Re: [PATCH] mm: vmscan: abort proactive reclaim early when freezing

[Richard Chang]

On Wed, Jul 8, 2026 at 12:54 PM Shakeel Butt <shakeel.butt@xxxxxxxxx> wrote:
>
> What's so special about proactive reclaim? Why the same situation can not happen
> for global or memcg reclaim?
>

The target batch size of the global/memcg reclaim is typically very
small -- usually SWAP_CLUSTER_MAX (32 pages), allowing the task to
yield or check signals between attempts.
Furthermore, kswapd is a kernel thread designed to be freezable, it
explicitly checks kthread_freezable_should_stop() in the main loop.
In contrast, the target batch size in proactive reclaim is
user-defined and can be extremely large. Without signal checks in the
inner loops, the task may continue scanning and evicting pages for
seconds at a time.