On Fri, 22 Jun 2018 13:58:13 -0700 "Paul E. McKenney" <paul...@linux.vnet.ibm.com> wrote:
> Something like this: > > IRQ entered > > And never exited. Ever. I actually saw this in 2011. I still believe this was actually a bug. And perhaps you made the RCU code robust enough to handle this bug ;-) > > Or something like this: > > IRQ exited > > Without a corresponding IRQ enter. > > The current code handles both of these situations, at least assuming > that the interrupt entry/exit happens during a non-idle period. > > > > So why this function-call structure? Well, you see, NMI handlers can > > > take what appear to RCU to be normal interrupts... > > > > > > (And I just added that fun fact to Requirements.html.) > > > > Yes, I'll definitely go through all the interrupt requirements in the doc > > and > > thanks for referring me to it. > > My concern may well be obsolete. It would be good if it was! ;-) I'd love to mandate that irq_enter() must be paired with irq_exit(). I don't really see any rationale for it to be otherwise. If there is a case, perhaps it needs to be fixed. -- Steve
