From: Bill Irwin <bill.irwin@oracle.com>
Convert mapping->tree_lock to an rwlock. The use of an rwlock was found to
be a significant improvement over a spinlock in performance testing at
Oracle. <insert upcoming results here>
Signed-off-by: Andrew Morton <akpm@osdl.org>
---
25-akpm/fs/buffer.c | 4 ++--
25-akpm/fs/inode.c | 2 +-
25-akpm/include/asm-arm/cacheflush.h | 4 ++--
25-akpm/include/asm-parisc/cacheflush.h | 4 ++--
25-akpm/include/linux/fs.h | 2 +-
25-akpm/mm/filemap.c | 32 ++++++++++++++++----------------
25-akpm/mm/page-writeback.c | 28 ++++++++++++++--------------
25-akpm/mm/readahead.c | 8 ++++----
25-akpm/mm/swap_state.c | 18 +++++++++---------
25-akpm/mm/swapfile.c | 12 ++++++------
25-akpm/mm/truncate.c | 6 +++---
25-akpm/mm/vmscan.c | 8 ++++----
12 files changed, 64 insertions(+), 64 deletions(-)
diff -puN fs/buffer.c~make-tree_lock-an-rwlock fs/buffer.c
--- 25/fs/buffer.c~make-tree_lock-an-rwlock Wed Jun 2 15:12:34 2004
+++ 25-akpm/fs/buffer.c Wed Jun 2 15:12:34 2004
@@ -947,7 +947,7 @@ int __set_page_dirty_buffers(struct page
spin_unlock(&mapping->private_lock);
if (!TestSetPageDirty(page)) {
- spin_lock_irq(&mapping->tree_lock);
+ write_lock_irq(&mapping->tree_lock);
if (page->mapping) { /* Race with truncate? */
if (!mapping->backing_dev_info->memory_backed)
inc_page_state(nr_dirty);
@@ -955,7 +955,7 @@ int __set_page_dirty_buffers(struct page
page_index(page),
PAGECACHE_TAG_DIRTY);
}
- spin_unlock_irq(&mapping->tree_lock);
+ write_unlock_irq(&mapping->tree_lock);
__mark_inode_dirty(mapping->host, I_DIRTY_PAGES);
}
diff -puN fs/inode.c~make-tree_lock-an-rwlock fs/inode.c
--- 25/fs/inode.c~make-tree_lock-an-rwlock Wed Jun 2 15:12:34 2004
+++ 25-akpm/fs/inode.c Wed Jun 2 15:12:34 2004
@@ -195,7 +195,7 @@ void inode_init_once(struct inode *inode
sema_init(&inode->i_sem, 1);
init_rwsem(&inode->i_alloc_sem);
INIT_RADIX_TREE(&inode->i_data.page_tree, GFP_ATOMIC);
- spin_lock_init(&inode->i_data.tree_lock);
+ rwlock_init(&inode->i_data.tree_lock);
spin_lock_init(&inode->i_data.i_mmap_lock);
atomic_set(&inode->i_data.truncate_count, 0);
INIT_LIST_HEAD(&inode->i_data.private_list);
diff -puN include/asm-arm/cacheflush.h~make-tree_lock-an-rwlock include/asm-arm/cacheflush.h
--- 25/include/asm-arm/cacheflush.h~make-tree_lock-an-rwlock Wed Jun 2 15:12:34 2004
+++ 25-akpm/include/asm-arm/cacheflush.h Wed Jun 2 15:12:34 2004
@@ -304,9 +304,9 @@ static inline void flush_dcache_page(str
}
#define flush_dcache_mmap_lock(mapping) \
- spin_lock_irq(&(mapping)->tree_lock)
+ write_lock_irq(&(mapping)->tree_lock)
#define flush_dcache_mmap_unlock(mapping) \
- spin_unlock_irq(&(mapping)->tree_lock)
+ write_unlock_irq(&(mapping)->tree_lock)
