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/inode.c b/fs/btrfs/inode.c
index 5e52920..220f0c3 100644
--- a/fs/btrfs/inode.c
+++ b/fs/btrfs/inode.c
@@ -1604,7 +1604,7 @@
* have pending delalloc work to be done.
*/
static void btrfs_set_bit_hook(struct inode *inode,
- struct extent_state *state, unsigned long *bits)
+ struct extent_state *state, unsigned *bits)
{
if ((*bits & EXTENT_DEFRAG) && !(*bits & EXTENT_DELALLOC))
@@ -1645,7 +1645,7 @@
*/
static void btrfs_clear_bit_hook(struct inode *inode,
struct extent_state *state,
- unsigned long *bits)
+ unsigned *bits)
{
u64 len = state->end + 1 - state->start;