From 105c8c42141b7b1ed119cbb93a2930a05f5e681a Mon Sep 17 00:00:00 2001 From: David Sterba Date: Fri, 8 Sep 2023 01:09:35 +0200 Subject: [PATCH] btrfs: reduce size of prelim_ref::level The values of level are bounded and fit into a byte so let's use it for the structure to reduce size from 88 to 80 bytes on a release build, which increases number of objects in the default 8K slab from 93 to 102. struct prelim_ref { struct rb_node rbnode __attribute__((__aligned__(8))); /* 0 24 */ u64 root_id; /* 24 8 */ struct btrfs_key key_for_search; /* 32 17 */ u8 level; /* 49 1 */ /* XXX 2 bytes hole, try to pack */ int count; /* 52 4 */ struct extent_inode_elem * inode_list; /* 56 8 */ /* --- cacheline 1 boundary (64 bytes) --- */ u64 parent; /* 64 8 */ u64 wanted_disk_byte; /* 72 8 */ /* size: 80, cachelines: 2, members: 8 */ /* sum members: 78, holes: 1, sum holes: 2 */ /* forced alignments: 1 */ /* last cacheline: 16 bytes */ } __attribute__((__aligned__(8))); Reviewed-by: Qu Wenruo Signed-off-by: David Sterba --- fs/btrfs/backref.h | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/fs/btrfs/backref.h b/fs/btrfs/backref.h index 1616e3e3f1e41..79742935399f4 100644 --- a/fs/btrfs/backref.h +++ b/fs/btrfs/backref.h @@ -247,7 +247,7 @@ struct prelim_ref { struct rb_node rbnode; u64 root_id; struct btrfs_key key_for_search; - int level; + u8 level; int count; struct extent_inode_elem *inode_list; u64 parent; -- 2.30.2