diff options
Diffstat (limited to 'kernel')
| -rw-r--r-- | kernel/irq/manage.c | 5 | ||||
| -rw-r--r-- | kernel/sched/syscalls.c | 13 |
2 files changed, 17 insertions, 1 deletions
diff --git a/kernel/irq/manage.c b/kernel/irq/manage.c index 7a09d96f4d2d..c812b6f48f2b 100644 --- a/kernel/irq/manage.c +++ b/kernel/irq/manage.c @@ -1239,7 +1239,10 @@ static int irq_thread(void *data) irq_thread_set_ready(desc, action); - sched_set_fifo(current); + if (action->handler == irq_forced_secondary_handler) + sched_set_fifo_secondary(current); + else + sched_set_fifo(current); if (force_irqthreads() && test_bit(IRQTF_FORCED_THREAD, &action->thread_flags)) diff --git a/kernel/sched/syscalls.c b/kernel/sched/syscalls.c index 77ae87f36e84..48347950ac48 100644 --- a/kernel/sched/syscalls.c +++ b/kernel/sched/syscalls.c @@ -856,6 +856,19 @@ void sched_set_fifo_low(struct task_struct *p) } EXPORT_SYMBOL_GPL(sched_set_fifo_low); +/* + * Used when the primary interrupt handler is forced into a thread, in addition + * to the (always threaded) secondary handler. The secondary handler gets a + * slightly lower priority so that the primary handler can preempt it, thereby + * emulating the behavior of a non-PREEMPT_RT system where the primary handler + * runs in hard interrupt context. + */ +void sched_set_fifo_secondary(struct task_struct *p) +{ + struct sched_param sp = { .sched_priority = MAX_RT_PRIO / 2 - 1 }; + WARN_ON_ONCE(sched_setscheduler_nocheck(p, SCHED_FIFO, &sp) != 0); +} + void sched_set_normal(struct task_struct *p, int nice) { struct sched_attr attr = { |