btrfs: switch extent_state state to unsigned
Currently there's a 4B hole in the structure between refs and state and there
are only 16 bits used so we can make it unsigned. This will get a better
packing and may save some stack space for local variables.
The size of extent_state gets reduced by 8B and there are usually a lot
of slab objects.
struct extent_state {
u64 start; /* 0 8 */
u64 end; /* 8 8 */
struct rb_node rb_node; /* 16 24 */
wait_queue_head_t wq; /* 40 24 */
/* --- cacheline 1 boundary (64 bytes) --- */
atomic_t refs; /* 64 4 */
/* XXX 4 bytes hole, try to pack */
long unsigned int state; /* 72 8 */
u64 private; /* 80 8 */
/* size: 88, cachelines: 2, members: 7 */
/* sum members: 84, holes: 1, sum holes: 4 */
/* last cacheline: 24 bytes */
};
Signed-off-by: David Sterba <dsterba@suse.cz>
Signed-off-by: Chris Mason <clm@fb.com>
diff --git a/fs/btrfs/extent_io.h b/fs/btrfs/extent_io.h
index 71268e5..695b0cc 100644
--- a/fs/btrfs/extent_io.h
+++ b/fs/btrfs/extent_io.h
@@ -4,22 +4,22 @@
#include <linux/rbtree.h>
/* bits for the extent state */
-#define EXTENT_DIRTY 1
-#define EXTENT_WRITEBACK (1 << 1)
-#define EXTENT_UPTODATE (1 << 2)
-#define EXTENT_LOCKED (1 << 3)
-#define EXTENT_NEW (1 << 4)
-#define EXTENT_DELALLOC (1 << 5)
-#define EXTENT_DEFRAG (1 << 6)
-#define EXTENT_BOUNDARY (1 << 9)
-#define EXTENT_NODATASUM (1 << 10)
-#define EXTENT_DO_ACCOUNTING (1 << 11)
-#define EXTENT_FIRST_DELALLOC (1 << 12)
-#define EXTENT_NEED_WAIT (1 << 13)
-#define EXTENT_DAMAGED (1 << 14)
-#define EXTENT_NORESERVE (1 << 15)
-#define EXTENT_IOBITS (EXTENT_LOCKED | EXTENT_WRITEBACK)
-#define EXTENT_CTLBITS (EXTENT_DO_ACCOUNTING | EXTENT_FIRST_DELALLOC)
+#define EXTENT_DIRTY (1U << 0)
+#define EXTENT_WRITEBACK (1U << 1)
+#define EXTENT_UPTODATE (1U << 2)
+#define EXTENT_LOCKED (1U << 3)
+#define EXTENT_NEW (1U << 4)
+#define EXTENT_DELALLOC (1U << 5)
+#define EXTENT_DEFRAG (1U << 6)
+#define EXTENT_BOUNDARY (1U << 9)
+#define EXTENT_NODATASUM (1U << 10)
+#define EXTENT_DO_ACCOUNTING (1U << 11)
+#define EXTENT_FIRST_DELALLOC (1U << 12)
+#define EXTENT_NEED_WAIT (1U << 13)
+#define EXTENT_DAMAGED (1U << 14)
+#define EXTENT_NORESERVE (1U << 15)
+#define EXTENT_IOBITS (EXTENT_LOCKED | EXTENT_WRITEBACK)
+#define EXTENT_CTLBITS (EXTENT_DO_ACCOUNTING | EXTENT_FIRST_DELALLOC)
/*
* flags for bio submission. The high bits indicate the compression
@@ -81,9 +81,9 @@
int (*writepage_end_io_hook)(struct page *page, u64 start, u64 end,
struct extent_state *state, int uptodate);
void (*set_bit_hook)(struct inode *inode, struct extent_state *state,
- unsigned long *bits);
+ unsigned *bits);
void (*clear_bit_hook)(struct inode *inode, struct extent_state *state,
- unsigned long *bits);
+ unsigned *bits);
void (*merge_extent_hook)(struct inode *inode,
struct extent_state *new,
struct extent_state *other);
@@ -108,7 +108,7 @@
/* ADD NEW ELEMENTS AFTER THIS */
wait_queue_head_t wq;
atomic_t refs;
- unsigned long state;
