Re: [PATCH REPOST] irq_poll: Add local_bh_disable() in cpu_dead notifier

[Thomas Gleixner]

On Thu, Feb 10 2022 at 22:34, Christoph Hellwig wrote:
> On Thu, Feb 10, 2022 at 01:33:39PM +0100, Sebastian Andrzej Siewior wrote:
>> You need to handle the pending softirqs. If you don't handle them
>> immediately or in a deterministic say (like on IRQ exit) then they will
>> be handled at a random point.
>
> Yes.  Just like regular interrupts.

But interrupts make sure they are handled. This code does not and as
Sebastian pointed out:

  "If you don't handle them at all, the CPU will go idle and at least
   the NO_HZ will complain about pending softirqs (can_stop_idle_tick())."

That's clearly a bug, but this should be part of the changelog.

Thanks,

        tglx