On Thu, 27 Jun 2019 10:24:36 -0400 Joel Fernandes <joel@xxxxxxxxxxxxxxxxx> wrote: > > What am I missing here? > > This issue I think is > > (in normal process context) > spin_lock_irqsave(rq_lock); // which disables both preemption and interrupt > // but this was done in normal process context, > // not from IRQ handler > rcu_read_lock(); > <---------- IPI comes in and sets exp_hint How would an IPI come in here with interrupts disabled? -- Steve > rcu_read_unlock() > -> rcu_read_unlock_special > -> raise_softirq_irqoff > -> wakeup_softirq <--- because in_interrupt returns false. > > I think the issue is in_interrupt() does not know about threaded interrupts. > If it did, then the ksoftirqd wake up would not happen. > > Did I get something wrong?
