Reorder structure ext4_inode_info to remove 16 bytes of alignment
padding on 64 bit builds. This shrinks its size from 904 to 888 bytes
with (CONFIG_EXT4_S_XATTR=y && CONFIG_QUOTA=n).
This will allow this structure to use one fewer cache lines.
Also change type of i_delalloc_reserved_flag to bool to better reflect
its usage.
compiled & tested on x86_64
Signed-off-by: Richard Kennedy <richard@xxxxxxxxxxxxxxx>
---
patch against 2.6.36-rc1
Early testing shows more consistent results ( i.e. smaller standard
deviations) on my AMD X2 setup, but I shall re-run these tests to check
if this is repeatable.
regards
Richard
diff --git a/fs/ext4/ext4.h b/fs/ext4/ext4.h
index 889ec9d..b63a8e3 100644
--- a/fs/ext4/ext4.h
+++ b/fs/ext4/ext4.h
@@ -750,10 +750,11 @@ struct ext4_inode_info {
* near to their parent directory's inode.
*/
ext4_group_t i_block_group;
- unsigned long i_state_flags; /* Dynamic state flags */
- unsigned long i_flags;
ext4_lblk_t i_dir_start_lookup;
+
+ unsigned long i_state_flags; /* Dynamic state flags */
+ unsigned long i_flags;
#ifdef CONFIG_EXT4_FS_XATTR
/*
* Extended attributes can be read independently of the main file
@@ -816,13 +817,14 @@ struct ext4_inode_info {
unsigned int i_reserved_data_blocks;
unsigned int i_reserved_meta_blocks;
unsigned int i_allocated_meta_blocks;
- unsigned short i_delalloc_reserved_flag;
- sector_t i_da_metadata_calc_last_lblock;
- int i_da_metadata_calc_len;
+ bool i_delalloc_reserved_flag;
/* on-disk additional length */
__u16 i_extra_isize;
+ sector_t i_da_metadata_calc_last_lblock;
+ int i_da_metadata_calc_len;
+
spinlock_t i_block_reservation_lock;
#ifdef CONFIG_QUOTA
/* quota space reservation, managed internally by quota code */
--
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