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/bio.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) (limited to 'fs/bio.c') diff --git a/fs/bio.c b/fs/bio.c index 73e664c01d30..49db9286a3b4 100644 --- a/fs/bio.c +++ b/fs/bio.c @@ -30,7 +30,7 @@ #define BIO_POOL_SIZE 256 -static kmem_cache_t *bio_slab; +static kmem_cache_t *bio_slab __read_mostly; #define BIOVEC_NR_POOLS 6 @@ -39,7 +39,7 @@ static kmem_cache_t *bio_slab; * basically we just need to survive */ #define BIO_SPLIT_ENTRIES 8 -mempool_t *bio_split_pool; +mempool_t *bio_split_pool __read_mostly; struct biovec_slab { int nr_vecs; -- cgit v1.2.3-59-g8ed1b