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| author | Eric Dumazet <dada1@cosmosbay.com> | 2006-03-26 01:37:24 -0800 |
|---|---|---|
| committer | Linus Torvalds <torvalds@g5.osdl.org> | 2006-03-26 08:56:56 -0800 |
| commit | fa3536cc144c1298f2ed9416c33f3b77fa2cd37a (patch) | |
| tree | 5484541319b86ae7dac0def4db7925f7cc7008e7 /fs/block_dev.c | |
| parent | 878a9f30d7b13015f3aa4534d7877d985f150183 (diff) | |
| download | lwn-fa3536cc144c1298f2ed9416c33f3b77fa2cd37a.tar.gz lwn-fa3536cc144c1298f2ed9416c33f3b77fa2cd37a.zip | |
[PATCH] Use __read_mostly on some hot fs variables
I discovered on oprofile hunting on a SMP platform that dentry lookups were
slowed down because d_hash_mask, d_hash_shift and dentry_hashtable were in
a cache line that contained inodes_stat. So each time inodes_stats is
changed by a cpu, other cpus have to refill their cache line.
This patch moves some variables to the __read_mostly section, in order to
avoid false sharing. RCU dentry lookups can go full speed.
Signed-off-by: Eric Dumazet <dada1@cosmosbay.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Diffstat (limited to 'fs/block_dev.c')
| -rw-r--r-- | fs/block_dev.c | 4 |
1 files changed, 2 insertions, 2 deletions
diff --git a/fs/block_dev.c b/fs/block_dev.c index 573fc8e0b67a..9a451a9ffad4 100644 --- a/fs/block_dev.c +++ b/fs/block_dev.c @@ -234,7 +234,7 @@ static int block_fsync(struct file *filp, struct dentry *dentry, int datasync) */ static __cacheline_aligned_in_smp DEFINE_SPINLOCK(bdev_lock); -static kmem_cache_t * bdev_cachep; +static kmem_cache_t * bdev_cachep __read_mostly; static struct inode *bdev_alloc_inode(struct super_block *sb) { @@ -308,7 +308,7 @@ static struct file_system_type bd_type = { .kill_sb = kill_anon_super, }; -static struct vfsmount *bd_mnt; +static struct vfsmount *bd_mnt __read_mostly; struct super_block *blockdev_superblock; void __init bdev_cache_init(void) |