From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753456AbaGJMO0 (ORCPT ); Thu, 10 Jul 2014 08:14:26 -0400 Received: from zene.cmpxchg.org ([85.214.230.12]:53549 "EHLO zene.cmpxchg.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752495AbaGJMOX (ORCPT ); Thu, 10 Jul 2014 08:14:23 -0400 Date: Thu, 10 Jul 2014 08:14:19 -0400 From: Johannes Weiner To: Mel Gorman Cc: Andrew Morton , Linux Kernel , Linux-MM , Linux-FSDevel Subject: Re: [PATCH 5/6] mm: page_alloc: Abort fair zone allocation policy when remotes nodes are encountered Message-ID: <20140710121419.GM29639@cmpxchg.org> References: <1404893588-21371-1-git-send-email-mgorman@suse.de> <1404893588-21371-6-git-send-email-mgorman@suse.de> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1404893588-21371-6-git-send-email-mgorman@suse.de> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, Jul 09, 2014 at 09:13:07AM +0100, Mel Gorman wrote: > The purpose of numa_zonelist_order=zone is to preserve lower zones > for use with 32-bit devices. If locality is preferred then the > numa_zonelist_order=node policy should be used. Unfortunately, the fair > zone allocation policy overrides this by skipping zones on remote nodes > until the lower one is found. While this makes sense from a page aging > and performance perspective, it breaks the expected zonelist policy. This > patch restores the expected behaviour for zone-list ordering. > > Signed-off-by: Mel Gorman 32-bit NUMA? :-) Anyway, this change also cuts down the fair pass overhead on bigger NUMA machines, so I'm all for it. Acked-by: Johannes Weiner