2023-08-09 13:17:10

by Mihai Carabas

Subject: [PATCH 4/7] governors/haltpoll: Drop kvm_para_available() check

From: Joao Martins <[email protected]>

This is duplicated already in the haltpoll idle driver,
and there's no need to re-check KVM guest availability in
the governor.

Either guests uses the module which explicitly selects this
governor, and given that it has the lowest rating of all governors
(menu=20,teo=19,ladder=10/25,haltpoll=9) means that unless it's
the only one compiled in, it won't be selected.

Dropping such check also allows to test haltpoll in baremetal.

Signed-off-by: Joao Martins <[email protected]>
Signed-off-by: Mihai Carabas <[email protected]>
---
drivers/cpuidle/governors/haltpoll.c | 5 +----
1 file changed, 1 insertion(+), 4 deletions(-)

diff --git a/drivers/cpuidle/governors/haltpoll.c b/drivers/cpuidle/governors/haltpoll.c
index 1dff3a52917d..c9b69651d377 100644
--- a/drivers/cpuidle/governors/haltpoll.c
+++ b/drivers/cpuidle/governors/haltpoll.c
@@ -143,10 +143,7 @@ static int haltpoll_enable_device(struct cpuidle_driver *drv,

static int __init init_haltpoll(void)
{
- if (kvm_para_available())
- return cpuidle_register_governor(&haltpoll_governor);
-
- return 0;
+ return cpuidle_register_governor(&haltpoll_governor);
}

postcore_initcall(init_haltpoll);
--
1.8.3.1

2023-08-10 19:31:42

by Rafael J. Wysocki

Subject: Re: [PATCH 4/7] governors/haltpoll: Drop kvm_para_available() check

On Wed, Aug 9, 2023 at 2:54 PM Mihai Carabas <[email protected]> wrote:
>
> From: Joao Martins <[email protected]>
>
> This is duplicated already in the haltpoll idle driver,
> and there's no need to re-check KVM guest availability in
> the governor.
>
> Either guests uses the module which explicitly selects this
> governor, and given that it has the lowest rating of all governors
> (menu=20,teo=19,ladder=10/25,haltpoll=9) means that unless it's
> the only one compiled in, it won't be selected.
>
> Dropping such check also allows to test haltpoll in baremetal.

Fair enough.

> Signed-off-by: Joao Martins <[email protected]>
> Signed-off-by: Mihai Carabas <[email protected]>

Acked-by: Rafael J. Wysocki <[email protected]>

> ---
> drivers/cpuidle/governors/haltpoll.c | 5 +----
> 1 file changed, 1 insertion(+), 4 deletions(-)
>
> diff --git a/drivers/cpuidle/governors/haltpoll.c b/drivers/cpuidle/governors/haltpoll.c
> index 1dff3a52917d..c9b69651d377 100644
> --- a/drivers/cpuidle/governors/haltpoll.c
> +++ b/drivers/cpuidle/governors/haltpoll.c
> @@ -143,10 +143,7 @@ static int haltpoll_enable_device(struct cpuidle_driver *drv,
>
> static int __init init_haltpoll(void)
> {
> - if (kvm_para_available())
> - return cpuidle_register_governor(&haltpoll_governor);
> -
> - return 0;
> + return cpuidle_register_governor(&haltpoll_governor);
> }
>
> postcore_initcall(init_haltpoll);
> --
> 1.8.3.1
>