From nobody Fri Sep 25 21:02:39 2026 Received: from foss.arm.com (foss.arm.com [217.140.110.172]) by smtp.subspace.kernel.org (Postfix) with ESMTP id 393F847B439; Mon, 21 Sep 2026 10:40:17 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=217.140.110.172 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1789987220; cv=none; b=rFIcLqmchbrjMqVD2xnpi2Mfwi/eal/ImutrNXU1/SZK7h5CZuc6246K0IzITEqDt7K5cI8D3sYQicagV/z4t+08OQthnl/kmgAghkZE1sZtCr8YsMwUQzDDRpCVhmdEZSf5cKysMMmRAO4Pa5TcHjGexeqF/L/7DIPks1KPNnE= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1789987220; c=relaxed/simple; bh=nAZ5Nu8/Na8ryFI4SAROqdpt5betZtOhodIgZ1vFN/Q=; h=From:Date:Subject:MIME-Version:Content-Type:Message-Id:References: In-Reply-To:To:Cc; b=dT/j2+ZSpQT2Flmhzy3JaL5XnxNFgHF57E0s3C8LP6oLaBztCrvCwDqbO/krHXsC0D4nY2bH7av9OLdFERNA0cKKLN0oQHjoHqWospgh1rx22UeT/7vImQ6nGKYOFiu66MLJFHV+Z3JbX3taS6wh2gXvsAaUEzpPKjR1Y3FtocU= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=arm.com; spf=pass smtp.mailfrom=arm.com; dkim=pass (1024-bit key) header.d=arm.com header.i=@arm.com header.b=QSuAO5qf; arc=none smtp.client-ip=217.140.110.172 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=arm.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=arm.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=arm.com header.i=@arm.com header.b="QSuAO5qf" Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.121.207.14]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id D9C531CE0; Mon, 21 Sep 2026 03:40:13 -0700 (PDT) Received: from e129823.arm.com (e129823.arm.com [10.2.213.3]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 603FB3F86C; Mon, 21 Sep 2026 03:40:14 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=simple/simple; d=arm.com; s=foss; t=1789987217; bh=nAZ5Nu8/Na8ryFI4SAROqdpt5betZtOhodIgZ1vFN/Q=; h=From:Date:Subject:References:In-Reply-To:To:Cc:From; b=QSuAO5qfdzbTBibtYalj0EBb9NUMvqfJDkEzxiDY4t6TCHh5A8OVXvvXEkZOXyuPN 9w/gciK3NISvJLcCd7tpD1zOypNB0ER7HlT6QXFWHKFTpl00TijpVcWh1gcEh3hUVI wbh7e19sl5OpXZCLVbJSbN2aATyAwAjJIHCEglEQ= From: Yeoreum Yun Date: Mon, 21 Sep 2026 11:40:07 +0100 Subject: [PATCH v7 1/3] kselftest: mm: prevent random failure of huge page split for khugepaged Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: quoted-printable Message-Id: <20260921-fix_split-v7-1-d25ec991159f@arm.com> References: <20260921-fix_split-v7-0-d25ec991159f@arm.com> In-Reply-To: <20260921-fix_split-v7-0-d25ec991159f@arm.com> To: Andrew Morton , David Hildenbrand , Lorenzo Stoakes , Zi Yan , Baolin Wang , "Liam R. Howlett" , Nico Pache , Ryan Roberts , Dev Jain , Barry Song , Lance Yang , Usama Arif , Vlastimil Babka , Mike Rapoport , Suren Baghdasaryan , Michal Hocko , Shuah Khan , Kevin Brodsky Cc: linux-mm@kvack.org, linux-kselftest@vger.kernel.org, linux-kernel@vger.kernel.org, Yeoreum Yun X-Mailer: b4 0.13.0 X-Developer-Signature: v=1; a=openpgp-sha256; l=2772; i=yeoreum.yun@arm.com; h=from:subject:message-id; bh=nAZ5Nu8/Na8ryFI4SAROqdpt5betZtOhodIgZ1vFN/Q=; b=owEB7QES/pANAwAKAW3Vw9FaxTEzAcsmYgBqsQmJS49uY0WTGO7xDTb8XJ1buCo74SJ77Ym0b 1aLUL4K+WiJAbMEAAEKAB0WIQQtg+CS3QUzuFh1pJ1t1cPRWsUxMwUCarEJiQAKCRBt1cPRWsUx M35vDACoT1PIgox1YUsx6mvHqeplFUSysSKEFx5zDxzyaHYhM7XddIhMZuQbuRPtxopLYkvGoXH 95U134cSKw9csvK5zS9PkJwkCcBRVzGElv0U5EkqPRtZtSRBjofPqir5KsLhAbsnaV46XfkRcGx B4xn3KQ6R0cB4Yl5hg9YygocTcfDVrRRw3wTgh2TXTKfSW4DrV9mFBH79WTXHEA0ed7GPd6MdPa