kernel-ark/include/linux/ext2_fs_sb.h
Pekka J Enberg 18a82eb9f9 ext2: allocate ->s_blockgroup_lock separately
As spotted by kmemtrace, struct ext2_sb_info is 17024 bytes on 64-bit
which makes it a very bad fit for SLAB allocators.  The culprit of the
wasted memory is ->s_blockgroup_lock which can be as big as 16 KB when
NR_CPUS >= 32.

To fix that, allocate ->s_blockgroup_lock, which fits nicely in a order 2
page in the worst case, separately.  This shinks down struct ext2_sb_info
enough to fit a 1 KB slab cache so now we allocate 16 KB + 1 KB instead of
32 KB saving 15 KB of memory.

Acked-by: Andreas Dilger <adilger@sun.com>
Signed-off-by: Pekka Enberg <penberg@cs.helsinki.fi>
Cc: <linux-ext4@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-01-08 08:31:00 -08:00

118 lines
3.7 KiB
C

/*
* linux/include/linux/ext2_fs_sb.h
*
* Copyright (C) 1992, 1993, 1994, 1995
* Remy Card (card@masi.ibp.fr)
* Laboratoire MASI - Institut Blaise Pascal
* Universite Pierre et Marie Curie (Paris VI)
*
* from
*
* linux/include/linux/minix_fs_sb.h
*
* Copyright (C) 1991, 1992 Linus Torvalds
*/
#ifndef _LINUX_EXT2_FS_SB
#define _LINUX_EXT2_FS_SB
#include <linux/blockgroup_lock.h>
#include <linux/percpu_counter.h>
#include <linux/rbtree.h>
/* XXX Here for now... not interested in restructing headers JUST now */
/* data type for block offset of block group */
typedef int ext2_grpblk_t;
/* data type for filesystem-wide blocks number */
typedef unsigned long ext2_fsblk_t;
#define E2FSBLK "%lu"
struct ext2_reserve_window {
ext2_fsblk_t _rsv_start; /* First byte reserved */
ext2_fsblk_t _rsv_end; /* Last byte reserved or 0 */
};
struct ext2_reserve_window_node {
struct rb_node rsv_node;
__u32 rsv_goal_size;
__u32 rsv_alloc_hit;
struct ext2_reserve_window rsv_window;
};
struct ext2_block_alloc_info {
/* information about reservation window */
struct ext2_reserve_window_node rsv_window_node;
/*
* was i_next_alloc_block in ext2_inode_info
* is the logical (file-relative) number of the
* most-recently-allocated block in this file.
* We use this for detecting linearly ascending allocation requests.
*/
__u32 last_alloc_logical_block;
/*
* Was i_next_alloc_goal in ext2_inode_info
* is the *physical* companion to i_next_alloc_block.
* it the the physical block number of the block which was most-recentl
* allocated to this file. This give us the goal (target) for the next
* allocation when we detect linearly ascending requests.
*/
ext2_fsblk_t last_alloc_physical_block;
};
#define rsv_start rsv_window._rsv_start
#define rsv_end rsv_window._rsv_end
/*
* second extended-fs super-block data in memory
*/
struct ext2_sb_info {
unsigned long s_frag_size; /* Size of a fragment in bytes */
unsigned long s_frags_per_block;/* Number of fragments per block */
unsigned long s_inodes_per_block;/* Number of inodes per block */
unsigned long s_frags_per_group;/* Number of fragments in a group */
unsigned long s_blocks_per_group;/* Number of blocks in a group */
unsigned long s_inodes_per_group;/* Number of inodes in a group */
unsigned long s_itb_per_group; /* Number of inode table blocks per group */
unsigned long s_gdb_count; /* Number of group descriptor blocks */
unsigned long s_desc_per_block; /* Number of group descriptors per block */
unsigned long s_groups_count; /* Number of groups in the fs */
unsigned long s_overhead_last; /* Last calculated overhead */
unsigned long s_blocks_last; /* Last seen block count */
struct buffer_head * s_sbh; /* Buffer containing the super block */
struct ext2_super_block * s_es; /* Pointer to the super block in the buffer */
struct buffer_head ** s_group_desc;
unsigned long s_mount_opt;
unsigned long s_sb_block;
uid_t s_resuid;
gid_t s_resgid;
unsigned short s_mount_state;
unsigned short s_pad;
int s_addr_per_block_bits;
int s_desc_per_block_bits;
int s_inode_size;
int s_first_ino;
spinlock_t s_next_gen_lock;
u32 s_next_generation;
unsigned long s_dir_count;
u8 *s_debts;
struct percpu_counter s_freeblocks_counter;
struct percpu_counter s_freeinodes_counter;
struct percpu_counter s_dirs_counter;
struct blockgroup_lock *s_blockgroup_lock;
/* root of the per fs reservation window tree */
spinlock_t s_rsv_window_lock;
struct rb_root s_rsv_window_root;
struct ext2_reserve_window_node s_rsv_window_head;
};
static inline spinlock_t *
sb_bgl_lock(struct ext2_sb_info *sbi, unsigned int block_group)
{
return bgl_lock_ptr(sbi->s_blockgroup_lock, block_group);
}
#endif /* _LINUX_EXT2_FS_SB */