For khugepaged to support different mTHP orders, we must generalize this
to check if the PMD is not shared by another VMA and the order is enabled.
To ensure madvise_collapse can support working on mTHP orders without the
PMD order enabled, we need to convert hugepage_vma_revalidate to take a
bitmap of orders.
No functional change in this patch.
Reviewed-by: Baolin Wang <baolin.wang@xxxxxxxxxxxxxxxxx>
Acked-by: David Hildenbrand <david@xxxxxxxxxx>
Co-developed-by: Dev Jain <dev.jain@xxxxxxx>
Signed-off-by: Dev Jain <dev.jain@xxxxxxx>
Signed-off-by: Nico Pache <npache@xxxxxxxxxx>
---
mm/khugepaged.c | 13 ++++++++-----
1 file changed, 8 insertions(+), 5 deletions(-)
diff --git a/mm/khugepaged.c b/mm/khugepaged.c
index b7b98aebb670..2d192ec961d2 100644
--- a/mm/khugepaged.c
+++ b/mm/khugepaged.c
@@ -917,7 +917,7 @@ static int collapse_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, unsigned long orders)
{
struct vm_area_struct *vma;
enum tva_type type = cc->is_khugepaged ? TVA_KHUGEPAGED :
@@ -930,9 +930,10 @@ static int hugepage_vma_revalidate(struct mm_struct *mm, unsigned long address,
if (!vma)
return SCAN_VMA_NULL;
+ /* Always check the PMD order to insure its not shared by another VMA */
if (!thp_vma_suitable_order(vma, address, PMD_ORDER))
return SCAN_ADDRESS_RANGE;
- if (!thp_vma_allowable_order(vma, vma->vm_flags, type, PMD_ORDER))
+ if (!thp_vma_allowable_orders(vma, vma->vm_flags, type, orders))
return SCAN_VMA_CHECK;
/*
* Anon VMA expected, the address may be unmapped then
@@ -1134,7 +1135,8 @@ 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,
+ BIT(HPAGE_PMD_ORDER));
if (result != SCAN_SUCCEED) {
mmap_read_unlock(mm);
goto out_nolock;
@@ -1168,7 +1170,8 @@ 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,
+ BIT(HPAGE_PMD_ORDER));
if (result != SCAN_SUCCEED)
goto out_up_write;
/* check if the pmd is still valid */
@@ -2807,7 +2810,7 @@ int madvise_collapse(struct vm_area_struct *vma, unsigned long start,
mmap_read_lock(mm);
mmap_locked = true;
result = hugepage_vma_revalidate(mm, addr, false, &vma,
- cc);
+ cc, BIT(HPAGE_PMD_ORDER));
if (result != SCAN_SUCCEED) {
last_fail = result;
goto out_nolock;
--
2.50.1
