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| author | Eric Dumazet <dada1@cosmosbay.com> | 2006-03-26 01:37:24 -0800 |
|---|---|---|
| committer | Linus Torvalds <torvalds@g5.osdl.org> | 2006-03-26 08:56:56 -0800 |
| commit | fa3536cc144c1298f2ed9416c33f3b77fa2cd37a (patch) | |
| tree | 5484541319b86ae7dac0def4db7925f7cc7008e7 /fs/inode.c | |
| parent | 878a9f30d7b13015f3aa4534d7877d985f150183 (diff) | |
| download | lwn-fa3536cc144c1298f2ed9416c33f3b77fa2cd37a.tar.gz lwn-fa3536cc144c1298f2ed9416c33f3b77fa2cd37a.zip | |
[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 <dada1@cosmosbay.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Diffstat (limited to 'fs/inode.c')
| -rw-r--r-- | fs/inode.c | 8 |
1 files changed, 4 insertions, 4 deletions
diff --git a/fs/inode.c b/fs/inode.c index 85da11044adc..1fddf2803af8 100644 --- a/fs/inode.c +++ b/fs/inode.c @@ -56,8 +56,8 @@ #define I_HASHBITS i_hash_shift #define I_HASHMASK i_hash_mask -static unsigned int i_hash_mask; -static unsigned int i_hash_shift; +static unsigned int i_hash_mask __read_mostly; +static unsigned int i_hash_shift __read_mostly; /* * Each inode can be on two separate lists. One is @@ -73,7 +73,7 @@ static unsigned int i_hash_shift; LIST_HEAD(inode_in_use); LIST_HEAD(inode_unused); -static struct hlist_head *inode_hashtable; +static struct hlist_head *inode_hashtable __read_mostly; /* * A simple spinlock to protect the list manipulations. @@ -98,7 +98,7 @@ static DEFINE_MUTEX(iprune_mutex); */ struct inodes_stat_t inodes_stat; -static kmem_cache_t * inode_cachep; +static kmem_cache_t * inode_cachep __read_mostly; static struct inode *alloc_inode(struct super_block *sb) { |