Message-ID: <48e9a5de-3131-4e36-8a21-5f77669116a9@redhat.com>
Date: Tue, 1 Jul 2025 21:31:56 +0200
From: David Hildenbrand <david@...hat.com>
To: Lorenzo Stoakes <lorenzo.stoakes@...cle.com>
Cc: linux-kernel@...r.kernel.org, linux-mm@...ck.org,
 linux-doc@...r.kernel.org, linuxppc-dev@...ts.ozlabs.org,
 virtualization@...ts.linux.dev, linux-fsdevel@...r.kernel.org,
 Andrew Morton <akpm@...ux-foundation.org>, Jonathan Corbet <corbet@....net>,
 Madhavan Srinivasan <maddy@...ux.ibm.com>,
 Michael Ellerman <mpe@...erman.id.au>, Nicholas Piggin <npiggin@...il.com>,
 Christophe Leroy <christophe.leroy@...roup.eu>,
 Jerrin Shaji George <jerrin.shaji-george@...adcom.com>,
 Arnd Bergmann <arnd@...db.de>,
 Greg Kroah-Hartman <gregkh@...uxfoundation.org>,
 "Michael S. Tsirkin" <mst@...hat.com>, Jason Wang <jasowang@...hat.com>,
 Xuan Zhuo <xuanzhuo@...ux.alibaba.com>, Eugenio Pérez
 <eperezma@...hat.com>, Alexander Viro <viro@...iv.linux.org.uk>,
 Christian Brauner <brauner@...nel.org>, Jan Kara <jack@...e.cz>,
 Zi Yan <ziy@...dia.com>, Matthew Brost <matthew.brost@...el.com>,
 Joshua Hahn <joshua.hahnjy@...il.com>, Rakie Kim <rakie.kim@...com>,
 Byungchul Park <byungchul@...com>, Gregory Price <gourry@...rry.net>,
 Ying Huang <ying.huang@...ux.alibaba.com>,
 Alistair Popple <apopple@...dia.com>,
 "Liam R. Howlett" <Liam.Howlett@...cle.com>, Vlastimil Babka
 <vbabka@...e.cz>, Mike Rapoport <rppt@...nel.org>,
 Suren Baghdasaryan <surenb@...gle.com>, Michal Hocko <mhocko@...e.com>,
 "Matthew Wilcox (Oracle)" <willy@...radead.org>,
 Minchan Kim <minchan@...nel.org>,
 Sergey Senozhatsky <senozhatsky@...omium.org>,
 Brendan Jackman <jackmanb@...gle.com>, Johannes Weiner <hannes@...xchg.org>,
 Jason Gunthorpe <jgg@...pe.ca>, John Hubbard <jhubbard@...dia.com>,
 Peter Xu <peterx@...hat.com>, Xu Xin <xu.xin16@....com.cn>,
 Chengming Zhou <chengming.zhou@...ux.dev>, Miaohe Lin
 <linmiaohe@...wei.com>, Naoya Horiguchi <nao.horiguchi@...il.com>,
 Oscar Salvador <osalvador@...e.de>, Rik van Riel <riel@...riel.com>,
 Harry Yoo <harry.yoo@...cle.com>, Qi Zheng <zhengqi.arch@...edance.com>,
 Shakeel Butt <shakeel.butt@...ux.dev>
Subject: Re: [PATCH v1 22/29] mm/page-flags: rename PAGE_MAPPING_MOVABLE to
 PAGE_MAPPING_ANON_KSM

On 01.07.25 14:54, Lorenzo Stoakes wrote:
> On Mon, Jun 30, 2025 at 03:00:03PM +0200, David Hildenbrand wrote:
>> KSM is the only remaining user, let's rename the flag. While at it,
>> adjust to remaining page -> folio in the doc.
> 
> Hm I wonder if we could just ideally have this be a separate flag rather than a
> bitwise combination, however I bet there's code that does somehow rely on this.

Well, KSM folios are anon folios, so that must hold.

Of course, now you could make folio_test_anon() test both bits, and have 
KSM folios only set a PAGE_MAPPING_KSM bit.

That should be possible on top of this change, but not sure if that's 
really what we want. After all, KSM folios are special ANON folios.

> 
> I know for sure there's code that has to do a folio_test_ksm() on something
> folio_test_anon()'d because the latter isn't sufficient.
 > > But this is one for the future I guess :)

Yes :)

> 
> Nice: re change to folio, that is a nice cleanup based on fact you've now made
> the per-page mapping op stuff not be part of this.
> 
>>
>> 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

Powered by blists - more mailing lists