From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-alma10-1.taild15c8.ts.net [100.103.45.18]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id D8278355819 for ; Mon, 13 Jul 2026 19:26:05 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=100.103.45.18 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1783970767; cv=none; b=GaLEM91xVemzsGJbhzYzWnfizlaCQT41kd1T6XsenRx5PwPjRUUWTM8/x62rtM0BzHMQdWcX3sDl+va2wiBh2M6328McLr0DtzEvjroy3ClJOOdyLxLKlsGft0TAUPvlY2EXqUjZ8eRlzRRUTWKBogX7RgRXnhNR68H4mqmR2Pw= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1783970767; c=relaxed/simple; bh=JgGizYJg1A/J3wH8n1WjXhVjBW/XTc4Y5/+14+DMCJI=; h=Date:To:From:Subject:Message-Id; b=MNuNBJRoP3W25/LUxMnIbu1In85/cN4+OyjKwuvGf6k8EH+4UKD6Drz5MH9CvOuE3hA/WbcY06/8N3ua5c7O4HGsmcw9diW6s7uZ6fTjxmAhwDaIWxKZjNn6XqtZf7B9RA7CG8jSsDMW0XaJ9trFJ+3le3IseE0m+MowF2JnQ94= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linux-foundation.org header.i=@linux-foundation.org header.b=qmvPk1pY; arc=none smtp.client-ip=100.103.45.18 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linux-foundation.org header.i=@linux-foundation.org header.b="qmvPk1pY" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 6373C1F000E9; Mon, 13 Jul 2026 19:26:05 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux-foundation.org; s=korg; t=1783970765; bh=C6428fyLQK40Ce9mcPADEIynvybcAJzQREzia0DDLfI=; h=Date:To:From:Subject; b=qmvPk1pYHetSV3KvryvCstzUmg1ffZ9Ri5V8Wl3ljByKwRD2viQkmjGP7VwCGRX5J GfHmTNcNEaA4V9yq9CMSgXnW8AoMrVTtlR8u+dmvNuf/Vwncb0UkZqp57WD1ItFiNj 7VXVAMpwaD7GItM480muw/G8zuQ8LXp2/NGo+1YQ= Date: Mon, 13 Jul 2026 12:26:04 -0700 To: mm-commits@vger.kernel.org,vbabka@kernel.org,ryan.roberts@arm.com,riel@surriel.com,osalvador@suse.de,muchun.song@linux.dev,ljs@kernel.org,liam@infradead.org,lance.yang@linux.dev,jannh@google.com,harry@kernel.org,david@kernel.org,anshuman.khandual@arm.com,dev.jain@arm.com,akpm@linux-foundation.org From: Andrew Morton Subject: + mm-rmap-refactor-anon-folio-unmap-in-try_to_unmap_one.patch added to mm-new branch Message-Id: <20260713192605.6373C1F000E9@smtp.kernel.org> Precedence: bulk X-Mailing-List: mm-commits@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: The patch titled Subject: mm/rmap: refactor anon folio unmap in try_to_unmap_one has been added to the -mm mm-new branch. Its filename is mm-rmap-refactor-anon-folio-unmap-in-try_to_unmap_one.patch This patch will shortly appear at https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches/mm-rmap-refactor-anon-folio-unmap-in-try_to_unmap_one.patch This patch will later appear in the mm-new branch at git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm Note, mm-new is a provisional staging ground for work-in-progress patches, and acceptance into mm-new is a notification for others take notice and to finish up reviews. Please do not hesitate to respond to review feedback and post updated versions to replace or incrementally fixup patches in mm-new. The mm-new branch of mm.git is not included in linux-next If a few days of testing in mm-new is successful, the patch will me moved into mm.git's mm-unstable branch, which is included in linux-next Before you just go and hit "reply", please: a) Consider who else should be cc'ed b) Prefer to cc a suitable mailing list as well c) Ideally: find the original patch on the mailing list and do a reply-to-all to that, adding suitable additional cc's *** Remember to use Documentation/process/submit-checklist.rst