From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (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 0F642284B2E for ; Thu, 10 Jul 2025 05:44:59 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1752126299; cv=none; b=Qa7U4L04KSGEibdsDn2ebvRZDWIQy4a3tZD8gBTTqC+2VWNbIvQBPyIEhmlaJ3hdSThT8IHLEufPjpP7IooBLPuf8JVjg+tyR/8GSQ4aEGMa4OTMWWCtwNIrOy/PaE6/rPcAx7/zvJTuI6/1DNdkxW6tI9aupG46tpskn5ZKWFQ= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1752126299; c=relaxed/simple; bh=kS0gGM0X8ULvJaDtjLXCVp+WxTjkcbZB+xDgydUan/w=; h=Date:To:From:Subject:Message-Id; b=SDSB9r6PuHUl6fx2fdy+4HJDJT4vYgKpfdmLORxG9g5CcPURhpKbFBhvh2ZGW3HzYyHIXUUDBsB02svNvI8izVQBCW2NGQBy6VhUTKmcD1Drhlmyvot64pzrlj0bfAYan1o0ReCNbKKsFn4y5U5o+iwW4ZmivRnwztB5l3Far2o= 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=MwCJ0MkO; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linux-foundation.org header.i=@linux-foundation.org header.b="MwCJ0MkO" Received: by smtp.kernel.org (Postfix) with ESMTPSA id D8FFCC4CEF6; Thu, 10 Jul 2025 05:44:58 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linux-foundation.org; s=korg; t=1752126298; bh=kS0gGM0X8ULvJaDtjLXCVp+WxTjkcbZB+xDgydUan/w=; h=Date:To:From:Subject:From; b=MwCJ0MkOsfw3xO+OkIuvn+eHQMcoHwHAuDrmhihCmhIGDDOUZj7Q+vI8g/QDmyfFr YkKvTrKvl7/udHCVh+9qeLbyWLo+pGyTgoNsnDxm/02U+AmPr4F8hzCk0NdL4YydXC 3XOJAah56fOkA9SIaviTTF9+s3y6HEcecu8cjUUI= Date: Wed, 09 Jul 2025 22:44:58 -0700 To: mm-commits@vger.kernel.org,ziy@nvidia.com,vbabka@suse.cz,surenb@google.com,ryan.roberts@arm.com,rppt@kernel.org,osalvador@suse.de,npache@redhat.com,mhocko@suse.com,lorenzo.stoakes@oracle.com,liam.howlett@oracle.com,jgg@nvidia.com,dev.jain@arm.com,dan.j.williams@intel.com,baolin.wang@linux.alibaba.com,apopple@nvidia.com,david@redhat.com,akpm@linux-foundation.org From: Andrew Morton Subject: [merged mm-stable] mm-huge_memory-dont-mark-refcounted-folios-special-in-vmf_insert_folio_pmd.patch removed from -mm tree Message-Id: <20250710054458.D8FFCC4CEF6@smtp.kernel.org> Precedence: bulk X-Mailing-List: mm-commits@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: The quilt patch titled Subject: mm/huge_memory: don't mark refcounted folios special in vmf_insert_folio_pmd() has been removed from the -mm tree. Its filename was mm-huge_memory-dont-mark-refcounted-folios-special-in-vmf_insert_folio_pmd.patch This patch was dropped because it was merged into the mm-stable branch of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm ------------------------------------------------------ From: David Hildenbrand Subject: mm/huge_memory: don't mark refcounted folios special in vmf_insert_folio_pmd() Date: Fri, 13 Jun 2025 11:27:01 +0200 Marking PMDs that map a "normal" refcounted folios as special is against our rules documented for vm_normal_page(): normal (refcounted) folios shall never have the page table mapping marked as special. Fortunately, there are not that many pmd_special() check that can be mislead, and most vm_normal_page_pmd()/vm_normal_folio_pmd() users that would get this wrong right now are rather harmless: e.g., none so far bases decisions whether to grab a folio reference on that decision. Well, and GUP-fast will fallback to GUP-slow. All in all, so far no big implications as