From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753119Ab2GZVk2 (ORCPT ); Thu, 26 Jul 2012 17:40:28 -0400 Received: from mail-yw0-f46.google.com ([209.85.213.46]:55921 "EHLO mail-yw0-f46.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753229Ab2GZVaX (ORCPT ); Thu, 26 Jul 2012 17:30:23 -0400 From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: Greg KH , torvalds@linux-foundation.org, akpm@linux-foundation.org, alan@lxorguk.ukuu.org.uk, Dimitri Sivanich , Christoph Lameter , Mel Gorman , Mel Gorman Subject: [ 07/40] mm/vmstat.c: cache align vm_stat Date: Thu, 26 Jul 2012 14:29:25 -0700 Message-Id: <20120726211411.751682159@linuxfoundation.org> X-Mailer: git-send-email 1.7.10.1.362.g242cab3 In-Reply-To: <20120726211411.164006056@linuxfoundation.org> References: <20120726211424.GA7709@kroah.com> <20120726211411.164006056@linuxfoundation.org> User-Agent: quilt/0.60-20.4 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Greg KH 3.0-stable review patch. If anyone has any objections, please let me know. ------------------ From: Dimitri Sivanich commit a1cb2c60ddc98ff4e5246f410558805401ceee67 upstream. Stable note: Not tracked on Bugzilla. This patch is known to make a big difference to tmpfs performance on larger machines. This was found to adversely affect tmpfs I/O performance. Tests run on a 640 cpu UV system. With 120 threads doing parallel writes, each to different tmpfs mounts: No patch: ~300 MB/sec With vm_stat alignment: ~430 MB/sec Signed-off-by: Dimitri Sivanich Acked-by: Christoph Lameter Acked-by: Mel Gorman Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds Signed-off-by: Mel Gorman --- mm/vmstat.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) --- a/mm/vmstat.c +++ b/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