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/fcntl.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) (limited to 'fs/fcntl.c') diff --git a/fs/fcntl.c b/fs/fcntl.c index 03c789560fb8..2a2479196f96 100644 --- a/fs/fcntl.c +++ b/fs/fcntl.c @@ -412,7 +412,7 @@ out: /* Table to convert sigio signal codes into poll band bitmaps */ -static long band_table[NSIGPOLL] = { +static const long band_table[NSIGPOLL] = { POLLIN | POLLRDNORM, /* POLL_IN */ POLLOUT | POLLWRNORM | POLLWRBAND, /* POLL_OUT */ POLLIN | POLLRDNORM | POLLMSG, /* POLL_MSG */ @@ -531,7 +531,7 @@ int send_sigurg(struct fown_struct *fown) } static DEFINE_RWLOCK(fasync_lock); -static kmem_cache_t *fasync_cache; +static kmem_cache_t *fasync_cache __read_mostly; /* * fasync_helper() is used by some character device drivers (mainly mice) -- cgit v1.2.3