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[4/4] Btrfs: reduce size of struct btrfs_inode

Message ID 20171219100247.13880-5-nefelim4ag@gmail.com (mailing list archive)
State New, archived
Headers show

Commit Message

Timofey Titovets Dec. 19, 2017, 10:02 a.m. UTC 
Currently btrfs_inode have size equal 1136 bytes. (On x86_64).

struct btrfs_inode store several vars releated to compression code,
all states use 1 or 2 bits.

Lets declare bitfields for compression releated vars, to reduce
sizeof btrfs_inode to 1128 bytes.

Signed-off-by: Timofey Titovets <nefelim4ag@gmail.com>
---
 fs/btrfs/btrfs_inode.h | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)
diff mbox

Patch

diff --git a/fs/btrfs/btrfs_inode.h b/fs/btrfs/btrfs_inode.h
index 9eb0c92ee4b4..9d29d7e68757 100644
--- a/fs/btrfs/btrfs_inode.h
+++ b/fs/btrfs/btrfs_inode.h
@@ -181,13 +181,13 @@  struct btrfs_inode {
 	/*
 	 * Cached values of inode properties
 	 */
-	unsigned prop_compress;		/* per-file compression algorithm */
+	unsigned prop_compress : 2;	/* per-file compression algorithm */
 	/*
 	 * Force compression on the file using the defrag ioctl, could be
 	 * different from prop_compress and takes precedence if set
 	 */
-	unsigned defrag_compress;
-	unsigned change_compress;
+	unsigned defrag_compress : 2;
+	unsigned change_compress : 1;
 
 	struct btrfs_delayed_node *delayed_node;