[PATCH 5/5] ARM: Allow to enable RT

[Sebastian Andrzej Siewior]

On 2025-10-30 16:18:45 [+0100], Arnd Bergmann wrote:
> On Wed, Oct 29, 2025, at 16:59, Sebastian Andrzej Siewior wrote:
> > All known issues have been adressed.
> > Allow to select RT.
> >
> > Signed-off-by: Sebastian Andrzej Siewior <bigeasy at linutronix.de>
> > ---
> >  arch/arm/Kconfig | 2 ++
> >  1 file changed, 2 insertions(+)
> >
> > diff --git a/arch/arm/Kconfig b/arch/arm/Kconfig
> > index 99c9b1c320af8..002db8da69ee5 100644
> > --- a/arch/arm/Kconfig
> > +++ b/arch/arm/Kconfig
> > @@ -41,6 +41,7 @@ config ARM
> >  	select ARCH_SUPPORTS_CFI
> >  	select ARCH_SUPPORTS_HUGETLBFS if ARM_LPAE
> >  	select ARCH_SUPPORTS_PER_VMA_LOCK
> > +	select ARCH_SUPPORTS_RT if HAVE_POSIX_CPU_TIMERS_TASK_WORK
> >  	select ARCH_USE_BUILTIN_BSWAP
> >  	select ARCH_USE_CMPXCHG_LOCKREF
> >  	select ARCH_USE_MEMTEST
> > @@ -129,6 +130,7 @@ config ARM
> >  	select HAVE_PERF_EVENTS
> >  	select HAVE_PERF_REGS
> >  	select HAVE_PERF_USER_STACK_DUMP
> > +	select HAVE_POSIX_CPU_TIMERS_TASK_WORK if !KVM
> >  	select MMU_GATHER_RCU_TABLE_FREE if SMP && ARM_LPAE
> >  	select HAVE_REGS_AND_STACK_ACCESS_API
> >  	select HAVE_RSEQ
> 
> This can be simplified slightly since CONFIG_KVM is long gone on
> ARM, so you can just select both HAVE_POSIX_CPU_TIMERS_TASK_WORK
> and ARCH_SUPPORTS_RT unconditionally.

If ARM does not have KVM then I would not depend on
HAVE_POSIX_CPU_TIMERS_TASK_WORK since selecting it without providing it
is wrong. This can be implemented without the need of KVM or RT.

>       Arnd

Sebastian