Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752939AbaBSIdl (ORCPT ); Wed, 19 Feb 2014 03:33:41 -0500 Received: from cantor2.suse.de ([195.135.220.15]:50920 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752511AbaBSId3 (ORCPT ); Wed, 19 Feb 2014 03:33:29 -0500 Date: Wed, 19 Feb 2014 09:33:27 +0100 From: Michal Hocko To: David Rientjes Cc: Nishanth Aravamudan , linux-mm@kvack.org, linuxppc-dev@lists.ozlabs.org, Anton Blanchard , LKML Subject: Re: ppc: RECLAIM_DISTANCE 10? Message-ID: <20140219083327.GC14783@dhcp22.suse.cz> References: <20140218090658.GA28130@dhcp22.suse.cz> <20140218233404.GB10844@linux.vnet.ibm.com> <20140218235800.GC10844@linux.vnet.ibm.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.5.21 (2010-09-15) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue 18-02-14 17:43:38, David Rientjes wrote: > On Tue, 18 Feb 2014, Nishanth Aravamudan wrote: > > > How about the following? > > > > diff --git a/mm/page_alloc.c b/mm/page_alloc.c > > index 5de4337..1a0eced 100644 > > --- a/mm/page_alloc.c > > +++ b/mm/page_alloc.c > > @@ -1854,7 +1854,8 @@ static void __paginginit init_zone_allows_reclaim(int nid) > > int i; > > > > for_each_online_node(i) > > - if (node_distance(nid, i) <= RECLAIM_DISTANCE) > > + if (node_distance(nid, i) <= RECLAIM_DISTANCE || > > + !NODE_DATA(i)->node_present_pages) > > node_set(i, NODE_DATA(nid)->reclaim_nodes); > > else > > zone_reclaim_mode = 1; > > [ I changed the above from NODE_DATA(nid) -> NODE_DATA(i) as you caught > so we're looking at the right code. ] > > That can't be right, it would allow reclaiming from a memoryless node. I > think what you want is > > for_each_online_node(i) { > if (!node_present_pages(i)) > continue; > if (node_distance(nid, i) <= RECLAIM_DISTANCE) { > node_set(i, NODE_DATA(nid)->reclaim_nodes); > continue; > } > /* Always try to reclaim locally */ > zone_reclaim_mode = 1; > } > > but we really should be able to do for_each_node_state(i, N_MEMORY) here > and memoryless nodes should already be excluded from that mask. Agreed! Actually the code I am currently interested in is based on 3.0 kernel where zone_reclaim_mode is set in build_zonelists which relies on find_next_best_node which iterates only N_HIGH_MEMORY nodes which should have non 0 present pages. [...] -- Michal Hocko SUSE Labs -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/