Re: [RFC PATCH v4 1/3] mm/zswap: release retired pools via queue_rcu_work() instead of synchronize_rcu()

[Jianyue Wu]

On Tue, Sep 1, 2026 at 11:38 PM Johannes Weiner <hannes@xxxxxxxxxxx> wrote:
>
> On Sun, Aug 30, 2026 at 07:47:29PM +0800, Jianyue Wu wrote:
> > When a pool's last reference is dropped, __zswap_pool_empty() removes it
> > from the pool list and schedules __zswap_pool_release(), which calls
> > synchronize_rcu() to wait for readers before tearing the pool down.
> >
> > synchronize_rcu() is a synchronous, potentially long wait.  Replace it
> > with queue_rcu_work(): __zswap_pool_empty() hands the pool to
> > queue_rcu_work(), which waits for a grace period asynchronously and then
> > runs __zswap_pool_release() from a worker for the sleepable teardown
> > (__zswap_pool_empty() can run in atomic context and must not block).
> > The grace-period guarantee is unchanged; the retirement path just no
> > longer blocks on it.
> >
> > Suggested-by: Yosry Ahmed <yosry@xxxxxxxxxx>
> > Signed-off-by: Jianyue Wu <wujianyue000@xxxxxxxxx>
>
> With "release_rwork",
>
> Reviewed-by: Johannes Weiner <hannes@xxxxxxxxxxx>

Thanks, I will use release_rwork instead.

Best regards,
Jianyue