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 379D62E92B8 for ; Wed, 3 Sep 2025 22:23:44 +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=1756938224; cv=none; b=Opxh6tFAWYNuuyl95QwiGt6EcmtzLd8CABLO96VR7hI/1DTiQ27eH1L6t73qLbLV5YcxxoPLwn2empxGeO95m6OvbvN8F2LkIwVfVPeuWssk10uJ3p7rVXw0Jk+UZzbwQ6y8g9KbOvYp6cfq9O6HAS8Qzw/7YnesZubbgXNH0Y0= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1756938224; c=relaxed/simple; bh=mZIKv558XOjbafWKfRMAgy+qA4u2EK0eWpLDeZWITQ4=; h=Date:To:From:Subject:Message-Id; b=sFsu23FD3R5RrZV8aGMEkvi1Z+O+LMn+1Zo5zxzvNUO2eLttxHX0dsMxIXwgBfyGf6d/ayF2qU/wOI/GfI7Z0HEc6lvbfYOlN5xqkqNYPvAD3SQcD6gt1CZ/o7b/o7FBFIsR2rXRwP9pMsxm81clp3HMdedPtHLIwZrq7Nwpxv4= 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=LE5j9FXf; 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="LE5j9FXf" Received: by smtp.kernel.org (Postfix) with ESMTPSA id D73F2C4CEE7; Wed, 3 Sep 2025 22:23:43 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linux-foundation.org; s=korg; t=1756938223; bh=mZIKv558XOjbafWKfRMAgy+qA4u2EK0eWpLDeZWITQ4=; h=Date:To:From:Subject:From; b=LE5j9FXfbO2XveVqvcermkQAnwumQ6JesAYh+OHql6aTL2mFuvR87/42LiWeDI09/ y8TwSPLTkshQdTnh1I7hb3OD042i5IoTw10BHXaN5EXnnXAa75Qy5kXrugJVzylC0i XkAkmKmr72aQhcbWsBuyHfGvZF7GQUasZzxAR7Z8= Date: Wed, 03 Sep 2025 15:23:43 -0700 To: mm-commits@vger.kernel.org,ziy@nvidia.com,ryan.roberts@arm.com,richard.weiyang@gmail.com,npache@redhat.com,lorenzo.stoakes@oracle.com,liam.howlett@oracle.com,dev.jain@arm.com,baolin.wang@linux.alibaba.com,baohua@kernel.org,david@redhat.com,akpm@linux-foundation.org From: Andrew Morton Subject: + selftests-mm-split_huge_page_test-fix-occasional-is_backed_by_folio-wrong-results.patch added to mm-new branch Message-Id: <20250903222343.D73F2C4CEE7@smtp.kernel.org> Precedence: bulk X-Mailing-List: mm-commits@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: The patch titled Subject: selftests/mm: split_huge_page_test: fix occasional is_backed_by_folio() wrong results has been added to the -mm mm-new branch. Its filename is selftests-mm-split_huge_page_test-fix-occasional-is_backed_by_folio-wrong-results.patch This patch will shortly appear at https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches/selftests-mm-split_huge_page_test-fix-occasional-is_backed_by_folio-wrong-results.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. 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 the mm-everything branch at git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm and is updated there every 2-3 working days ------------------------------------------------------ From: David Hildenbrand Subject: selftests/mm: split_huge_page_test: fix occasional is_backed_by_folio() wrong results Date: Wed, 3 Sep 2025 09:02:52 +0200 Patch series "selftests/mm: split_huge_page_test: split_pte_mapped_thp improvements", v2. One fix for occasional failures I found while testing and a bunch of cleanups that should make that test easier to digest. This patch (of 2): When checking for actual tail or head pages of a folio, we must make sure that the KPF_COMPOUND_HEAD/KPF_COMPOUND_TAIL flag is paired with KPF_THP. For example, if we have another large folio after our