From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from e38.co.us.ibm.com (e38.co.us.ibm.com [32.97.110.159]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (No client certificate requested) by ozlabs.org (Postfix) with ESMTPS id 6B3182C00AE for ; Thu, 20 Feb 2014 03:57:29 +1100 (EST) Received: from /spool/local by e38.co.us.ibm.com with IBM ESMTP SMTP Gateway: Authorized Use Only! Violators will be prosecuted for from ; Wed, 19 Feb 2014 09:57:26 -0700 Received: from b03cxnp08026.gho.boulder.ibm.com (b03cxnp08026.gho.boulder.ibm.com [9.17.130.18]) by d03dlp01.boulder.ibm.com (Postfix) with ESMTP id AAA34C40001 for ; Wed, 19 Feb 2014 09:57:23 -0700 (MST) Received: from d03av02.boulder.ibm.com (d03av02.boulder.ibm.com [9.17.195.168]) by b03cxnp08026.gho.boulder.ibm.com (8.13.8/8.13.8/NCO v10.0) with ESMTP id s1JGuxH337421274 for ; Wed, 19 Feb 2014 17:57:00 +0100 Received: from d03av02.boulder.ibm.com (localhost [127.0.0.1]) by d03av02.boulder.ibm.com (8.14.4/8.14.4/NCO v10.0 AVout) with ESMTP id s1JGcxO3001461 for ; Wed, 19 Feb 2014 09:39:00 -0700 Date: Wed, 19 Feb 2014 08:33:45 -0800 From: Nishanth Aravamudan To: David Rientjes Subject: Re: ppc: RECLAIM_DISTANCE 10? Message-ID: <20140219163345.GD27108@linux.vnet.ibm.com> References: <20140218090658.GA28130@dhcp22.suse.cz> <20140218233404.GB10844@linux.vnet.ibm.com> <20140218235800.GC10844@linux.vnet.ibm.com> <20140219162438.GB27108@linux.vnet.ibm.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii In-Reply-To: <20140219162438.GB27108@linux.vnet.ibm.com> Cc: Michal Hocko , linux-mm@kvack.org, linuxppc-dev@lists.ozlabs.org, Anton Blanchard , LKML List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , On 19.02.2014 [08:24:38 -0800], Nishanth Aravamudan wrote: > On 18.02.2014 [17:43:38 -0800], 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 > > Gah, you're right. > > > 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. > > Yep, I found that afterwards, which simplifies the logic. I'll add this > to my series :) In looking at the code, I am wondering about the following: init_zone_allows_reclaim() is called for each nid from free_area_init_node(). Which means that calculate_node_totalpages for other "later" nids and check_for_memory() [which sets up the N_MEMORY nodemask] hasn't been called yet. So, would it make sense to pull up the /* Any memory on that node */ if (pgdat->node_present_pages) node_set_state(nid, N_MEMORY); check_for_memory(pgdat, nid); into free_area_init_node()? Thanks, Nish