On Tuesday, 20 October 2020, 13:30:09 CEST, Peter Zijlstra wrote: > On Mon, Oct 19, 2020 at 05:09:35PM +0200, Sebastian Andrzej Siewior wrote: > > On 2020-10-19 12:21:06 [+0200], Christian Eggers wrote: > > > I have problems with the latest 5.9-rt releases on i.MX6ULL (! CONFIG_SMP): > > … > > > > > Any hints? > > > > Thank you for the report. The reason is the migrate_disable() > > implementation for !SMP. > > This should fix things I suppose. I'll fold it in. > > --- > --- a/include/linux/preempt.h > +++ b/include/linux/preempt.h > @@ -378,7 +378,12 @@ static inline void preempt_notifier_init > extern void migrate_disable(void); > extern void migrate_enable(void); > > -#else /* !(CONFIG_SMP && CONFIG_PREEMPT_RT) */ > +#elif defined(CONFIG_PREEMPT_RT) > + > +static inline void migrate_disable(void) { } > +static inline void migrate_enable(void { } closing bracket missing > + > +#else /* !CONFIG_PREEMPT_RT */ > > /** > * migrate_disable - Prevent migration of the current task I didn't understand much of you discussion with Sebastian, but my system is able to boot now. # uname -r 5.9.0-rt16+ Best regards Christian