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Subject: Re: [PATCH v6 4/4] of/fdt: mark hotpluggable memory
To: Reza Arbab <arbab@linux.vnet.ibm.com>,
 Michael Ellerman <mpe@ellerman.id.au>,
 Benjamin Herrenschmidt <benh@kernel.crashing.org>,
 Paul Mackerras <paulus@samba.org>, Andrew Morton
 <akpm@linux-foundation.org>, Rob Herring <robh+dt@kernel.org>,
 Frank Rowand <frowand.list@gmail.com>, Thomas Gleixner <tglx@linutronix.de>,
 Ingo Molnar <mingo@redhat.com>, "H. Peter Anvin" <hpa@zytor.com>
References: <1478562276-25539-1-git-send-email-arbab@linux.vnet.ibm.com>
 <1478562276-25539-5-git-send-email-arbab@linux.vnet.ibm.com>
Cc: linuxppc-dev@lists.ozlabs.org, linux-mm@kvack.org,
 devicetree@vger.kernel.org, Bharata B Rao <bharata@linux.vnet.ibm.com>,
 Nathan Fontenot <nfont@linux.vnet.ibm.com>,
 Stewart Smith <stewart@linux.vnet.ibm.com>,
 Alistair Popple <apopple@au1.ibm.com>,
 "Aneesh Kumar K.V" <aneesh.kumar@linux.vnet.ibm.com>,
 linux-kernel@vger.kernel.org
From: Balbir Singh <bsingharora@gmail.com>
Message-ID: <2627373d-b90c-10f6-90b6-2ee74029b74f@gmail.com>
Date: Fri, 11 Nov 2016 12:17:18 +1100
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On 08/11/16 10:44, Reza Arbab wrote:
> When movable nodes are enabled, any node containing only hotpluggable
> memory is made movable at boot time.
> 
> On x86, hotpluggable memory is discovered by parsing the ACPI SRAT,
> making corresponding calls to memblock_mark_hotplug().
> 
> If we introduce a dt property to describe memory as hotpluggable,
> configs supporting early fdt may then also do this marking and use
> movable nodes.
> 
> Signed-off-by: Reza Arbab <arbab@linux.vnet.ibm.com>
> ---

Tested-by: Balbir Singh <bsingharora@gmail.com>

I tested this with a custom device tree and it worked quite well for me.
It also means that the guest and bare-metal have two different mechanisms
of marking something as hotpluggable. But given that your patch enables
all architectures using OF, it might be worth it.

Balbir Singh.