From nobody Fri Sep 25 10:37:43 2026 Received: from foss.arm.com (foss.arm.com [217.140.110.172]) by smtp.subspace.kernel.org (Postfix) with ESMTP id 80DEA3E3163; Mon, 14 Sep 2026 07:30:21 +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=1789371023; cv=none; b=SiUmQLK7Z3vByh2NbNynO+bqeujNZPtUPS4twUXEfLQyuOd80yfeUcjgmi4+Od/BsimRJxerA5czpgWrI7lm4TglxC+8ZZ2H4FLJgI3WuvBR0bHdm8V+wHadbEdXO8K9H9I7KLAR7PLDdvUtMtYJvVIwvvMQdmadNzLlbDRkBQ8= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1789371023; c=relaxed/simple; bh=SlD7ZbVM7WnFOn0I9sN0RsC4FPCdY4XpHKn67Smm3qg=; h=From:Date:Subject:MIME-Version:Content-Type:Message-Id:References: In-Reply-To:To:Cc; b=Jo06AeiJH4rnQtC71PzovlYE/LS2iDFeI5+MXLOJZekvSjtsP90m17WAD4ST3m5pwDW5mkb6j5uRfP9wxTUOhuPgG3SVS3q1zEmbufMTALdgvhkTIqGF50hfxXeanlW3eZ0oEJnoLcnwEuOeqyb/cE47SJBtVQiefT6sYTb7ZHg= 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=Cl9+8G5o; 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="Cl9+8G5o" 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 192AA1570; Mon, 14 Sep 2026 00:30:17 -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 C5F053F59E; Mon, 14 Sep 2026 00:30:17 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=simple/simple; d=arm.com; s=foss; t=1789371020; bh=SlD7ZbVM7WnFOn0I9sN0RsC4FPCdY4XpHKn67Smm3qg=; h=From:Date:Subject:References:In-Reply-To:To:Cc:From; b=Cl9+8G5oMdP7lh+WHNE+fCbazaEny8SPmxKwgj1dFpDiT2ssk7ppCGxxjdzRMq06C /zoIkoQFHy0NpNotetR3VDpQRW96FOjmkdKLOjMq5ZZeAPKux2A9UUbVvFiyURJEDi rvJwvfnYCTpRqKKOdv+Ce6ZjXo7FLj8uEX4OKkFA= From: Yeoreum Yun Date: Mon, 14 Sep 2026 08:30:10 +0100 Subject: [PATCH v6 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: <20260914-fix_split-v6-1-16ed7123800b@arm.com> References: <20260914-fix_split-v6-0-16ed7123800b@arm.com> In-Reply-To: <20260914-fix_split-v6-0-16ed7123800b@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=2770; i=yeoreum.yun@arm.com; h=from:subject:message-id; bh=SlD7ZbVM7WnFOn0I9sN0RsC4FPCdY4XpHKn67Smm3qg=; b=owEB7QES/pANAwAKAW3Vw9FaxTEzAcsmYgBqp6KE5jWbWA6Vl/LXzSbh4vusoY1JIpxqui00b WCllym4YfWJAbMEAAEKAB0WIQQtg+CS3QUzuFh1pJ1t1cPRWsUxMwUCaqeihAAKCRBt1cPRWsUx MyaxC/4q7Yi8BdaNwgF0uMQXrfTyws7nuywQBhuRw2f17xDGs+9SWebUV/TRY5zorq5APlq2rDn vAUc+bmXYBEZwGbDMjf1ge7BNaUlLdNacCsSVHLerps2U/Xf/DhVnI1Vzd84p5FeskRGOK9qUED NBiob6Xsls1V5MgdJlmPP3Vsajbq1LuPWT5QqEAbjgVbxsm1IxlwVlIARb7qVV44vCAPWAKUiqQ eMRpCJlIor1Hqu3v0RlbmqDD+Iyt5jJyzEwBN72cP2ZZT0puysglKmmG3NpZFqOa2BV06M7Jy/g 74W98j8VURt3oU/3voT6uRYQgdn49bok7Fe3SraE5W9QZDt9Dro+1hdTbRnYi86satdvGQf+pkA Q/jmXBA93OT83ye7CmKMfzkPv1DQRi5wDIP0apRp2OHqYOwvevdfA04ncD4OrpOYoR+uXXb4waA Nw/pwiqvqKAevRt8Fu6fYf0WuOabIzy+4wWqxYSOrvva3ehFb+CcX0lwQqEOcHFTP4Xvo= 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 c01d227d7fd6..cba327f77873 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 10:37:43 2026 Received: