Date: Fri, 9 Jun 2017 12:49:47 +0200
From: Michal Hocko <mhocko@kernel.org>
To: Wei Yang <richard.weiyang@gmail.com>
Cc: Andrew Morton <akpm@linux-foundation.org>,
        Linux-MM <linux-mm@kvack.org>, Mel Gorman <mgorman@suse.de>,
        Vlastimil Babka <vbabka@suse.cz>,
        Andrea Arcangeli <aarcange@redhat.com>,
        Jerome Glisse <jglisse@redhat.com>,
        Reza Arbab <arbab@linux.vnet.ibm.com>,
        Yasuaki Ishimatsu <yasu.isimatu@gmail.com>, qiuxishi@huawei.com,
        Kani Toshimitsu <toshi.kani@hpe.com>, slaoub@gmail.com,
        Joonsoo Kim <js1304@gmail.com>, Andi Kleen <ak@linux.intel.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>,
        Balbir Singh <bsingharora@gmail.com>,
        Dan Williams <dan.j.williams@intel.com>,
        Heiko Carstens <heiko.carstens@de.ibm.com>,
        Martin Schwidefsky <schwidefsky@de.ibm.com>,
        Tobias Regnery <tobias.regnery@gmail.com>,
        Yasuaki Ishimatsu <isimatu.yasuaki@jp.fujitsu.com>
Subject: Re: [PATCH -v4 0/14] mm: make movable onlining suck less
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On Fri 09-06-17 17:51:24, Wei Yang wrote:
> Hi, Michal
> 
> I am not that familiar with hotplug and trying to catch up the issue
>  and your solution.
> 
> One potential issue I found is we don't check the physical boundary
> when add_memory_resource().
> 
> For example, on x86-64, only 64T physical memory is supported currently.
> Looks it is expanded after 5-level pagetable is introduced. While there is
> still some limitations on this. But we don't check the boundary I think.
> 
> During the bootup, this is ensured by the max_pfn which is guaranteed to
> be under MAX_ARCH_PFN. I don't see some limitation on this when doing
>  hotplug.

This might be true and I would have to double check but this rework
doesn't change anything in that regards. Or do I miss something?
-- 
Michal Hocko
SUSE Labs