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

Message-ID: <aXlY04m0FuX-9LRE@linux.dev>
Date: Fri, 30 Jan 2026 15:35:26 -0800
From: Shakeel Butt <shakeel.butt@...ux.dev>
To: Bing Jiao <bingjiao@...gle.com>
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

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.
>