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charset="utf-8" Content-Transfer-Encoding: quoted-printable From: Barry Song In the case of do_swap_page(), a new anonymous folio isn=E2=80=99t necessar= ily exclusive. This patch extends the rmap flags to allow treating a new anon folio as either exclusive or non-exclusive. To maintain the current behavior, we always use EXCLUSIVE as arguments. Suggested-by: David Hildenbrand Signed-off-by: Barry Song --- include/linux/rmap.h | 2 +- kernel/events/uprobes.c | 2 +- mm/huge_memory.c | 2 +- mm/khugepaged.c | 2 +- mm/memory.c | 10 +++++----- mm/migrate_device.c | 2 +- mm/rmap.c | 15 +++++++++------ mm/swapfile.c | 2 +- mm/userfaultfd.c | 2 +- 9 files changed, 21 insertions(+), 18 deletions(-) diff --git a/include/linux/rmap.h b/include/linux/rmap.h index cae38a2a643d..01a64e7e72b9 100644 --- a/include/linux/rmap.h +++ b/include/linux/rmap.h @@ -244,7 +244,7 @@ void folio_add_anon_rmap_ptes(struct folio *, struct pa= ge *, int nr_pages, void folio_add_anon_rmap_pmd(struct folio *, struct page *, struct vm_area_struct *, unsigned long address, rmap_t flags); void folio_add_new_anon_rmap(struct folio *, struct vm_area_struct *, - unsigned long address); + unsigned long address, rmap_t flags); void folio_add_file_rmap_ptes(struct folio *, struct page *, int nr_pages, struct vm_area_struct *); #define folio_add_file_rmap_pte(folio, page, vma) \ diff --git a/kernel/events/uprobes.c b/kernel/events/uprobes.c index 2c83ba776fc7..c20368aa33dd 100644 --- a/kernel/events/uprobes.c +++ b/kernel/events/uprobes.c @@ -181,7 +181,7 @@ static int __replace_page(struct vm_area_struct *vma, u= nsigned long addr, =20 if (new_page) { folio_get(new_folio); - folio_add_new_anon_rmap(new_folio, vma, addr); + folio_add_new_anon_rmap(new_folio, vma, addr, RMAP_EXCLUSIVE); folio_add_lru_vma(new_folio, vma); } else /* no new page, just dec_mm_counter for old_page */ diff --git a/mm/huge_memory.c b/mm/huge_memory.c index f409ea9fcc18..09a83e43c71a 100644 --- a/mm/huge_memory.c +++ b/mm/huge_memory.c @@ -973,7 +973,7 @@ static vm_fault_t __do_huge_pmd_anonymous_page(struct v= m_fault *vmf, =20 entry =3D mk_huge_pmd(page, vma->vm_page_prot); entry =3D maybe_pmd_mkwrite(pmd_mkdirty(entry), vma); - folio_add_new_anon_rmap(folio, vma, haddr); + folio_add_new_anon_rmap(folio, vma, haddr, RMAP_EXCLUSIVE); folio_add_lru_vma(folio, vma); pgtable_trans_huge_deposit(vma->vm_mm, vmf->pmd, pgtable); set_pmd_at(vma->vm_mm, haddr, vmf->pmd, entry); diff --git a/mm/khugepaged.c b/mm/khugepaged.c index 774a97e6e2da..4d759a7487d0 100644 --- a/mm/khugepaged.c +++ b/mm/khugepaged.c @@ -1213,7 +1213,7 @@ static int collapse_huge_page(struct mm_struct *mm, u= nsigned long address, =20 spin_lock(pmd_ptl); BUG_ON(!pmd_none(*pmd)); - folio_add_new_anon_rmap(folio, vma, address); + folio_add_new_anon_rmap(folio, vma, address, RMAP_EXCLUSIVE); folio_add_lru_vma(folio, vma); pgtable_trans_huge_deposit(mm, pmd, pgtable); set_pmd_at(mm, address, pmd, _pmd); diff --git a/mm/memory.c b/mm/memory.c index 54d7d2acdf39..2f94921091fb 100644 --- a/mm/memory.c +++ b/mm/memory.c @@ -930,7 +930,7 @@ copy_present_page(struct vm_area_struct *dst_vma, struc= t vm_area_struct *src_vma *prealloc =3D NULL; copy_user_highpage(&new_folio->page, page, addr, src_vma); __folio_mark_uptodate(new_folio); - folio_add_new_anon_rmap(new_folio, dst_vma, addr); + folio_add_new_anon_rmap(new_folio, dst_vma, addr, RMAP_EXCLUSIVE); folio_add_lru_vma(new_folio, dst_vma); rss[MM_ANONPAGES]++; =20 @@ -3400,7 +3400,7 @@ static vm_fault_t wp_page_copy(struct vm_fault *vmf) * some TLBs while the old PTE remains in others. */ ptep_clear_flush(vma, vmf->address, vmf->pte); - folio_add_new_anon_rmap(new_folio, vma, vmf->address); + folio_add_new_anon_rmap(new_folio, vma, vmf->address, RMAP_EXCLUSIVE); folio_add_lru_vma(new_folio, vma); BUG_ON(unshare && pte_write(entry)); set_pte_at(mm, vmf->address, vmf->pte, entry); @@ -4337,7 +4337,7 @@ vm_fault_t do_swap_page(struct vm_fault *vmf) =20 /* ksm created a completely new copy */ if (unlikely(folio !