"Paul E. McKenney" <[email protected]> writes:
> On Wed, May 20, 2020 at 09:51:17AM -0700, Andy Lutomirski wrote:
>> Paul, the major change here is that if an IRQ hits normal kernel code
>> (i.e. code where RCU is watching and we're not in an EQS), the IRQ
>> won't call rcu_irq_enter() and rcu_irq_exit(). Instead it will call
>> rcu_tickle() on entry and nothing on exit. Does that cover all the
>> bases?
>
> From an RCU viewpoint, yes, give or take my concerns about someone
> putting rcu_tickle() on entry and rcu_irq_exit() on exit. Perhaps
> I can bring some lockdep trickery to bear.
An surplus rcu_irq_exit() should already trigger alarms today.
> But I must defer to Thomas and Peter on the non-RCU/non-NO_HZ_FULL
> portions of this.
I don't see a problem. Let me write that into actual testable patch
form.
Thanks,
tglx
