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 331D941BA98 for ; Wed, 15 Jul 2026 18:25:38 +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=1784139946; cv=none; b=CnkWdGhQFBfY2mzeFo0JS+rCzxy3bn6dKtn2Id4cdL9eq8OuOSKeN5L59lxAjHB7RWDwcwGwIxG+3tJO1U+ULeapSdEyCRvr77LRpngkTn8Bq3suIG+sbDsdTDRBaTwIC+J8rTk7ztQMl9dTTJev4/CGLnWEGYyc0pglT+mVozo= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1784139946; c=relaxed/simple; bh=9XNEnfXIPOBZVFgRIiCBbOnBAzp8hslY8epYmhlrB5k=; h=Date:To:From:Subject:Message-Id; b=tN8fFEmkH6m4rWPJRy0bMK2qQohvsYtH8WYtpY0a3gZm0ZSFQ+WqPWoALX8cDtIbob2ximVTkulK4xNmrJTeqInYtchBvJAEdlfr0M4hl5GokJXxTURv5Seu67xUfTkfsKj8s6ghNrNa7+OVyQNXHir0hR8fyWh3xFvYpKbGsTk= 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=DL5o8EYg; 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="DL5o8EYg" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 9972E1F000E9; Wed, 15 Jul 2026 18:25:33 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux-foundation.org; s=korg; t=1784139933; bh=bOzUWmkOT4hP3m+wTdCll78PG7fK03RaxK1KlbvbouU=; h=Date:To:From:Subject; b=DL5o8EYgaPXx0F+mcbxf6YCm/kCe5mgxbcACpHo3/OESDlJkQagsZmAiVQUmUqJYC VgHzEmk50baLNWkLujz5ZoXU4VSBwEqwxi8HlU0Ps6fl4tryCCKuqaNGQL71nZIQLf 6lPlsa36HbQeBnb6ZAhAZhnNesjdQi5DEDZ1Rm9Q= Date: Wed, 15 Jul 2026 11:25:33 -0700 To: mm-commits@vger.kernel.org,zenghui.yu@linux.dev,vbabka@kernel.org,usama.anjum@arm.com,surenb@google.com,shuah@kernel.org,rppt@kernel.org,pfalcato@suse.de,peterx@redhat.com,mhocko@suse.com,ljs@kernel.org,liam@infradead.org,jannh@google.com,david@kernel.org,kas@kernel.org,akpm@linux-foundation.org From: Andrew Morton Subject: + selftests-mm-add-pagemap_scan-test-for-thp-pmd-holes.patch added to mm-new branch Message-Id: <20260715182533.9972E1F000E9@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: add PAGEMAP_SCAN test for THP PMD holes has been added to the -mm mm-new branch. Its filename is selftests-mm-add-pagemap_scan-test-for-thp-pmd-holes.patch This patch will shortly appear at https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches/selftests-mm-add-pagemap_scan-test-for-thp-pmd-holes.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: add PAGEMAP_SCAN test for THP PMD holes Date: Wed, 15 Jul 2026 15:42:34 +0100 Add coverage for the PMD-hole case fixed by "fs/proc/task_mmu: fix PAGEMAP_SCAN written state for PMD holes": a MAP_PRIVATE|MAP_ANON THP that is uffd-wp'd and then dropped with MADV_DONTNEED leaves a pmd_none hole with no page table, which PAGEMAP_SCAN must still report as written -- checked via both the fast and generic query paths, mirroring unpopulated_scan_test(). Include for MADV_COLLAPSE; lacks it on older glibc (e.g. 2.34). Same approach as commit fd5295afae91 ("selftests/mm: hmm-tests: include linux/mman.h to access MADV_COLLAPSE"). Link: https://lore.kernel.org/20260715144234.442721-3-kirill@shutemov.name Signed-off-by: Kiryl Shutsemau Cc: Muhammad Usama Anjum Cc: Peter Xu Cc: Zenghui Yu Cc: David Hildenbrand Cc: Jann Horn Cc: Liam R. Howlett Cc: Lorenzo Stoakes Cc: Michal Hocko Cc: Mike Rapoport Cc: Pedro Falcato Cc: Shuah Khan Cc: Suren Baghdasaryan Cc: Vlastimil Babka Assisted-by: Claude:claude-fable-5 Signed-off-by: Andrew Morton --- tools/testing/selftests/mm/pagemap_ioctl.c | 66 ++++++++++++++++++- 1 file changed, 65 insertions(+), 1 deletion(-) --- a/tools/testing/selftests/mm/pagemap_ioctl.c~selftests-mm-add-pagemap_scan-test-for-thp-pmd-holes +++ a/tools/testing/selftests/mm/pagemap_ioctl.c @@ -8,6 +8,7 @@ #include #include #include +#include #include #include #include @@ -1102,6 +1103,68 @@ static void unpopulated_scan_test(void) munmap(mem, mem_size); } +/* + * Like unpopulated_scan_test(), but the range is a MAP_PRIVATE|MAP_ANON THP + * that is uffd-wp'd