Re: [PATCH v2 7/9] sched: define TIF_ALLOW_RESCHED

Geert Uytterhoeven
2023-10-06T13:02:09Z

Hi Thomas,

On Tue, Sep 19, 2023 at 9:57 PM Thomas Gleixner <tglx@linutronix.de> wrote:
> Though it just occured to me that there are dragons lurking:
>
> arch/alpha/Kconfig: select ARCH_NO_PREEMPT
> arch/hexagon/Kconfig: select ARCH_NO_PREEMPT
> arch/m68k/Kconfig: select ARCH_NO_PREEMPT if !COLDFIRE
> arch/um/Kconfig: select ARCH_NO_PREEMPT
>
> So we have four architectures which refuse to enable preemption points,
> i.e. the only model they allow is NONE and they rely on cond_resched()
> for breaking large computations.

Looks like there is a fifth one hidden: although openrisc does not
select ARCH_NO_PREEMPT, it does not call preempt_schedule_irq() or
select GENERIC_ENTRY?

Gr{oetje,eeting}s,

Geert

--
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@linux-m68k.org

In personal conversations with technical people, I call myself a hacker. But
when I'm talking to journalists I just say "programmer" or something like that.
-- Linus Torvalds