On Mon, Sep 01, 2025 at 10:35:07AM +0200, Peter Zijlstra wrote:
> On Thu, Aug 28, 2025 at 08:13:51PM +0530, Shrikanth Hegde wrote:
>
> > > --- a/arch/powerpc/Kconfig
> > > +++ b/arch/powerpc/Kconfig
> > > @@ -170,6 +170,9 @@ config PPC
> > > select ARCH_STACKWALK
> > > select ARCH_SUPPORTS_ATOMIC_RMW
> > > select ARCH_SUPPORTS_DEBUG_PAGEALLOC if PPC_BOOK3S || PPC_8xx
> > > + select ARCH_SUPPORTS_SCHED_SMT if PPC64 && SMP
> > > + select ARCH_SUPPORTS_SCHED_MC if PPC64 && SMP
> > > + select SCHED_MC if ARCH_SUPPORTS_SCHED_MC
> >
> > Wondering if this SCHED_MC is necessary here? shouldn't it be set by
> > arch/Kconfig?
>
> Ah, so without this SCHED_MC becomes a user selectable option, with this
> it is an always on option (for ppc64) -- no user prompt.
>
> That is, this is the only way I found to have similar semantics to this:
>
> > > -config SCHED_MC
> > > - def_bool y
> > > - depends on PPC64 && SMP
> > > -
>
> Which is also not a user selectable option.
>
> > nit: Also, can we have so they are still sorted?
> > select ARCH_SUPPORTS_SCHED_MC if PPC64 && SMP
> > select ARCH_SUPPORTS_SCHED_SMT if PPC64 && SMP
>
> Sure, let me flip them. I need to prod that that patch anyway, built
> robot still ain'ted happy.
Looks like 44x/iss476-smp_defconfig (iow 32bit power) also wants
SCHED_MC, so it should be:
config SCHED_MC
def_bool y
depends on SMP
Its just SMT that's a PPC64 special.