from foss.arm.com (foss.arm.com [217.140.110.172]) by smtp.subspace.kernel.org (Postfix) with ESMTP id A3ABF3E63B0; Mon, 14 Sep 2026 07:30:24 +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; s=arc-20240116; t=1789371027; cv=none; b=kXSRCO5rCtvXXafLIJi6YF+KwTYMbTUBB6kJK282DL0eardxY5v+Xfmc6gtCl7zfbovcI8g+b2m7jgQGLbWC2oJseml0Ed5L9O1JfH6J57/Xa8wj+pZHp0gMHCu/2lNE1QxBD+ZEsrvlFjGeHylW+yjzp7uZOE7phLJRwSW2Qfo= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1789371027; c=relaxed/simple; bh=psBRrjsPYCPSu2tJEDRB3gqzN+yAJ2X+dvQbQmhBcA8=; h=From:Date:Subject:MIME-Version:Content-Type:Message-Id:References: In-Reply-To:To:Cc; b=u5RDu7DFRfODy+5z5xdX4QxK//Xpqtt+NqRrSrV5ntWWtrXD672T7SbZsDf+dAh9AI+eXh24tz9DF/okx1HBECq7tLqgQMsL7/20IH+jH8UgESSW3okUZ+4u6ioeE+cr7ubIsJI7KRa43XTEgKpTy4wYL2DbSnme18Zo0/LEzJU= 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=enKKDepr; 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="enKKDepr" 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 5B4BA143D; Mon, 14 Sep 2026 00:30:20 -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 155003F59E; Mon, 14 Sep 2026 00:30:20 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=simple/simple; d=arm.com; s=foss; t=1789371024; bh=psBRrjsPYCPSu2tJEDRB3gqzN+yAJ2X+dvQbQmhBcA8=; h=From:Date:Subject:References:In-Reply-To:To:Cc:From; b=enKKDeprlnK7CvhjVpIQPtx6Sf4EDDszYb1y5zlzb0EKM44M1/+/o0EPdUsQknlZo t5qOpwGirwAk/N2kHOTifnyZTs7xj1uQ3K8MMb6N3isWzse0aSsqIrknrI+yo7g/xE ukQVmaiFSroC7KcdfL6yrZcGcaQdKvRAZ2tIBCgY= From: Yeoreum Yun Date: Mon, 14 Sep 2026 08:30:11 +0100 Subject: [PATCH v6 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: <20260914-fix_split-v6-2-16ed7123800b@arm.com> References: <20260914-fix_split-v6-0-16ed7123800b@arm.com> In-Reply-To: <20260914-fix_split-v6-0-16ed7123800b@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=8293; i=yeoreum.yun@arm.com; h=from:subject:message-id; bh=psBRrjsPYCPSu2tJEDRB3gqzN+yAJ2X+dvQbQmhBcA8=; b=owEB7QES/pANAwAKAW3Vw9FaxTEzAcsmYgBqp6KFvQ0pjSfmUCROiwZbCfsd+W2h1LsFCxAsp CFCJWyPuvSJAbMEAAEKAB0WIQQtg+CS3QUzuFh1pJ1t1cPRWsUxMwUCaqeihQAKCRBt1cPRWsUx Mw01C/0T+NmhZYs82D7yU5QvwupWDcg8177MCf9NgqwnggUdNsLUOXawl7wKsWeLy4neZuu6H0K AbtJBezh2vYhHucyC5EfUFBUTILp1VNt/qxcz/1gR/1xy2gWaIu5eTrRX+vLJn7dR0v9gGh3pVj J+FuoRMeJwgK+nLv9XByZpL9fQE770VcuK5vckLLPYETF2+/gk8pS260Z3NtQt95ijYnmQaNu/t Ih9cqeCNfaQeh25oxCtEsMMsVub8yPDO8TKhrXj2ahDaKmcFsgLQImoEuepGP/by2OhiuAsmjZa 1X+e1K8wPmN04wY95mLgGkHpcHzdVPxwBuQUAYW5zvdVpQU0QznVWmRV0UEHn9DLGkL0RbbD5Y4 VPubEW+4R+pYez3BW3H4QxVWrAe6cYH7X7tqSvwZPaxPoSMcz49Q83vwll0EiSu5KryjXUbC/YZ YhyydOAxsloI8eIw2LLBp65gBoio9HmMK6zwctIEetNDmPALSakI7t3GfO4vKLGTY2NJo= 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. Suggested-by: David Hildenbrand (Arm) Suggested-by: Zi Yan Reviewed-by: Zi Yan Reviewed-by: Baolin Wang Tested-by: Baolin Wang