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

[Shakeel Butt]

On Wed, Jul 08, 2026 at 12:14:50PM +0800, Richard Chang wrote:
> On Wed, Jul 8, 2026 at 3:48 AM Shakeel Butt <shakeel.butt@xxxxxxxxx> wrote:
> >
> > Can you please explain how freezing operation was delayed due to proactive
> > reclaim?
> >
> Hi Shakeel,
> 
> When system suspend is initiated, the Power Management (PM) freezer
> attempts to freeze all user-space processes by calling
> freeze_processes(), signaling user space processes to enter the
> refrigerator. When a user-space task writes to memory.reclaim to
> trigger proactive reclaim, it executes in kernel context and enters
> the reclaim loop. Currently the task does not check  signal_pending()
> within the inner loops, it cannot abort the reclaim pass early. It
> continues reclaiming memory, ignoring the freeze request. The PM
> freezer waits for all tasks to freeze. If the proactive reclaim task
> remains in the inner loops longer than the freeze timeout, the freezer
> times out, and suspend fails.

What's so special about proactive reclaim? Why the same situation can not happen
for global or memcg reclaim?