hzVCq1NKEk1V6tnk8/2d5eSzTtPNpOw7jDX+CzLSNHZieAm+ofDMKVOIHhna6qEzoR4xo0/40qh wdyL+afQBouI4BC/Nli8X7BSN9xqlpFv5+D2Gk6muNYYGceRMYgeOO+6o4Jgj+NV+xJoNO1o10q /ewTkqDsTHxxeElOg+EcOTOay1fUmd65mYl+ydB3oxDHonMZCyTdO2F0sd6leullFPRteOIPS7k 6xZqRkiQK1IiUFE+DgrXm4s02W0VNYd6bYXoFvscCkU4R2Iy6EtIqd2gO/VFrWtAgy5os= X-Developer-Key: i=yeoreum.yun@arm.com; a=openpgp; fpr=2D83E092DD0533B85875A49D6DD5C3D15AC53133 There're some random failure for split_huge_page_test when khugepaged collapses pages into pmd again which had split by the test. Prevent the khugepaged's collapses for split page by setting the mapped pmd-huge-page with MADV_NOHUGEPAGE before split. Suggested-by: Kevin Brodsky Suggested-by: Lorenzo Stoakes (ARM) Reviewed-by: Lorenzo Stoakes (ARM) Reviewed-by: Zi Yan Acked-by: David Hildenbrand (Arm) Signed-off-by: Yeoreum Yun --- tools/testing/selftests/mm/split_huge_page_test.c | 19 +++++++++++++++++++ 1 file changed, 19 insertions(+) diff --git a/tools/testing/selftests/mm/split_huge_page_test.c b/tools/test= ing/selftests/mm/split_huge_page_test.c index c01d227d7fd6d..cba327f778734 100644 --- a/tools/testing/selftests/mm/split_huge_page_test.c +++ b/tools/testing/selftests/mm/split_huge_page_test.c @@ -167,6 +167,18 @@ static char *allocate_zero_filled_hugepage(size_t len) return result; } =20 +static void disable_khugepaged(void *addr, size_t len) +{ + /* + * Disables khugepaged from collapsing THPs in range, existing THP + * pages remain. + */ + if (!madvise(addr, len, MADV_NOHUGEPAGE)) + return; + + ksft_exit_fail_msg("MADV_NOHUGEPAGE failed, err=3D%d\n", errno); +} + static void verify_rss_anon_split_huge_page_all_zeroes(char *one_page, int= nr_hpages, size_t len) { unsigned long rss_anon_before, rss_anon_after; @@ -179,6 +191,8 @@ static void verify_rss_anon_split_huge_page_all_zeroes(= char *one_page, int nr_hp if (!rss_anon_before) ksft_exit_fail_msg("No RssAnon is allocated before split\n"); =20 + disable_khugepaged(one_page, len); + /* split all THPs */ write_debugfs(PID_FMT, getpid(), (uint64_t)one_page, (uint64_t)one_page + len, 0); @@ -226,6 +240,8 @@ static void split_pmd_thp_to_order(int order) if (!check_huge_anon(one_page, 4 * pmd_pagesize, 4, pmd_pagesize)) ksft_exit_fail_msg("No THP is allocated\n"); =20 + disable_khugepaged(one_page, len); + /* split all THPs */ write_debugfs(PID_FMT, getpid(), (uint64_t)one_page, (uint64_t)one_page + len, order); @@ -274,6 +290,8 @@ static void split_pte_mapped_thp(void) goto out; } =20 + disable_khugepaged(thp_area, thp_area_size); + /* * To challenge spitting code, we will mremap a single page of each * THP (page[i] of thp[i]) in the thp_area into page_area. This will @@ -541,6 +559,7 @@ static int create_pagecache_thp_and_fd(const char *test= file, size_t fd_size, ksft_test_result_skip("Pagecache folio split skipped\n"); return -2; } + disable_khugepaged(*addr, fd_size); return 0; err_out_close: close(*fd); --=20 2.43.0 From nobody Fri Sep 25 21:02:39 2026 Received: from foss.arm.com (foss.arm.com [217.140.110.172]) by smtp.subspace.kernel.org (Postfix) with ESMTP id 7D59947C102; Mon, 21 Sep 2026 10:40:21 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=217.140.110.172 