Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 23.128.96.18 as permitted sender) client-ip=23.128.96.18;
Subject: Re: [PATCH 03/10] mm/migrate: update node demotion order during on
 hotplug events
To:     Oscar Salvador <osalvador@suse.de>
Cc:     Dave Hansen <dave.hansen@linux.intel.com>, linux-mm@kvack.org,
        linux-kernel@vger.kernel.org, shy828301@gmail.com,
        weixugc@google.com, rientjes@google.com, ying.huang@intel.com,
        dan.j.williams@intel.com
References: <20210401183216.443C4443@viggo.jf.intel.com>
 <20210401183221.977831DE@viggo.jf.intel.com>
 <YG7Sc3i54IV6KyPn@localhost.localdomain> <20210409101400.GA32159@linux>
 <fb51273c-12e5-f47f-064b-86f5b30b1072@redhat.com>
 <20210412071936.GA27818@linux>
From:   David Hildenbrand <david@redhat.com>
Organization: Red Hat
Message-ID: <d72377e1-770f-555a-3559-14215039510f@redhat.com>
Date:   Mon, 12 Apr 2021 11:19:15 +0200
User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:78.0) Gecko/20100101
 Thunderbird/78.8.1
MIME-Version: 1.0
In-Reply-To: <20210412071936.GA27818@linux>
Content-Type: text/plain; charset=utf-8; format=flowed
Content-Language: en-US
Content-Transfer-Encoding: 7bit
Precedence: bulk

On 12.04.21 09:19, Oscar Salvador wrote:
> On Fri, Apr 09, 2021 at 08:59:21PM +0200, David Hildenbrand wrote:
>   
>> The only way to add more System RAM is via add_memory() and friends like
>> add_memory_driver_managed(). These all require CONFIG_MEMORY_HOTPLUG.
> 
> Yeah, my point was more towards whether PMEM can come in a way that it does
> not have to be hotplugged, but come functional by default (as RAM).
> But after having read all papers out there, I do not think that it is possible.
> 

You mean e.g., configuring in the BIOS/firmware how an NVDIMM will get 
exposed to the OS (pmem vs. RAM). I once heard something about that, not 
sure if it's real. But from Linux' perspective, it would simply be 
System RAM and it would get treated like that.

-- 
Thanks,

David / dhildenb