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

[Johannes Weiner]

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>