This also updates the callers' hugetlb mapcounting code to handle
mapcount properly for subpage-mapped hugetlb pages.
Signed-off-by: James Houghton <[email protected]>
---
mm/migrate.c | 2 +-
mm/rmap.c | 17 +++++++++++++----
2 files changed, 14 insertions(+), 5 deletions(-)
diff --git a/mm/migrate.c b/mm/migrate.c
index a0105fa6e3b2..8712b694c5a7 100644
--- a/mm/migrate.c
+++ b/mm/migrate.c
@@ -235,7 +235,7 @@ static bool remove_migration_pte(struct folio *folio,
#ifdef CONFIG_HUGETLB_PAGE
if (folio_test_hugetlb(folio)) {
- unsigned int shift = huge_page_shift(hstate_vma(vma));
+ unsigned int shift = pvmw.pte_order + PAGE_SHIFT;
pte = arch_make_huge_pte(pte, shift, vma->vm_flags);
if (folio_test_anon(folio))
diff --git a/mm/rmap.c b/mm/rmap.c
index 9bba65b30e4d..19850d955aea 100644
--- a/mm/rmap.c
+++ b/mm/rmap.c
@@ -1626,7 +1626,7 @@ static bool try_to_unmap_one(struct folio *folio, struct vm_area_struct *vma,
if (PageHWPoison(subpage) && !(flags & TTU_IGNORE_HWPOISON)) {
pteval = swp_entry_to_pte(make_hwpoison_entry(subpage));
if (folio_test_hugetlb(folio)) {
- hugetlb_count_sub(folio_nr_pages(folio), mm);
+ hugetlb_count_sub(1UL << pvmw.pte_order, mm);
set_huge_pte_at(mm, address, pvmw.pte, pteval);
} else {
dec_mm_counter(mm, mm_counter(&folio->page));
@@ -1785,7 +1785,11 @@ static bool try_to_unmap_one(struct folio *folio, struct vm_area_struct *vma,
*
* See Documentation/mm/mmu_notifier.rst
*/
- page_remove_rmap(subpage, vma, folio_test_hugetlb(folio));
+ if (folio_test_hugetlb(folio))
+ page_remove_rmap(&folio->page, vma, true);
+ else
+ page_remove_rmap(subpage, vma, false);
+
if (vma->vm_flags & VM_LOCKED)
mlock_page_drain_local();
folio_put(folio);
@@ -2034,7 +2038,7 @@ static bool try_to_migrate_one(struct folio *folio, struct vm_area_struct *vma,
} else if (PageHWPoison(subpage)) {
pteval = swp_entry_to_pte(make_hwpoison_entry(subpage));
if (folio_test_hugetlb(folio)) {
- hugetlb_count_sub(folio_nr_pages(folio), mm);
+ hugetlb_count_sub(1L << pvmw.pte_order, mm);
set_huge_pte_at(mm, address, pvmw.pte, pteval);
} else {
dec_mm_counter(mm, mm_counter(&folio->page));
@@ -2126,7 +2130,10 @@ static bool try_to_migrate_one(struct folio *folio, struct vm_area_struct *vma,
*
* See Documentation/mm/mmu_notifier.rst
*/
- page_remove_rmap(subpage, vma, folio_test_hugetlb(folio));
+ if (folio_test_hugetlb(folio))
+ page_remove_rmap(&folio->page, vma, true);
+ else
+ page_remove_rmap(subpage, vma, false);
if (vma->vm_flags & VM_LOCKED)
mlock_page_drain_local();
folio_put(folio);
@@ -2210,6 +2217,8 @@ static bool page_make_device_exclusive_one(struct folio *folio,
args->owner);
mmu_notifier_invalidate_range_start(&range);
+ VM_BUG_ON_FOLIO(folio_test_hugetlb(folio), folio);
+
while (page_vma_mapped_walk(&pvmw)) {
/* Unexpected PMD-mapped THP? */
VM_BUG_ON_FOLIO(!pvmw.pte, folio);
--
2.38.0.135.g90850a2211-goog