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authorEric Dumazet <dada1@cosmosbay.com>2006-03-26 01:37:24 -0800
committerLinus Torvalds <torvalds@g5.osdl.org>2006-03-26 08:56:56 -0800
commitfa3536cc144c1298f2ed9416c33f3b77fa2cd37a (patch)
tree5484541319b86ae7dac0def4db7925f7cc7008e7 /fs/block_dev.c
parent878a9f30d7b13015f3aa4534d7877d985f150183 (diff)
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[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.c4
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)