linux-kernel - Re: [PATCH v1 18/29] mm: remove __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: <aGUIACa5JyuBKrAA@hyeyoo>
Date: Wed, 2 Jul 2025 19:20:48 +0900
From: Harry Yoo <harry.yoo@...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,
        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>,
        Lorenzo Stoakes <lorenzo.stoakes@...cle.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>
Subject: Re: [PATCH v1 18/29] mm: remove __folio_test_movable()

On Mon, Jun 30, 2025 at 02:59:59PM +0200, David Hildenbrand wrote:
> Convert to page_has_movable_ops(). While at it, cleanup relevant code
> a bit.
> 
> The data_race() in migrate_folio_unmap() is questionable: we already
> hold a page reference, and concurrent modifications can no longer
> happen (iow: __ClearPageMovable() no longer exists). Drop it for now,
> we'll rework page_has_movable_ops() soon either way to no longer
> rely on page->mapping.
> 
> Wherever we cast from folio to page now is a clear sign that this
> code has to be decoupled.
> 
> Reviewed-by: Zi Yan <ziy@...dia.com>
> Signed-off-by: David Hildenbrand <david@...hat.com>
> ---

LGTM

Reviewed-by: Harry Yoo <harry.yoo@...cle.com>

> diff --git a/mm/vmscan.c b/mm/vmscan.c
> index 098bcc821fc74..103dfc729a823 100644
> --- a/mm/vmscan.c
> +++ b/mm/vmscan.c
> @@ -1658,9 +1658,11 @@ unsigned int reclaim_clean_pages_from_list(struct zone *zone,
>  	unsigned int noreclaim_flag;
>  
>  	list_for_each_entry_safe(folio, next, folio_list, lru) {
> +		/* TODO: these pages should not even appear in this list. */
> +		if (page_has_movable_ops(&folio->page))
> +			continue;

Looking forward to see how this TODO will be addressed :)

-- 
Cheers,
Harry / Hyeonggon