and then dropped with MADV_DONTNEED. That leaves a + * pmd_none hole with no page table, which pagemap_page_category() never sees; + * PAGEMAP_SCAN must still report it written via pagemap_scan_pte_hole(). + */ +static void unpopulated_thp_scan_test(void) +{ + struct page_region regions[16]; + long fast = 0, slow = 0, ret; + int npages, i; + char *area, *mem; + + if (!hpage_size) { + ksft_test_result_skip("%s THP not supported\n", __func__); + return; + } + npages = hpage_size / page_size; + + /* Over-allocate so a PMD-aligned, THP-sized range fits inside. */ + area = mmap(NULL, 2 * hpage_size, PROT_READ | PROT_WRITE, + MAP_PRIVATE | MAP_ANONYMOUS, -1, 0); + if (area == MAP_FAILED) { + ksft_test_result_skip("%s mmap failed\n", __func__); + return; + } + mem = (char *)(((unsigned long)area + hpage_size - 1) & ~(hpage_size - 1)); + + wp_init(mem, hpage_size); + + /* Populate, collapse to a THP, then drop: a pmd_none hole, no marker. */ + memset(mem, 1, hpage_size); + if (madvise(mem, hpage_size, MADV_COLLAPSE) || + !check_huge_anon(mem, 1, hpage_size)) { + ksft_test_result_skip("%s could not form a THP\n", __func__); + goto out; + } + if (madvise(mem, hpage_size, MADV_DONTNEED)) { + ksft_test_result_skip("%s MADV_DONTNEED failed\n", __func__); + goto out; + } + + /* Fast path: category_mask == return_mask == PAGE_IS_WRITTEN. */ + ret = pagemap_ioctl(mem, hpage_size, regions, ARRAY_SIZE(regions), 0, 0, + PAGE_IS_WRITTEN, 0, 0, PAGE_IS_WRITTEN); + for (i = 0; ret > 0 && i < ret; i++) + fast += LEN(regions[i]); + + /* Generic path: same query expressed via category_anyof_mask. */ + ret = pagemap_ioctl(mem, hpage_size, regions, ARRAY_SIZE(regions), 0, 0, + 0, PAGE_IS_WRITTEN, 0, PAGE_IS_WRITTEN); + for (i = 0; ret > 0 && i < ret; i++) + slow += LEN(regions[i]); + + ksft_test_result(fast == npages && slow == npages, + "%s pmd-hole reported written by both paths (%ld, %ld of %d)\n", + __func__, fast, slow, npages); +out: + wp_free(mem, hpage_size); + munmap(area, 2 * hpage_size); +} + int sanity_tests(void) { unsigned long long mem_size, vec_size; @@ -1610,7 +1673,7 @@ int main(int __attribute__((unused)) arg if (!hugetlb_setup_default(4)) ksft_print_msg("HugeTLB test will be skipped\n"); - ksft_set_plan(118); + ksft_set_plan(119); page_size = getpagesize(); hpage_size = read_pmd_pagesize(); @@ -1790,6 +1853,7 @@ int main(int __attribute__((unused)) arg /* 18. Unpopulated pte scan-path consistency */ unpopulated_scan_test(); + unpopulated_thp_scan_test(); close(pagemap_fd); ksft_finished(); _ Patches currently in -mm which might be from kas@kernel.org are fs-proc-task_mmu-fix-pagemap_scan-written-state-for-unpopulated-ptes.patch mm-hugetlb-fix-swap-entry-corruption-when-clearing-uffd-wp-at-fork.patch fs-proc-task_mmu-fix-pagemap_scan-written-state-for-pmd-holes.patch mm-decouple-protnone-helpers-from-config_numa_balancing.patch mm-rename-uffd-wp-pte-bit-macros-to-uffd.patch mm-rename-uffd-wp-pte-accessors-to-uffd.patch userfaultfd-test-uffd-vma-flags-through-the-vma_flags_t-api.patch mm-add-vm_uffd_rwp-vma-flag.patch mm-add-mm_cp_uffd_rwp-change_protection-flag.patch mm-preserve-rwp-marker-across-pte-rewrites.patch mm-handle-vm_uffd_rwp-in-khugepaged-rmap-and-gup.patch userfaultfd-add-uffdio_register_mode_rwp-and-uffdio_rwprotect-plumbing.patch mm-userfaultfd-add-rwp-fault-delivery-and-expose-uffdio_register_mode_rwp.patch mm-pagemap-add-page_is_accessed-for-rwp-tracking.patch userfaultfd-add-uffd_feature_rwp_async-for-async-fault-resolution.patch userfaultfd-add-uffdio_set_mode-for-runtime-sync-async-toggle.patch selftests-mm-add-userfaultfd-rwp-tests.patch documentation-userfaultfd-document-rwp-working-set-tracking.patch selftests-mm-add-pagemap_scan-test-for-thp-pmd-holes.patch