return retval;
}
@@ -531,17 +491,18 @@
*/
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;
}
@@ -586,7 +547,7 @@
{
int (*writepage)(struct page *) = mapping->a_ops->writepage;
- spin_lock(&pagecache_lock);
+ spin_lock(&mapping->i_shared_lock);
while (!list_empty(&mapping->dirty_pages)) {
struct page *page = list_entry(mapping->dirty_pages.next, struct page, list);
@@ -598,7 +559,7 @@
continue;
page_cache_get(page);
- spin_unlock(&pagecache_lock);
+ spin_unlock(&mapping->i_shared_lock);
lock_page(page);
@@ -609,9 +570,9 @@
UnlockPage(page);
page_cache_release(page);
- spin_lock(&pagecache_lock);
+ spin_lock(&mapping->i_shared_lock);
}
- spin_unlock(&pagecache_lock);
+ spin_unlock(&mapping->i_shared_lock);
}
/**
@@ -623,7 +584,7 @@
*/
void filemap_fdatawait(struct address_space * mapping)
{
- spin_lock(&pagecache_lock);
+ spin_lock(&mapping->i_shared_lock);
while (!list_empty(&mapping->locked_pages)) {
struct page *page = list_entry(mapping->locked_pages.next, struct page, list);
@@ -635,14 +596,14 @@
continue;
page_cache_get(page);
- spin_unlock(&pagecache_lock);
+ spin_unlock(&mapping->i_shared_lock);
___wait_on_page(page);
page_cache_release(page);
- spin_lock(&pagecache_lock);
+ spin_lock(&mapping->i_shared_lock);
}
- spin_unlock(&pagecache_lock);
+ spin_unlock(&mapping->i_shared_lock);
}
/*
@@ -658,10 +619,11 @@
page->index = index;
page_cache_get(page);
- spin_lock(&pagecache_lock);
+ spin_lock (&mapping->i_shared_lock);
add_page_to_inode_queue(mapping, page);
- add_page_to_hash_queue(page, page_hash(mapping, index));
- spin_unlock(&pagecache_lock);
+ page_splay_tree_insert (&mapping->root, page);
+ atomic_inc(&page_cache_size);
+ spin_unlock(&mapping->i_shared_lock);
lru_cache_add(page);
}
@@ -671,8 +633,7 @@
* owned by us, but unreferenced, not uptodate and with no errors.
*/
static inline void __add_to_page_cache(struct page * page,
- struct address_space *mapping, unsigned long offset,
- struct page **hash)
+ struct address_space *mapping, unsigned long offset)
{
unsigned long flags;
@@ -681,34 +642,34 @@
page_cache_get(page);
page->index = offset;
add_page_to_inode_queue(mapping, page);
- add_page_to_hash_queue(page, hash);
+ page_splay_tree_insert (&mapping->root, page);
+ atomic_inc(&page_cache_size);
}
void 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);
+ spin_lock(&mapping->i_shared_lock);
+ __add_to_page_cache(page, mapping, offset);
+ spin_unlock(&mapping->i_shared_lock);
lru_cache_add(page);
}
int add_to_page_cache_unique(struct page * page,
- struct address_space *mapping, unsigned long offset,
- struct page **hash)
+ struct address_space *mapping, unsigned long offset)
{
int err;
struct page *alias;
- spin_lock(&pagecache_lock);
- alias = __find_page_nolock(mapping, offset, *hash);
+ spin_lock(&mapping->i_shared_lock);
+ alias = page_splay_tree_find (&mapping->root, offset);
err = 1;
if (!alias) {
- __add_to_page_cache(page,mapping,offset,hash);
+ __add_to_page_cache(page,mapping,offset);
err = 0;
}
- spin_unlock(&pagecache_lock);
+ spin_unlock(&mapping->i_shared_lock);
if (!err)
lru_cache_add(page);
return err;
@@ -722,12 +683,11 @@
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;
- spin_lock(&pagecache_lock);
- page = __find_page_nolock(mapping, offset, *hash);
- spin_unlock(&pagecache_lock);
+ spin_lock(&mapping->i_shared_lock);
+ page = page_splay_tree_find (&mapping->root, offset);
+ spin_unlock(&mapping->i_shared_lock);
if (page)
return 0;
@@ -735,7 +695,7 @@
if (!page)
return -ENOMEM;
- if (!add_to_page_cache_unique(page, mapping, offset, hash)) {
+ if (!add_to_page_cache_unique(page, mapping, offset)) {
int error = mapping->a_ops->readpage(file, page);
page_cache_release(page);
return error;
@@ -844,7 +804,7 @@
* hashed page atomically.
