Let's batch the rmap operations, as a preparation to making individual
page_add_anon_rmap() calls more expensive.
While at it, use more folio operations (but only in the code branch we're
touching), use VM_WARN_ON_FOLIO(), and pass RMAP_COMPOUND instead of
manually setting PageAnonExclusive.
We should never see non-anon pages on that branch: otherwise, the
existing page_add_anon_rmap() call would have been flawed already.
Signed-off-by: David Hildenbrand <david@xxxxxxxxxx>
---
mm/huge_memory.c | 23 +++++++++++++++--------
1 file changed, 15 insertions(+), 8 deletions(-)
diff --git a/mm/huge_memory.c b/mm/huge_memory.c
index fd7251923557..f47971d1afbf 100644
--- a/mm/huge_memory.c
+++ b/mm/huge_memory.c
@@ -2100,6 +2100,7 @@ static void __split_huge_pmd_locked(struct vm_area_struct *vma, pmd_t *pmd,
unsigned long haddr, bool freeze)
{
struct mm_struct *mm = vma->vm_mm;
+ struct folio *folio;
struct page *page;
pgtable_t pgtable;
pmd_t old_pmd, _pmd;
@@ -2195,16 +2196,18 @@ static void __split_huge_pmd_locked(struct vm_area_struct *vma, pmd_t *pmd,
uffd_wp = pmd_swp_uffd_wp(old_pmd);
} else {
page = pmd_page(old_pmd);
+ folio = page_folio(page);
if (pmd_dirty(old_pmd)) {
dirty = true;
- SetPageDirty(page);
+ folio_set_dirty(folio);
}
write = pmd_write(old_pmd);
young = pmd_young(old_pmd);
soft_dirty = pmd_soft_dirty(old_pmd);
uffd_wp = pmd_uffd_wp(old_pmd);
- VM_BUG_ON_PAGE(!page_count(page), page);
+ VM_WARN_ON_FOLIO(!folio_ref_count(folio), folio);
+ VM_WARN_ON_FOLIO(!folio_test_anon(folio), folio);
/*
* Without "freeze", we'll simply split the PMD, propagating the
@@ -2221,11 +2224,18 @@ static void __split_huge_pmd_locked(struct vm_area_struct *vma, pmd_t *pmd,
*
* See page_try_share_anon_rmap(): invalidate PMD first.
*/
- anon_exclusive = PageAnon(page) && PageAnonExclusive(page);
+ anon_exclusive = PageAnonExclusive(page);
if (freeze && anon_exclusive && page_try_share_anon_rmap(page))
freeze = false;
- if (!freeze)
- page_ref_add(page, HPAGE_PMD_NR - 1);
+ if (!freeze) {
+ rmap_t rmap_flags = RMAP_NONE;
+
+ folio_ref_add(folio, HPAGE_PMD_NR - 1);
+ if (anon_exclusive)
+ rmap_flags = RMAP_EXCLUSIVE;
+ folio_add_anon_rmap_range(folio, page, HPAGE_PMD_NR,
+ vma, haddr, rmap_flags);
+ }
}
/*
@@ -2268,8 +2278,6 @@ static void __split_huge_pmd_locked(struct vm_area_struct *vma, pmd_t *pmd,
entry = mk_pte(page + i, READ_ONCE(vma->vm_page_prot));
if (write)
entry = pte_mkwrite(entry, vma);
- if (anon_exclusive)
- SetPageAnonExclusive(page + i);
if (!young)
entry = pte_mkold(entry);
/* NOTE: this may set soft-dirty too on some archs */
@@ -2279,7 +2287,6 @@ static void __split_huge_pmd_locked(struct vm_area_struct *vma, pmd_t *pmd,
entry = pte_mksoft_dirty(entry);
if (uffd_wp)
entry = pte_mkuffd_wp(entry);
- page_add_anon_rmap(page + i, vma, addr, RMAP_NONE);
}
VM_BUG_ON(!pte_none(ptep_get(pte)));
set_pte_at(mm, addr, pte, entry);
--
2.41.0
