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Date: Tue, 30 Jul 2019 10:14:15 +0200
From: Michal Hocko <mhocko@kernel.org>
Subject: Re: [PATCH v2 0/5] mm: Enable CONFIG_NODES_SPAN_OTHER_NODES by
 default for NUMA
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To: Hoan Tran OS <hoan@os.amperecomputing.com>
Cc: Will Deacon <will@kernel.org>, Catalin Marinas <catalin.marinas@arm.com>, Heiko Carstens <heiko.carstens@de.ibm.com>, "open list:MEMORY MANAGEMENT" <linux-mm@kvack.org>, Paul Mackerras <paulus@samba.org>, "H . Peter Anvin" <hpa@zytor.com>, "sparclinux@vger.kernel.org" <sparclinux@vger.kernel.org>, Alexander Duyck <alexander.h.duyck@linux.intel.com>, "linux-s390@vger.kernel.org" <linux-s390@vger.kernel.org>, Michael Ellerman <mpe@ellerman.id.au>, "x86@kernel.org" <x86@kernel.org>, Mike Rapoport <rppt@linux.ibm.com>, Christian Borntraeger <borntraeger@de.ibm.com>, Ingo Molnar <mingo@redhat.com>, Vlastimil Babka <vbabka@suse.cz>, Benjamin Herrenschmidt <benh@kernel.crashing.org>, Open Source Submission <patches@amperecomputing.com>, Pavel Tatashin <pavel.tatashin@microsoft.com>, Vasily Gorbik <gor@linux.ibm.com>, Will Deacon <will.deacon@arm.com>, Borislav Petkov <bp@alien8.de>, Thomas Gleixner <tglx@linutronix.de>, "linux-arm-kernel@lists.infradead.org" <linux-arm-kernel@lists.infradead.org>, Oscar Salvador <osalvador@suse.de>, "linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>, Andrew Morton <akpm@linux-foundation.org>, "linuxppc-dev@lists.ozlabs.org" <linuxppc-dev@lists.ozlabs.org>, "David S . Miller" <davem@davemloft.net>, "willy@infradead.org" <willy@infradead.org>

[Sorry for a late reply]

On Mon 15-07-19 17:55:07, Hoan Tran OS wrote:
> Hi,
> 
> On 7/12/19 10:00 PM, Michal Hocko wrote:
[...]
> > Hmm, I thought this was selectable. But I am obviously wrong here.
> > Looking more closely, it seems that this is indeed only about
> > __early_pfn_to_nid and as such not something that should add a config
> > symbol. This should have been called out in the changelog though.
> 
> Yes, do you have any other comments about my patch?

Not really. Just make sure to explicitly state that
CONFIG_NODES_SPAN_OTHER_NODES is only about __early_pfn_to_nid and that
doesn't really deserve it's own config and can be pulled under NUMA.

> > Also while at it, does HAVE_MEMBLOCK_NODE_MAP fall into a similar
> > bucket? Do we have any NUMA architecture that doesn't enable it?
> > 
> 
> As I checked with arch Kconfig files, there are 2 architectures, riscv 
> and microblaze, do not support NUMA but enable this config.
> 
> And 1 architecture, alpha, supports NUMA but does not enable this config.

Care to have a look and clean this up please?

-- 
Michal Hocko
SUSE Labs