linux-kernel - Re: [PATCH v1 23/29] mm/page-alloc: remove PageMappingFlags()

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Message-ID: <d7e29c51-6826-49da-ab63-5d71a3db414f@lucifer.local>
Date: Wed, 2 Jul 2025 09:49:06 +0100
From: Lorenzo Stoakes <lorenzo.stoakes@...cle.com>
To: David Hildenbrand <david@...hat.com>
Cc: linux-kernel@...r.kernel.org, linux-mm@...ck.org,
        linux-doc@...r.kernel.org, linuxppc-dev@...ts.ozlabs.org,
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        Shakeel Butt <shakeel.butt@...ux.dev>
Subject: Re: [PATCH v1 23/29] mm/page-alloc: remove PageMappingFlags()

On Tue, Jul 01, 2025 at 09:34:41PM +0200, David Hildenbrand wrote:
> On 01.07.25 15:02, Lorenzo Stoakes wrote:
> > On Mon, Jun 30, 2025 at 03:00:04PM +0200, David Hildenbrand wrote:
> > > We can now simply check for PageAnon() and remove PageMappingFlags().
> > >
> > > ... and while at it, use the folio instead and operate on
> > > folio->mapping.
> >
> > Probably worth mentioning to be super crystal clear that this is because
> > now it's either an anon folio or a KSM folio, both of which set the
> > FOLIO_MAPPING_ANON flag.
>
> "As PageMappingFlags() now only indicates anon (incl. ksm) folios, we can
> now simply check for PageAnon() and remove PageMappingFlags()."

Sounds good! Though the extremely nitty part of me says 'capitalise KSM' :P

>
>
> >
> > I wonder if there's other places that could be fixed up similarly that do
> > folio_test_anon() || folio_test_ksm() or equivalent?
>
> I think you spotted the one in patch #25 :)

:)

>
> I looked for others while crafting this patch, but there might be more
> hiding that I didn't catch.

Yeah, one we can keep an eye out for.

>
> >
> > >
> > > Reviewed-by: Zi Yan <ziy@...dia.com>
> > > Signed-off-by: David Hildenbrand <david@...hat.com>
> >
> > LGTM, so:
> >
> > Reviewed-by: Lorenzo Stoakes <lorenzo.stoakes@...cle.com>
> >
>
> Thanks!
>
> --
> Cheers,
>
> David / dhildenb
>