From c516610cfec5c50f84ff8cc315628548481f4990 Mon Sep 17 00:00:00 2001 From: Jan Kara Date: Mon, 26 Jan 2009 15:32:46 +0100 Subject: [PATCH] quota: Make global quota locks cacheline aligned Andrew Morton has suggested that three global quota locks can end up in the same cacheline which can result in bad cacheline ping-pong on SMP machines. Make locks cacheline aligned so that we avoid this problem (thanks goes to Andrew for the idea). Signed-off-by: Jan Kara CC: Andrew Morton --- fs/quota/dquot.c | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) diff --git a/fs/quota/dquot.c b/fs/quota/dquot.c index 28aa14667602..e840fa2b112e 100644 --- a/fs/quota/dquot.c +++ b/fs/quota/dquot.c @@ -129,9 +129,9 @@ * i_mutex on quota files is special (it's below dqio_mutex) */ -static DEFINE_SPINLOCK(dq_list_lock); -static DEFINE_SPINLOCK(dq_state_lock); -DEFINE_SPINLOCK(dq_data_lock); +static __cacheline_aligned_in_smp DEFINE_SPINLOCK(dq_list_lock); +static __cacheline_aligned_in_smp DEFINE_SPINLOCK(dq_state_lock); +__cacheline_aligned_in_smp DEFINE_SPINLOCK(dq_data_lock); EXPORT_SYMBOL(dq_data_lock); static char *quotatypes[] = INITQFNAMES;