Re: [PATCH V7 4/5] asm-generic: spinlock: Add combo spinlock (ticket & queued)

Peter Zijlstra
2022-07-04T13:46:28Z

On Mon, Jul 04, 2022 at 09:13:40PM +0800, Guo Ren wrote:

> > Urggghhhh....
> >
> > I really don't think you want this in generic code. Also, I'm thinking
> > any arch that does this wants to make sure it doesn't inline any of this
> Your advice is the same with Arnd, I would move static_branch out of generic.
>
> > stuff. That is, said arch must not have ARCH_INLINE_SPIN_*
> What do you mean? I've tested with ARCH_INLINE_SPIN_* and it's okay
> with EXPORT_SYMBOL(use_qspinlock_key).

Well, with the static_branch and the two paths I just don't see the code
being sane/small enough to inline. I mean, sure, you can force it to
inline the thing, but I'm not sure that's wise.