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1789987223; cv=none; b=KoYC7bKP3xkf+8I4zVbUzYA4rrKtYQq9OaS60Wke2AeQPNAxYshy6L46eqJDVn6EPKHnm3/wPLeOANOtp3bjZ/NXrzq11MKkCCPzIYsSTguFQe2dwXGiP2D2zuHIZt+ZFpZfHdK1hpMeWKCfLMR2JPfXKi5TOulO93vTRk58gIU= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1789987223; c=relaxed/simple; bh=EdKZk9/jwDQIH8zFOg73ZY28l1qbx+55/Tqq3ekXyzM=; h=From:Date:Subject:MIME-Version:Content-Type:Message-Id:References: In-Reply-To:To:Cc; b=Tog97e9IowUzGaOaBTAZP+VOTCdahn68ZAfIyP2LJvI4Zra1PfqAtcbFE9eJwJfMJ8dHpSbHZTM9yVeHxvFtbgk5nb+e3KShJz55WhKbAbWLRwTbNL52q+mY+RfmygBnkDyMKJLlin/myRKIIFEaRYyOZ4hFkqYwXzu3YWEHGZ0= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=arm.com; spf=pass smtp.mailfrom=arm.com; dkim=pass (1024-bit key) header.d=arm.com header.i=@arm.com header.b=edH+WGXv; arc=none smtp.client-ip=217.140.110.172 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=arm.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=arm.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=arm.com header.i=@arm.com header.b="edH+WGXv" Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.121.207.14]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id 38BED2F; Mon, 21 Sep 2026 03:40:17 -0700 (PDT) Received: from e129823.arm.com (e129823.arm.com [10.2.213.3]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id B72DD3F86C; Mon, 21 Sep 2026 03:40:17 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=simple/simple; d=arm.com; s=foss; t=1789987220; bh=EdKZk9/jwDQIH8zFOg73ZY28l1qbx+55/Tqq3ekXyzM=; h=From:Date:Subject:References:In-Reply-To:To:Cc:From; b=edH+WGXvFOoqTmFzW/qAYeuRkSbYB6GoWYchgnXWGvg+ykyVLn72hrrdSESDJNbtg SqvbwjgLAhzrP/wucnb1SJNssIUgMhCqFI6kvt7xa91iqxEvl6a9P42itW5mSsEcWt KMinCG5BbLF0Jt7L9zI8coH2iDy5CZEbXUvOUYrE= From: Yeoreum Yun Date: Mon, 21 Sep 2026 11:40:08 +0100 Subject: [PATCH v7 2/3] kselftest: mm: replace usage of /proc/self/smaps for check_huge_xxx() helper Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: quoted-printable Message-Id: <20260921-fix_split-v7-2-d25ec991159f@arm.com> References: <20260921-fix_split-v7-0-d25ec991159f@arm.com> In-Reply-To: <20260921-fix_split-v7-0-d25ec991159f@arm.com> To: Andrew Morton , David Hildenbrand , Lorenzo Stoakes , Zi Yan , Baolin Wang , "Liam R. Howlett" , Nico Pache , Ryan Roberts , Dev Jain , Barry Song , Lance Yang , Usama Arif , Vlastimil Babka , Mike Rapoport , Suren Baghdasaryan , Michal Hocko , Shuah Khan , Kevin Brodsky Cc: linux-mm@kvack.org, linux-kselftest@vger.kernel.org, linux-kernel@vger.kernel.org, Yeoreum Yun X-Mailer: b4 0.13.0 X-Developer-Signature: v=1; a=openpgp-sha256; l=7429; i=yeoreum.yun@arm.com; h=from:subject:message-id; bh=EdKZk9/jwDQIH8zFOg73ZY28l1qbx+55/Tqq3ekXyzM=; b=owEB7QES/pANAwAKAW3Vw9FaxTEzAcsmYgBqsQmJmsEaafXH26QPIpE3mc5C7ESbc2MlpKPoS c7L30rdhyKJAbMEAAEKAB0WIQQtg+CS3QUzuFh1pJ1t1cPRWsUxMwUCarEJiQAKCRBt1cPRWsUx MzXrC/0TBjJtiyR2c/wJJd55mqoYa7VS2P9VnxgPc6FtQX4KqIXS6rrQ9ffuNCJqGf2TJffEe3x 6NnvLtDZcdMd4iPg6OUy5TZ59DQSlZdLMtiHfrsDi5TKjgqRzy0lFLXJiFYvFl4+Z9Wt0Vsur5i SMEWYViWoEvo/B+mNtThYRUYxReqj08ecc6cdO3pQy5SZ1/4MVVHjyGI5aMg96T1uxuEBHmUWrA MXPVICjJp9DVnCYs71frynxaS3TaZ84c/ooFFU3FUT0q+HPksl5msxvs7KdVGRCv7ZH0qjySf3S tyQmlgdWZUns2U1OVeRsKE3KiFdSd1xZq8LpeiP3OAboubkfBXXp8+HAHSQQ5Afks8R/1rlFyLr jBuRZaOq6PROy6ZPUGKuGyi4o7rsirU50HxLdzGUKQ6WY9xX9GzXwpGTec2HjU4NDkvxbqyFU80 x4CZdTbOT40GThnn17nyNl+rU6L1/ay+tyJgsX8BtpgAMilEQeLn7BQYrMVwiF9NxPjrQ= X-Developer-Key: i=yeoreum.yun@arm.com; a=openpgp; fpr=2D83E092DD0533B85875A49D6DD5C3D15AC53133 Since glibc commit 321e1fc73f (=E2=80=9Cmalloc: Enable 2MB THP by default o= n AArch64=E2=80=9D), 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_huge_xxx() 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 and large folios: 1. If hpage_size =3D=3D pmd_pagesize, check PAGE_IS_HUGE instead of using check_large_folios(), since only the mapping type matters. This identifies PMD-mapped huge pages. 