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 { } + +#else /* !CONFIG_PREEMPT_RT */ /** * migrate_disable - Prevent migration of the current task