Re: [RFC PATCH 4/8] preempt: Introduce CONFIG_PREEMPT_DYNAMIC

[Frederic Weisbecker]

On Fri, Jan 22, 2021 at 05:53:43PM +0100, Peter Zijlstra wrote:
> On Mon, Jan 18, 2021 at 03:12:19PM +0100, Frederic Weisbecker wrote:
> > +config HAVE_PREEMPT_DYNAMIC
> > +	bool
> > +	depends on HAVE_STATIC_CALL_INLINE
> 
> I think we can relax this to HAVE_STATIC_CALL, using trampolines
> shouldn't be too bad, and that would put it in reach of arm64.

Why not, but then I need to make CONFIG_PREEMPT_DYNAMIC optional
in order not to make the overhead mandatory for everyone.

> 
> > +	depends on GENERIC_ENTRY
> > +	help
> > +	   Select this if the architecture support boot time preempt setting
> > +	   on top of static calls. It is strongly advised to support inline
> > +	   static call to avoid any overhead.