The quilt patch titled Subject: mm: support page_mapcount() on page_has_type() pages has been removed from the -mm tree. Its filename was mm-support-page_mapcount-on-page_has_type-pages.patch

This patch was dropped because it was merged into the mm-hotfixes-stable branch of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm

------------------------------------------------------ From: "Matthew Wilcox (Oracle)" willy@infradead.org Subject: mm: support page_mapcount() on page_has_type() pages Date: Thu, 21 Mar 2024 14:24:42 +0000

Return 0 for pages which can't be mapped. This matches how page_mapped() works. It is more convenient for users to not have to filter out these pages.

Link: https://lkml.kernel.org/r/20240321142448.1645400-5-willy@infradead.org Fixes: 9c5ccf2db04b ("mm: remove HUGETLB_PAGE_DTOR") Signed-off-by: Matthew Wilcox (Oracle) willy@infradead.org Reviewed-by: David Hildenbrand david@redhat.com Acked-by: Vlastimil Babka vbabka@suse.cz Cc: Miaohe Lin linmiaohe@huawei.com Cc: Muchun Song muchun.song@linux.dev Cc: Oscar Salvador osalvador@suse.de Cc: stable@vger.kernel.org Signed-off-by: Andrew Morton akpm@linux-foundation.org ---

fs/proc/page.c | 7 ++----- include/linux/mm.h | 8 +++++--- include/linux/page-flags.h | 4 ++-- 3 files changed, 9 insertions(+), 10 deletions(-)

--- a/fs/proc/page.c~mm-support-page_mapcount-on-page_has_type-pages +++ a/fs/proc/page.c @@ -67,7 +67,7 @@ static ssize_t kpagecount_read(struct fi */ ppage = pfn_to_online_page(pfn);

- if (!ppage || PageSlab(ppage) || page_has_type(ppage)) + if (!ppage) pcount = 0; else pcount = page_mapcount(ppage); @@ -124,11 +124,8 @@ u64 stable_page_flags(struct page *page)

/* * pseudo flags for the well known (anonymous) memory mapped pages - * - * Note that page->_mapcount is overloaded in SLAB, so the - * simple test in page_mapped() is not enough. */ - if (!PageSlab(page) && page_mapped(page)) + if (page_mapped(page)) u |= 1 << KPF_MMAP; if (PageAnon(page)) u |= 1 << KPF_ANON; --- a/include/linux/mm.h~mm-support-page_mapcount-on-page_has_type-pages +++ a/include/linux/mm.h @@ -1223,14 +1223,16 @@ static inline void page_mapcount_reset(s * a large folio, it includes the number of times this page is mapped * as part of that folio. * - * The result is undefined for pages which cannot be mapped into userspace. - * For example SLAB or special types of pages. See function page_has_type(). - * They use this field in struct page differently. + * Will report 0 for pages which cannot be mapped into userspace, eg + * slab, page tables and similar. */ static inline int page_mapcount(struct page *page) { int mapcount = atomic_read(&page->_mapcount) + 1;

+ /* Handle page_has_type() pages */ + if (mapcount < 0) + mapcount = 0; if (unlikely(PageCompound(page))) mapcount += folio_entire_mapcount(page_folio(page));

--- a/include/linux/page-flags.h~mm-support-page_mapcount-on-page_has_type-pages +++ a/include/linux/page-flags.h @@ -971,12 +971,12 @@ static inline bool is_page_hwpoison(stru * page_type may be used. Because it is initialised to -1, we invert the * sense of the bit, so __SetPageFoo *clears* the bit used for PageFoo, and * __ClearPageFoo *sets* the bit used for PageFoo. We reserve a few high and - * low bits so that an underflow or overflow of page_mapcount() won't be + * low bits so that an underflow or overflow of _mapcount won't be * mistaken for a page type value. */

#define PAGE_TYPE_BASE 0xf0000000 -/* Reserve 0x0000007f to catch underflows of page_mapcount */ +/* Reserve 0x0000007f to catch underflows of _mapcount */ #define PAGE_MAPCOUNT_RESERVE -128 #define PG_buddy 0x00000080 #define PG_offline 0x00000100 _