#define flush_icache_user_range(vma,page,addr,len) \
flush_dcache_page(page)
diff -puN include/asm-parisc/cacheflush.h~make-tree_lock-an-rwlock include/asm-parisc/cacheflush.h
--- 25/include/asm-parisc/cacheflush.h~make-tree_lock-an-rwlock Wed Jun 2 15:12:34 2004
+++ 25-akpm/include/asm-parisc/cacheflush.h Wed Jun 2 15:12:34 2004
@@ -79,9 +79,9 @@ static inline void flush_dcache_page(str
}
#define flush_dcache_mmap_lock(mapping) \
- spin_lock_irq(&(mapping)->tree_lock)
+ write_lock_irq(&(mapping)->tree_lock)
#define flush_dcache_mmap_unlock(mapping) \
- spin_unlock_irq(&(mapping)->tree_lock)
+ write_unlock_irq(&(mapping)->tree_lock)
#define flush_icache_page(vma,page) do { flush_kernel_dcache_page(page_address(page)); flush_kernel_icache_page(page_address(page)); } while (0)
diff -puN include/linux/fs.h~make-tree_lock-an-rwlock include/linux/fs.h
--- 25/include/linux/fs.h~make-tree_lock-an-rwlock Wed Jun 2 15:12:34 2004
+++ 25-akpm/include/linux/fs.h Wed Jun 2 15:12:34 2004
@@ -326,7 +326,7 @@ struct backing_dev_info;
struct address_space {
struct inode *host; /* owner: inode, block_device */
struct radix_tree_root page_tree; /* radix tree of all pages */
- spinlock_t tree_lock; /* and spinlock protecting it */
+ rwlock_t tree_lock; /* and rwlock protecting it */
unsigned long nrpages; /* number of total pages */
pgoff_t writeback_index;/* writeback starts here */
struct address_space_operations *a_ops; /* methods */
diff -puN mm/filemap.c~make-tree_lock-an-rwlock mm/filemap.c
--- 25/mm/filemap.c~make-tree_lock-an-rwlock Wed Jun 2 15:12:34 2004
+++ 25-akpm/mm/filemap.c Wed Jun 2 15:12:34 2004
@@ -114,9 +114,9 @@ void remove_from_page_cache(struct page
if (unlikely(!PageLocked(page)))
PAGE_BUG(page);
- spin_lock_irq(&mapping->tree_lock);
+ write_lock_irq(&mapping->tree_lock);
__remove_from_page_cache(page);
- spin_unlock_irq(&mapping->tree_lock);
+ write_unlock_irq(&mapping->tree_lock);
}
static inline int sync_page(struct page *page)
@@ -253,7 +253,7 @@ int add_to_page_cache(struct page *page,
int error = radix_tree_preload(gfp_mask & ~__GFP_HIGHMEM);
if (error == 0) {
- spin_lock_irq(&mapping->tree_lock);
+ write_lock_irq(&mapping->tree_lock);
error = radix_tree_insert(&mapping->page_tree, offset, page);
if (!error) {
page_cache_get(page);
@@ -263,7 +263,7 @@ int add_to_page_cache(struct page *page,
mapping->nrpages++;
pagecache_acct(1);
}
- spin_unlock_irq(&mapping->tree_lock);
+ write_unlock_irq(&mapping->tree_lock);
radix_tree_preload_end();
}
return error;
@@ -436,11 +436,11 @@ struct page * find_get_page(struct addre
* We scan the hash list read-only. Addition to and removal from
* the hash-list needs a held write-lock.
