From: Filipe Manana <fdmanana@suse.com>
Date: Thu, 14 Aug 2014 11:25:14 +0000 (+0100)
Subject: Btrfs: shrink further sizeof(struct extent_buffer)
X-Git-Tag: v3.18-rc1~91^2~64
X-Git-Url: https://openfabrics.org/gitweb/?a=commitdiff_plain;h=2a39e5980257c77f48b5c31f9fb483a72a03b213;p=~emulex%2Finfiniband.git

Btrfs: shrink further sizeof(struct extent_buffer)

The map_start and map_len fields aren't used anywhere, so just remove
them. On a x86_64 system, this reduced sizeof(struct extent_buffer)
from 296 bytes to 280 bytes, and therefore 14 extent_buffer structs can
now fit into a page instead of 13.

Signed-off-by: Filipe Manana <fdmanana@suse.com>
Reviewed-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 1f608166fe6..844b4c5029c 100644
--- a/fs/btrfs/extent_io.h
+++ b/fs/btrfs/extent_io.h
@@ -125,8 +125,6 @@ struct extent_state {
 struct extent_buffer {
 	u64 start;
 	unsigned long len;
-	unsigned long map_start;
-	unsigned long map_len;
 	unsigned long bflags;
 	struct btrfs_fs_info *fs_info;
 	spinlock_t refs_lock;