Patches currently in -mm which might be from willy@infradead.org are

mm-always-initialise-folio-_deferred_list.patch mm-remove-folio_prep_large_rmappable.patch mm-remove-a-call-to-compound_head-from-is_page_hwpoison.patch mm-free-up-pg_slab.patch mm-free-up-pg_slab-fix.patch mm-improve-dumping-of-mapcount-and-page_type.patch hugetlb-remove-mention-of-destructors.patch sh-remove-use-of-pg_arch_1-on-individual-pages.patch xtensa-remove-uses-of-pg_arch_1-on-individual-pages.patch mm-make-page_ext_get-take-a-const-argument.patch mm-make-folio_test_idle-and-folio_test_young-take-a-const-argument.patch mm-make-is_free_buddy_page-take-a-const-argument.patch mm-make-page_mapped-take-a-const-argument.patch mm-convert-arch_clear_hugepage_flags-to-take-a-folio.patch mm-convert-arch_clear_hugepage_flags-to-take-a-folio-fix.patch slub-remove-use-of-page-flags.patch remove-references-to-page-flags-in-documentation.patch proc-rewrite-stable_page_flags.patch proc-rewrite-stable_page_flags-fix.patch proc-rewrite-stable_page_flags-fix-2.patch sparc-use-is_huge_zero_pmd.patch mm-add-is_huge_zero_folio.patch mm-add-pmd_folio.patch mm-convert-migrate_vma_collect_pmd-to-use-a-folio.patch mm-convert-huge_zero_page-to-huge_zero_folio.patch mm-convert-do_huge_pmd_anonymous_page-to-huge_zero_folio.patch dax-use-huge_zero_folio.patch mm-rename-mm_put_huge_zero_page-to-mm_put_huge_zero_folio.patch mm-use-rwsem-assertion-macros-for-mmap_lock.patch filemap-remove-__set_page_dirty.patch mm-correct-page_mapped_in_vma-for-large-folios.patch mm-remove-vma_address.patch mm-rename-vma_pgoff_address-back-to-vma_address.patch khugepaged-inline-hpage_collapse_alloc_folio.patch khugepaged-convert-alloc_charge_hpage-to-alloc_charge_folio.patch khugepaged-remove-hpage-from-collapse_huge_page.patch khugepaged-pass-a-folio-to-__collapse_huge_page_copy.patch khugepaged-remove-hpage-from-collapse_file.patch khugepaged-use-a-folio-throughout-collapse_file.patch khugepaged-use-a-folio-throughout-collapse_file-fix.patch khugepaged-use-a-folio-throughout-hpage_collapse_scan_file.patch proc-convert-clear_refs_pte_range-to-use-a-folio.patch proc-convert-smaps_account-to-use-a-folio.patch mm-remove-page_idle-and-page_young-wrappers.patch mm-generate-page_idle_flag-definitions.patch proc-convert-gather_stats-to-use-a-folio.patch proc-convert-smaps_page_accumulate-to-use-a-folio.patch proc-pass-a-folio-to-smaps_page_accumulate.patch proc-convert-smaps_pmd_entry-to-use-a-folio.patch mm-remove-struct-page-from-get_shadow_from_swap_cache.patch hugetlb-convert-alloc_buddy_hugetlb_folio-to-use-a-folio.patch mm-convert-pagecache_isize_extended-to-use-a-folio.patch mm-free-non-hugetlb-large-folios-in-a-batch.patch mm-combine-free_the_page-and-free_unref_page.patch mm-inline-destroy_large_folio-into-__folio_put_large.patch mm-combine-__folio_put_small-__folio_put_large-and-__folio_put.patch mm-convert-free_zone_device_page-to-free_zone_device_folio.patch doc-improve-the-description-of-__folio_mark_dirty.patch buffer-add-kernel-doc-for-block_dirty_folio.patch buffer-add-kernel-doc-for-try_to_free_buffers.patch buffer-fix-__bread-and-__bread_gfp-kernel-doc.patch buffer-add-kernel-doc-for-brelse-and-__brelse.patch buffer-add-kernel-doc-for-bforget-and-__bforget.patch buffer-improve-bdev_getblk-documentation.patch doc-split-bufferrst-out-of-api-summaryrst.patch doc-split-bufferrst-out-of-api-summaryrst-fix.patch mm-memory-failure-remove-fsdax_pgoff-argument-from-__add_to_kill.patch mm-memory-failure-pass-addr-to-__add_to_kill.patch mm-return-the-address-from-page_mapped_in_vma.patch mm-make-page_mapped_in_vma-conditional-on-config_memory_failure.patch mm-memory-failure-convert-shake_page-to-shake_folio.patch mm-convert-hugetlb_page_mapping_lock_write-to-folio.patch mm-memory-failure-convert-memory_failure-to-use-a-folio.patch mm-memory-failure-convert-hwpoison_user_mappings-to-take-a-folio.patch mm-memory-failure-add-some-folio-conversions-to-unpoison_memory.patch mm-memory-failure-use-folio-functions-throughout-collect_procs.patch mm-memory-failure-pass-the-folio-to-collect_procs_ksm.patch fscrypt-convert-bh_get_inode_and_lblk_num-to-use-a-folio.patch f2fs-convert-f2fs_clear_page_cache_dirty_tag-to-use-a-folio.patch memory-failure-remove-calls-to-page_mapping.patch migrate-expand-the-use-of-folio-in-__migrate_device_pages.patch userfault-expand-folio-use-in-mfill_atomic_install_pte.patch mm-remove-page_mapping.patch mm-remove-page_cache_alloc.patch mm-remove-put_devmap_managed_page.patch mm-convert-put_devmap_managed_page_refs-to-put_devmap_managed_folio_refs.patch mm-remove-page_ref_sub_return.patch gup-use-folios-for-gup_devmap.patch mm-add-kernel-doc-for-folio_mark_accessed.patch mm-remove-pagereferenced.patch