*/
- spin_lock_irq(&mapping->tree_lock);
+ read_lock_irq(&mapping->tree_lock);
page = radix_tree_lookup(&mapping->page_tree, offset);
if (page)
page_cache_get(page);
- spin_unlock_irq(&mapping->tree_lock);
+ read_unlock_irq(&mapping->tree_lock);
return page;
}
@@ -453,11 +453,11 @@ struct page *find_trylock_page(struct ad
{
struct page *page;
- spin_lock_irq(&mapping->tree_lock);
+ read_lock_irq(&mapping->tree_lock);
page = radix_tree_lookup(&mapping->page_tree, offset);
if (page && TestSetPageLocked(page))
page = NULL;
- spin_unlock_irq(&mapping->tree_lock);
+ read_unlock_irq(&mapping->tree_lock);
return page;
}
@@ -479,15 +479,15 @@ struct page *find_lock_page(struct addre
{
struct page *page;
- spin_lock_irq(&mapping->tree_lock);
+ read_lock_irq(&mapping->tree_lock);
repeat:
page = radix_tree_lookup(&mapping->page_tree, offset);
if (page) {
page_cache_get(page);
if (TestSetPageLocked(page)) {
- spin_unlock_irq(&mapping->tree_lock);
+ read_unlock_irq(&mapping->tree_lock);
lock_page(page);
- spin_lock_irq(&mapping->tree_lock);
+ read_lock_irq(&mapping->tree_lock);
/* Has the page been truncated while we slept? */
if (page->mapping != mapping || page->index != offset) {
@@ -497,7 +497,7 @@ repeat:
}
}
}
- spin_unlock_irq(&mapping->tree_lock);
+ read_unlock_irq(&mapping->tree_lock);
return page;
}
@@ -571,12 +571,12 @@ unsigned find_get_pages(struct address_s
unsigned int i;
unsigned int ret;
- spin_lock_irq(&mapping->tree_lock);
+ read_lock_irq(&mapping->tree_lock);
ret = radix_tree_gang_lookup(&mapping->page_tree,
(void **)pages, start, nr_pages);
for (i = 0; i < ret; i++)
page_cache_get(pages[i]);
- spin_unlock_irq(&mapping->tree_lock);
+ read_unlock_irq(&mapping->tree_lock);
return ret;
}
@@ -590,14 +590,14 @@ unsigned find_get_pages_tag(struct addre
unsigned int i;
unsigned int ret;
- spin_lock_irq(&mapping->tree_lock);
+ read_lock_irq(&mapping->tree_lock);
ret = radix_tree_gang_lookup_tag(&mapping->page_tree,
(void **)pages, *index, nr_pages, tag);
for (i = 0; i < ret; i++)
page_cache_get(pages[i]);
if (ret)
*index = pages[ret - 1]->index + 1;
- spin_unlock_irq(&mapping->tree_lock);
+ read_unlock_irq(&mapping->tree_lock);
return ret;
}
diff -puN mm/page-writeback.c~make-tree_lock-an-rwlock mm/page-writeback.c
--- 25/mm/page-writeback.c~make-tree_lock-an-rwlock Wed Jun 2 15:12:34 2004
+++ 25-akpm/mm/page-writeback.c Wed Jun 2 15:12:34 2004
@@ -566,7 +566,7 @@ int __set_page_dirty_nobuffers(struct pa
struct address_space *mapping = page_mapping(page);
if (mapping) {
- spin_lock_irq(&mapping->tree_lock);
+ write_lock_irq(&mapping->tree_lock);
mapping = page_mapping(page);
if (page_mapping(page)) { /* Race with truncate? */
BUG_ON(page_mapping(page) != mapping);
@@ -575,7 +575,7 @@ int __set_page_dirty_nobuffers(struct pa
radix_tree_tag_set(&mapping->page_tree,
page_index(page), PAGECACHE_TAG_DIRTY);
}
- spin_unlock_irq(&mapping->tree_lock);
+ write_unlock_irq(&mapping->tree_lock);
if (mapping->host) {
/* !PageAnon && !swapper_space */
