tree 5484541319b86ae7dac0def4db7925f7cc7008e7
parent 878a9f30d7b13015f3aa4534d7877d985f150183
author Eric Dumazet <dada1@cosmosbay.com> 1143365844 -0800
committer Linus Torvalds <torvalds@g5.osdl.org> 1143392216 -0800

[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>