=3D swapcache && swapcache)) { - folio_add_new_anon_rmap(folio, vma, address); + folio_add_new_anon_rmap(folio, vma, address, RMAP_EXCLUSIVE); folio_add_lru_vma(folio, vma); } else { folio_add_anon_rmap_ptes(folio, page, nr_pages, vma, address, @@ -4592,7 +4592,7 @@ static vm_fault_t do_anonymous_page(struct vm_fault *= vmf) #ifdef CONFIG_TRANSPARENT_HUGEPAGE count_mthp_stat(folio_order(folio), MTHP_STAT_ANON_FAULT_ALLOC); #endif - folio_add_new_anon_rmap(folio, vma, addr); + folio_add_new_anon_rmap(folio, vma, addr, RMAP_EXCLUSIVE); folio_add_lru_vma(folio, vma); setpte: if (vmf_orig_pte_uffd_wp(vmf)) @@ -4790,7 +4790,7 @@ void set_pte_range(struct vm_fault *vmf, struct folio= *folio, /* copy-on-write page */ if (write && !(vma->vm_flags & VM_SHARED)) { VM_BUG_ON_FOLIO(nr !=3D 1, folio); - folio_add_new_anon_rmap(folio, vma, addr); + folio_add_new_anon_rmap(folio, vma, addr, RMAP_EXCLUSIVE); folio_add_lru_vma(folio, vma); } else { folio_add_file_rmap_ptes(folio, page, nr, vma); diff --git a/mm/migrate_device.c b/mm/migrate_device.c index 051d0a3ccbee..6d66dc1c6ffa 100644 --- a/mm/migrate_device.c +++ b/mm/migrate_device.c @@ -658,7 +658,7 @@ static void migrate_vma_insert_page(struct migrate_vma = *migrate, goto unlock_abort; =20 inc_mm_counter(mm, MM_ANONPAGES); - folio_add_new_anon_rmap(folio, vma, addr); + folio_add_new_anon_rmap(folio, vma, addr, RMAP_EXCLUSIVE); if (!folio_is_zone_device(folio)) folio_add_lru_vma(folio, vma); folio_get(folio); diff --git a/mm/rmap.c b/mm/rmap.c index b9e5943c8349..e612d999811a 100644 --- a/mm/rmap.c +++ b/mm/rmap.c @@ -1406,14 +1406,14 @@ void folio_add_anon_rmap_pmd(struct folio *folio, s= truct page *page, * This means the inc-and-test can be bypassed. * The folio does not have to be locked. * - * If the folio is pmd-mappable, it is accounted as a THP. As the folio - * is new, it's assumed to be mapped exclusively by a single process. + * If the folio is pmd-mappable, it is accounted as a THP. */ void folio_add_new_anon_rmap(struct folio *folio, struct vm_area_struct *v= ma, - unsigned long address) + unsigned long address, rmap_t flags) { int nr =3D folio_nr_pages(folio); int nr_pmdmapped =3D 0; + bool exclusive =3D flags & RMAP_EXCLUSIVE; =20 VM_WARN_ON_FOLIO(folio_test_hugetlb(folio), folio); VM_BUG_ON_VMA(address < vma->vm_start || @@ -1424,7 +1424,8 @@ void folio_add_new_anon_rmap(struct folio *folio, str= uct vm_area_struct *vma, if (likely(!folio_test_large(folio))) { /* increment count (starts at -1) */ atomic_set(&folio->_mapcount, 0); - SetPageAnonExclusive(&folio->page); + if (exclusive) + SetPageAnonExclusive(&folio->page); } else if (!folio_test_pmd_mappable(folio)) { int i; =20 @@ -1433,7 +1434,8 @@ void folio_add_new_anon_rmap(struct folio *folio, str= uct vm_area_struct *vma, =20 /* increment count (starts at -1) */ atomic_set(&page->_mapcount, 0); - SetPageAnonExclusive(page); + if (exclusive) + SetPageAnonExclusive(page); } =20 /* increment count (starts at -1) */ @@ -1445,7 +1447,8 @@ void folio_add_new_anon_rmap(struct folio *folio, str= uct vm_area_struct *vma, /* increment count (starts at -1) */ atomic_set(&folio->_large_mapcount, 0); atomic_set(&folio->_nr_pages_mapped, ENTIRELY_MAPPED); - SetPageAnonExclusive(&folio->page); + if (exclusive) + SetPageAnonExclusive(&folio->page); nr_pmdmapped =3D nr; } =20 diff --git a/mm/swapfile.c b/mm/swapfile.c index 9c6d8e557c0f..ae1d2700f6a3 100644 --- a/mm/swapfile.c +++ b/mm/swapfile.c @@ -1911,7 +1911,7 @@ static int unuse_pte(struct vm_area_struct *vma, pmd_= t *pmd, =20 folio_add_anon_rmap_pte(folio, page, vma, addr, rmap_flags); } else { /* ksm created a completely new copy */ - folio_add_new_anon_rmap(folio, vma, addr); + folio_add_new_anon_rmap(folio, vma, addr, RMAP_EXCLUSIVE); folio_add_lru_vma(folio, vma); } new_pte =3D pte_mkold(mk_pte(page, vma->vm_page_prot)); diff --git a/mm/userfaultfd.c b/mm/userfaultfd.c index 5e7f2801698a..8dedaec00486 100644 --- a/mm/userfaultfd.c +++ b/mm/userfaultfd.c @@ -216,7 +216,7 @@ int mfill_atomic_install_pte(pmd_t *dst_pmd, folio_add_lru(folio); folio_add_file_rmap_pte(folio, page, dst_vma); } else { - folio_add_new_anon_rmap(folio, dst_vma, dst_addr); + folio_add_new_anon_rmap(folio, dst_vma, dst_addr, RMAP_EXCLUSIVE); folio_add_lru_vma(folio, dst_vma); } =20 --=20 2.34.1