__mark_inode_dirty(mapping->host,
@@ -650,17 +650,17 @@ int test_clear_page_dirty(struct page *p
unsigned long flags;
if (mapping) {
- spin_lock_irqsave(&mapping->tree_lock, flags);
+ write_lock_irqsave(&mapping->tree_lock, flags);
if (TestClearPageDirty(page)) {
radix_tree_tag_clear(&mapping->page_tree,
page_index(page),
PAGECACHE_TAG_DIRTY);
- spin_unlock_irqrestore(&mapping->tree_lock, flags);
+ write_unlock_irqrestore(&mapping->tree_lock, flags);
if (!mapping->backing_dev_info->memory_backed)
dec_page_state(nr_dirty);
return 1;
}
- spin_unlock_irqrestore(&mapping->tree_lock, flags);
+ write_unlock_irqrestore(&mapping->tree_lock, flags);
return 0;
}
return TestClearPageDirty(page);
@@ -707,15 +707,15 @@ int __clear_page_dirty(struct page *page
if (mapping) {
unsigned long flags;
- spin_lock_irqsave(&mapping->tree_lock, flags);
+ write_lock_irqsave(&mapping->tree_lock, flags);
if (TestClearPageDirty(page)) {
radix_tree_tag_clear(&mapping->page_tree,
page_index(page),
PAGECACHE_TAG_DIRTY);
- spin_unlock_irqrestore(&mapping->tree_lock, flags);
+ write_unlock_irqrestore(&mapping->tree_lock, flags);
return 1;
}
- spin_unlock_irqrestore(&mapping->tree_lock, flags);
+ write_unlock_irqrestore(&mapping->tree_lock, flags);
return 0;
}
return TestClearPageDirty(page);
@@ -729,13 +729,13 @@ int test_clear_page_writeback(struct pag
if (mapping) {
unsigned long flags;
- spin_lock_irqsave(&mapping->tree_lock, flags);
+ write_lock_irqsave(&mapping->tree_lock, flags);
ret = TestClearPageWriteback(page);
if (ret)
radix_tree_tag_clear(&mapping->page_tree,
page_index(page),
PAGECACHE_TAG_WRITEBACK);
- spin_unlock_irqrestore(&mapping->tree_lock, flags);
+ write_unlock_irqrestore(&mapping->tree_lock, flags);
} else {
ret = TestClearPageWriteback(page);
}
@@ -750,7 +750,7 @@ int test_set_page_writeback(struct page
if (mapping) {
unsigned long flags;
- spin_lock_irqsave(&mapping->tree_lock, flags);
+ write_lock_irqsave(&mapping->tree_lock, flags);
ret = TestSetPageWriteback(page);
if (!ret)
radix_tree_tag_set(&mapping->page_tree,
@@ -760,7 +760,7 @@ int test_set_page_writeback(struct page
radix_tree_tag_clear(&mapping->page_tree,
page_index(page),
PAGECACHE_TAG_DIRTY);
- spin_unlock_irqrestore(&mapping->tree_lock, flags);
+ write_unlock_irqrestore(&mapping->tree_lock, flags);
} else {
ret = TestSetPageWriteback(page);
}
@@ -778,9 +778,9 @@ int mapping_tagged(struct address_space
unsigned long flags;
int ret;
- spin_lock_irqsave(&mapping->tree_lock, flags);
+ read_lock_irqsave(&mapping->tree_lock, flags);
ret = radix_tree_tagged(&mapping->page_tree, tag);
- spin_unlock_irqrestore(&mapping->tree_lock, flags);
+ read_unlock_irqrestore(&mapping->tree_lock, flags);
return ret;
}
EXPORT_SYMBOL(mapping_tagged);
diff -puN mm/readahead.c~make-tree_lock-an-rwlock mm/readahead.c
--- 25/mm/readahead.c~make-tree_lock-an-rwlock Wed Jun 2 15:12:34 2004
+++ 25-akpm/mm/readahead.c Wed Jun 2 15:12:34 2004
@@ -234,7 +234,7 @@ __do_page_cache_readahead(struct address
/*
* Preallocate as many pages as we will need.
