Messages in this thread | | | Date | Thu, 31 Mar 2022 16:25:40 +0200 | Subject | Re: [PATCH] efi: Allow to enable EFI runtime services with PREEMPT_RT | From | Javier Martinez Canillas <> |
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Hello Sebastian,
On 3/31/22 16:13, Sebastian Andrzej Siewior wrote: > On 2022-03-31 16:10:38 [+0200], Javier Martinez Canillas wrote: >> Commit d9f283ae71af ("efi: Disable runtime services on RT") disabled EFI >> runtime services when the CONFIG_PREEMPT_RT option is enabled. >> >> The rationale for the change is that some EFI calls could take too much >> time, leading to large latencies which are an issue for RT kernels. >> >> But a side effect of that commit is that now is not possible anymore to >> enable the EFI runtime services by default when CONFIG_PREEMPT_RT is set >> to y, even for platforms that could guarantee bounded time for EFI calls. >> >> Instead, let's add a new EFI_DISABLE_RUNTIME boolean Kconfig option, that >> would be set to n by default but to y if CONFIG_PREEMPT_RT is enabled. >> >> That way, the current behaviour is preserved but gives users a mechanism >> to enable the EFI runtimes services in their kernels if that is required. > > Is the command line switch > efi=runtime > > not working? >
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.
In the same vein, I could ask if efi=noruntime wasn't enough instead of commit ("efi: Disable runtime services on RT").
-- Best regards,
Javier Martinez Canillas Linux Engineering Red Hat
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