From: Anton Blanchard <anton@samba.org>
Reduce the size of struct inode on 64bit architectures by reducing padding.
This assumes spinlocks are 32bit or less which is the case on most
architectures.
This reduces inode structs by 24 bytes on ppc64, and on ext2 increases the
number of inodes in a 4kB slab from 5 to 6.
Signed-off-by: Anton Blanchard <anton@samba.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
---
25-akpm/include/linux/fs.h | 13 +++++++------
1 files changed, 7 insertions(+), 6 deletions(-)
diff -puN include/linux/fs.h~reduce-size-of-struct-inode-on-64bit include/linux/fs.h
--- 25/include/linux/fs.h~reduce-size-of-struct-inode-on-64bit 2004-08-25 22:31:34.064644464 -0700
+++ 25-akpm/include/linux/fs.h 2004-08-25 22:31:34.069643704 -0700
@@ -335,14 +335,14 @@ struct address_space {
struct inode *host; /* owner: inode, block_device */
struct radix_tree_root page_tree; /* radix tree of all pages */
spinlock_t tree_lock; /* and spinlock protecting it */
- unsigned long nrpages; /* number of total pages */
- pgoff_t writeback_index;/* writeback starts here */
- struct address_space_operations *a_ops; /* methods */
- struct prio_tree_root i_mmap; /* tree of private mappings */
unsigned int i_mmap_writable;/* count VM_SHARED mappings */
+ struct prio_tree_root i_mmap; /* tree of private mappings */
struct list_head i_mmap_nonlinear;/*list VM_NONLINEAR mappings */
spinlock_t i_mmap_lock; /* protect tree, count, list */
atomic_t truncate_count; /* Cover race condition with truncate */
+ unsigned long nrpages; /* number of total pages */
+ pgoff_t writeback_index;/* writeback starts here */
+ struct address_space_operations *a_ops; /* methods */
unsigned long flags; /* error bits/gfp mask */
struct backing_dev_info *backing_dev_info; /* device readahead, etc */
spinlock_t private_lock; /* for use by the address_space */
@@ -437,6 +437,7 @@ struct inode {
unsigned long i_version;
unsigned long i_blocks;
unsigned short i_bytes;
+ unsigned char i_sock;
spinlock_t i_lock; /* i_blocks, i_bytes, maybe i_size */
struct semaphore i_sem;
struct rw_semaphore i_alloc_sem;
@@ -456,6 +457,8 @@ struct inode {
struct cdev *i_cdev;
int i_cindex;
+ __u32 i_generation;
+
unsigned long i_dnotify_mask; /* Directory notify events */
struct dnotify_struct *i_dnotify; /* for directory notifications */
@@ -463,11 +466,9 @@ struct inode {
unsigned long dirtied_when; /* jiffies of first dirtying */
unsigned int i_flags;
- unsigned char i_sock;
atomic_t i_writecount;
void *i_security;
- __u32 i_generation;
union {
void *generic_ip;
} u;
_