linux-kernel - RE: [PATCH v4 6/8] cpuidle-haltpoll: ARM64 support

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Date: Mon, 26 Feb 2024 08:30:50 +0000
From: "Tomohiro Misono (Fujitsu)" <misono.tomohiro@...itsu.com>
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Subject: RE: [PATCH v4 6/8] cpuidle-haltpoll: ARM64 support

Hi,
> Subject: [PATCH v4 6/8] cpuidle-haltpoll: ARM64 support
> 
> From: Joao Martins <joao.m.martins@...cle.com>
> 
> To test whether it's a guest or not for the default cases, the haltpoll
> driver uses the kvm_para* helpers to find out if it's a guest or not.
> 
> ARM64 doesn't have or defined any of these, so it remains disabled on
> the default. Although it allows to be force-loaded.
> 
> Signed-off-by: Joao Martins <joao.m.martins@...cle.com>
> Signed-off-by: Mihai Carabas <mihai.carabas@...cle.com>
> ---
>  drivers/cpuidle/Kconfig | 4 ++--
>  1 file changed, 2 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/cpuidle/Kconfig b/drivers/cpuidle/Kconfig
> index cac5997dca50..067927eda466 100644
> --- a/drivers/cpuidle/Kconfig
> +++ b/drivers/cpuidle/Kconfig
> @@ -35,7 +35,7 @@ config CPU_IDLE_GOV_TEO
> 
>  config CPU_IDLE_GOV_HALTPOLL
>  	bool "Haltpoll governor (for virtualized systems)"
> -	depends on KVM_GUEST
> +	depends on (X86 && KVM_GUEST) || ARM64
>  	help
>  	  This governor implements haltpoll idle state selection, to be
>  	  used in conjunction with the haltpoll cpuidle driver, allowing
> @@ -73,7 +73,7 @@ endmenu
> 
>  config HALTPOLL_CPUIDLE
>  	tristate "Halt poll cpuidle driver"

I noticed that to build as a module, arch_cpu_idle needs to
be exported in arch/arm64/kernel/idle.c like x86.

Regards,
Tomohiro

> -	depends on X86 && KVM_GUEST
> +	depends on (X86 && KVM_GUEST) || ARM64
>  	select CPU_IDLE_GOV_HALTPOLL
>  	default y
>  	help
> --
> 1.8.3.1
> 
> 
> _______________________________________________
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> linux-arm-kernel@...ts.infradead.org
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