From: Johannes Weiner <hannes@cmpxchg.org>
To: Jianyue Wu <wujianyue000@gmail.com>
Cc: Yosry Ahmed <yosry@kernel.org>, Nhat Pham <nphamcs@gmail.com>,
Chengming Zhou <chengming.zhou@linux.dev>,
Andrew Morton <akpm@linux-foundation.org>,
Chris Li <chrisl@kernel.org>,
linux-mm@kvack.org, linux-kernel@vger.kernel.org
Subject: Re: [RFC PATCH v4 1/3] mm/zswap: release retired pools via queue_rcu_work() instead of synchronize_rcu()
Date: Tue, 1 Sep 2026 11:38:52 -0400 [thread overview]
Message-ID: <20260901153852.GH3004@cmpxchg.org> (raw)
In-Reply-To: <20260830114731.8322-2-wujianyue000@gmail.com>
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@kernel.org>
> Signed-off-by: Jianyue Wu <wujianyue000@gmail.com>
With "release_rwork",
Reviewed-by: Johannes Weiner <hannes@cmpxchg.org>
next prev parent reply other threads:[~2026-09-01 15:38 UTC|newest]
Thread overview: 12+ messages / expand[flat|nested] mbox.gz Atom feed top
2026-08-30 11:47 [RFC PATCH v4 0/3] mm/zswap: shrink zswap_entry via a fixed pool index Jianyue Wu
2026-08-30 11:47 ` [RFC PATCH v4 1/3] mm/zswap: release retired pools via queue_rcu_work() instead of synchronize_rcu() Jianyue Wu
2026-08-31 15:20 ` Yosry Ahmed
2026-09-01 14:33 ` Jianyue Wu
2026-09-01 15:38 ` Johannes Weiner [this message]
2026-09-02 0:53 ` Jianyue Wu
2026-08-30 11:47 ` [RFC PATCH v4 2/3] mm/zswap: replace the zswap_pools list with a fixed pools array Jianyue Wu
2026-08-31 15:28 ` Yosry Ahmed
2026-09-01 16:13 ` Johannes Weiner
2026-09-02 0:50 ` Jianyue Wu
2026-08-30 11:47 ` [RFC PATCH v4 3/3] mm/zswap: reference the pool by index to shrink struct zswap_entry Jianyue Wu
2026-08-31 15:30 ` Yosry Ahmed
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