Re: [PATCH v2 3/9] mm: hugetlb: directly pass order when allocate a hugetlb folio

Zi Yan
2025-09-09T01:11:35Z

On 2 Sep 2025, at 8:48, Kefeng Wang wrote:

> Use order instead of struct hstate to remove huge_page_order() call
> from all hugetlb folio allocation.
>
> Reviewed-by: Sidhartha Kumar <sidhartha.kumar@oracle.com>
> Reviewed-by: Jane Chu <jane.chu@oracle.com>
> Signed-off-by: Kefeng Wang <wangkefeng.wang@huawei.com>
> ---
> mm/hugetlb.c | 27 +++++++++++++--------------
> mm/hugetlb_cma.c | 3 +--
> mm/hugetlb_cma.h | 6 +++---
> 3 files changed, 17 insertions(+), 19 deletions(-)
>
> diff --git a/mm/hugetlb.c b/mm/hugetlb.c
> index 4131467fc1cd..5c93faf82674 100644
> --- a/mm/hugetlb.c
> +++ b/mm/hugetlb.c
> @@ -1473,17 +1473,16 @@ static int hstate_next_node_to_free(struct hstate *h, nodemask_t *nodes_allowed)
>
> #ifdef CONFIG_ARCH_HAS_GIGANTIC_PAGE
> #ifdef CONFIG_CONTIG_ALLOC
> -static struct folio *alloc_gigantic_folio(struct hstate *h, gfp_t gfp_mask,
> +static struct folio *alloc_gigantic_folio(int order, gfp_t gfp_mask,
> int nid, nodemask_t *nodemask)
> {
> struct folio *folio;
> - int order = huge_page_order(h);
> bool retried = false;
>
> if (nid == NUMA_NO_NODE)
> nid = numa_mem_id();
> retry:
> - folio = hugetlb_cma_alloc_folio(h, gfp_mask, nid, nodemask);
> + folio = hugetlb_cma_alloc_folio(order, gfp_mask, nid, nodemask);
> if (!folio) {
> if (hugetlb_cma_exclusive_alloc())
> return NULL;
> @@ -1506,16 +1505,16 @@ static struct folio *alloc_gigantic_folio(struct hstate *h, gfp_t gfp_mask,
> }
>
> #else /* !CONFIG_CONTIG_ALLOC */
> -static struct folio *alloc_gigantic_folio(struct hstate *h, gfp_t gfp_mask,
> - int nid, nodemask_t *nodemask)
> +static struct folio *alloc_gigantic_folio(int order, gfp_t gfp_mask, int nid,
> + nodemask_t *nodemask)
> {
> return NULL;
> }
> #endif /* CONFIG_CONTIG_ALLOC */
>
> #else /* !CONFIG_ARCH_HAS_GIGANTIC_PAGE */
> -static struct folio *alloc_gigantic_folio(struct hstate *h, gfp_t gfp_mask,
> - int nid, nodemask_t *nodemask)
> +static struct folio *alloc_gigantic_folio(int order, gfp_t gfp_mask, int nid,
> + nodemask_t *nodemask)
> {
> return NULL;
> }
> @@ -1926,11 +1925,9 @@ struct address_space *hugetlb_folio_mapping_lock_write(struct folio *folio)
> return NULL;
> }
>
> -static struct folio *alloc_buddy_hugetlb_folio(struct hstate *h,
> - gfp_t gfp_mask, int nid, nodemask_t *nmask,
> - nodemask_t *node_alloc_noretry)
> +static struct folio *alloc_buddy_hugetlb_folio(int order, gfp_t gfp_mask,
> + int nid, nodemask_t *nmask, nodemask_t *node_alloc_noretry)
> {
> - int order = huge_page_order(h);
> struct folio *folio;
> bool alloc_try_hard = true;
>
> @@ -1980,11 +1977,13 @@ static struct folio *only_alloc_fresh_hugetlb_folio(struct hstate *h,
> nodemask_t *node_alloc_noretry)
> {
> struct folio *folio;
> + int order = huge_page_order(h);
>
> - if (hstate_is_gigantic(h))
> - folio = alloc_gigantic_folio(h, gfp_mask, nid, nmask);
> + if (order > MAX_PAGE_ORDER)

Would it be better to add

bool order_is_gigantic(unsigned int order)
{
return order > MAX_PAGE_ORDER;
}

for this check? And change hstate_is_gigantic() to

return order_is_gigantic(huge_page_order(h));

To make _is_gigantic() check more consistent.
BTW, isolate_or_dissolve_huge_folio() can use order_is_gigantic() too.

Otherwise, Reviewed-by: Zi Yan <ziy@nvidia.com>

> + folio = alloc_gigantic_folio(order, gfp_mask, nid, nmask);
> else
> - folio = alloc_buddy_hugetlb_folio(h, gfp_mask, nid, nmask, node_alloc_noretry);
> + folio = alloc_buddy_hugetlb_folio(order, gfp_mask, nid, nmask,
> + node_alloc_noretry);
> if (folio)
> init_new_hugetlb_folio(h, folio);
> return folio;
> diff --git a/mm/hugetlb_cma.c b/mm/hugetlb_cma.c
> index f58ef4969e7a..e8e4dc7182d5 100644
> --- a/mm/hugetlb_cma.c
> +++ b/mm/hugetlb_cma.c
> @@ -26,11 +26,10 @@ void hugetlb_cma_free_folio(struct folio *folio)
> }
>
>
> -struct folio *hugetlb_cma_alloc_folio(struct hstate *h, gfp_t gfp_mask,
> +struct folio *hugetlb_cma_alloc_folio(int order, gfp_t gfp_mask,
> int nid, nodemask_t *nodemask)
> {
> int node;
> - int order = huge_page_order(h);
> struct folio *folio = NULL;
>
> if (hugetlb_cma[nid])
> diff --git a/mm/hugetlb_cma.h b/mm/hugetlb_cma.h
> index f7d7fb9880a2..2c2ec8a7e134 100644
> --- a/mm/hugetlb_cma.h
> +++ b/mm/hugetlb_cma.h
> @@ -4,7 +4,7 @@
>
> #ifdef CONFIG_CMA
> void hugetlb_cma_free_folio(struct folio *folio);
> -struct folio *hugetlb_cma_alloc_folio(struct hstate *h, gfp_t gfp_mask,
> +struct folio *hugetlb_cma_alloc_folio(int order, gfp_t gfp_mask,
> int nid, nodemask_t *nodemask);
> struct huge_bootmem_page *hugetlb_cma_alloc_bootmem(struct hstate *h, int *nid,
> bool node_exact);
> @@ -18,8 +18,8 @@ static inline void hugetlb_cma_free_folio(struct folio *folio)
> {
> }
>
> -static inline struct folio *hugetlb_cma_alloc_folio(struct hstate *h,
> - gfp_t gfp_mask, int nid, nodemask_t *nodemask)
> +static inline struct folio *hugetlb_cma_alloc_folio(int order, gfp_t gfp_mask,
> + int nid, nodemask_t *nodemask)
> {
> return NULL;
> }
> --
> 2.27.0

Best Regards,
Yan, Zi