2. Otherwise, use check_large_folios() to detect large folios. This covers mTHP cases. 3. Check the folio flags according to the type of huge page. Since shmem pages are also file-backed, simply check whether the page is file-backed. Suggested-by: David Hildenbrand (Arm) Suggested-by: Zi Yan Signed-off-by: Yeoreum Yun --- tools/testing/selftests/mm/vm_util.c | 137 +++++++++++++++++++++----------= ---- 1 file changed, 84 insertions(+), 53 deletions(-) diff --git a/tools/testing/selftests/mm/vm_util.c b/tools/testing/selftests= /mm/vm_util.c index 4821a35630363..a7c5caf6925e0 100644 --- a/tools/testing/selftests/mm/vm_util.c +++ b/tools/testing/selftests/mm/vm_util.c @@ -351,31 +351,13 @@ char *__get_smap_entry(void *addr, const char *patter= n, char *buf, size_t len) return entry; } =20 -static bool __check_pmd_huge(void *addr, char *pattern, int nr_hpages, - uint64_t hpage_size) -{ - char buffer[MAX_LINE_LENGTH]; - uint64_t thp =3D -1; - char *entry; - - entry =3D __get_smap_entry(addr, pattern, buffer, sizeof(buffer)); - if (!entry) - goto err_out; - - if (sscanf(entry, "%9" SCNu64 " kB", &thp) !=3D 1) - ksft_exit_fail_msg("Reading smap error\n"); - -err_out: - return thp =3D=3D (nr_hpages * (hpage_size >> 10)); -} - -static bool check_large_folios(void *addr, size_t len, int nr_hpages, - uint64_t hpage_size) +static bool check_large_folios(int pagemap_fd, int kpageflags_fd, + void *addr, size_t len, int nr_hpages, + uint64_t hpage_size) { int order =3D 0, pagesize =3D getpagesize(); unsigned int nr_pages =3D hpage_size / pagesize; int orders[MAX_NR_ORDERS], status; - int pagemap_fd, kpageflags_fd; bool ret =3D false; =20 if (!nr_pages) @@ -386,15 +368,6 @@ static bool check_large_folios(void *addr, size_t len,= int nr_hpages, ksft_exit_fail_msg("invalid order\n"); =20 memset(orders, 0, sizeof(int) * MAX_NR_ORDERS); - pagemap_fd =3D open(PAGEMAP_PATH, O_RDONLY); - if (pagemap_fd =3D=3D -1) - ksft_exit_fail_msg("read pagemap fail\n"); - - kpageflags_fd =3D open(KPAGEFLAGS_PATH, O_RDONLY); - if (kpageflags_fd =3D=3D -1) { - close(pagemap_fd); - ksft_exit_fail_msg("read kpageflags fail\n"); - } =20 status =3D gather_folio_orders(addr, len, pagemap_fd, kpageflags_fd, orders, MAX_NR_ORDERS); @@ -405,48 +378,106 @@ static bool check_large_folios(void *addr, size_t le= n, int nr_hpages, ret =3D true; =20 out: - close(pagemap_fd); - close(kpageflags_fd); return ret; } =20 -bool check_huge_anon(void *addr, size_t len, int nr_hpages, uint64_t hpage= _size) -{ - uint64_t pmd_pagesize =3D read_pmd_pagesize(); +enum check_huge_type { + CHECK_HUGE_ANON, + CHECK_HUGE_FILE, +}; =20 - if (!pmd_pagesize) - ksft_exit_fail_msg("reading PMD pagesize failed\n"); +static bool check_huge_type(uint64_t categories, uint64_t kpageflags, + enum check_huge_type type) +{ + const bool file =3D categories & PAGE_IS_FILE; =20 - if (hpage_size =3D=3D pmd_pagesize) - return __check_pmd_huge(addr, "AnonHugePages: ", nr_hpages, hpage_size); + switch (type) { + case CHECK_HUGE_ANON: + return !file; + case CHECK_HUGE_FILE: + return file; + } =20 - return check_large_folios(addr, len, nr_hpages, hpage_size); + return false; } =20 -bool check_huge_file(void *addr, size_t len, int nr_hpages, uint64_t hpage= _size) +static bool __check_huge(void *addr, size_t len, int nr_hpages, + uint64_t hpage_size, enum check_huge_type type) { - uint64_t pmd_pagesize =3D read_pmd_pagesize(); + bool ret =3D false; + int pagemap_fd, kpageflags_fd; + int nr_pmd_mappings =3D 0; + uint64_t pmd_pagesize, scan_mapping_size; + uint64_t categories, kpf; + unsigned long pfn; + bool check_pmd_mapping, allow_nonpresent; + char *start =3D addr; + char *end =3D start + len; =20 + pmd_pagesize =3D read_pmd_pagesize(); if (!pmd_pagesize) ksft_exit_fail_msg("reading PMD pagesize failed\n"); =20 - if (hpage_size =3D=3D pmd_pagesize) - return __check_pmd_huge(addr, "FilePmdMapped:", nr_hpages, hpage_size); + check_pmd_mapping =3D (hpage_size =3D=3D pmd_pagesize); + scan_mapping_size =3D (nr_hpages > 0) ? hpage_size : psize(); + /* Some mTHP tests check a partially populated PMD-sized range. */ + allow_nonpresent =3D (uint64_t)nr_hpages * hpage_size < len; =20 - return check_large_folios(addr, len, nr_hpages, hpage_size); + pagemap_fd =3D open(PAGEMAP_PATH, O_RDONLY); + if (pagemap_fd < 0) + ksft_exit_fail_msg("open pagemap fail\n"); + + kpageflags_fd =3D open(KPAGEFLAGS_PATH, O_RDONLY); + if (kpageflags_fd < 0) + ksft_exit_fail_msg("open kpageflags fail\n"); + + if (!check_pmd_mapping && + !check_large_folios(pagemap_fd, kpageflags_fd, + addr, len, nr_hpages, hpage_size)) + goto out; + + for (; start < end; start +=3D scan_mapping_size) { + categories =3D pagemap_scan_get_categories(pagemap_fd, start); + pfn =3D pagemap_get_pfn(pagemap_fd, start); + if (pfn =3D=3D -1UL) { + if (!allow_nonpresent) + goto out; + else + continue; + } + if (pageflags_get(pfn, kpageflags_fd, &kpf)) + ksft_exit_fail_msg("read kpageflags: %s\n", strerror(errno)); + if (check_pmd_mapping && (categories & PAGE_IS_HUGE)) + nr_pmd_mappings++; + if (kpf & KPF_COMPOUND_TAIL) + continue; + if (!check_huge_type(categories, kpf, type)) + goto out; + } + + if (check_pmd_mapping && (nr_pmd_mappings !=3D nr_hpages)) + goto out; + ret =3D true; + +out: + close(pagemap_fd); + close(kpageflags_fd); + return ret; } =20 -bool check_huge_shmem(void *addr, size_t len, int nr_hpages, uint64_t hpag= e_size) +bool check_huge_anon(void *addr, size_t len, int nr_hpages, uint64_t hpage= _size) { - uint64_t pmd_pagesize =3D read_pmd_pagesize(); - - if (!pmd_pagesize) - ksft_exit_fail_msg("reading PMD pagesize failed\n"); + return __check_huge(addr, len, nr_hpages, hpage_size, CHECK_HUGE_ANON); +} =20 - if (hpage_size =3D=3D pmd_pagesize) - return __check_pmd_huge(addr, "ShmemPmdMapped:", nr_hpages, hpage_size); +bool check_huge_file(void *addr, size_t len, int nr_hpages, uint64_t hpage= _size) +{ + return __check_huge(addr, len, nr_hpages, hpage_size, CHECK_HUGE_FILE); +} =20 - return check_large_folios(addr, len, nr_hpages, hpage_size); +bool check_huge_shmem(void *addr, size_t len, int nr_hpages, uint64_t hpag= e_size) +{ + return __check_huge(addr, len, nr_hpages, hpage_size, CHECK_HUGE_FILE); } =20 int64_t allocate_transhuge(void *ptr, int pagemap_fd) --=20 2.43.0 From nobody Fri Sep 25 21:02:39 2026 Received: from foss.arm.com (foss.arm.com [217.140.110.172]) by smtp.subspace.kernel.org (Postfix) with ESMTP id 990F547CA89; Mon, 21 Sep 2026 10:40:24 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=217.140.110.172 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; 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spf=pass smtp.mailfrom=arm.