From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1758678Ab2IKKTU (ORCPT ); Tue, 11 Sep 2012 06:19:20 -0400 Received: from fgwmail5.fujitsu.co.jp ([192.51.44.35]:46408 "EHLO fgwmail5.fujitsu.co.jp" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753311Ab2IKKTR (ORCPT ); Tue, 11 Sep 2012 06:19:17 -0400 X-SecurityPolicyCheck: OK by SHieldMailChecker v1.7.4 Message-ID: <504F0FE6.5090709@jp.fujitsu.com> Date: Tue, 11 Sep 2012 19:18:14 +0900 From: Yasuaki Ishimatsu User-Agent: Mozilla/5.0 (Windows NT 5.1; rv:15.0) Gecko/20120824 Thunderbird/15.0 MIME-Version: 1.0 To: Lai Jiangshan CC: Mel Gorman , David Rientjes , LKML , x86 maintainers , Jiang Liu , Rusty Russell , Yinghai Lu , KAMEZAWA Hiroyuki , Andrew Morton , "'FNST-Wen Congyang'" Subject: Re: [V4 PATCH 27/27] memory,hotplug: Don't modify the zone_start_pfn outside of zone_span_writelock() References: <1347267558-6707-1-git-send-email-laijs@cn.fujitsu.com> <504E8874.5020605@jp.fujitsu.com> <504F07ED.3070502@cn.fujitsu.com> In-Reply-To: <504F07ED.3070502@cn.fujitsu.com> Content-Type: text/plain; charset="UTF-8"; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi Lai, 2012/09/11 18:44, Lai Jiangshan wrote: > On 09/11/2012 08:40 AM, Yasuaki Ishimatsu wrote: >> Hi Lai, >> >> Using memory_online to hot-added node's memory, the following kernel messages >> were shown. Is this a known issue? > > Fixed. > > Subject: Don't modify the zone_start_pfn outside of zone_span_writelock() > > Original __add_zone() and new online_movable/online_kernel > maybe call sleep-able init_currently_empty_zone() to init wait_table, > > but this function also modifies the zone_start_pfn without lock. > so we move this code out, and ensure the modification of zone_start_pfn is done > with zone_span_writelock() held or booting. > > Since zone_start_pfn is not modified by init_currently_empty_zone() > grow_zone_span() needs to be updated to be aware of empty zone. > > Signed-off-by: Lai Jiangshan > Reported-by: Yasuaki ISIMATU > Tested-by: Wen Congyang Applying the patch, the kernel messages disappeared. Thanks. But I have a question. Using online_movable, the following messages are shown. [ 608.314608] Built 3 zonelists in Node order, mobility grouping on. Total pages: 7844412 [ 608.411478] Policy zone: Normal I think memory is allocated to ZONE_MOVABLE by using online_movable. So why is "Policy zone: Normal" shown? It should be "Policy zone: Movable" Thanks, Yasuaki Ishimatsu > --- > diff --git a/mm/memory_hotplug.c b/mm/memory_hotplug.c > index 3ad25f9..c26a4ea 100644 > --- a/mm/memory_hotplug.c > +++ b/mm/memory_hotplug.c > @@ -201,7 +201,7 @@ static void grow_zone_span(struct zone *zone, unsigned long start_pfn, > zone_span_writelock(zone); > > old_zone_end_pfn = zone->zone_start_pfn + zone->spanned_pages; > - if (start_pfn < zone->zone_start_pfn) > + if (!zone->zone_start_pfn || start_pfn < zone->zone_start_pfn) > zone->zone_start_pfn = start_pfn; > > zone->spanned_pages = max(old_zone_end_pfn, end_pfn) - > diff --git a/mm/page_alloc.c b/mm/page_alloc.c > index 009ac28..637b4f8 100644 > --- a/mm/page_alloc.c > +++ b/mm/page_alloc.c > @@ -3991,8 +3991,6 @@ int __meminit init_currently_empty_zone(struct zone *zone, > return ret; > pgdat->nr_zones = zone_idx(zone) + 1; > > - zone->zone_start_pfn = zone_start_pfn; > - > mminit_dprintk(MMINIT_TRACE, "memmap_init", > "Initialising map node %d zone %lu pfns %lu -> %lu\n", > pgdat->node_id, > @@ -4459,6 +4457,7 @@ static void __paginginit free_area_init_core(struct pglist_data *pgdat, > ret = init_currently_empty_zone(zone, zone_start_pfn, > size, MEMMAP_EARLY); > BUG_ON(ret); > + zone->zone_start_pfn = zone_start_pfn; > memmap_init(size, nid, j, zone_start_pfn); > zone_start_pfn += size; > } >