*/
- spin_lock_irq(&mapping->tree_lock);
+ read_lock_irq(&mapping->tree_lock);
for (page_idx = 0; page_idx < nr_to_read; page_idx++) {
unsigned long page_offset = offset + page_idx;
@@ -245,16 +245,16 @@ __do_page_cache_readahead(struct address
if (page)
continue;
- spin_unlock_irq(&mapping->tree_lock);
+ read_unlock_irq(&mapping->tree_lock);
page = page_cache_alloc_cold(mapping);
- spin_lock_irq(&mapping->tree_lock);
+ read_lock_irq(&mapping->tree_lock);
if (!page)
break;
page->index = page_offset;
list_add(&page->lru, &page_pool);
ret++;
}
- spin_unlock_irq(&mapping->tree_lock);
+ read_unlock_irq(&mapping->tree_lock);
/*
* Now start the IO. We ignore I/O errors - if the page is not
diff -puN mm/swapfile.c~make-tree_lock-an-rwlock mm/swapfile.c
--- 25/mm/swapfile.c~make-tree_lock-an-rwlock Wed Jun 2 15:12:34 2004
+++ 25-akpm/mm/swapfile.c Wed Jun 2 15:12:34 2004
@@ -290,10 +290,10 @@ 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 swapcache lock held.. */
- spin_lock_irq(&swapper_space.tree_lock);
+ write_lock_irq(&swapper_space.tree_lock);
if (page_count(page) == 2)
retval = 1;
- spin_unlock_irq(&swapper_space.tree_lock);
+ write_unlock_irq(&swapper_space.tree_lock);
}
swap_info_put(p);
}
@@ -361,13 +361,13 @@ int remove_exclusive_swap_page(struct pa
retval = 0;
if (p->swap_map[swp_offset(entry)] == 1) {
/* Recheck the page count with the swapcache lock held.. */
- spin_lock_irq(&swapper_space.tree_lock);
+ write_lock_irq(&swapper_space.tree_lock);
if ((page_count(page) == 2) && !PageWriteback(page)) {
__delete_from_swap_cache(page);
SetPageDirty(page);
retval = 1;
}
- spin_unlock_irq(&swapper_space.tree_lock);
+ write_unlock_irq(&swapper_space.tree_lock);
}
swap_info_put(p);
@@ -391,12 +391,12 @@ void free_swap_and_cache(swp_entry_t ent
p = swap_info_get(entry);
if (p) {
if (swap_entry_free(p, swp_offset(entry)) == 1) {
- spin_lock_irq(&swapper_space.tree_lock);
+ read_lock_irq(&swapper_space.tree_lock);
page = radix_tree_lookup(&swapper_space.page_tree,
entry.val);
if (page && TestSetPageLocked(page))
page = NULL;
- spin_unlock_irq(&swapper_space.tree_lock);
+ read_unlock_irq(&swapper_space.tree_lock);
}
swap_info_put(p);
}
diff -puN mm/swap_state.c~make-tree_lock-an-rwlock mm/swap_state.c
--- 25/mm/swap_state.c~make-tree_lock-an-rwlock Wed Jun 2 15:12:34 2004
+++ 25-akpm/mm/swap_state.c Wed Jun 2 15:12:34 2004
@@ -35,7 +35,7 @@ static struct backing_dev_info swap_back
struct address_space swapper_space = {
.page_tree = RADIX_TREE_INIT(GFP_ATOMIC),
- .tree_lock = SPIN_LOCK_UNLOCKED,
+ .tree_lock = RW_LOCK_UNLOCKED,
.a_ops = &swap_aops,
.i_mmap_nonlinear = LIST_HEAD_INIT(swapper_space.i_mmap_nonlinear),
.backing_dev_info = &swap_backing_dev_info,
@@ -73,7 +73,7 @@ static int __add_to_swap_cache(struct pa
BUG_ON(PagePrivate(page));
error = radix_tree_preload(gfp_mask);
if (!error) {
- spin_lock_irq(&swapper_space.tree_lock);
+ write_lock_irq(&swapper_space.tree_lock);
error = radix_tree_insert(&swapper_space.page_tree,
entry.val, page);
if (!error) {
@@ -84,7 +84,7 @@ static int __add_to_swap_cache(struct pa
total_swapcache_pages++;
pagecache_acct(1);
}
- spin_unlock_irq(&swapper_space.tree_lock);
+ write_unlock_irq(&swapper_space.tree_lock);
radix_tree_preload_end();
}
return error;
@@ -211,9 +211,9 @@ void delete_from_swap_cache(struct page
entry.val = page->private;
- spin_lock_irq(&swapper_space.tree_lock);
+ write_lock_irq(&swapper_space.tree_lock);
__delete_from_swap_cache(page);
- spin_unlock_irq(&swapper_space.tree_lock);
+ write_unlock_irq(&swapper_space.tree_lock);
swap_free(entry);
page_cache_release(page);
@@ -312,13 +312,13 @@ struct page * lookup_swap_cache(swp_entr
{
struct page *page;
- spin_lock_irq(&swapper_space.tree_lock);
+ read_lock_irq(&swapper_space.tree_lock);
page = radix_tree_lookup(&swapper_space.page_tree, entry.val);
if (page) {
page_cache_get(page);
INC_CACHE_INFO(find_success);
}
- spin_unlock_irq(&swapper_space.tree_lock);
+ read_unlock_irq(&swapper_space.tree_lock);
INC_CACHE_INFO(find_total);
return page;
}
@@ -341,12 +341,12 @@ struct page *read_swap_cache_async(swp_e
* called after lookup_swap_cache() failed, re-calling
* that would confuse statistics.
