From: David Hildenbrand Subject: mm/rmap: drop "compound" parameter from page_add_new_anon_rmap() New anonymous pages are always mapped natively: only THP/khugepagd code maps a new compound anonymous page and passes "true". Otherwise, we're just dealing with simple, non-compound pages. Let's give the interface clearer semantics and document these. Link: https://lkml.kernel.org/r/20220329160440.193848-9-david@redhat.com Signed-off-by: David Hildenbrand Acked-by: Vlastimil Babka Cc: Andrea Arcangeli Cc: Christoph Hellwig Cc: David Rientjes Cc: Don Dutile Cc: Hugh Dickins Cc: Jan Kara Cc: Jann Horn Cc: Jason Gunthorpe Cc: John Hubbard Cc: Khalid Aziz Cc: "Kirill A. Shutemov" Cc: Liang Zhang Cc: Matthew Wilcox (Oracle) Cc: Michal Hocko Cc: Mike Kravetz Cc: Mike Rapoport Cc: Nadav Amit Cc: Oded Gabbay Cc: Oleg Nesterov Cc: Pedro Demarchi Gomes Cc: Peter Xu Cc: Rik van Riel Cc: Roman Gushchin Cc: Shakeel Butt Cc: Yang Shi Signed-off-by: Andrew Morton --- include/linux/rmap.h | 3 ++- 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 | 9 ++++++--- mm/swapfile.c | 2 +- mm/userfaultfd.c | 2 +- 9 files changed, 19 insertions(+), 15 deletions(-) --- a/include/linux/rmap.h~mm-rmap-drop-compound-parameter-from-page_add_new_anon_rmap +++ a/include/linux/rmap.h @@ -185,11 +185,12 @@ void page_move_anon_rmap(struct page *, void page_add_anon_rmap(struct page *, struct vm_area_struct *, unsigned long address, rmap_t flags); void page_add_new_anon_rmap(struct page *, struct vm_area_struct *, - unsigned long address, bool compound); + unsigned long address); void page_add_file_rmap(struct page *, struct vm_area_struct *, bool compound); void page_remove_rmap(struct page *, struct vm_area_struct *, bool compound); + void hugepage_add_anon_rmap(struct page *, struct vm_area_struct *, unsigned long address, rmap_t flags); void hugepage_add_new_anon_rmap(struct page *, struct vm_area_struct *, --- a/kernel/events/uprobes.c~mm-rmap-drop-compound-parameter-from-page_add_new_anon_rmap +++ a/kernel/events/uprobes.c @@ -180,7 +180,7 @@ static int __replace_page(struct vm_area if (new_page) { get_page(new_page); - page_add_new_anon_rmap(new_page, vma, addr, false); + page_add_new_anon_rmap(new_page, vma, addr); lru_cache_add_inactive_or_unevictable(new_page, vma); } else /* no new page, just dec_mm_counter for old_page */ --- a/mm/huge_memory.c~mm-rmap-drop-compound-parameter-from-page_add_new_anon_rmap +++ a/mm/huge_memory.c @@ -647,7 +647,7 @@ static vm_fault_t __do_huge_pmd_anonymou entry = mk_huge_pmd(page, vma->vm_page_prot); entry = maybe_pmd_mkwrite(pmd_mkdirty(entry), vma); - page_add_new_anon_rmap(page, vma, haddr, true); + page_add_new_anon_rmap(page, vma, haddr); lru_cache_add_inactive_or_unevictable(page, vma); pgtable_trans_huge_deposit(vma->vm_mm, vmf->pmd, pgtable); set_pmd_at(vma->vm_mm, haddr, vmf->pmd, entry); --- a/mm/khugepaged.c~mm-rmap-drop-compound-parameter-from-page_add_new_anon_rmap +++ a/mm/khugepaged.c @@ -1183,7 +1183,7 @@ static void collapse_huge_page(struct mm spin_lock(pmd_ptl); BUG_ON(!pmd_none(*pmd)); - page_add_new_anon_rmap(new_page, vma, address, true); + page_add_new_anon_rmap(new_page, vma, address); lru_cache_add_inactive_or_unevictable(new_page, vma); pgtable_trans_huge_deposit(mm, pmd, pgtable); set_pmd_at(mm, address, pmd, _pmd); --- a/mm/memory.c~mm-rmap-drop-compound-parameter-from-page_add_new_anon_rmap +++ a/mm/memory.c @@ -893,7 +893,7 @@ copy_present_page(struct vm_area_struct *prealloc = NULL; copy_user_highpage(new_page, page, addr, src_vma); __SetPageUptodate(new_page); - page_add_new_anon_rmap(new_page, dst_vma, addr, false); + page_add_new_anon_rmap(new_page, dst_vma, addr); lru_cache_add_inactive_or_unevictable(new_page, dst_vma); rss[mm_counter(new_page)]++; @@ -3058,7 +3058,7 @@ static vm_fault_t wp_page_copy(struct vm * some TLBs