Re: [PATCH v6 44/45] mm: shrinker: hold write lock to reparent shrinker nr_deferred

From: Muchun Song
Date: Mon Sep 18 2023 - 03:19:22 EST




> On Sep 11, 2023, at 17:44, Qi Zheng <zhengqi.arch@xxxxxxxxxxxxx> wrote:
>
> For now, reparent_shrinker_deferred() is the only holder of read lock of
> shrinker_rwsem. And it already holds the global cgroup_mutex, so it will
> not be called in parallel.
>
> Therefore, in order to convert shrinker_rwsem to shrinker_mutex later,
> here we change to hold the write lock of shrinker_rwsem to reparent.
>
> Signed-off-by: Qi Zheng <zhengqi.arch@xxxxxxxxxxxxx>

Reviewed-by: Muchun Song <songmuchun@xxxxxxxxxxxxx>

Thanks.