Re: [PATCH v2 2/6] genirq: Allow an interrupt to be marked as 'raw'

[Peter Zijlstra]

On Thu, Nov 26, 2020 at 06:18:33PM +0000, Valentin Schneider wrote:
> If I got the RCU bits right from what Thomas mentioned in
> 
>   https://lore.kernel.org/r/87ft5q18qs.fsf@xxxxxxxxxxxxxxxxxxxxxxx
>   https://lore.kernel.org/r/87lfewnmdz.fsf@xxxxxxxxxxxxxxxxxxxxxxx
> 
> then we're still missing something to notify RCU in the case the IRQ hits
> the idle task. All I see on our entry path is
> 
>   trace_hardirqs_off();
>   ...
>   irq_handler()
>     handle_domain_irq();
>   ...
>   trace_hardirqs_on();
> 
> so we do currently rely on handle_domain_irq()'s irq_enter() + irq_exit()
> for that. rcu_irq_enter() says CONFIG_RCU_EQS_DEBUG=y can detect missing
> bits, but I don't get any warnings with your series on my Juno.

The scheduler IPI really doesn't need RCU either ;-)