*/
struct page * __find_get_page(struct address_space *mapping,
- unsigned long offset, struct page **hash)
+ unsigned long offset)
{
struct page *page;
@@ -852,11 +812,11 @@
* 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);
+ spin_lock(&mapping->i_shared_lock);
+ page = page_splay_tree_find (&mapping->root, offset);
if (page)
page_cache_get(page);
- spin_unlock(&pagecache_lock);
+ spin_unlock(&mapping->i_shared_lock);
return page;
}
@@ -866,15 +826,14 @@
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);
+ spin_lock(&mapping->i_shared_lock);
+ page = page_splay_tree_find (&mapping->root, offset);
if (page) {
if (TryLockPage(page))
page = NULL;
}
- spin_unlock(&pagecache_lock);
+ spin_unlock(&mapping->i_shared_lock);
return page;
}
@@ -883,9 +842,9 @@
* 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 * FASTCALL(__find_lock_page_helper(struct address_space *, unsigned long));
static struct page * __find_lock_page_helper(struct address_space *mapping,
- unsigned long offset, struct page *hash)
+ unsigned long offset)
{
struct page *page;
@@ -894,13 +853,13 @@
* the hash-list needs a held write-lock.
*/
repeat:
- page = __find_page_nolock(mapping, offset, hash);
+ page = page_splay_tree_find (&mapping->root, offset);
if (page) {
page_cache_get(page);
if (TryLockPage(page)) {
- spin_unlock(&pagecache_lock);
+ spin_unlock(&mapping->i_shared_lock);
lock_page(page);
- spin_lock(&pagecache_lock);
+ spin_lock(&mapping->i_shared_lock);
/* Has the page been re-allocated while we slept? */
if (page->mapping != mapping || page->index != offset) {
@@ -918,13 +877,13 @@
* it's still valid once we own it.
*/
struct page * __find_lock_page (struct address_space *mapping,
- unsigned long offset, struct page **hash)
+ unsigned long offset)
{
struct page *page;
- spin_lock(&pagecache_lock);
- page = __find_lock_page_helper(mapping, offset, *hash);
- spin_unlock(&pagecache_lock);
+ spin_lock(&mapping->i_shared_lock);
+ page = __find_lock_page_helper(mapping, offset);
+ spin_unlock(&mapping->i_shared_lock);
return page;
}
@@ -934,23 +893,22 @@
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);
+ spin_lock(&mapping->i_shared_lock);
+ page = __find_lock_page_helper(mapping, index);
+ spin_unlock(&mapping->i_shared_lock);
if (!page) {
struct page *newpage = alloc_page(gfp_mask);
page = ERR_PTR(-ENOMEM);
if (newpage) {
- spin_lock(&pagecache_lock);
- page = __find_lock_page_helper(mapping, index, *hash);
+ spin_lock(&mapping->i_shared_lock);
+ page = __find_lock_page_helper(mapping, index);
if (likely(!page)) {
page = newpage;
- __add_to_page_cache(page, mapping, index, hash);
+ __add_to_page_cache(page, mapping, index);
newpage = NULL;
}
- spin_unlock(&pagecache_lock);
+ spin_unlock(&mapping->i_shared_lock);
if (newpage == NULL)
lru_cache_add(page);
else
@@ -977,10 +935,9 @@
*/
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) ) {
@@ -1005,7 +962,7 @@
if ( unlikely(!page) )
return NULL; /* Failed to allocate a page */
- if ( unlikely(add_to_page_cache_unique(page, mapping, index, hash)) ) {
+ if ( unlikely(add_to_page_cache_unique(page, mapping, index)) ) {
/* Someone else grabbed the page already. */
page_cache_release(page);
return NULL;
@@ -1330,7 +1287,7 @@
}
for (;;) {
- struct page *page, **hash;
+ struct page *page;
unsigned long end_index, nr, ret;
end_index = inode->i_size >> PAGE_CACHE_SHIFT;
@@ -1349,15 +1306,14 @@
/*
* 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);
+ spin_lock(&mapping->i_shared_lock);
+ page = page_splay_tree_find (&mapping->root, index);
if (!page)
goto no_cached_page;
found_page:
page_cache_get(page);
- spin_unlock(&pagecache_lock);
+ spin_unlock(&mapping->i_shared_lock);
if (!Page_Uptodate(page))
goto page_not_up_to_date;
@@ -1451,7 +1407,7 @@
* We get here with the page cache lock held.
*/
if (!cached_page) {
- spin_unlock(&pagecache_lock);
+ spin_unlock(&mapping->i_shared_lock);
cached_page = page_cache_alloc(mapping);
if (!cached_page) {
desc->error = -ENOMEM;
@@ -1462,8 +1418,8 @@
* 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);
+ spin_lock(&mapping->i_shared_lock);
+ page = page_splay_tree_find (&mapping->root, index);
if (page)
goto found_page;
}
@@ -1472,8 +1428,8 @@
* Ok, add the new page to the hash-queues...
