From mboxrd@z Thu Jan  1 00:00:00 1970
From: mhocko@kernel.org (Michal Hocko)
Date: Thu, 15 Mar 2018 19:21:10 +0100
Subject: [PATCH v2] Revert "mm/page_alloc: fix memmap_init_zone pageblock
 alignment"
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Message-ID: <20180315182110.GR23100@dhcp22.suse.cz>
To: linux-arm-kernel@lists.infradead.org
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On Thu 15-03-18 15:48:47, Ard Biesheuvel wrote:
> On 15 March 2018 at 15:34, Daniel Vacek <neelx@redhat.com> wrote:
[...]
> > Hence I was asking what is the abstract meaning
> > of it. As I see two *way_different* implementations so I am not sure
> > how I should understand that.
> >
> 
> My interpretation is that it has a struct page associated with it, but
> it seems the semantics of pfn_valid() aren't well defined.

Well, pfn_valid says that a given pfn is backed by a real memory and it
has a valid struct page backing it.
-- 
Michal Hocko
SUSE Labs