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/tests/extent-io-tests.c b/fs/btrfs/tests/extent-io-tests.c
index 7e99c2f..9e9f236 100644
--- a/fs/btrfs/tests/extent-io-tests.c
+++ b/fs/btrfs/tests/extent-io-tests.c
@@ -258,8 +258,7 @@
}
ret = 0;
out_bits:
- clear_extent_bits(&tmp, 0, total_dirty - 1,
- (unsigned long)-1, GFP_NOFS);
+ clear_extent_bits(&tmp, 0, total_dirty - 1, (unsigned)-1, GFP_NOFS);
out:
if (locked_page)
page_cache_release(locked_page);