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 6E5123F12E5 for ; Thu, 24 Sep 2026 20:06:42 +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=1790280403; cv=none; b=mUwfIG2lWvGq/xVbyJkN0aXGUH9KAhzWGAuJhTLBDqHB3KuS9FXUFNhEUUnKVKXiOPnxKFMsK2gtg57tq/pz9UNWgXkZVdN1bp81S17mBx/KfMMuSTUorpuENpCsJxz+bWE0sGHuVDtEApvpMQUk0KItCGUtqvBw2evec3AHyLw= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1790280403; c=relaxed/simple; bh=n32WG1NR9S2ecQiWZhTkgNcsrvtPBZ/fIrD/Z7ipkcg=; h=Date:To:From:Subject:Message-Id; b=Ywnf8Yc0UvpuhtVtxEZ0fMNodJGf2mX6XBViQnIUXJseF8kv54R6XOaXTmvyWdW9uKJHd13+zhc8+gua3jt+KQVOvfFLdgO5rRo3b4SMfagvzpZEws5inkxTQOxcqhmOAcTZJM3OP0drcMju7E1qsTUKuSui28pCEKkpEpx6tTM= 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=J+w/hVYb; 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="J+w/hVYb" Received: by smtp.kernel.org (Postfix) with ESMTPSA id DB8E91F000FF; Thu, 24 Sep 2026 20:06:41 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux-foundation.org; s=korg; t=1790280402; bh=Du7YPS+ZMGWNHVVurM4wC1zWfaWdNJaTKc1IyGeGWNU=; h=Date:To:From:Subject; b=J+w/hVYbYl0MjAhlB5Lcz/f2DKzgCypu4iIbbkfIMa8GsOKyioZdRhgGtDoj/VaF+ qD2z+n1SsbtMVO7aRpkYLSduwebt120wY/7R8txiSvamlH5Ey5ADzqG3hfutz7FuXc R7rUx4o6m5x2Y2XF7lyyH6Nmbmg5rrMqw7y7tYs4= Date: Thu, 24 Sep 2026 13:06:41 -0700 To: mm-commits@vger.kernel.org,ziy@nvidia.com,vbabka@kernel.org,usama.arif@linux.dev,surenb@google.com,shuah@kernel.org,ryan.roberts@arm.com,rppt@kernel.org,nico.pache@linux.dev,mhocko@suse.com,ljs@kernel.org,liam@infradead.org,lance.yang@linux.dev,kevin.brodsky@arm.com,dev.jain@arm.com,david@kernel.org,baolin.wang@linux.alibaba.com,baohua@kernel.org,yeoreum.yun@arm.com,akpm@linux-foundation.org From: Andrew Morton Subject: + kselftest-mm-replace-usage-of-proc-self-smaps-for-__check_pmd_huge.patch added to mm-new branch Message-Id: <20260924200641.DB8E91F000FF@smtp.kernel.org> Precedence: bulk X-Mailing-List: mm-commits@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: The patch titled Subject: kselftest: mm: replace usage of /proc/self/smaps for __check_pmd_huge() has been added to the -mm mm-new branch. Its filename is kselftest-mm-replace-usage-of-proc-self-smaps-for-__check_pmd_huge.patch This patch will shortly appear at https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches/kselftest-mm-replace-usage-of-proc-self-smaps-for-__check_pmd_huge.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: Yeoreum Yun Subject: kselftest: mm: replace usage of /proc/self/smaps for __check_pmd_huge() Date: Thu, 24 Sep 2026 20:11:17 +0100 Since glibc commit 321e1fc73f (“malloc: Enable 2MB THP by default on AArch64”), glibc may call madvise(MADV_HUGEPAGE) for sufficiently large allocations made by memalign(). The underlying VMA may start at a different address from the aligned address returned by memalign(). Furthermore, a subsequent madvise(MADV_HUGEPAGE) call does not split the VMA because the flag is already set. This causes split_huge_page_test to fail because the check_pmd_huge() helpers incorrectly require the address returned by memalign() to match the VMA start address reported in /proc/self/smaps. Instead of relying on /proc/self/smaps, use /proc/self/pagemap and /proc/kpageflags to detect huge-page mappings checking PAGE_IS_HUGE and PAGE_IS_FILE accroding to type of huge page. Since shmem pages are also file-backed, simply check whether the page is file-backed. Link: https://lore.kernel.org/20260924-fix_split-v8-2-cba7359d882a@arm.com Fixes: 642bc52aed9 ("selftests: vm: bring common functions to a new file") Signed-off-by: Yeoreum Yun Signed-off-by: Andrew Morton Suggested-by: David Hildenbrand (Arm) Cc: Lorenzo Stoakes Cc: Zi Yan Cc: Baolin Wang Cc: Liam R. Howlett Cc: Nico Pache Cc: Ryan Roberts Cc: Dev Jain Cc: Barry Song Cc: Lance Yang Cc: Usama Arif Cc: Vlastimil Babka Cc: Mike Rapoport Cc: Suren Baghdasaryan Cc: Michal Hocko Cc: Shuah Khan Cc: Kevin Brodsky --- tools/testing/selftests/mm/vm_util.c | 78 +++++++++++++++---------- 1 file changed, 49 insertions(+), 29 