linux-kernel - Re: [PATCH v1 17/29] mm/page_isolation: drop __folio_test

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <aGUBx9PUkSMm3pTf@hyeyoo>
Date: Wed, 2 Jul 2025 18:54:15 +0900
From: Harry Yoo <harry.yoo@...cle.com>
To: David Hildenbrand <david@...hat.com>
Cc: Lorenzo Stoakes <lorenzo.stoakes@...cle.com>, 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>,
        Qi Zheng <zhengqi.arch@...edance.com>,
        Shakeel Butt <shakeel.butt@...ux.dev>,
        Tangquan Zheng <zhengtangquan@...o.com>,
        Barry Song <v-songbaohua@...o.com>, Barry Song <21cnbao@...il.com>
Subject: Re: [PATCH v1 17/29] mm/page_isolation: drop __folio_test_movable()
 check for large folios

On Tue, Jul 01, 2025 at 02:32:54PM +0200, David Hildenbrand wrote:
> On 01.07.25 13:03, Lorenzo Stoakes wrote:
> > On Mon, Jun 30, 2025 at 02:59:58PM +0200, David Hildenbrand wrote:
> > > Currently, we only support migration of individual movable_ops pages, so
> > > we can not run into that.
> > > 
> > > Reviewed-by: Zi Yan <ziy@...dia.com>
> > > Signed-off-by: David Hildenbrand <david@...hat.com>
> > 
> > Seems sensible, so:
> > 
> > Reviewed-by: Lorenzo Stoakes <lorenzo.stoakes@...cle.com>
> > 
> > Maybe worth adding a VM_WARN_ON_ONCE() just in case? Or do you think not worth it?
> 
> Not for now I think. Whoever wants to support compound pages has to fixup a
> bunch of other stuff first, before running into that one here.
> 
> So a full audit of all paths that handle page_has_movable_ops() is required
> either way.

IIRC there was an RFC series last year [1] that adds support for
order > 0 pages in zsmalloc.

Cc'ing Barry and Tangquan in case it's still on their TODO list... 

[1] https://lore.kernel.org/linux-mm/20241121222521.83458-2-21cnbao@gmail.com

-- 
Cheers,
Harry / Hyeonggon