From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751103AbdGDFLw (ORCPT ); Tue, 4 Jul 2017 01:11:52 -0400 Received: from mail-pg0-f66.google.com ([74.125.83.66]:33888 "EHLO mail-pg0-f66.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750820AbdGDFLv (ORCPT ); Tue, 4 Jul 2017 01:11:51 -0400 Date: Tue, 4 Jul 2017 14:11:41 +0900 From: Joonsoo Kim To: Michal Hocko Cc: Yang Shi , Mel Gorman , Andrew Morton , Vlastimil Babka , linux-mm@kvack.org, LKML Subject: Re: "mm: use early_pfn_to_nid in page_ext_init" broken on some configurations? Message-ID: <20170704051138.GA28589@js1304-desktop> References: <20170630141847.GN22917@dhcp22.suse.cz> <20170630154224.GA9714@dhcp22.suse.cz> <20170630154416.GB9714@dhcp22.suse.cz> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20170630154416.GB9714@dhcp22.suse.cz> User-Agent: Mutt/1.5.24 (2015-08-30) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Fri, Jun 30, 2017 at 05:44:16PM +0200, Michal Hocko wrote: > On Fri 30-06-17 17:42:24, Michal Hocko wrote: > [...] > > diff --git a/include/linux/mmzone.h b/include/linux/mmzone.h > > index 16532fa0bb64..894697c1e6f5 100644 > > --- a/include/linux/mmzone.h > > +++ b/include/linux/mmzone.h > > @@ -1055,6 +1055,7 @@ static inline struct zoneref *first_zones_zonelist(struct zonelist *zonelist, > > !defined(CONFIG_HAVE_MEMBLOCK_NODE_MAP) > > static inline unsigned long early_pfn_to_nid(unsigned long pfn) > > { > > + BUILD_BUG_ON(!IS_ENABLED(CONFIG_NUMA)); > > Err, this should read BUILD_BUG_ON(IS_ENABLED(CONFIG_NUMA)) of course Agreed. However, AFAIK, ARM can set CONFIG_NUMA but it doesn't have CONFIG_HAVE_ARCH_EARLY_PFN_TO_NID and CONFIG_HAVE_MEMBLOCK_NODE_MAP. If page_ext uses early_pfn_to_nid(), it will cause build error in ARM. Therefore, I suggest following change. CONFIG_DEFERRED_STRUCT_PAGE_INIT depends on proper early_pfn_to_nid(). So, following code will always work as long as CONFIG_DEFERRED_STRUCT_PAGE_INIT works. Thanks. ----------->8--------------- diff --git a/mm/page_ext.c b/mm/page_ext.c index 88ccc044..e3db259 100644 --- a/mm/page_ext.c +++ b/mm/page_ext.c @@ -384,6 +384,7 @@ void __init page_ext_init(void) for_each_node_state(nid, N_MEMORY) { unsigned long start_pfn, end_pfn; + int page_nid; start_pfn = node_start_pfn(nid); end_pfn = node_end_pfn(nid); @@ -405,8 +406,15 @@ void __init page_ext_init(void) * * Take into account DEFERRED_STRUCT_PAGE_INIT. */ - if (early_pfn_to_nid(pfn) != nid) +#ifdef CONFIG_DEFERRED_STRUCT_PAGE_INIT + page_nid = early_pfn_to_nid(pfn); +#else + page_nid = pfn_to_nid(pfn); +#endif + + if (page_nid != nid) continue; + if (init_section_page_ext(pfn, nid)) goto oom; }