Re: [PATCH][RFC] workqueue: Fix kernel panic on CPU hot-unplug

From: Tejun Heo
Date: Mon Feb 05 2024 - 12:45:12 EST


Hello,

On Mon, Feb 05, 2024 at 10:58:26AM +0100, Helge Deller wrote:
> It seems the commit 0921244f6f4f ("parisc: Only list existing CPUs in cpu_possible_mask")
> is the culprit. Reverting that patch makes cpu hot-unplug work again.
> Furthermore this commit breaks the cpumask Kunit test as reported by Guenter:
> https://lkml.org/lkml/2024/2/4/146
>
> So, I've added the revert to the parisc git tree and if my further tests
> go well I'll push it upstream.

Yeah, it probably just needs to happen way earlier so that the
cpu_possible_mask doesn't change while the kernel is already half
initialized.

Thanks.

--
tejun