Re: [PATCH v4 03/12] khugepaged: generalize hugepage_vma_revalidate for mTHP support

Baolin Wang
2025-04-23T06:55:57Z

On 2025/4/17 08:02, Nico Pache wrote:
> For khugepaged to support different mTHP orders, we must generalize this
> function for arbitrary orders.
>
> No functional change in this patch.
>
> Co-developed-by: Dev Jain <dev.jain@arm.com>
> Signed-off-by: Dev Jain <dev.jain@arm.com>
> Signed-off-by: Nico Pache <npache@redhat.com>

LGTM.
Reviewed-by: Baolin Wang <baolin.wang@linux.alibaba.com>

> ---
> mm/khugepaged.c | 12 ++++++------
> 1 file changed, 6 insertions(+), 6 deletions(-)
>
> diff --git a/mm/khugepaged.c b/mm/khugepaged.c
> index b6281c04f1e5..54d7f43da69c 100644
> --- a/mm/khugepaged.c
> +++ b/mm/khugepaged.c
> @@ -920,7 +920,7 @@ static int khugepaged_find_target_node(struct collapse_control *cc)
> static int hugepage_vma_revalidate(struct mm_struct *mm, unsigned long address,
> bool expect_anon,
> struct vm_area_struct **vmap,
> - struct collapse_control *cc)
> + struct collapse_control *cc, int order)
> {
> struct vm_area_struct *vma;
> unsigned long tva_flags = cc->is_khugepaged ? TVA_ENFORCE_SYSFS : 0;
> @@ -932,9 +932,9 @@ static int hugepage_vma_revalidate(struct mm_struct *mm, unsigned long address,
> if (!vma)
> return SCAN_VMA_NULL;
>
> - if (!thp_vma_suitable_order(vma, address, PMD_ORDER))
> + if (!thp_vma_suitable_order(vma, address, order))
> return SCAN_ADDRESS_RANGE;
> - if (!thp_vma_allowable_order(vma, vma->vm_flags, tva_flags, PMD_ORDER))
> + if (!thp_vma_allowable_order(vma, vma->vm_flags, tva_flags, order))
> return SCAN_VMA_CHECK;
> /*
> * Anon VMA expected, the address may be unmapped then
> @@ -1130,7 +1130,7 @@ static int collapse_huge_page(struct mm_struct *mm, unsigned long address,
> goto out_nolock;
>
> mmap_read_lock(mm);
> - result = hugepage_vma_revalidate(mm, address, true, &vma, cc);
> + result = hugepage_vma_revalidate(mm, address, true, &vma, cc, HPAGE_PMD_ORDER);
> if (result != SCAN_SUCCEED) {
> mmap_read_unlock(mm);
> goto out_nolock;
> @@ -1164,7 +1164,7 @@ static int collapse_huge_page(struct mm_struct *mm, unsigned long address,
> * mmap_lock.
> */
> mmap_write_lock(mm);
> - result = hugepage_vma_revalidate(mm, address, true, &vma, cc);
> + result = hugepage_vma_revalidate(mm, address, true, &vma, cc, HPAGE_PMD_ORDER);
> if (result != SCAN_SUCCEED)
> goto out_up_write;
> /* check if the pmd is still valid */
> @@ -2790,7 +2790,7 @@ int madvise_collapse(struct vm_area_struct *vma, struct vm_area_struct **prev,
> mmap_read_lock(mm);
> mmap_locked = true;
> result = hugepage_vma_revalidate(mm, addr, false, &vma,
> - cc);
> + cc, HPAGE_PMD_ORDER);
> if (result != SCAN_SUCCEED) {
> last_fail = result;
> goto out_nolock;