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=arm.com header.i=@arm.com header.b="JmnlIL+m" Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.121.207.14]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id 924111D13; Mon, 21 Sep 2026 03:40:20 -0700 (PDT) Received: from e129823.arm.com (e129823.arm.com [10.2.213.3]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 18FF53F86C; Mon, 21 Sep 2026 03:40:20 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=simple/simple; d=arm.com; s=foss; t=1789987224; bh=vNyGx9dWLGfndZvGwi3n6mprkCkP24UQCpKsoclyTK0=; h=From:Date:Subject:References:In-Reply-To:To:Cc:From; b=JmnlIL+mnXS1cE2ebOZ6S8vEUxpG5ggfpnFAM7XevhVZpwxPVqdKFcP+w8GH6AAJw TZNFyXHUd78aAnwv+Je01e3ayo4o7ccX5CGjcPwxpuQTh7T6mykQgmfMqlG5ds+1du zGp+Bj2tIbGctVVRVflnnIalHca1DR8YgP7dhIGA= From: Yeoreum Yun Date: Mon, 21 Sep 2026 11:40:09 +0100 Subject: [PATCH v7 3/3] kselftest: mm: remove check_huge_shmem() Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: quoted-printable Message-Id: <20260921-fix_split-v7-3-d25ec991159f@arm.com> References: <20260921-fix_split-v7-0-d25ec991159f@arm.com> In-Reply-To: <20260921-fix_split-v7-0-d25ec991159f@arm.com> To: Andrew Morton , David Hildenbrand , Lorenzo Stoakes , Zi Yan , Baolin Wang , "Liam R. Howlett" , Nico Pache , Ryan Roberts , Dev Jain , Barry Song , Lance Yang , Usama Arif , Vlastimil Babka , Mike Rapoport , Suren Baghdasaryan , Michal Hocko , Shuah Khan , Kevin Brodsky Cc: linux-mm@kvack.org, linux-kselftest@vger.kernel.org, linux-kernel@vger.kernel.org, Yeoreum Yun X-Mailer: b4 0.13.0 X-Developer-Signature: v=1; a=openpgp-sha256; l=7237; i=yeoreum.yun@arm.com; h=from:subject:message-id; bh=vNyGx9dWLGfndZvGwi3n6mprkCkP24UQCpKsoclyTK0=; b=owEB7QES/pANAwAKAW3Vw9FaxTEzAcsmYgBqsQmKJ2J7KWDEU19n5jwKF20S9WkGF4nlx76mN 03QJZsJXguJAbMEAAEKAB0WIQQtg+CS3QUzuFh1pJ1t1cPRWsUxMwUCarEJigAKCRBt1cPRWsUx MzovDAC0XHwhw0B7epbkr2rl9Z2mlMCavJWdhf5vb8iwQiM+ePshFqmUKE8OcJbILg3kQRkwQ2n rSLo2HIbt2QAxwbDcMMlo9EFz2Z3H7sXFb/sEWhTKJX7//ipnPlfhhy66aNqFTF5dmhQ9ipo0nG gOesvqQsiRUYrQtxps33FVcgUSb0p2pwl/UymGwKg2MlRgV8txOKQ9u/Gv1W2h5UrIMrlFUTd8q g94fq5fTmqBxT4UYl/bcJbi750YrJSURY/3A9LkhaWmHvjOVFke6VdBTEpMols2BdfzYoHxI17C TspGFYVPDOHCB8mXvIDmBV7Qgh34Y/xM+bOEGRKwrwevJgaAkeaV3wMGoCvukV1XWQVs3qZ5OfS DE/8w2QrSURlYSGZ0juNW/ikvbo2tTLd88jwEZb6KZB5m58bosJ0RfQvIeZuoUDaxv338zs26d+ Lkc8dND4Z8rVvJR1xBazj3lMBCh/8UaY4iIzk2xRqsTSW6SwWI5MIFANWtMa099pqf77I= X-Developer-Key: i=yeoreum.yun@arm.com; a=openpgp; fpr=2D83E092DD0533B85875A49D6DD5C3D15AC53133 check_huge_shmem() was required to distinguish shmem huge pages because /proc/self/smaps reports them using a dedicated =E2=80=9CShmemPmdMapped=E2= =80=9D entry, as opposed to =E2=80=9CFilePmdMapped=E2=80=9D for file-backed huge pages. Now that /proc/self/smaps is no longer used to detect huge pages and /proc/kpageflags is used instead, it is sufficient