deletions(-) --- a/tools/testing/selftests/mm/vm_util.c~kselftest-mm-replace-usage-of-proc-self-smaps-for-__check_pmd_huge +++ a/tools/testing/selftests/mm/vm_util.c @@ -351,24 +351,6 @@ err_out: return entry; } -static bool __check_pmd_huge(void *addr, char *pattern, int nr_hpages, - uint64_t hpage_size) -{ - char buffer[MAX_LINE_LENGTH]; - uint64_t thp = -1; - char *entry; - - entry = __get_smap_entry(addr, pattern, buffer, sizeof(buffer)); - if (!entry) - goto err_out; - - if (sscanf(entry, "%9" SCNu64 " kB", &thp) != 1) - ksft_exit_fail_msg("Reading smap error\n"); - -err_out: - return thp == (nr_hpages * (hpage_size >> 10)); -} - static bool check_large_folios(void *addr, size_t len, int nr_hpages, uint64_t hpage_size) { @@ -410,20 +392,51 @@ out: return ret; } -bool check_huge_anon(void *addr, size_t len, int nr_hpages, uint64_t hpage_size) +enum check_huge_type { + CHECK_HUGE_ANON, + CHECK_HUGE_FILE, +}; + +static bool check_huge_type(uint64_t categories, enum check_huge_type type) { - uint64_t pmd_pagesize = read_pmd_pagesize(); + const bool file = categories & PAGE_IS_FILE; - if (!pmd_pagesize) - ksft_exit_fail_msg("reading PMD pagesize failed\n"); + switch (type) { + case CHECK_HUGE_ANON: + return !file; + case CHECK_HUGE_FILE: + return file; + } - if (hpage_size == pmd_pagesize) - return __check_pmd_huge(addr, "AnonHugePages: ", nr_hpages, hpage_size); + return false; +} - return check_large_folios(addr, len, nr_hpages, hpage_size); +static bool __check_pmd_huge(void *addr, size_t len, int nr_hpages, + uint64_t hpage_size, enum check_huge_type type) +{ + int pagemap_fd; + int nr_pmd_mappings = 0; + uint64_t categories; + char *start = addr; + char *end = start + len; + + pagemap_fd = open(PAGEMAP_PATH, O_RDONLY); + if (pagemap_fd < 0) + ksft_exit_fail_msg("open pagemap fail\n"); + + for (; start < end; start += hpage_size) { + categories = pagemap_scan_get_categories(pagemap_fd, start); + if (!(categories & PAGE_IS_HUGE)) + continue; + if (check_huge_type(categories, type)) + nr_pmd_mappings++; + } + close(pagemap_fd); + + return nr_hpages == nr_pmd_mappings; } -bool check_huge_file(void *addr, size_t len, int nr_hpages, uint64_t hpage_size) +bool check_huge_anon(void *addr, size_t len, int nr_hpages, uint64_t hpage_size) { uint64_t pmd_pagesize = read_pmd_pagesize(); @@ -431,12 +444,13 @@ bool check_huge_file(void *addr, size_t ksft_exit_fail_msg("reading PMD pagesize failed\n"); if (hpage_size == pmd_pagesize) - return __check_pmd_huge(addr, "FilePmdMapped:", nr_hpages, hpage_size); + return __check_pmd_huge(addr, len, nr_hpages, hpage_size, + CHECK_HUGE_ANON); return check_large_folios(addr, len, nr_hpages, hpage_size); } -bool check_huge_shmem(void *addr, size_t len, int nr_hpages, uint64_t hpage_size) +bool check_huge_file(void *addr, size_t len, int nr_hpages, uint64_t hpage_size) { uint64_t pmd_pagesize = read_pmd_pagesize(); @@ -444,11 +458,17 @@ bool check_huge_shmem(void *addr, size_t ksft_exit_fail_msg("reading PMD pagesize failed\n"); if (hpage_size == pmd_pagesize) - return __check_pmd_huge(addr, "ShmemPmdMapped:", nr_hpages, hpage_size); + return __check_pmd_huge(addr, len, nr_hpages, hpage_size, + CHECK_HUGE_FILE); return check_large_folios(addr, len, nr_hpages, hpage_size); } +bool check_huge_shmem(void *addr, size_t len, int nr_hpages, uint64_t hpage_size) +{ + return check_huge_file(addr, len, nr_hpages, hpage_size); +} + int64_t allocate_transhuge(void *ptr, int pagemap_fd) { uint64_t ent[2]; _ Patches currently in -mm which might be from yeoreum.yun@arm.com are kselftest-mm-fix-potential-failure-for-merged-vma-in-guard-regions.patch kselftest-mm-remove-exclusion-of-building-soft-dirty-test-in-arm64.patch kselftest-mm-return-fail-when-child-test-result-is-fail-in-khugepaged.patch kselftest-mm-fix-intermittent-failure-khugepaged-test.patch kselftest-mm-prevent-random-failure-of-huge-page-split-for-khugepaged.patch kselftest-mm-replace-usage-of-proc-self-smaps-for-__check_pmd_huge.patch kselftest-mm-integrate-huge-page-checks.patch kselftest-mm-remove-check_huge_shmem.patch