From fa3536cc144c1298f2ed9416c33f3b77fa2cd37a Mon Sep 17 00:00:00 2001 From: Eric Dumazet Date: Sun, 26 Mar 2006 01:37:24 -0800 Subject: [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 Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- fs/dnotify.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) (limited to 'fs/dnotify.c') diff --git a/fs/dnotify.c b/fs/dnotify.c index f3b540dd5d1..f932591df5a 100644 --- a/fs/dnotify.c +++ b/fs/dnotify.c @@ -21,9 +21,9 @@ #include #include -int dir_notify_enable = 1; +int dir_notify_enable __read_mostly = 1; -static kmem_cache_t *dn_cache; +static kmem_cache_t *dn_cache __read_mostly; static void redo_inode_mask(struct inode *inode) { -- cgit v1.2.3-18-g5258