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Btrfs: Use an array of pages in the extent buffers to reduce the cost of find_get_page

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Signed-off-by: Chris Mason <chris.mason@oracle.com>
This commit is contained in:
Chris Mason
2007-10-15 16:17:04 -04:00
parent 14048ed0c4
commit 09e71a3263
3 changed files with 13 additions and 19 deletions
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6
fs/btrfs/disk-io.c
View File

@@ -647,20 +647,20 @@ int close_ctree(struct btrfs_root *root)
int btrfs_buffer_uptodate(struct extent_buffer *buf) int btrfs_buffer_uptodate(struct extent_buffer *buf)
{ {
struct inode *btree_inode = buf->first_page->mapping->host; struct inode *btree_inode = buf->pages[0]->mapping->host;
return extent_buffer_uptodate(&BTRFS_I(btree_inode)->extent_tree, buf); return extent_buffer_uptodate(&BTRFS_I(btree_inode)->extent_tree, buf);
} }
int btrfs_set_buffer_uptodate(struct extent_buffer *buf) int btrfs_set_buffer_uptodate(struct extent_buffer *buf)
{ {
struct inode *btree_inode = buf->first_page->mapping->host; struct inode *btree_inode = buf->pages[0]->mapping->host;
return set_extent_buffer_uptodate(&BTRFS_I(btree_inode)->extent_tree, return set_extent_buffer_uptodate(&BTRFS_I(btree_inode)->extent_tree,
buf); buf);
} }
void btrfs_mark_buffer_dirty(struct extent_buffer *buf) void btrfs_mark_buffer_dirty(struct extent_buffer *buf)
{ {
struct btrfs_root *root = BTRFS_I(buf->first_page->mapping->host)->root; struct btrfs_root *root = BTRFS_I(buf->pages[0]->mapping->host)->root;
u64 transid = btrfs_header_generation(buf); u64 transid = btrfs_header_generation(buf);
struct inode *btree_inode = root->fs_info->btree_inode; struct inode *btree_inode = root->fs_info->btree_inode;

22
fs/btrfs/extent_map.c
View File

@@ -1961,16 +1961,12 @@ static void __free_extent_buffer(struct extent_buffer *eb)
static inline struct page *extent_buffer_page(struct extent_buffer *eb, int i) static inline struct page *extent_buffer_page(struct extent_buffer *eb, int i)
{ {
struct page *p; struct page *p;
if (i == 0)
return eb->first_page;
if (i < EXTENT_INLINE_PAGES)
return eb->pages[i];
i += eb->start >> PAGE_CACHE_SHIFT; i += eb->start >> PAGE_CACHE_SHIFT;
if (eb->last_page && eb->last_page->index == i) p = find_get_page(eb->pages[0]->mapping, i);
return eb->last_page;
p = find_get_page(eb->first_page->mapping, i);
page_cache_release(p); page_cache_release(p);
eb->last_page = p;
return p; return p;
} }
@@ -2012,8 +2008,8 @@ struct extent_buffer *alloc_extent_buffer(struct extent_map_tree *tree,
goto fail; goto fail;
} }
set_page_extent_mapped(p); set_page_extent_mapped(p);
if (i == 0) if (i < EXTENT_INLINE_PAGES)
eb->first_page = p; eb->pages[i] = p;
if (!PageUptodate(p)) if (!PageUptodate(p))
uptodate = 0; uptodate = 0;
unlock_page(p); unlock_page(p);
@@ -2059,8 +2055,8 @@ struct extent_buffer *find_extent_buffer(struct extent_map_tree *tree,
goto fail; goto fail;
} }
set_page_extent_mapped(p); set_page_extent_mapped(p);
if (i == 0) if (i < EXTENT_INLINE_PAGES)
eb->first_page = p; eb->pages[i] = p;
if (!PageUptodate(p)) if (!PageUptodate(p))
uptodate = 0; uptodate = 0;
unlock_page(p); unlock_page(p);
@@ -2087,9 +2083,7 @@ void free_extent_buffer(struct extent_buffer *eb)
num_pages = num_extent_pages(eb->start, eb->len); num_pages = num_extent_pages(eb->start, eb->len);
if (eb->first_page) for (i = 0; i < num_pages; i++) {
page_cache_release(eb->first_page);
for (i = 1; i < num_pages; i++) {
page_cache_release(extent_buffer_page(eb, i)); page_cache_release(extent_buffer_page(eb, i));
} }
__free_extent_buffer(eb); __free_extent_buffer(eb);

4
fs/btrfs/extent_map.h
View File

@@ -62,6 +62,7 @@ struct extent_state {
struct list_head list; struct list_head list;
}; };
#define EXTENT_INLINE_PAGES 32
struct extent_buffer { struct extent_buffer {
u64 start; u64 start;
unsigned long len; unsigned long len;
@@ -69,13 +70,12 @@ struct extent_buffer {
int flags; int flags;
struct list_head list; struct list_head list;
struct list_head leak_list; struct list_head leak_list;
struct page *first_page;
struct page *last_page;
unsigned long alloc_addr; unsigned long alloc_addr;
char *map_token; char *map_token;
char *kaddr; char *kaddr;
unsigned long map_start; unsigned long map_start;
unsigned long map_len; unsigned long map_len;
struct page *pages[EXTENT_INLINE_PAGES];
}; };
typedef struct extent_map *(get_extent_t)(struct inode *inode, typedef struct extent_map *(get_extent_t)(struct inode *inode,