Acked-by: Lorenzo Stoakes (ARM) Signed-off-by: Yeoreum Yun --- tools/testing/selftests/mm/vm_util.c | 143 ++++++++++++++++++++++---------= ---- tools/testing/selftests/mm/vm_util.h | 1 + 2 files changed, 90 insertions(+), 54 deletions(-) diff --git a/tools/testing/selftests/mm/vm_util.c b/tools/testing/selftests= /mm/vm_util.c index 4821a3563036..98f110098179 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 +378,110 @@ 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(); - - if (!pmd_pagesize) - ksft_exit_fail_msg("reading PMD pagesize failed\n"); +enum check_huge_type { + CHECK_HUGE_ANON, + CHECK_HUGE_FILE, + CHECK_HUGE_SHMEM, +}; =20 - if (hpage_size =3D=3D pmd_pagesize) - return __check_pmd_huge(addr, "AnonHugePages: ", nr_hpages, hpage_size); +static bool check_huge_type(uint64_t categories, uint64_t kpageflags, + enum check_huge_type type) +{ + const bool file =3D categories & PAGE_IS_FILE; + const bool swapbacked =3D kpageflags & KPF_SWAPBACKED; + + switch (type) { + case CHECK_HUGE_ANON: + return !file; + case CHECK_HUGE_FILE: + return file && !swapbacked; + case CHECK_HUGE_SHMEM: + return file && swapbacked; + } =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_SHMEM); } =20 int64_t allocate_transhuge(void *ptr, int pagemap_fd) diff --git a/tools/testing/selftests/mm/vm_util.h b/tools/testing/selftests= /mm/vm_util.h index 9a49af88702e..f19bd17817e5 100644 --- a/tools/testing/selftests/mm/vm_util.h +++ b/tools/testing/selftests/mm/vm_util.h @@ -18,6 +18,7 @@ #define PM_SWAP BIT_ULL(62) #define PM_PRESENT BIT_ULL(63) =20 +#define KPF_SWAPBACKED BIT_ULL(14) #define KPF_COMPOUND_HEAD BIT_ULL(15) #define KPF_COMPOUND_TAIL BIT_ULL(16) #define KPF_HWPOISON BIT_ULL(19) --=20 2.43.0 From nobody Fri Sep 25 10:37:43 2026 Received: from foss.arm.com (foss.arm.com [217.140.110.172]) by smtp.subspace.kernel.org (Postfix) with ESMTP id ECF373ED5C3; 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charset="utf-8" Content-Transfer-Encoding: quoted-printable Message-Id: <20260914-fix_split-v6-3-16ed7123800b@arm.com> References: <20260914-fix_split-v6-0-16ed7123800b@arm.com> In-Reply-To: <20260914-fix_split-v6-0-16ed7123800b@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=5763; i=yeoreum.yun@arm.com; h=from:subject:message-id; bh=wGlC3x6B+YeFTS+wPx/ip9iVJG9tdNzDpN4kixOrAIQ=; b=owEB7QES/pANAwAKAW3Vw9FaxTEzAcsmYgBqp6KFnDSPIySJuA1qhfL4+Y+ej5BNPPQFp/TfE moVKbr0hJWJAbMEAAEKAB0WIQQtg+CS3QUzuFh1pJ1t1cPRWsUxMwUCaqeihQAKCRBt1cPRWsUx M3+eC/wN0LE1QiKBQiXu3bsjAMd7q2V3+BzmLi6SweD3okNMFuud5JNtkA3pT3d43XhuYEad3TD E4sHuD0y7GNWa7srSMT1U4pZv798dzi/wPiddVeNMUE5yLZWajm+z732ShV2FBmRiyIG+r6+2uV T/faG0bqjk5xkTM3Z20OrxZTv2bfBEsogdg01zzgHG1JxFsc8bdxaKzh0tPOcsGwwL3waAUd2Nd UCtyEBjZlZ1bCU9PFM3PJiveZjcKSOf++h+v5Xn3mOzflx6S9WE7nyXMN3SkZYf6WYUNFeWiknp