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Subject: Re: [PATCH v2 2/3] powerpc/mm: allow memory hotplug into a memoryless
 node
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>, Rob Herring <robh+dt@kernel.org>,
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        Jonathan Corbet <corbet@lwn.net>,
        Andrew Morton <akpm@linux-foundation.org>
References: <1473883618-14998-1-git-send-email-arbab@linux.vnet.ibm.com>
 <1473883618-14998-3-git-send-email-arbab@linux.vnet.ibm.com>
Cc: 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>, linux-doc@vger.kernel.org,
        linux-kernel@vger.kernel.org, linuxppc-dev@lists.ozlabs.org,
        devicetree@vger.kernel.org, linux-mm@kvack.org
From: Balbir Singh <bsingharora@gmail.com>
Message-ID: <15d62e9c-38e6-dfd3-0ee2-6885cbfbe315@gmail.com>
Date: Mon, 19 Sep 2016 21:53:49 +1000
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On 15/09/16 06:06, Reza Arbab wrote:
> Remove the check which prevents us from hotplugging into an empty node.
> 
> This limitation has been questioned before [1], and judging by the
> response, there doesn't seem to be a reason we can't remove it. No issues
> have been found in light testing.
> 
> [1] http://lkml.kernel.org/r/CAGZKiBrmkSa1yyhbf5hwGxubcjsE5SmkSMY4tpANERMe2UG4bg@mail.gmail.com
>     http://lkml.kernel.org/r/20160511215051.GF22115@arbab-laptop.austin.ibm.com
> 
> Signed-off-by: Reza Arbab <arbab@linux.vnet.ibm.com>
> Acked-by: Balbir Singh <bsingharora@gmail.com>
> Cc: Nathan Fontenot <nfont@linux.vnet.ibm.com>
> Cc: Bharata B Rao <bharata@linux.vnet.ibm.com>
> ---
>  arch/powerpc/mm/numa.c | 13 +------------
>  1 file changed, 1 insertion(+), 12 deletions(-)
> 

I presume you've tested with CONFIG_NODES_SHIFT of 8 (255 nodes?)

Balbir Singh.