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Date:   Thu, 22 Apr 2021 13:03:58 +0300
From:   Mike Rapoport <rppt@kernel.org>
To:     David Hildenbrand <david@redhat.com>
Cc:     Anshuman Khandual <anshuman.khandual@arm.com>, linux-mm@kvack.org,
        akpm@linux-foundation.org,
        Catalin Marinas <catalin.marinas@arm.com>,
        Will Deacon <will@kernel.org>,
        linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org
Subject: Re: [RFC V2] mm: Enable generic pfn_valid() to handle early sections
 with memmap holes
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On Thu, Apr 22, 2021 at 11:48:58AM +0200, David Hildenbrand wrote:
> > 
> > > IOW, avoiding having to adjust generic pfn_valid()/pfn_to_online_page() at
> > > all. Am i missing something or should that be possible?
> > 
> > We are back again to the question "should arm64 free its memmap".
> > If the answer is no, we don't need arm64::pfn_valid() for SPARSEMEM at all.
> > If the answer is yes, Anshuman's patch is way better than a custom
> > pfn_valid().
> 
> Well, I propose something in between: stop freeing with SPARSEMEM, continue
> freeing with FLATMEM.

I'm all for it.

-- 
Sincerely yours,
Mike.