it seems. Getting this right will get more important as we use folio_normal_page_pmd() in more places. Fix it by teaching insert_pfn_pmd() to properly handle folios and pfns -- moving refcount/mapcount/etc handling in there, renaming it to insert_pmd(), and distinguishing between both cases using a new simple "struct folio_or_pfn" structure. Use folio_mk_pmd() to create a pmd for a folio cleanly. Link: https://lkml.kernel.org/r/20250613092702.1943533-3-david@redhat.com Fixes: 6c88f72691f8 ("mm/huge_memory: add vmf_insert_folio_pmd()") Signed-off-by: David Hildenbrand Reviewed-by: Jason Gunthorpe Reviewed-by: Lorenzo Stoakes Reviewed-by: Dan Williams Tested-by: Dan Williams Reviewed-by: Oscar Salvador Cc: Alistair Popple Cc: Baolin Wang Cc: Dev Jain Cc: Liam Howlett Cc: Mariano Pache Cc: Michal Hocko Cc: Mike Rapoport Cc: Ryan Roberts Cc: Suren Baghdasaryan Cc: Vlastimil Babka Cc: Zi Yan Signed-off-by: Andrew Morton --- mm/huge_memory.c | 59 ++++++++++++++++++++++++++++++--------------- 1 file changed, 40 insertions(+), 19 deletions(-) --- a/mm/huge_memory.c~mm-huge_memory-dont-mark-refcounted-folios-special-in-vmf_insert_folio_pmd +++ a/mm/huge_memory.c @@ -1372,9 +1372,17 @@ vm_fault_t do_huge_pmd_anonymous_page(st return __do_huge_pmd_anonymous_page(vmf); } -static int insert_pfn_pmd(struct vm_area_struct *vma, unsigned long addr, - pmd_t *pmd, pfn_t pfn, pgprot_t prot, bool write, - pgtable_t pgtable) +struct folio_or_pfn { + union { + struct folio *folio; + pfn_t pfn; + }; + bool is_folio; +}; + +static int insert_pmd(struct vm_area_struct *vma, unsigned long addr, + pmd_t *pmd, struct folio_or_pfn fop, pgprot_t prot, + bool write, pgtable_t pgtable) { struct mm_struct *mm = vma->vm_mm; pmd_t entry; @@ -1382,8 +1390,11 @@ static int insert_pfn_pmd(struct vm_area lockdep_assert_held(pmd_lockptr(mm, pmd)); if (!pmd_none(*pmd)) { + const unsigned long pfn = fop.is_folio ? folio_pfn(fop.folio) : + pfn_t_to_pfn(fop.pfn); + if (write) { - if (pmd_pfn(*pmd) != pfn_t_to_pfn(pfn)) { + if (pmd_pfn(*pmd) != pfn) { WARN_ON_ONCE(!is_huge_zero_pmd(*pmd)); return -EEXIST; } @@ -1396,11 +1407,20 @@ static int insert_pfn_pmd(struct vm_area return -EEXIST; } - entry = pmd_mkhuge(pfn_t_pmd(pfn, prot)); - if (pfn_t_devmap(pfn)) - entry = pmd_mkdevmap(entry); - else - entry = pmd_mkspecial(entry); + if (fop.is_folio) { + entry = folio_mk_pmd(fop.folio, vma->vm_page_prot); + + folio_get(fop.folio); + folio_add_file_rmap_pmd(fop.folio, &fop.folio->page, vma); + add_mm_counter(mm, mm_counter_file(fop.folio), HPAGE_PMD_NR); + } else { + entry = pmd_mkhuge(pfn_t_pmd(fop.pfn, prot)); + + if (pfn_t_devmap(fop.pfn)) + entry = pmd_mkdevmap(entry); + else + entry = pmd_mkspecial(entry); + } if (write) { entry = pmd_mkyoung(pmd_mkdirty(entry)); entry = maybe_pmd_mkwrite(entry, vma); @@ -1431,6 +1451,9 @@ vm_fault_t vmf_insert_pfn_pmd(struct vm_ unsigned long addr = vmf->address & PMD_MASK; struct vm_area_struct *vma = vmf->vma; pgprot_t pgprot = vma->vm_page_prot; + struct folio_or_pfn fop = { + .pfn = pfn, + }; pgtable_t pgtable = NULL; spinlock_t *ptl; int error; @@ -1458,8 +1481,8 @@ vm_fault_t vmf_insert_pfn_pmd(struct vm_ pfnmap_setup_cachemode_pfn(pfn_t_to_pfn(pfn), &pgprot); ptl = pmd_lock(vma->vm_mm, vmf->pmd); - error = insert_pfn_pmd(vma, addr, vmf->pmd, pfn, pgprot, write, - pgtable); + error = insert_pmd(vma, addr, vmf->pmd, fop, pgprot, write, + pgtable); spin_unlock(ptl); if (error && pgtable) pte_free(vma->vm_mm, pgtable); @@ -1474,6 +1497,10 @@ vm_fault_t vmf_insert_folio_pmd(struct v struct vm_area_struct *vma = vmf->vma; unsigned long addr = vmf->address & PMD_MASK; struct mm_struct *mm = vma->vm_mm; + struct folio_or_pfn fop = { + .folio = folio, + .is_folio = true, + }; spinlock_t *ptl; pgtable_t pgtable = NULL; int error; @@ -1491,14 +1518,8 @@ vm_fault_t vmf_insert_folio_pmd(struct v } ptl = pmd_lock(mm, vmf->pmd); - if (pmd_none(*vmf->pmd)) { - folio_get(folio); - folio_add_file_rmap_pmd(folio, &folio->page, vma); - add_mm_counter(mm, mm_counter_file(folio), HPAGE_PMD_NR); - } - error = insert_pfn_pmd(vma, addr, vmf->pmd, - pfn_to_pfn_t(folio_pfn(folio)), vma->vm_page_prot, - write, pgtable); + error = insert_pmd(vma, addr, vmf->pmd, fop, vma->vm_page_prot, + write, pgtable); spin_unlock(ptl); if (error && pgtable) pte_free(mm, pgtable); _ Patches currently in -mm which might be from david@redhat.com are mm-balloon_compaction-we-cannot-have-isolated-pages-in-the-balloon-list.patch mm-balloon_compaction-convert-balloon_page_delete-to-balloon_page_finalize.patch mm-zsmalloc-drop-pageisolated-related-vm_bug_ons.patch mm-page_alloc-let-page-freeing-clear-any-set-page-type.patch mm-balloon_compaction-make-pageoffline-sticky-until-the-page-is-freed.patch mm-zsmalloc-make-pagezsmalloc-sticky-until-the-page-is-freed.patch mm-migrate-rename-isolate_movable_page-to-isolate_movable_ops_page.patch mm-migrate-rename-putback_movable_folio-to-putback_movable_ops_page.patch mm-migrate-factor-out-movable_ops-page-handling-into-migrate_movable_ops_page.patch mm-migrate-remove-folio_test_movable-and-folio_movable_ops.patch mm-migrate-move-movable_ops-page-handling-out-of-move_to_new_folio.patch mm-zsmalloc-stop-using-__clearpagemovable.patch mm-balloon_compaction-stop-using-__clearpagemovable.patch mm-migrate-remove-__clearpagemovable.patch mm-migration-remove-pagemovable.patch mm-rename-__pagemovable-to-page_has_movable_ops.patch mm-page_isolation-drop-__folio_test_movable-check-for-large-folios.patch mm-remove-__folio_test_movable.patch mm-stop-storing-migration_ops-in-page-mapping.patch mm-convert-movable-flag-in-page-mapping-to-a-page-flag.patch mm-rename-pg_isolated-to-pg_movable_ops_isolated.patch mm-page-flags-rename-page_mapping_movable-to-page_mapping_anon_ksm.patch mm-page-alloc-remove-pagemappingflags.patch mm-page-flags-remove-folio_mapping_flags.patch mm-simplify-folio_expected_ref_count.patch mm-rename-page_mapping_-to-folio_mapping_.patch docs-mm-convert-from-non-lru-page-migration-to-movable_ops-page-migration.patch mm-balloon_compaction-movable_ops-doc-updates.patch mm-balloon_compaction-provide-single-balloon_page_insert-and-balloon_mapping_gfp_mask.patch mm-convert-fpb_ignore_-into-fpb_respect_.patch mm-smaller-folio_pte_batch-improvements.patch mm-split-folio_pte_batch-into-folio_pte_batch-and-folio_pte_batch_flags.patch mm-remove-boolean-output-parameters-from-folio_pte_batch_ext.patch mm-memory-introduce-is_huge_zero_pfn-and-use-it-in-vm_normal_page_pmd.patch