while the old PTE remains in others. */ ptep_clear_flush_notify(vma, vmf->address, vmf->pte); - page_add_new_anon_rmap(new_page, vma, vmf->address, false); + page_add_new_anon_rmap(new_page, vma, vmf->address); lru_cache_add_inactive_or_unevictable(new_page, vma); /* * We call the notify macro here because, when using secondary @@ -3698,7 +3698,7 @@ vm_fault_t do_swap_page(struct vm_fault /* ksm created a completely new copy */ if (unlikely(page != swapcache && swapcache)) { - page_add_new_anon_rmap(page, vma, vmf->address, false); + page_add_new_anon_rmap(page, vma, vmf->address); lru_cache_add_inactive_or_unevictable(page, vma); } else { page_add_anon_rmap(page, vma, vmf->address, rmap_flags); @@ -3848,7 +3848,7 @@ static vm_fault_t do_anonymous_page(stru } inc_mm_counter_fast(vma->vm_mm, MM_ANONPAGES); - page_add_new_anon_rmap(page, vma, vmf->address, false); + page_add_new_anon_rmap(page, vma, vmf->address); lru_cache_add_inactive_or_unevictable(page, vma); setpte: set_pte_at(vma->vm_mm, vmf->address, vmf->pte, entry); @@ -4035,7 +4035,7 @@ void do_set_pte(struct vm_fault *vmf, st /* copy-on-write page */ if (write && !(vma->vm_flags & VM_SHARED)) { inc_mm_counter_fast(vma->vm_mm, MM_ANONPAGES); - page_add_new_anon_rmap(page, vma, addr, false); + page_add_new_anon_rmap(page, vma, addr); lru_cache_add_inactive_or_unevictable(page, vma); } else { inc_mm_counter_fast(vma->vm_mm, mm_counter_file(page)); --- a/mm/migrate_device.c~mm-rmap-drop-compound-parameter-from-page_add_new_anon_rmap +++ a/mm/migrate_device.c @@ -610,7 +610,7 @@ static void migrate_vma_insert_page(stru goto unlock_abort; inc_mm_counter(mm, MM_ANONPAGES); - page_add_new_anon_rmap(page, vma, addr, false); + page_add_new_anon_rmap(page, vma, addr); if (!is_zone_device_page(page)) lru_cache_add_inactive_or_unevictable(page, vma); get_page(page); --- a/mm/rmap.c~mm-rmap-drop-compound-parameter-from-page_add_new_anon_rmap +++ a/mm/rmap.c @@ -1182,19 +1182,22 @@ void page_add_anon_rmap(struct page *pag } /** - * page_add_new_anon_rmap - add pte mapping to a new anonymous page + * page_add_new_anon_rmap - add mapping to a new anonymous page * @page: the page to add the mapping to * @vma: the vm area in which the mapping is added * @address: the user virtual address mapped - * @compound: charge the page as compound or small page + * + * If it's a compound page, it is accounted as a compound page. As the page + * is new, it's assume to get mapped exclusively by a single process. * * Same as page_add_anon_rmap but must only be called on *new* pages. * This means the inc-and-test can be bypassed. * Page does not have to be locked. */ void page_add_new_anon_rmap(struct page *page, - struct vm_area_struct *vma, unsigned long address, bool compound) + struct vm_area_struct *vma, unsigned long address) { + const bool compound = PageCompound(page); int nr = compound ? thp_nr_pages(page) : 1; VM_BUG_ON_VMA(address < vma->vm_start || address >= vma->vm_end, vma); --- a/mm/swapfile.c~mm-rmap-drop-compound-parameter-from-page_add_new_anon_rmap +++ a/mm/swapfile.c @@ -1802,7 +1802,7 @@ static int unuse_pte(struct vm_area_stru if (page == swapcache) { page_add_anon_rmap(page, vma, addr, RMAP_NONE); } else { /* ksm created a completely new copy */ - page_add_new_anon_rmap(page, vma, addr, false); + page_add_new_anon_rmap(page, vma, addr); lru_cache_add_inactive_or_unevictable(page, vma); } set_pte_at(vma->vm_mm, addr, pte, --- a/mm/userfaultfd.c~mm-rmap-drop-compound-parameter-from-page_add_new_anon_rmap +++ a/mm/userfaultfd.c @@ -104,7 +104,7 @@ int mfill_atomic_install_pte(struct mm_s lru_cache_add(page); page_add_file_rmap(page, dst_vma, false); } else { - page_add_new_anon_rmap(page, dst_vma, dst_addr, false); + page_add_new_anon_rmap(page, dst_vma, dst_addr); lru_cache_add_inactive_or_unevictable(page, dst_vma); } _