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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/fcntl.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/fcntl.c')
| -rw-r--r-- | fs/fcntl.c | 4 |
1 files changed, 2 insertions, 2 deletions
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) |