Re: [PATCH v2 1/4] mm: support promotion-only NUMA hinting scans

[Peter Zijlstra]

On Thu, Sep 10, 2026 at 08:18:23PM -0400, Gregory Price wrote:

> diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c
> index 8dff37059faf..81359b414947 100644
> --- a/kernel/sched/fair.c
> +++ b/kernel/sched/fair.c
> @@ -4129,8 +4129,10 @@ static void task_numa_work(struct callback_head *work)
>  	unsigned long nr_pte_updates = 0;
>  	long pages, virtpages;
>  	struct vma_iterator vmi;
> +	unsigned int numab_mode = READ_ONCE(sysctl_numa_balancing_mode);

This thing sticks out like a sort thumb, does that want to be on top?
Typically reverse xmas is preferred and all that.

>  	bool vma_pids_skipped;
>  	bool vma_pids_forced = false;
> +	bool promo_only;
>  
>  	WARN_ON_ONCE(p != container_of(work, struct task_struct, numa_work));
>  

> --- a/mm/internal.h
> +++ b/mm/internal.h
> @@ -1237,11 +1237,12 @@ static inline bool vma_is_single_threaded_private(struct vm_area_struct *vma)
>  
>  #ifdef CONFIG_NUMA_BALANCING
>  bool folio_can_map_prot_numa(struct folio *folio, struct vm_area_struct *vma,
> -		bool is_private_single_threaded);
> +		bool is_private_single_threaded, bool promo_only);

Two bools rather than updating the existing bool to a flags?