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/eventpoll.c | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) (limited to 'fs/eventpoll.c') diff --git a/fs/eventpoll.c b/fs/eventpoll.c index a0f682cdd03e..e067a06c6464 100644 --- a/fs/eventpoll.c +++ b/fs/eventpoll.c @@ -281,13 +281,13 @@ static struct mutex epmutex; static struct poll_safewake psw; /* Slab cache used to allocate "struct epitem" */ -static kmem_cache_t *epi_cache; +static kmem_cache_t *epi_cache __read_mostly; /* Slab cache used to allocate "struct eppoll_entry" */ -static kmem_cache_t *pwq_cache; +static kmem_cache_t *pwq_cache __read_mostly; /* Virtual fs used to allocate inodes for eventpoll files */ -static struct vfsmount *eventpoll_mnt; +static struct vfsmount *eventpoll_mnt __read_mostly; /* File callbacks that implement the eventpoll file behaviour */ static struct file_operations eventpoll_fops = { -- cgit v1.2.3-59-g8ed1b