From: David Hildenbrand david@redhat.com
mainline inclusion from mainline-6.8-rc1 commit 91b2978a348073db0e47b380fa66c865eb25f3d8 category: feature bugzilla: https://gitee.com/openeuler/kernel/issues/I9CESE CVE: NA
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Let's use folio_add_anon_rmap_ptes(), batching the rmap operations.
While at it, use more folio operations (but only in the code branch we're touching), use VM_WARN_ON_FOLIO(), and pass RMAP_EXCLUSIVE 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.
Link: https://lkml.kernel.org/r/20231220224504.646757-16-david@redhat.com Signed-off-by: David Hildenbrand david@redhat.com Reviewed-by: Yin Fengwei fengwei.yin@intel.com Cc: Hugh Dickins hughd@google.com Cc: Matthew Wilcox (Oracle) willy@infradead.org Cc: Muchun Song muchun.song@linux.dev Cc: Muchun Song songmuchun@bytedance.com Cc: Peter Xu peterx@redhat.com Cc: Ryan Roberts ryan.roberts@arm.com Signed-off-by: Andrew Morton akpm@linux-foundation.org (cherry picked from commit 91b2978a348073db0e47b380fa66c865eb25f3d8) Signed-off-by: Kefeng Wang wangkefeng.wang@huawei.com --- 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 83d249b4433b..1f2e9eec7cef 100644 --- a/mm/huge_memory.c +++ b/mm/huge_memory.c @@ -2253,6 +2253,7 @@ 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; @@ -2349,16 +2350,18 @@ 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 @@ -2375,11 +2378,18 @@ 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_ptes(folio, page, HPAGE_PMD_NR, + vma, haddr, rmap_flags); + } }
/* @@ -2422,8 +2432,6 @@ 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 */ @@ -2433,7 +2441,6 @@ 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);