UfAcrANMHe0/eUKh+dlHTb1ZjeAUHlvEA3DJxGYvP9JCE0oSUeuAntWyRSsb5a1HlCL/OhhH2aD sPU715QWjY0zY61kFV8KfsgOnXqBMiH3Tqv2t6wQ5U0WJFgBc3otCzLAqljY+QuuyS83XV6Rlyo 1p+1DeSpge9l03m2p/ICge8rZPk4lL8yRaUKvBUsW0G94KU/6F+ejuNdK72mpNzsIOucQ= 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. Suggested-by: David Hildenbrand (Arm) Signed-off-by: Yeoreum Yun --- tools/testing/selftests/mm/folio_split_race_test.c | 2 +- tools/testing/selftests/mm/khugepaged.c | 5 ++--- tools/testing/selftests/mm/uffd-common.c | 4 ++-- tools/testing/selftests/mm/vm_util.c | 11 +---------- tools/testing/selftests/mm/vm_util.h | 2 -- 5 files changed, 6 insertions(+), 18 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 1960635a953e..4c0d3b6a411b 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 f82673f5f6b4..6cd1effea465 100644 --- a/tools/testing/selftests/mm/khugepaged.c +++ b/tools/testing/selftests/mm/khugepaged.c @@ -416,9 +416,8 @@ static bool file_check_huge(void *addr, size_t len, int= nr_hpages, { 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); + return check_huge_file(addr, len, nr_hpages, hpage_size); default: ksft_exit_fail_msg("Unknown VMA type\n"); return false; @@ -451,7 +450,7 @@ static void shmem_cleanup_area(void *p, unsigned long s= ize) 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); + return check_huge_file(addr, len, nr_hpages, hpage_size); } =20 static struct mem_ops __anon_ops =3D { diff --git a/tools/testing/selftests/mm/uffd-common.c b/tools/testing/selft= ests/mm/uffd-common.c index 1fb967ef4985..a76851aced4d 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 98f110098179..e31e88d5af76 100644 --- a/tools/testing/selftests/mm/vm_util.c +++ b/tools/testing/selftests/mm/vm_util.c @@ -384,22 +384,18 @@ static bool check_large_folios(int pagemap_fd, int kp= ageflags_fd, enum check_huge_type { CHECK_HUGE_ANON, CHECK_HUGE_FILE, - CHECK_HUGE_SHMEM, }; =20 static bool check_huge_type(uint64_t categories, uint64_t kpageflags, enum check_huge_type type) { const bool file =3D categories & PAGE_IS_FILE; - const bool swapbacked =3D kpageflags & KPF_SWAPBACKED; =20 switch (type) { case CHECK_HUGE_ANON: return !file; case CHECK_HUGE_FILE: - return file && !swapbacked; - case CHECK_HUGE_SHMEM: - return file && swapbacked; + return file; } =20 return false; @@ -479,11 +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_SHMEM); -} - 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 f19bd17817e5..fc9c93235f6f 100644 --- a/tools/testing/selftests/mm/vm_util.h +++ b/tools/testing/selftests/mm/vm_util.h @@ -18,7 +18,6 @@ #define PM_SWAP BIT_ULL(62) #define PM_PRESENT BIT_ULL(63) =20 -#define KPF_SWAPBACKED BIT_ULL(14) #define KPF_COMPOUND_HEAD BIT_ULL(15) #define KPF_COMPOUND_TAIL BIT_ULL(16) #define KPF_HWPOISON BIT_ULL(19) @@ -93,7 +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