Re: [PATCH] sched: Further restrict the preemption modes

Christian Borntraeger
2026-02-25T16:34:08Z

Am 24.02.26 um 21:30 schrieb Ilya Leoshkevich:
> Finally, what is the worker doing? I looked at __queue_work() kstacks, and they all come from irqfd_wakeup().
>
> irqfd_wakeup() calls arch-specific kvm_arch_set_irq_inatomic(), which is implemented on x86 and not implemented on s390.
>
>
> This may explain why we on s390 are the first to see this.
>
>
> Christian, do you think if it would make sense to implement kvm_arch_set_irq_inatomic() on s390?

So in fact Doug is working on that at the moment. There are some corner
cases where we had concerns as we have to pin the guest pages holding
the interrupt bits. This was secure execution, I need to followup if
we have already solved those cases. But we can try if the current patch
will help this particular problem.

If yes, then we can try to speed up the work on this.

Christian