Date: Tue, 4 Apr 2017 09:34:12 +0200
From: Michal Hocko <mhocko@kernel.org>
To: Reza Arbab <arbab@linux.vnet.ibm.com>, Mel Gorman <mgorman@suse.de>
Cc: linux-mm@kvack.org, Andrew Morton <akpm@linux-foundation.org>,
        Vlastimil Babka <vbabka@suse.cz>,
        Andrea Arcangeli <aarcange@redhat.com>,
        Yasuaki Ishimatsu <yasu.isimatu@gmail.com>,
        Tang Chen <tangchen@cn.fujitsu.com>, qiuxishi@huawei.com,
        Kani Toshimitsu <toshi.kani@hpe.com>, slaoub@gmail.com,
        Joonsoo Kim <js1304@gmail.com>, Andi Kleen <ak@linux.intel.com>,
        Zhang Zhen <zhenzhang.zhang@huawei.com>,
        David Rientjes <rientjes@google.com>,
        Daniel Kiper <daniel.kiper@oracle.com>,
        Igor Mammedov <imammedo@redhat.com>,
        Vitaly Kuznetsov <vkuznets@redhat.com>,
        LKML <linux-kernel@vger.kernel.org>,
        Chris Metcalf <cmetcalf@mellanox.com>,
        Dan Williams <dan.j.williams@gmail.com>,
        Heiko Carstens <heiko.carstens@de.ibm.com>,
        Lai Jiangshan <laijs@cn.fujitsu.com>,
        Martin Schwidefsky <schwidefsky@de.ibm.com>
Subject: Re: [PATCH 0/6] mm: make movable onlining suck less
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On Tue 04-04-17 09:23:29, Michal Hocko wrote:
> [Let's add Gary who as introduced this code c04fc586c1a48]

OK, so Gary's email doesn't exist anymore. Does anybody can comment on
this? I suspect this code is just-in-case... Mel?
 
> On Mon 03-04-17 15:42:13, Reza Arbab wrote:
[...]
> > Almost there. I'm seeing the memory in the correct node now, but the
> > /sys/devices/system/node/nodeX/memoryY links are not being created.
> > 
> > I think it's tripping up here, in register_mem_sect_under_node():
> > 
> > 		page_nid = get_nid_for_pfn(pfn);
> > 		if (page_nid < 0)
> > 			continue;
> 
> Huh, this code is confusing. How can we have a memblock spanning more
> nodes? If not then the loop over all sections in the memblock seem
> pointless as well.  Also why do we require page_initialized() in
> get_nid_for_pfn? The changelog doesn't explain that and there are no
> comments that would help either.
> 
> Gary, could you clarify this please?
> -- 
> Michal Hocko
> SUSE Labs

-- 
Michal Hocko
SUSE Labs