Due to the TIMER_IRQSAFE flag, the timer callback is invoked with disabled interrupts. On -RT the callback is invoked in softirq context with enabled interrupts. Since the interrupts are threaded, there are are no in_irq() users. The local_bh_disable() around the threaded handler ensures that there is either a timer or a threaded handler active on the CPU.
Disable interrupts before __queue_work() is invoked from the timer callback. Signed-off-by: Sebastian Andrzej Siewior <bige...@linutronix.de> --- kernel/workqueue.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) diff --git a/kernel/workqueue.c b/kernel/workqueue.c index 601d61150b65d..a3c2959e5c4f0 100644 --- a/kernel/workqueue.c +++ b/kernel/workqueue.c @@ -1611,9 +1611,11 @@ EXPORT_SYMBOL_GPL(queue_work_node); void delayed_work_timer_fn(struct timer_list *t) { struct delayed_work *dwork = from_timer(dwork, t, timer); + unsigned long flags; - /* should have been called from irqsafe timer with irq already off */ + local_irq_save(flags); __queue_work(dwork->cpu, dwork->wq, &dwork->work); + local_irq_restore(flags); } EXPORT_SYMBOL(delayed_work_timer_fn); -- 2.20.1