large folio in physical memory, our "pfn_flags & (KPF_THP | KPF_COMPOUND_TAIL)" would trigger even though it's actually a head page of the next folio. If is_backed_by_folio() returns a wrong result, split_pte_mapped_thp() can fail with "Some THPs are missing during mremap". Fix it by checking for head/tail pages of folios properly. Add folio_tail_flags/folio_head_flags to improve readability and use these masks also when just testing for any compound page. Link: https://lkml.kernel.org/r/20250903070253.34556-1-david@redhat.com Link: https://lkml.kernel.org/r/20250903070253.34556-2-david@redhat.com Fixes: 169b456b0162 ("selftests/mm: reimplement is_backed_by_thp() with more precise check") Signed-off-by: David Hildenbrand Reviewed-by: Zi Yan Reviewed-by: Wei Yang Cc: Baolin Wang Cc: Barry Song Cc: Dev Jain Cc: Liam Howlett Cc: Lorenzo Stoakes Cc: Mariano Pache Cc: Ryan Roberts Signed-off-by: Andrew Morton --- tools/testing/selftests/mm/split_huge_page_test.c | 15 +++++------- 1 file changed, 7 insertions(+), 8 deletions(-) --- a/tools/testing/selftests/mm/split_huge_page_test.c~selftests-mm-split_huge_page_test-fix-occasional-is_backed_by_folio-wrong-results +++ a/tools/testing/selftests/mm/split_huge_page_test.c @@ -44,6 +44,8 @@ int kpageflags_fd; static bool is_backed_by_folio(char *vaddr, int order, int pagemap_fd, int kpageflags_fd) { + const uint64_t folio_head_flags = KPF_THP | KPF_COMPOUND_HEAD; + const uint64_t folio_tail_flags = KPF_THP | KPF_COMPOUND_TAIL; const unsigned long nr_pages = 1UL << order; unsigned long pfn_head; uint64_t pfn_flags; @@ -61,7 +63,7 @@ static bool is_backed_by_folio(char *vad /* check for order-0 pages */ if (!order) { - if (pfn_flags & (KPF_THP | KPF_COMPOUND_HEAD | KPF_COMPOUND_TAIL)) + if (pfn_flags & (folio_head_flags | folio_tail_flags)) return false; return true; } @@ -76,14 +78,14 @@ static bool is_backed_by_folio(char *vad goto fail; /* head PFN has no compound_head flag set */ - if (!(pfn_flags & (KPF_THP | KPF_COMPOUND_HEAD))) + if ((pfn_flags & folio_head_flags) != folio_head_flags) return false; /* check all tail PFN flags */ for (i = 1; i < nr_pages; i++) { if (pageflags_get(pfn_head + i, kpageflags_fd, &pfn_flags)) goto fail; - if (!(pfn_flags & (KPF_THP | KPF_COMPOUND_TAIL))) + if ((pfn_flags & folio_tail_flags) != folio_tail_flags) return false; } @@ -94,11 +96,8 @@ static bool is_backed_by_folio(char *vad if (pageflags_get(pfn_head + nr_pages, kpageflags_fd, &pfn_flags)) return true; - /* this folio is bigger than the given order */ - if (pfn_flags & (KPF_THP | KPF_COMPOUND_TAIL)) - return false; - - return true; + /* If we find another tail page, then the folio is larger. */ + return (pfn_flags & folio_tail_flags) != folio_tail_flags; fail: ksft_exit_fail_msg("Failed to get folio info\n"); return false; _ Patches currently in -mm which might be from david@redhat.com are mm-migrate-remove-migratepage_unmap.patch mm-migrate-remove-migratepage_unmap-fix.patch treewide-remove-migratepage_success.patch mm-huge_memory-move-more-common-code-into-insert_pmd.patch mm-huge_memory-move-more-common-code-into-insert_pud.patch mm-huge_memory-support-huge-zero-folio-in-vmf_insert_folio_pmd.patch