Re: [PATCH v2 03/44] cpuidle/poll: Ensure IRQ state is invariant

Frederic Weisbecker
2022-09-19T13:19:56Z

On Mon, Sep 19, 2022 at 11:59:42AM +0200, Peter Zijlstra wrote:
> cpuidle_state::enter() methods should be IRQ invariant

Got a bit confused with the invariant thing since the first chunck I
see in this patch is a conversion to an non-traceable local_irq_enable().

Maybe just add a short mention about that and why?

Thanks.

>
> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
> Reviewed-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
> ---
> drivers/cpuidle/poll_state.c | 4 +++-
> 1 file changed, 3 insertions(+), 1 deletion(-)
>
> --- a/drivers/cpuidle/poll_state.c
> +++ b/drivers/cpuidle/poll_state.c
> @@ -17,7 +17,7 @@ static int __cpuidle poll_idle(struct cp
>
> dev->poll_time_limit = false;
>
> - local_irq_enable();
> + raw_local_irq_enable();
> if (!current_set_polling_and_test()) {
> unsigned int loop_count = 0;
> u64 limit;
> @@ -36,6 +36,8 @@ static int __cpuidle poll_idle(struct cp
> }
> }
> }
> + raw_local_irq_disable();
> +
> current_clr_polling();
>
> return index;
>
>