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authorEric Dumazet <dada1@cosmosbay.com>2006-03-26 04:37:24 -0500
committerLinus Torvalds <torvalds@g5.osdl.org>2006-03-26 11:56:56 -0500
commitfa3536cc144c1298f2ed9416c33f3b77fa2cd37a (patch)
tree5484541319b86ae7dac0def4db7925f7cc7008e7 /fs/fcntl.c
parent878a9f30d7b13015f3aa4534d7877d985f150183 (diff)
[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.c4
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:
412 412
413/* Table to convert sigio signal codes into poll band bitmaps */ 413/* Table to convert sigio signal codes into poll band bitmaps */
414 414
415static long band_table[NSIGPOLL] = { 415static const long band_table[NSIGPOLL] = {
416 POLLIN | POLLRDNORM, /* POLL_IN */ 416 POLLIN | POLLRDNORM, /* POLL_IN */
417 POLLOUT | POLLWRNORM | POLLWRBAND, /* POLL_OUT */ 417 POLLOUT | POLLWRNORM | POLLWRBAND, /* POLL_OUT */
418 POLLIN | POLLRDNORM | POLLMSG, /* POLL_MSG */ 418 POLLIN | POLLRDNORM | POLLMSG, /* POLL_MSG */
@@ -531,7 +531,7 @@ int send_sigurg(struct fown_struct *fown)
531} 531}
532 532
533static DEFINE_RWLOCK(fasync_lock); 533static DEFINE_RWLOCK(fasync_lock);
534static kmem_cache_t *fasync_cache; 534static kmem_cache_t *fasync_cache __read_mostly;
535 535
536/* 536/*
537 * fasync_helper() is used by some character device drivers (mainly mice) 537 * fasync_helper() is used by some character device drivers (mainly mice)