when testing your code *** The -mm tree is included into linux-next via various branches at git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm and is updated there most days ------------------------------------------------------ From: Dev Jain Subject: mm/rmap: refactor anon folio unmap in try_to_unmap_one Date: Mon, 13 Jul 2026 05:00:47 +0000 Refactor anonymous swapbacked folio unmap to ttu_anon_swapbacked_folio(). While at it, rename the remaining subpage variables to page; folios have pages, not subpages. No functional change intended. Link: https://lore.kernel.org/20260713050050.1017741-5-dev.jain@arm.com Signed-off-by: Dev Jain Cc: Anshuman Khandual Cc: David Hildenbrand (Arm) Cc: Harry Yoo Cc: Jann Horn Cc: Lance Yang Cc: Liam R. Howlett Cc: Lorenzo Stoakes Cc: Muchun Song Cc: Oscar Salvador Cc: Rik van Riel Cc: Ryan Roberts Cc: Vlastimil Babka Signed-off-by: Andrew Morton --- mm/rmap.c | 115 ++++++++++++++++++++++++++++++---------------------- 1 file changed, 68 insertions(+), 47 deletions(-) --- a/mm/rmap.c~mm-rmap-refactor-anon-folio-unmap-in-try_to_unmap_one +++ a/mm/rmap.c @@ -2112,6 +2112,66 @@ static bool ttu_anon_lazyfree_folio(stru return true; } +static pte_t swp_pte_prepare(swp_entry_t entry, pte_t old_pte, + bool anon_exclusive) +{ + pte_t swp_pte = swp_entry_to_pte(entry); + + if (anon_exclusive) + swp_pte = pte_swp_mkexclusive(swp_pte); + + if (likely(pte_present(old_pte))) { + if (pte_soft_dirty(old_pte)) + swp_pte = pte_swp_mksoft_dirty(swp_pte); + if (pte_uffd(old_pte)) + swp_pte = pte_swp_mkuffd(swp_pte); + } else { + /* Device-exclusive entry */ + if (pte_swp_soft_dirty(old_pte)) + swp_pte = pte_swp_mksoft_dirty(swp_pte); + if (pte_swp_uffd(old_pte)) + swp_pte = pte_swp_mkuffd(swp_pte); + } + + return swp_pte; +} + +static bool ttu_anon_swapbacked_folio(struct vm_area_struct *vma, + struct folio *folio, struct page *page, unsigned long address, + pte_t *ptep, pte_t pteval) +{ + const bool anon_exclusive = folio_test_anon(folio) && + PageAnonExclusive(page); + swp_entry_t entry = page_swap_entry(page); + struct mm_struct *mm = vma->vm_mm; + + if (folio_dup_swap(folio, page) < 0) + return false; + + /* + * arch_unmap_one() is expected to be a NOP on + * architectures where we could have PFN swap PTEs, + * so we'll not check/care. + */ + if (arch_unmap_one(mm, vma, address, pteval) < 0) { + folio_put_swap(folio, page); + return false; + } + + /* See folio_try_share_anon_rmap(): clear PTE first. */ + if (anon_exclusive && folio_try_share_anon_rmap_pte(folio, page)) { + folio_put_swap(folio, page); + return false; + } + + mm_prepare_for_swap_entries(mm); + dec_mm_counter(mm, MM_ANONPAGES); + inc_mm_counter(mm, MM_SWAPENTS); + set_pte_at(mm, address, ptep, + swp_pte_prepare(entry, pteval, anon_exclusive)); + return true; +} + /* * @arg: enum ttu_flags will be passed to this argument */ @@ -2120,9 +2180,9 @@ static bool try_to_unmap_one(struct foli { struct mm_struct *mm = vma->vm_mm; DEFINE_FOLIO_VMA_WALK(pvmw, folio, vma, address, 0); - bool anon_exclusive, ret = true; + bool ret = true; pte_t pteval; - struct page *subpage; + struct page *page; struct mmu_notifier_range range; enum ttu_flags flags = (enum ttu_flags)(long)arg; unsigned long nr_pages = 1, end_addr; @@ -2233,9 +2293,7 @@ static bool try_to_unmap_one(struct foli pfn = softleaf_to_pfn(entry); } - subpage = folio_page(folio, pfn - folio_pfn(folio)); - anon_exclusive = folio_test_anon(folio) && - PageAnonExclusive(subpage); + page = folio_page(folio, pfn - folio_pfn(folio)); if (likely(pte_present(pteval))) { nr_pages = folio_unmap_pte_batch(folio, &pvmw, flags, pteval); @@ -2274,7 +2332,7 @@ static bool try_to_unmap_one(struct foli /* With TTU_HWPOISON, we only expect small folios here. */ if (folio_test_hwpoison(folio) && (flags & TTU_HWPOISON)) { - pteval = swp_entry_to_pte(make_hwpoison_entry(subpage)); + pteval = swp_entry_to_pte(make_hwpoison_entry(page)); dec_mm_counter(mm, mm_counter(folio)); set_pte_at(mm, address, pvmw.pte, pteval); } else if (likely(pte_present(pteval)) && pte_unused(pteval) && @@ -2291,8 +2349,6 @@ static bool try_to_unmap_one(struct foli */ dec_mm_counter(mm, mm_counter(folio)); } else if (folio_test_anon(folio)) { - swp_entry_t entry = page_swap_entry(subpage); - pte_t swp_pte; /* * Store the swap location in the pte. * See handle_pte_fault() ... @@ -2313,47 +2369,12 @@ static bool try_to_unmap_one(struct foli goto finish_unmap; } - if (folio_dup_swap(folio, subpage) < 0) { + if (!ttu_anon_swapbacked_folio(vma, folio, page, address, + pvmw.pte, pteval)) { set_pte_at(mm, address, pvmw.pte, pteval); goto walk_abort; } - - /* - * arch_unmap_one() is expected to be a NOP on - * architectures where we could have PFN swap PTEs, - * so we'll not check/care. - */ - if (arch_unmap_one(mm, vma, address, pteval) < 0) { - folio_put_swap(folio, subpage); - set_pte_at(mm, address, pvmw.pte, pteval); - goto walk_abort; - } - - /* See folio_try_share_anon_rmap(): clear PTE first. */ - if (anon_exclusive && - folio_try_share_anon_rmap_pte(folio, subpage)) { - folio_put_swap(folio, subpage); - set_pte_at(mm, address, pvmw.pte, pteval); - goto walk_abort; - } - mm_prepare_for_swap_entries(mm); - dec_mm_counter(mm, MM_ANONPAGES); - inc_mm_counter(mm, MM_SWAPENTS); - swp_pte = swp_entry_to_pte(entry); - if (anon_exclusive) - swp_pte = pte_swp_mkexclusive(swp_pte); - if (likely(pte_present(pteval))) { - if (pte_soft_dirty(pteval)) - swp_pte = pte_swp_mksoft_dirty(swp_pte); - if (pte_uffd(pteval)) - swp_pte = pte_swp_mkuffd(swp_pte); - } else { - if (pte_swp_soft_dirty(pteval)) - swp_pte = pte_swp_mksoft_dirty(swp_pte); - if (pte_swp_uffd(pteval)) - swp_pte = pte_swp_mkuffd(swp_pte); - } - set_pte_at(mm, address, pvmw.pte, swp_pte); + goto finish_unmap; } else { /* * This is a locked file-backed folio, @@ -2369,7 +2390,7 @@ static bool try_to_unmap_one(struct foli add_mm_counter(mm, mm_counter_file(folio), -nr_pages); } finish_unmap: - folio_remove_rmap_ptes(folio, subpage, nr_pages, vma); + folio_remove_rmap_ptes(folio, page, nr_pages, vma); if (vma->vm_flags & VM_LOCKED) mlock_drain_local(); folio_put_refs(folio, nr_pages); _ Patches currently in -mm which might be from dev.jain@arm.com are mm-swap-rename-subpage-page-in-folio_dup_swap-folio_put_swap.patch mm-mprotect-drop-sub-from-batching-context.patch arm64-make-huge_ptep_get-handled-unaligned-addresses.patch mm-rmap-use-huge_ptep_get-in-try_to_unmap_one.patch mm-rmap-use-huge_ptep_get-in-try_to_migrate_one.patch mm-migrate-use-huge_ptep_get-in-remove_migration_pte.patch mm-page_vma_mapped-use-huge_ptep_get-for-hugetlb.patch mm-mprotect-use-huge_ptep_get-for-hugetlb.patch mm-rmap-convert-page-folio-for-hwpoison-checks.patch mm-rmap-add-try_to_unmap_hugetlb_one.patch mm-rmap-refactor-some-code-around-lazyfree-folio-unmapping.patch mm-rmap-refactor-anon-folio-unmap-in-try_to_unmap_one.patch mm-rmap-add-anon-folio-unmap-dispatcher.patch