fs-dax-use-vmf_insert_folio_pmd-to-insert-the-huge-zero-folio.patch mm-huge_memory-mark-pmd-mappings-of-the-huge-zero-folio-special.patch powerpc-ptdump-rename-struct-pgtable_level-to-struct-ptdump_pglevel.patch mm-rmap-convert-enum-rmap_level-to-enum-pgtable_level.patch mm-memory-convert-print_bad_pte-to-print_bad_page_map.patch mm-memory-convert-print_bad_pte-to-print_bad_page_map-fix.patch mm-memory-factor-out-common-code-from-vm_normal_page_.patch mm-introduce-and-use-vm_normal_page_pud.patch mm-rename-vm_ops-find_special_page-to-vm_ops-find_normal_page.patch prctl-extend-pr_set_thp_disable-to-optionally-exclude-vm_hugepage.patch mm-huge_memory-convert-tva_flags-to-enum-tva_type.patch mm-huge_memory-respect-madv_collapse-with-pr_thp_disable_except_advised.patch mm-stop-making-sparsemem_vmemmap-user-selectable.patch arm64-kconfig-drop-superfluous-select-sparsemem_vmemmap.patch s390-kconfig-drop-superfluous-select-sparsemem_vmemmap.patch x86-kconfig-drop-superfluous-select-sparsemem_vmemmap.patch wireguard-selftests-remove-config_sparsemem_vmemmap=y-from-qemu-kernel-config.patch mm-page_alloc-reject-unreasonable-folio-compound-page-sizes-in-alloc_contig_range_noprof.patch mm-memremap-reject-unreasonable-folio-compound-page-sizes-in-memremap_pages.patch mm-hugetlb-check-for-unreasonable-folio-sizes-when-registering-hstate.patch mm-mm_init-make-memmap_init_compound-look-more-like-prep_compound_page.patch mm-sanity-check-maximum-folio-size-in-folio_set_order.patch mm-limit-folio-compound-page-sizes-in-problematic-kernel-configs.patch mm-simplify-folio_page-and-folio_page_idx.patch mm-hugetlb-cleanup-hugetlb_folio_init_tail_vmemmap.patch mm-mm-percpu-km-drop-nth_page-usage-within-single-allocation.patch fs-hugetlbfs-remove-nth_page-usage-within-folio-in-adjust_range_hwpoison.patch fs-hugetlbfs-cleanup-folio-in-adjust_range_hwpoison.patch mm-pagewalk-drop-nth_page-usage-within-folio-in-folio_walk_start.patch mm-gup-drop-nth_page-usage-within-folio-when-recording-subpages.patch mm-gup-remove-record_subpages.patch io_uring-zcrx-remove-nth_page-usage-within-folio.patch mips-mm-convert-__flush_dcache_pages-to-__flush_dcache_folio_pages.patch mm-cma-refuse-handing-out-non-contiguous-page-ranges.patch dma-remap-drop-nth_page-in-dma_common_contiguous_remap.patch scatterlist-disallow-non-contigous-page-ranges-in-a-single-sg-entry.patch ata-libata-sff-drop-nth_page-usage-within-sg-entry.patch drm-i915-gem-drop-nth_page-usage-within-sg-entry.patch mspro_block-drop-nth_page-usage-within-sg-entry.patch memstick-drop-nth_page-usage-within-sg-entry.patch mmc-drop-nth_page-usage-within-sg-entry.patch scsi-scsi_lib-drop-nth_page-usage-within-sg-entry.patch scsi-sg-drop-nth_page-usage-within-sg-entry.patch vfio-pci-drop-nth_page-usage-within-sg-entry.patch crypto-remove-nth_page-usage-within-sg-entry.patch mm-gup-drop-nth_page-usage-in-unpin_user_page_range_dirty_lock.patch kfence-drop-nth_page-usage.patch block-update-comment-of-struct-bio_vec-regarding-nth_page.patch mm-remove-nth_page.patch selftests-mm-split_huge_page_test-fix-occasional-is_backed_by_folio-wrong-results.patch selftests-mm-split_huge_page_test-cleanups-for-split_pte_mapped_thp-test.patch