*/
- spin_lock_irq(&swapper_space.tree_lock);
+ read_lock_irq(&swapper_space.tree_lock);
found_page = radix_tree_lookup(&swapper_space.page_tree,
entry.val);
if (found_page)
page_cache_get(found_page);
- spin_unlock_irq(&swapper_space.tree_lock);
+ read_unlock_irq(&swapper_space.tree_lock);
if (found_page)
break;
diff -puN mm/truncate.c~make-tree_lock-an-rwlock mm/truncate.c
--- 25/mm/truncate.c~make-tree_lock-an-rwlock Wed Jun 2 15:12:34 2004
+++ 25-akpm/mm/truncate.c Wed Jun 2 15:12:34 2004
@@ -74,13 +74,13 @@ invalidate_complete_page(struct address_
if (PagePrivate(page) && !try_to_release_page(page, 0))
return 0;
- spin_lock_irq(&mapping->tree_lock);
+ write_lock_irq(&mapping->tree_lock);
if (PageDirty(page)) {
- spin_unlock_irq(&mapping->tree_lock);
+ write_unlock_irq(&mapping->tree_lock);
return 0;
}
__remove_from_page_cache(page);
- spin_unlock_irq(&mapping->tree_lock);
+ write_unlock_irq(&mapping->tree_lock);
ClearPageUptodate(page);
page_cache_release(page); /* pagecache ref */
return 1;
diff -puN mm/vmscan.c~make-tree_lock-an-rwlock mm/vmscan.c
--- 25/mm/vmscan.c~make-tree_lock-an-rwlock Wed Jun 2 15:12:34 2004
+++ 25-akpm/mm/vmscan.c Wed Jun 2 15:12:34 2004
@@ -409,7 +409,7 @@ shrink_list(struct list_head *page_list,
if (!mapping)
goto keep_locked; /* truncate got there first */
- spin_lock_irq(&mapping->tree_lock);
+ write_lock_irq(&mapping->tree_lock);
/*
* The non-racy check for busy page. It is critical to check
@@ -417,7 +417,7 @@ shrink_list(struct list_head *page_list,
* not in use by anybody. (pagecache + us == 2)
*/
if (page_count(page) != 2 || PageDirty(page)) {
- spin_unlock_irq(&mapping->tree_lock);
+ write_unlock_irq(&mapping->tree_lock);
goto keep_locked;
}
@@ -425,7 +425,7 @@ shrink_list(struct list_head *page_list,
if (PageSwapCache(page)) {
swp_entry_t swap = { .val = page->private };
__delete_from_swap_cache(page);
- spin_unlock_irq(&mapping->tree_lock);
+ write_unlock_irq(&mapping->tree_lock);
swap_free(swap);
__put_page(page); /* The pagecache ref */
goto free_it;
@@ -433,7 +433,7 @@ shrink_list(struct list_head *page_list,
#endif /* CONFIG_SWAP */
__remove_from_page_cache(page);
- spin_unlock_irq(&mapping->tree_lock);
+ write_unlock_irq(&mapping->tree_lock);
__put_page(page);
free_it:
_