*/
page = cached_page;
- __add_to_page_cache(page, mapping, index, hash);
- spin_unlock(&pagecache_lock);
+ __add_to_page_cache(page, mapping, index);
+ spin_unlock(&mapping->i_shared_lock);
lru_cache_add(page);
cached_page = NULL;
@@ -1873,7 +1829,7 @@
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;
@@ -1895,9 +1851,8 @@
/*
* 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;
@@ -2582,13 +2537,13 @@
{
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;
- spin_lock(&pagecache_lock);
- page = __find_page_nolock(as, pgoff, *hash);
+ spin_lock(&as->i_shared_lock);
+ page = page_splay_tree_find (&as->root, pgoff);
if ((page) && (Page_Uptodate(page)))
present = 1;
- spin_unlock(&pagecache_lock);
+ spin_unlock(&as->i_shared_lock);
return present;
}
@@ -2731,11 +2686,10 @@
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);
@@ -2743,7 +2697,7 @@
return ERR_PTR(-ENOMEM);
}
page = cached_page;
- if (add_to_page_cache_unique(page, mapping, index, hash))
+ if (add_to_page_cache_unique(page, mapping, index))
goto repeat;
cached_page = NULL;
err = filler(data, page);
@@ -2799,9 +2753,9 @@
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);
+ 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);
@@ -2809,7 +2763,7 @@
return NULL;
}
page = *cached_page;
- if (add_to_page_cache_unique(page, mapping, index, hash))
+ if (add_to_page_cache_unique(page, mapping, index))
goto repeat;
*cached_page = NULL;
}
@@ -3072,29 +3026,3 @@
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 *));
-}
diff -Nru a/mm/page_splay.c b/mm/page_splay.c
--- /dev/null Wed Dec 31 16:00:00 1969
+++ b/mm/page_splay.c Sun Nov 25 16:39:44 2001
@@ -0,0 +1,136 @@
+/* Self-adjusting binary search tree (splay tree).
+ *
+ * Copyright (C) 1999, 2000, 2001 Momchil Velikov
+ *
+ * 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/mm.h>
+
+struct page *
+page_splay_tree_splay (struct page *t, unsigned long k)
+{
+ struct page N, *l, *r, *x;
+
+ if (t == 0)
+ return 0;
+
+ N.left = N.right = 0;
+ l = r = &N;
+
+ for (;;) {
+ if (k < t->index) {
+ x = t->left;
+ if (x == 0)
+ break;
+ if (k < x->index) {
+ t->left = x->right;
+ x->right = t;
+ t = x;
+ if (t->left == 0)
+ break;
+ }
+ r->left = t;
+ r = t;
+ t = t->left;
+ } else if (k > t->index) {
+ x = t->right;
+ if (x == 0)
+ break;
+ if (k > x->index) {
+ t->right = x->left;
+ x->left = t;
+ t = x;
+ if (t->right == 0)
+ break;
+ }
+ l->right = t;
+ l = t;
+ t = t->right;
+ }
+ else
+ break;
+ }
+
+ l->right = r->left = 0;
+
+ l->right = t->left;
+ r->left = t->right;
+ t->left = N.right;
+ t->right = N.left;
+
+ return t;
+}
+
+int
+page_splay_tree_insert (struct page **pt, struct page *k)
+{
+ struct page *t;
+
+ t = *pt;
+ if (t == 0) {
+ *pt = k;
+ return 0;
+ }
+
+ t = page_splay_tree_splay (t, k->index);
+
+ if (k->index < t->index) {
+ k->left = t->left;
+ k->right = t;
+ t->left = 0;
+
+ *pt = k;
+ return 0;
+ }
+
+ if (k->index > t->index) {
+ k->right = t->right;
+ k->left = t;
+ t->right = 0;
+
+ *pt = k;
+ return 0;
+ }
+
+ return -1;
+}
+
+struct page *
+page_splay_tree_delete (struct page **r, unsigned long k)
+{
+ struct page *t, *x;
+
+ if ((t = *r) == 0)
+ return 0;
+
+ t = page_splay_tree_splay (t, k);
+
+ if (t->index == k) {
+ if (t->left == 0)
+ x = t->right;
+ else {
+ x = page_splay_tree_splay (t->left, k);
+ x->right = t->right;
+ }
+
+ *r = x;
+
+ t->left = t->right = 0;
+ return t;
+ } else {
+ *r = t;
+ return 0;
+ }
+}
diff -Nru a/mm/page_splay.h b/mm/page_splay.h
--- /dev/null Wed Dec 31 16:00:00 1969
+++ b/mm/page_splay.h Sun Nov 25 16:39:44 2001
@@ -0,0 +1,36 @@
+/* Self-adjusting binary search tree (splay tree).
