linux-kernel - Re: [PATCH v9 0/2] mm/vmscan: fix demotion targets checks in reclaim/demotion

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] [day] [month] [year] [list]

Message-ID: <aX6XQmBncndLdu1X@google.com>
Date: Sat, 31 Jan 2026 23:58:58 +0000
From: Bing Jiao <bingjiao@...gle.com>
To: Shakeel Butt <shakeel.butt@...ux.dev>
Cc: Andrew Morton <akpm@...ux-foundation.org>,
	David Hildenbrand <david@...nel.org>,
	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>,
	Axel Rasmussen <axelrasmussen@...gle.com>,
	Yuanchu Xie <yuanchu@...gle.com>, Wei Xu <weixugc@...gle.com>,
	Johannes Weiner <hannes@...xchg.org>,
	Qi Zheng <zhengqi.arch@...edance.com>,
	Gregory Price <gourry@...rry.net>,
	Joshua Hahn <joshua.hahnjy@...il.com>, muchun.song@...ux.dev,
	roman.gushchin@...ux.dev, tj@...nel.org, longman@...hat.com,
	chenridong@...weicloud.com, linux-mm@...ck.org,
	linux-kernel@...r.kernel.org, cgroups@...r.kernel.org
Subject: Re: [PATCH v9 0/2] mm/vmscan: fix demotion targets checks in
 reclaim/demotion

On Fri, Jan 30, 2026 at 03:35:26PM -0800, Shakeel Butt wrote:
> Hi Bing,
>
> Please don't reply (i.e. use In-Reply-To) to older revision of your
> series. Send each revision independently.
>
> On Wed, Jan 14, 2026 at 08:53:01PM +0000, Bing Jiao wrote:
> > This patch series addresses two issues in demote_folio_list(),
> > can_demote(), and next_demotion_node() in reclaim/demotion.
> >
> > 1. demote_folio_list() and can_demote() do not correctly check demotion
> >    target against cpuset.mems_effective, which will cause (a) pages are
> >    demoted
>
> pages to be demoted
>
> > to not-allowed nodes and (b) pages are failed to demote
>
> page fail to demote
>
> > even
> >    if the system still have allowed demotion nodes.
> >
> >    Patch 1 fixes this bug by update
>
> updating
>
> > cpuset_node_allowed() and
> >    mem_cgroup_node_allowed() to return effective_mems, allowing directly
> >    logic-and operation against demotion targets.
> >
> > 2. next_demotion_node() returns a preferred demotion target, but it does
>
> does or does not?
>
> >    check the node against allowed nodes.
> >
> >    Patch 2 ensures that next_demotion_node() filters against the allowed
> >    node mask and selects the closest demotion target to the source node.


Hi Shakeel,

Thank you for taking the time to review this patch series and for the
helpful corrections. I also appreciate the reminder about the patch
replying rule and will make sure to send future revisions independently.

Have a great weekend!

Best,
Bing