Re: [PATCH 1/7] mm: hugetlb: convert to alloc_fresh_hugetlb_hvo_folio()

[Sidhartha Kumar <sidhartha.kumar@oracle.com>]

On 8/2/25 3:31 AM, Kefeng Wang wrote:
> Now alloc_fresh_hugetlb_folio() is only called by
> alloc_migrate_hugetlb_folio(), cleanup it by converting to
> alloc_fresh_hugetlb_hvo_folio(), also simplify the
> alloc_and_dissolve_hugetlb_folio() and alloc_surplus_hugetlb_folio()
> too which help us to remove prep_new_hugetlb_folio() and
> __prep_new_hugetlb_folio().
> 
> Signed-off-by: Kefeng Wang <wangkefeng.wang@huawei.com>

Reviewed-by: Sidhartha Kumar <sidhartha.kumar@oracle.com>

> ---
>   mm/hugetlb.c | 48 +++++++++++++++---------------------------------
>   1 file changed, 15 insertions(+), 33 deletions(-)
> 
> diff --git a/mm/hugetlb.c b/mm/hugetlb.c
> index 753f99b4c718..5b4c19e7a5f7 100644
> --- a/mm/hugetlb.c
> +++ b/mm/hugetlb.c
> @@ -1906,20 +1906,6 @@ static void init_new_hugetlb_folio(struct hstate *h, struct folio *folio)
>   	set_hugetlb_cgroup_rsvd(folio, NULL);
>   }
>   
> -static void __prep_new_hugetlb_folio(struct hstate *h, struct folio *folio)
> -{
> -	init_new_hugetlb_folio(h, folio);
> -	hugetlb_vmemmap_optimize_folio(h, folio);
> -}
> -
> -static void prep_new_hugetlb_folio(struct hstate *h, struct folio *folio, int nid)
> -{
> -	__prep_new_hugetlb_folio(h, folio);
> -	spin_lock_irq(&hugetlb_lock);
> -	__prep_account_new_huge_page(h, nid);
> -	spin_unlock_irq(&hugetlb_lock);
> -}
> -
>   /*
>    * Find and lock address space (mapping) in write mode.
>    *
> @@ -2005,25 +1991,20 @@ static struct folio *only_alloc_fresh_hugetlb_folio(struct hstate *h,
>   }
>   
>   /*
> - * Common helper to allocate a fresh hugetlb page. All specific allocators
> - * should use this function to get new hugetlb pages
> + * Common helper to allocate a fresh hugetlb folio. All specific allocators
> + * should use this function to get new hugetlb folio
>    *
> - * Note that returned page is 'frozen':  ref count of head page and all tail
> + * Note that returned folio is 'frozen':  ref count of head page and all tail
>    * pages is zero.
>    */
> -static struct folio *alloc_fresh_hugetlb_folio(struct hstate *h,
> +static struct folio *alloc_fresh_hugetlb_hvo_folio(struct hstate *h,
>   		gfp_t gfp_mask, int nid, nodemask_t *nmask)
>   {
>   	struct folio *folio;
>   
> -	if (hstate_is_gigantic(h))
> -		folio = alloc_gigantic_folio(h, gfp_mask, nid, nmask);
> -	else
> -		folio = alloc_buddy_hugetlb_folio(h, gfp_mask, nid, nmask, NULL);
> -	if (!folio)
> -		return NULL;
> -
> -	prep_new_hugetlb_folio(h, folio, folio_nid(folio));
> +	folio = only_alloc_fresh_hugetlb_folio(h, gfp_mask, nid, nmask, NULL);
> +	if (folio)
> +		hugetlb_vmemmap_optimize_folio(h, folio);
>   	return folio;
>   }
>   
> @@ -2241,12 +2222,10 @@ static struct folio *alloc_surplus_hugetlb_folio(struct hstate *h,
>   		goto out_unlock;
>   	spin_unlock_irq(&hugetlb_lock);
>   
> -	folio = only_alloc_fresh_hugetlb_folio(h, gfp_mask, nid, nmask, NULL);
> +	folio = alloc_fresh_hugetlb_hvo_folio(h, gfp_mask, nid, nmask);
>   	if (!folio)
>   		return NULL;
>   
> -	hugetlb_vmemmap_optimize_folio(h, folio);
> -
>   	spin_lock_irq(&hugetlb_lock);
>   	/*
>   	 * nr_huge_pages needs to be adjusted within the same lock cycle
> @@ -2286,10 +2265,14 @@ static struct folio *alloc_migrate_hugetlb_folio(struct hstate *h, gfp_t gfp_mas
>   	if (hstate_is_gigantic(h))
>   		return NULL;
>   
> -	folio = alloc_fresh_hugetlb_folio(h, gfp_mask, nid, nmask);
> +	folio = alloc_fresh_hugetlb_hvo_folio(h, gfp_mask, nid, nmask);
>   	if (!folio)
>   		return NULL;
>   
> +	spin_lock_irq(&hugetlb_lock);
> +	__prep_account_new_huge_page(h, folio_nid(folio));
> +	spin_unlock_irq(&hugetlb_lock);
> +
>   	/* fresh huge pages are frozen */
>   	folio_ref_unfreeze(folio, 1);
>   	/*
> @@ -2836,11 +2819,10 @@ static int alloc_and_dissolve_hugetlb_folio(struct folio *old_folio,
>   		if (!new_folio) {
>   			spin_unlock_irq(&hugetlb_lock);
>   			gfp_mask = htlb_alloc_mask(h) | __GFP_THISNODE;
> -			new_folio = alloc_buddy_hugetlb_folio(h, gfp_mask, nid,
> -							      NULL, NULL);
> +			new_folio = alloc_fresh_hugetlb_hvo_folio(h, gfp_mask,
> +								  nid, NULL);
>   			if (!new_folio)
>   				return -ENOMEM;
> -			__prep_new_hugetlb_folio(h, new_folio);
>   			goto retry;
>   		}
>