|  9ee49a047d 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> | ||
|---|---|---|
| .. | ||
| btrfs-tests.c | ||
| btrfs-tests.h | ||
| extent-buffer-tests.c | ||
| extent-io-tests.c | ||
| free-space-tests.c | ||
| inode-tests.c | ||
| qgroup-tests.c | ||