Re: [GIT pull] irq fixes for 4.8

From: Thomas Gleixner
Date: Mon Sep 19 2016 - 03:19:23 EST


On Sun, 18 Sep 2016, Linus Torvalds wrote:
> On Sun, Sep 18, 2016 at 1:05 AM, Thomas Gleixner <tglx@xxxxxxxxxxxxx> wrote:
> >
> > Boris Brezillon (2):
> > genirq: Provide irq_gc_{lock_irqsave,unlock_irqrestore}() helpers
>
> This seems somewhat questionable.
>
> The non-irqsafe versions of these functions have specialized non-SMP
> versions for them. The new ones don't.
>
> I pulled it, because I think it's actually the old versions that are
> garbage (the locking should become a no-op on UP regardless - except
> for the preemption issue which I don't see why it wouldn't be real),
> but I think this is inconsistent and should be fixed (or a comment
> added about why it is ok).

Yes, it lacks a comment. The reason why the non save versions are empty is
that these primitives are solely used in the irq chip hotpath functions. UP
folks wanted to avoid the preempt disable/enable in these anyway interrupt
disabled contexts.

Thanks,

tglx