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/pipe.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'fs/pipe.c') diff --git a/fs/pipe.c b/fs/pipe.c index d976866a115..4384c929094 100644 --- a/fs/pipe.c +++ b/fs/pipe.c @@ -675,7 +675,7 @@ fail_page: return NULL; } -static struct vfsmount *pipe_mnt; +static struct vfsmount *pipe_mnt __read_mostly; static int pipefs_delete_dentry(struct dentry *dentry) { return 1; -- cgit v1.2.3-18-g5258