+ *
+ * Copyright (C) 1999, 2000, 2001 Momchil Velikov
+ *
+ * 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 _PAGE_SPLAY_H
+#define _PAGE_SPLAY_H
+
+struct page;
+extern struct page * page_splay_tree_splay (struct page *t, unsigned long k);
+extern int page_splay_tree_insert (struct page **pt, struct page *k);
+extern struct page *page_splay_tree_delete (struct page **r, unsigned long k);
+
+static inline struct page *
+page_splay_tree_find (struct page **r, unsigned long k) {
+ *r = page_splay_tree_splay (*r, k);
+
+ if (*r && (*r)->index == k)
+ return *r;
+ else
+ return 0;
+}
+#endif /* _PAGE_SPLAY_H */
diff -Nru a/mm/swap_state.c b/mm/swap_state.c
--- a/mm/swap_state.c Sun Nov 25 16:39:44 2001
+++ b/mm/swap_state.c Sun Nov 25 16:39:44 2001
@@ -75,8 +75,7 @@
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) {
+ if (add_to_page_cache_unique(page, &swapper_space, entry.val) != 0) {
swap_free(entry);
INC_CACHE_INFO(exist_race);
return -EEXIST;
@@ -121,9 +120,9 @@
entry.val = page->index;
- spin_lock(&pagecache_lock);
+ spin_lock(&swapper_space.i_shared_lock);
__delete_from_swap_cache(page);
- spin_unlock(&pagecache_lock);
+ spin_unlock(&swapper_space.i_shared_lock);
swap_free(entry);
page_cache_release(page);
diff -Nru a/mm/swapfile.c b/mm/swapfile.c
--- a/mm/swapfile.c Sun Nov 25 16:39:44 2001
+++ b/mm/swapfile.c Sun Nov 25 16:39:44 2001
@@ -239,10 +239,10 @@
/* 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);
+ spin_lock(&swapper_space.i_shared_lock);
if (page_count(page) - !!page->buffers == 2)
retval = 1;
- spin_unlock(&pagecache_lock);
+ spin_unlock(&swapper_space.i_shared_lock);
}
swap_info_put(p);
}
@@ -307,13 +307,13 @@
retval = 0;
if (p->swap_map[SWP_OFFSET(entry)] == 1) {
/* Recheck the page count with the pagecache lock held.. */
- spin_lock(&pagecache_lock);
+ spin_lock(&swapper_space.i_shared_lock);
if (page_count(page) - !!page->buffers == 2) {
__delete_from_swap_cache(page);
SetPageDirty(page);
retval = 1;
}
- spin_unlock(&pagecache_lock);
+ spin_unlock(&swapper_space.i_shared_lock);
}
swap_info_put(p);
diff -Nru a/mm/vmscan.c b/mm/vmscan.c
--- a/mm/vmscan.c Sun Nov 25 16:39:44 2001
+++ b/mm/vmscan.c Sun Nov 25 16:39:44 2001
@@ -337,6 +337,7 @@
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);
@@ -391,7 +392,9 @@
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
@@ -402,7 +405,7 @@
*/
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);
@@ -429,7 +432,7 @@
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
@@ -466,13 +469,22 @@
}
}
- spin_lock(&pagecache_lock);
+ /*
+ * Page is locked, so mapping can't change under our
+ * feet.
+ */
+ if (!mapping) {
+ UnlockPage (page);
+ goto page_mapped;
+ }
+
+ spin_lock(&mapping->i_shared_lock);
/*
* this is the non-racy check for busy page.
*/
- if (!page->mapping || !is_page_cache_freeable(page)) {
- spin_unlock(&pagecache_lock);
+ if (!is_page_cache_freeable(page)) {
+ spin_unlock(&mapping->i_shared_lock);
UnlockPage(page);
page_mapped:
if (--max_mapped >= 0)
@@ -492,7 +504,7 @@
* the page is freeable* so not in use by anybody.
*/
if (PageDirty(page)) {
- spin_unlock(&pagecache_lock);
+ spin_unlock(&mapping->i_shared_lock);
UnlockPage(page);
continue;
}
@@ -500,12 +512,12 @@
/* point of no return */
if (likely(!PageSwapCache(page))) {
__remove_inode_page(page);
- spin_unlock(&pagecache_lock);
+ spin_unlock(&mapping->i_shared_lock);
} else {
swp_entry_t swap;
swap.val = page->index;
__delete_from_swap_cache(page);
- spin_unlock(&pagecache_lock);
+ spin_unlock(&mapping->i_shared_lock);
swap_free(swap);
}
-
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