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 1C0CB2D3ED1 for ; Tue, 8 Sep 2026 19:50:09 +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=1788897010; cv=none; b=BBZ1FYjIqtGLLF4yDLr8ck0qJrz1sgC8JKYSzOKsFAZXxfgdCEYz398uy4Y/3fj1+1lvzgphYrBMKFrM8RK+IS0sL0Q4IwLX7EyJTK6mQMi60fN5tbaNSRUcdbSPgK8m40U5/lFFnynAOtVJ45gd5kPxuPprYPY1k31qn3ER/is= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1788897010; c=relaxed/simple; bh=LMdWOEfJaUs1WA29wcoKpOHWdEtmDkpffLfMxpC6hkY=; h=Date:To:From:Subject:Message-Id; b=nAo3NWUzPEMVTKGUGiY3L3CNQggyBhJnqr0fzGA1Kw/Ha43ZTB+MFoQ/FSgtbyRHDAuvealsLC9I9egg/f44B3yTKMShoJ1cFtmgueF9GvZy19jKPp5mRY6Lk/UX8v7jI8kgyuZWPQSoyDjiYBkWzq8hDMWi1Xgc8Z2Aj3yZ6Jk= 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=XgCITUma; 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="XgCITUma" Received: by smtp.kernel.org (Postfix) with ESMTPSA id E51B61F00A3A; Tue, 8 Sep 2026 19:50:08 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux-foundation.org; s=korg; t=1788897009; bh=EGC9XBGDSqOVyvaMqJHPPAPKeGV+ffCe80w+/aS5Rd4=; h=Date:To:From:Subject; b=XgCITUma4K28smI5heIGqAVPuxn0nvfmGQNM/Cd4Lph7WnU2zxufut4cSp4b2IzrR fotmbiVa+55wIhbOxNHv3CQzAl1y/nZihR5BDlkSk65RNs5EDelQRfQ7wSD27UzLtl hiZV+ac5LUicFWysEcMVFx9qGFpqA/2AfWEpDk9k= Date: Tue, 08 Sep 2026 12:50:08 -0700 To: mm-commits@vger.kernel.org,kas@kernel.org,akpm@linux-foundation.org From: Andrew Morton Subject: + selftests-mm-skip-khugepaged-page-cache-cases-without-a-pmd-folio.patch added to mm-new branch Message-Id: <20260908195008.E51B61F00A3A@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: skip khugepaged page cache cases without a PMD folio has been added to the -mm mm-new branch. Its filename is selftests-mm-skip-khugepaged-page-cache-cases-without-a-pmd-folio.patch This patch will shortly appear at https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches/selftests-mm-skip-khugepaged-page-cache-cases-without-a-pmd-folio.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: "Kiryl Shutsemau (Meta)" Subject: selftests/mm: skip khugepaged page cache cases without a PMD folio Date: Tue, 8 Sep 2026 13:50:50 +0100 The page cache caps folio order at MAX_PAGECACHE_ORDER, which is below the PMD order on arm64 with 64K pages, where a PMD is 512M. A PMD-sized page cache folio is impossible there, so the kernel refuses these collapses: MADV_COLLAPSE answers -EINVAL and khugepaged passes over the range. Four shmem cases ask for a PMD-sized folio anyway, fail, and the run bails out in the middle. Skip the shmem and file mem types where the cap is below the PMD order. The cap is not shmem-specific: it applies to every file folio. Add thp_file_supported_orders() to read the orders the page cache allows. Anonymous collapse is unaffected: its orders are not capped this way. Assisted-by: LLM Link: https://lore.kernel.org/20260908125105.1510704-5-kirill@shutemov.name Signed-off-by: Kiryl Shutsemau (Meta) Reviewed-by: Mike Rapoport (Microsoft) Tested-by: Muhammad Usama Anjum Cc: Alexander Gordeev Cc: Baolin Wang Cc: Barry Song Cc: David Hildenbrand Cc: Dev Jain Cc: Hugh Dickins Cc: Jason Gunthorpe Cc: Lance Yang Cc: Leon Romanovsky Cc: Liam R. Howlett Cc: Lorenzo Stoakes (ARM) Cc: Michal Hocko Cc: Ryan Roberts Cc: Shuah Khan Cc: Suren Baghdasaryan Cc: Usama Arif Cc: Vlastimil Babka Cc: Zi Yan Signed-off-by: Andrew Morton --- tools/lib/mm/hugepage_settings.h | 9 +++++++++ tools/testing/selftests/mm/khugepaged.c | 19 +++++++++++++++++++ 2 files changed, 28 insertions(+) --- a/tools/lib/mm/hugepage_settings.h~selftests-mm-skip-khugepaged-page-cache-cases-without-a-pmd-folio +++ a/tools/lib/mm/hugepage_settings.h @@ -87,6 +87,15 @@ void thp_set_read_ahead_path(char *path) unsigned long thp_supported_orders(void); unsigned long thp_shmem_supported_orders(void); +/* + * The per-order shmem_enabled attribute is created for the orders the page + * cache can hold, not just for shmem, so it answers for regular files too. + */ +static inline unsigned long thp_file_supported_orders(void) +{ + return thp_shmem_supported_orders(); +} + bool thp_available(void); bool thp_is_enabled(void); --- a/tools/testing/selftests/mm/khugepaged.c~selftests-mm-skip-khugepaged-page-cache-cases-without-a-pmd-folio +++ a/tools/testing/selftests/mm/khugepaged.c @@ -1358,6 +1358,25 @@ int main(int argc, char **argv) setbuf(stdout, NULL); + /* + * Without a PMD-order page cache folio the kernel refuses these + * collapses, so there is nothing to test. + */ + if (!(thp_file_supported_orders() & (1UL << hpage_pmd_order))) { + if (shmem_ops) { + ksft_print_msg("no PMD-order page cache folio: skipping shmem\n"); + shmem_ops = NULL; + } + if (read_only_file_ops) { + ksft_print_msg("no PMD-order page cache folio: skipping file\n"); + read_only_file_ops = NULL; + read_write_file_read_ops = NULL; + read_write_file_write_ops = NULL; + } + if (!anon_ops && !shmem_ops && !read_only_file_ops) + ksft_exit_skip("No mem_type left to run\n"); + } + default_settings.khugepaged.max_ptes_none = hpage_pmd_nr - 1; default_settings.khugepaged.max_ptes_swap = hpage_pmd_nr / 8; default_settings.khugepaged.max_ptes_shared = hpage_pmd_nr / 2; _ Patches currently in -mm which might be from kas@kernel.org are mm-huge_memory-do-not-touch-frozen-folios-in-deferred_split_isolate.patch mm-huge_memory-dequeue-the-deferred-split-after-the-split-freeze.patch selftests-mm-raise-the-khugepaged-test-case-cap.patch selftests-mm-skip-collapse_compound_extreme-where-the-pmd-is-too-large.patch selftests-mm-scale-khugepageds-collapse-wait-with-the-pmd-size.patch selftests-mm-skip-khugepaged-page-cache-cases-without-a-pmd-folio.patch selftests-mm-make-the-swap-cases-swapout-reliable.patch selftests-mm-stop-khugepaged-during-the-madv_collapse-cases.patch selftests-mm-move-is_backed_by_folio-into-vm_util.patch selftests-mm-add-folio-order-check-for-address-ranges.patch selftests-mm-add-folio-order-detection-self-check.patch selftests-mm-add-khugepaged-completion-barrier-helper.patch selftests-mm-add-order-parameterized-khugepaged-collapse-cases.patch selftests-mm-parameterize-the-mixed-source-collapse-case-by-source-order.patch selftests-mm-cover-a-shared-source-collapse-write-race.patch selftests-mm-run-every-supported-collapse-order-by-default.patch selftests-mm-check-that-one-khugepaged-pass-collapses-one-window.patch selftests-mm-add-khugepaged-race-harness.patch selftests-mm-race-the-collapse-of-windows-with-holes.patch selftests-mm-add-memory-pressure-threads-to-the-khugepaged-race-harness.patch selftests-mm-zap-whole-pte-tables-in-the-khugepaged-race-harness.patch