to distinguish between file-backed and anonymous pages since the ShmemPmdMapped is also kind of file-backed. Therefore, remove check_huge_shmem() and use check_huge_file() instead and cleanup khugepaged's check_huge operation in mem_ops. Suggested-by: David Hildenbrand (Arm) Signed-off-by: Yeoreum Yun Acked-by: David Hildenbrand (Arm) Acked-by: Lorenzo Stoakes (ARM) Acked-by: Zi Yan Reviewed-by: Baolin Wang --- tools/testing/selftests/mm/folio_split_race_test.c | 2 +- tools/testing/selftests/mm/khugepaged.c | 38 ++++--------------= ---- tools/testing/selftests/mm/uffd-common.c | 4 +-- tools/testing/selftests/mm/vm_util.c | 5 --- tools/testing/selftests/mm/vm_util.h | 1 - 5 files changed, 9 insertions(+), 41 deletions(-) diff --git a/tools/testing/selftests/mm/folio_split_race_test.c b/tools/tes= ting/selftests/mm/folio_split_race_test.c index 1960635a953eb..4c0d3b6a411b8 100644 --- a/tools/testing/selftests/mm/folio_split_race_test.c +++ b/tools/testing/selftests/mm/folio_split_race_test.c @@ -182,7 +182,7 @@ static uint64_t run_iteration(void) for (i =3D 0; i < TOTAL_PAGES; i++) fill_page(mmap_base, i); =20 - if (!check_huge_shmem(mmap_base, FILE_SIZE, NR_PMD_PAGE, pmd_pagesize)) + if (!check_huge_file(mmap_base, FILE_SIZE, NR_PMD_PAGE, pmd_pagesize)) ksft_exit_fail_msg("No shmem THP is allocated\n"); =20 if (pthread_barrier_init(&ctl.barrier, NULL, NUM_READER_THREADS + 1) !=3D= 0) diff --git a/tools/testing/selftests/mm/khugepaged.c b/tools/testing/selfte= sts/mm/khugepaged.c index f82673f5f6b47..f448278823678 100644 --- a/tools/testing/selftests/mm/khugepaged.c +++ b/tools/testing/selftests/mm/khugepaged.c @@ -53,7 +53,7 @@ struct mem_ops { void *(*setup_area)(int nr_hpages); void (*cleanup_area)(void *p, unsigned long size); void (*fault)(void *p, unsigned long start, unsigned long end); - bool (*check_huge)(void *addr, size_t len, int nr_hpages, unsigned long h= page_size); + bool (*check_huge)(void *addr, size_t len, int nr_hpages, uint64_t hpage_= size); const char *name; }; =20 @@ -314,12 +314,6 @@ static void anon_fault(void *p, unsigned long start, u= nsigned long end) fill_memory(p, start, end); } =20 -static bool anon_check_huge(void *addr, size_t len, int nr_hpages, - unsigned long hpage_size) -{ - return check_huge_anon(addr, len, nr_hpages, hpage_size); -} - static void *file_setup_area_common(int nr_hpages, enum file_setup_ops set= up) { const int open_opt =3D setup =3D=3D FILE_SETUP_READ_ONLY_FS ? O_RDONLY : = O_RDWR; @@ -411,20 +405,6 @@ static void file_fault_write(void *p, unsigned long st= art, unsigned long end) ksft_exit_fail_perror("madvise(MADV_POPULATE_WRITE)"); } =20 -static bool file_check_huge(void *addr, size_t len, int nr_hpages, - unsigned long hpage_size) -{ - switch (finfo.type) { - case VMA_FILE: - return check_huge_file(addr, len, nr_hpages, hpage_size); - case VMA_SHMEM: - return check_huge_shmem(addr, len, nr_hpages, hpage_size); - default: - ksft_exit_fail_msg("Unknown VMA type\n"); - return false; - } -} - static void *shmem_setup_area(int nr_hpages) { void *p; @@ -448,17 +428,11 @@ static void shmem_cleanup_area(void *p, unsigned long= size) close(finfo.fd); } =20 -static bool shmem_check_huge(void *addr, size_t len, int nr_hpages, - unsigned long hpage_size) -{ - return check_huge_shmem(addr, len, nr_hpages, hpage_size); -} - static