Re: [PATCH v3 19/30] mm: workingset: prevent lruvec release in workingset_refault()

From: Shakeel Butt

Date: Sat Jan 17 2026 - 18:02:45 EST


On Wed, Jan 14, 2026 at 07:32:46PM +0800, Qi Zheng wrote:
> From: Muchun Song <songmuchun@xxxxxxxxxxxxx>
>
> In the near future, a folio will no longer pin its corresponding
> memory cgroup. So an lruvec returned by folio_lruvec() could be
> released without the rcu read lock or a reference to its memory
> cgroup.
>
> In the current patch, the rcu read lock is employed to safeguard
> against the release of the lruvec in workingset_refault().
>
> This serves as a preparatory measure for the reparenting of the
> LRU pages.
>
> Signed-off-by: Muchun Song <songmuchun@xxxxxxxxxxxxx>
> Signed-off-by: Qi Zheng <zhengqi.arch@xxxxxxxxxxxxx>
> Reviewed-by: Harry Yoo <harry.yoo@xxxxxxxxxx>

Acked-by: Shakeel Butt <shakeel.butt@xxxxxxxxx>