+ unsigned state;
/* for use by the FS */
u64 private;
@@ -188,7 +188,7 @@
int try_release_extent_buffer(struct page *page);
int lock_extent(struct extent_io_tree *tree, u64 start, u64 end);
int lock_extent_bits(struct extent_io_tree *tree, u64 start, u64 end,
- unsigned long bits, struct extent_state **cached);
+ unsigned bits, struct extent_state **cached);
int unlock_extent(struct extent_io_tree *tree, u64 start, u64 end);
int unlock_extent_cached(struct extent_io_tree *tree, u64 start, u64 end,
struct extent_state **cached, gfp_t mask);
@@ -202,21 +202,21 @@
u64 count_range_bits(struct extent_io_tree *tree,
u64 *start, u64 search_end,
- u64 max_bytes, unsigned long bits, int contig);
+ u64 max_bytes, unsigned bits, int contig);
void free_extent_state(struct extent_state *state);
int test_range_bit(struct extent_io_tree *tree, u64 start, u64 end,
- unsigned long bits, int filled,
+ unsigned bits, int filled,
struct extent_state *cached_state);
int clear_extent_bits(struct extent_io_tree *tree, u64 start, u64 end,
- unsigned long bits, gfp_t mask);
+ unsigned bits, gfp_t mask);
int clear_extent_bit(struct extent_io_tree *tree, u64 start, u64 end,
- unsigned long bits, int wake, int delete,
+ unsigned bits, int wake, int delete,
struct extent_state **cached, gfp_t mask);
int set_extent_bits(struct extent_io_tree *tree, u64 start, u64 end,
- unsigned long bits, gfp_t mask);
+ unsigned bits, gfp_t mask);
int set_extent_bit(struct extent_io_tree *tree, u64 start, u64 end,
- unsigned long bits, u64 *failed_start,
+ unsigned bits, u64 *failed_start,
struct extent_state **cached_state, gfp_t mask);
int set_extent_uptodate(struct extent_io_tree *tree, u64 start, u64 end,
struct extent_state **cached_state, gfp_t mask);
@@ -229,14 +229,14 @@
int clear_extent_dirty(struct extent_io_tree *tree, u64 start, u64 end,
gfp_t mask);
int convert_extent_bit(struct extent_io_tree *tree, u64 start, u64 end,
- unsigned long bits, unsigned long clear_bits,
+ unsigned bits, unsigned clear_bits,
struct extent_state **cached_state, gfp_t mask);
int set_extent_delalloc(struct extent_io_tree *tree, u64 start, u64 end,
struct extent_state **cached_state, gfp_t mask);
int set_extent_defrag(struct extent_io_tree *tree, u64 start, u64 end,
struct extent_state **cached_state, gfp_t mask);
int find_first_extent_bit(struct extent_io_tree *tree, u64 start,
- u64 *start_ret, u64 *end_ret, unsigned long bits,
+ u64 *start_ret, u64 *end_ret, unsigned bits,
struct extent_state **cached_state);
int extent_invalidatepage(struct extent_io_tree *tree,
struct page *page, unsigned long offset);
@@ -323,7 +323,7 @@
int extent_range_redirty_for_io(struct inode *inode, u64 start, u64 end);
int extent_clear_unlock_delalloc(struct inode *inode, u64 start, u64 end,
struct page *locked_page,
- unsigned long bits_to_clear,
+ unsigned bits_to_clear,
unsigned long page_ops);
struct bio *
btrfs_bio_alloc(struct block_device *bdev, u64 first_sector, int nr_vecs,