From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail6.bemta12.messagelabs.com (mail6.bemta12.messagelabs.com [216.82.250.247]) by kanga.kvack.org (Postfix) with ESMTP id E34816B002D for ; Mon, 24 Oct 2011 12:10:40 -0400 (EDT) Date: Mon, 24 Oct 2011 11:10:35 -0500 From: Dimitri Sivanich Subject: [PATCH] cache align vm_stat Message-ID: <20111024161035.GA19820@sgi.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Sender: owner-linux-mm@kvack.org List-ID: To: linux-kernel@vger.kernel.org, linux-mm@kvack.org Cc: Andrew Morton , Christoph Lameter , David Rientjes , Andi Kleen , Mel Gorman Avoid false sharing of the vm_stat array. This was found to adversely affect tmpfs I/O performance. Signed-off-by: Dimitri Sivanich --- mm/vmstat.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) Index: linux/mm/vmstat.c =================================================================== --- linux.orig/mm/vmstat.c +++ linux/mm/vmstat.c @@ -78,7 +78,7 @@ void vm_events_fold_cpu(int cpu) * * vm_stat contains the global counters */ -atomic_long_t vm_stat[NR_VM_ZONE_STAT_ITEMS]; +atomic_long_t vm_stat[NR_VM_ZONE_STAT_ITEMS] __cacheline_aligned_in_smp; EXPORT_SYMBOL(vm_stat); #ifdef CONFIG_SMP -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Fight unfair telecom internet charges in Canada: sign http://stopthemeter.ca/ Don't email: email@kvack.org