struct mem_ops __anon_ops =3D { .setup_area =3D &anon_setup_area, .cleanup_area =3D &anon_cleanup_area, .fault =3D &anon_fault, - .check_huge =3D &anon_check_huge, + .check_huge =3D &check_huge_anon, .name =3D "anon", }; =20 @@ -466,7 +440,7 @@ static struct mem_ops __read_only_file_ops =3D { .setup_area =3D &file_setup_read_only_area, .cleanup_area =3D &file_cleanup_area, .fault =3D &file_fault_read, - .check_huge =3D &file_check_huge, + .check_huge =3D &check_huge_file, .name =3D "file", }; =20 @@ -474,7 +448,7 @@ static struct mem_ops __read_write_file_read_ops =3D { .setup_area =3D &file_setup_read_write_fs_read_area, .cleanup_area =3D &file_cleanup_area, .fault =3D &file_fault_read_and_flush, - .check_huge =3D &file_check_huge, + .check_huge =3D &check_huge_file, .name =3D "file", }; =20 @@ -482,7 +456,7 @@ static struct mem_ops __read_write_file_write_ops =3D { .setup_area =3D &file_setup_read_write_fs_write_area, .cleanup_area =3D &file_cleanup_area, .fault =3D &file_fault_write, - .check_huge =3D &file_check_huge, + .check_huge =3D &check_huge_file, .name =3D "file", }; =20 @@ -490,7 +464,7 @@ static struct mem_ops __shmem_ops =3D { .setup_area =3D &shmem_setup_area, .cleanup_area =3D &shmem_cleanup_area, .fault =3D &anon_fault, - .check_huge =3D &shmem_check_huge, + .check_huge =3D &check_huge_file, .name =3D "shmem", }; =20 diff --git a/tools/testing/selftests/mm/uffd-common.c b/tools/testing/selft= ests/mm/uffd-common.c index 1fb967ef49854..a76851aced4d0 100644 --- a/tools/testing/selftests/mm/uffd-common.c +++ b/tools/testing/selftests/mm/uffd-common.c @@ -196,8 +196,8 @@ static void shmem_check_pmd_mapping(uffd_global_test_op= ts_t *gopts, void *p, int { size_t len =3D expect_nr_hpages * read_pmd_pagesize(); =20 - if (!check_huge_shmem(gopts->area_dst_alias, len, expect_nr_hpages, - read_pmd_pagesize())) + if (!check_huge_file(gopts->area_dst_alias, len, expect_nr_hpages, + read_pmd_pagesize())) err("Did not find expected %d number of hugepages", expect_nr_hpages); } diff --git a/tools/testing/selftests/mm/vm_util.c b/tools/testing/selftests= /mm/vm_util.c index a7c5caf6925e0..e31e88d5af76d 100644 --- a/tools/testing/selftests/mm/vm_util.c +++ b/tools/testing/selftests/mm/vm_util.c @@ -475,11 +475,6 @@ bool check_huge_file(void *addr, size_t len, int nr_hp= ages, uint64_t hpage_size) return __check_huge(addr, len, nr_hpages, hpage_size, CHECK_HUGE_FILE); } =20 -bool check_huge_shmem(void *addr, size_t len, int nr_hpages, uint64_t hpag= e_size) -{ - return __check_huge(addr, len, nr_hpages, hpage_size, CHECK_HUGE_FILE); -} - int64_t allocate_transhuge(void *ptr, int pagemap_fd) { uint64_t ent[2]; diff --git a/tools/testing/selftests/mm/vm_util.h b/tools/testing/selftests= /mm/vm_util.h index 9a49af88702e4..fc9c93235f6fa 100644 --- a/tools/testing/selftests/mm/vm_util.h +++ b/tools/testing/selftests/mm/vm_util.h @@ -92,7 +92,6 @@ uint64_t read_pmd_pagesize(void); unsigned long rss_anon(void); bool check_huge_anon(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); -bool check_huge_shmem(void *addr, size_t len, int nr_hpages, uint64_t hpag= e_size); int64_t allocate_transhuge(void *ptr, int pagemap_fd); int pageflags_get(unsigned long pfn, int kpageflags_fd, uint64_t *flags); int gather_folio_orders(char *vaddr_start, size_t len, --=20 2.43.0