Re: [PATCH] efi: Allow to enable EFI runtime services with PREEMPT_RT

From: Javier Martinez Canillas
Date: Thu Mar 31 2022 - 10:50:17 EST


On 3/31/22 16:40, Sebastian Andrzej Siewior wrote:
> On 2022-03-31 16:25:40 [+0200], Javier Martinez Canillas wrote:
>> Hello Sebastian,
> Hi Javier,
>
>> Yes, it is but the motivation is to be able to have EFI runtime services
>> by default without the need for any kernel command line parameter.
>
> This part wasn't clear. It is not mentioned by the description but now
> that I look at Kconfig, it is there.
>

Sure, I can post a v2 with better wording in the description to make it clear.

>> In the same vein, I could ask if efi=noruntime wasn't enough instead of
>> commit ("efi: Disable runtime services on RT").
>
> No, it is not because it should not lead to any surprise latencies by
> default.
>

Yes, it was a rhetorical question. I understand the motivation of that commit
and agree with it. That's why $SUBJECT doesn't change the current behaviour,
and the EFI runtime services will still be disabled by default for RT.

It's just to allow a way to enable for RT users that may want to. But having
a separate boolean symbol also allow non RT users to disable it by default.

> Sebastian
>

--
Best regards,

Javier Martinez Canillas
Linux Engineering
Red Hat