[PATCH 05/33] sched/isolation: Save boot defined domain flags

[Waiman Long]

On 1/1/26 5:13 PM, Frederic Weisbecker wrote:
> HK_TYPE_DOMAIN will soon integrate not only boot defined isolcpus= CPUs
> but also cpuset isolated partitions.
>
> Housekeeping still needs a way to record what was initially passed
> to isolcpus= in order to keep these CPUs isolated after a cpuset
> isolated partition is modified or destroyed while containing some of
> them.
>
> Create a new HK_TYPE_DOMAIN_BOOT to keep track of those.
>
> Signed-off-by: Frederic Weisbecker <frederic at kernel.org>
> Reviewed-by: Phil Auld <pauld at redhat.com>
> ---
>   include/linux/sched/isolation.h | 4 ++++
>   kernel/sched/isolation.c        | 5 +++--
>   2 files changed, 7 insertions(+), 2 deletions(-)
>
> diff --git a/include/linux/sched/isolation.h b/include/linux/sched/isolation.h
> index d8501f4709b5..c7cf6934489c 100644
> --- a/include/linux/sched/isolation.h
> +++ b/include/linux/sched/isolation.h
> @@ -7,8 +7,12 @@
>   #include <linux/tick.h>
>   
>   enum hk_type {
> +	/* Inverse of boot-time isolcpus= argument */
> +	HK_TYPE_DOMAIN_BOOT,
>   	HK_TYPE_DOMAIN,
> +	/* Inverse of boot-time isolcpus=managed_irq argument */
>   	HK_TYPE_MANAGED_IRQ,
> +	/* Inverse of boot-time nohz_full= or isolcpus=nohz arguments */
>   	HK_TYPE_KERNEL_NOISE,
>   	HK_TYPE_MAX,
>   
> diff --git a/kernel/sched/isolation.c b/kernel/sched/isolation.c
> index 3ad0d6df6a0a..11a623fa6320 100644
> --- a/kernel/sched/isolation.c
> +++ b/kernel/sched/isolation.c
> @@ -11,6 +11,7 @@
>   #include "sched.h"
>   
>   enum hk_flags {
> +	HK_FLAG_DOMAIN_BOOT	= BIT(HK_TYPE_DOMAIN_BOOT),
>   	HK_FLAG_DOMAIN		= BIT(HK_TYPE_DOMAIN),
>   	HK_FLAG_MANAGED_IRQ	= BIT(HK_TYPE_MANAGED_IRQ),
>   	HK_FLAG_KERNEL_NOISE	= BIT(HK_TYPE_KERNEL_NOISE),
> @@ -239,7 +240,7 @@ static int __init housekeeping_isolcpus_setup(char *str)
>   
>   		if (!strncmp(str, "domain,", 7)) {
>   			str += 7;
> -			flags |= HK_FLAG_DOMAIN;
> +			flags |= HK_FLAG_DOMAIN | HK_FLAG_DOMAIN_BOOT;
>   			continue;
>   		}
>   
> @@ -269,7 +270,7 @@ static int __init housekeeping_isolcpus_setup(char *str)
>   
>   	/* Default behaviour for isolcpus without flags */
>   	if (!flags)
> -		flags |= HK_FLAG_DOMAIN;
> +		flags |= HK_FLAG_DOMAIN | HK_FLAG_DOMAIN_BOOT;
>   
>   	return housekeeping_setup(str, flags);
>   }
Reviewed-by: Waiman Long <longman at redhat.com>