On 2019-08-27 14:34:19 [+0200], Alexander Dahl wrote: > Hello Sebastian, Hello Alexander, > This causes build errors on my side now, I tested with the .config we use on > our custom tree on a tag "v5.2.10-rt5-rebase", cross-compiling with gcc 7.3.1 > for ARCH=arm: of course, !SMP. What about this: diff --git a/kernel/time/hrtimer.c b/kernel/time/hrtimer.c --- a/kernel/time/hrtimer.c +++ b/kernel/time/hrtimer.c @@ -934,7 +934,11 @@ void hrtimer_grab_expiry_lock(const struct hrtimer *timer) { struct hrtimer_clock_base *base = READ_ONCE(timer->base); +#ifdef CONFIG_SMP if (timer->is_soft && base != &migration_base) { +#else + if (timer->is_soft && base && base->cpu_base) { +#endif spin_lock(&base->cpu_base->softirq_expiry_lock); spin_unlock(&base->cpu_base->softirq_expiry_lock); } Sebastian