From nobody Wed Dec 17 20:59:17 2025 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id B89FAC61D97 for ; Wed, 22 Nov 2023 16:31:20 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1343803AbjKVQbV (ORCPT ); Wed, 22 Nov 2023 11:31:21 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:36868 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S235213AbjKVQa7 (ORCPT ); Wed, 22 Nov 2023 11:30:59 -0500 Received: from foss.arm.com (foss.arm.com [217.140.110.172]) by lindbergh.monkeyblade.net (Postfix) with ESMTP id A60351733 for ; Wed, 22 Nov 2023 08:30:34 -0800 (PST) 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 036CA1650; Wed, 22 Nov 2023 08:31:21 -0800 (PST) Received: from e125769.cambridge.arm.com (e125769.cambridge.arm.com [10.1.196.26]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 8A75A3F73F; Wed, 22 Nov 2023 08:30:31 -0800 (PST) From: Ryan Roberts To: Andrew Morton , Matthew Wilcox , Yin Fengwei , David Hildenbrand , Yu Zhao , Catalin Marinas , Anshuman Khandual , Yang Shi , "Huang, Ying" , Zi Yan , Luis Chamberlain , Itaru Kitayama , "Kirill A. Shutemov" , John Hubbard , David Rientjes , Vlastimil Babka , Hugh Dickins , Kefeng Wang Cc: Ryan Roberts , linux-mm@kvack.org, linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org Subject: [RESEND PATCH v7 10/10] selftests/mm/cow: Add tests for anonymous small-sized THP Date: Wed, 22 Nov 2023 16:29:50 +0000 Message-Id: <20231122162950.3854897-11-ryan.roberts@arm.com> X-Mailer: git-send-email 2.25.1 In-Reply-To: <20231122162950.3854897-1-ryan.roberts@arm.com> References: <20231122162950.3854897-1-ryan.roberts@arm.com> MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Type: text/plain; charset="utf-8" Add tests similar to the existing PMD-sized THP tests, but which operate on memory backed by (PTE-mapped) small-sized THP. This reuses all the existing infrastructure. If the test suite detects that small-sized THP is not supported by the kernel, the new tests are skipped. Signed-off-by: Ryan Roberts --- tools/testing/selftests/mm/cow.c | 71 +++++++++++++++++++++++++++++++- 1 file changed, 70 insertions(+), 1 deletion(-) diff --git a/tools/testing/selftests/mm/cow.c b/tools/testing/selftests/mm/= cow.c index d03c453cfd5c..3efc395c7077 100644 --- a/tools/testing/selftests/mm/cow.c +++ b/tools/testing/selftests/mm/cow.c @@ -29,15 +29,49 @@ #include "../../../../mm/gup_test.h" #include "../kselftest.h" #include "vm_util.h" +#include "thp_settings.h" static size_t pagesize; static int pagemap_fd; static size_t pmdsize; +static int nr_thpsmallsizes; +static size_t thpsmallsizes[20]; static int nr_hugetlbsizes; static size_t hugetlbsizes[10]; static int gup_fd; static bool has_huge_zeropage; +static int sz2ord(size_t size) +{ + return __builtin_ctzll(size / pagesize); +} + +static int detect_smallthp_sizes(size_t sizes[], int max) +{ + int count =3D 0; + unsigned long orders; + size_t kb; + int i; + + /* thp not supported at all. */ + if (!pmdsize) + return 0; + + orders =3D thp_supported_orders(); + + /* Only interested in small-sized THP (less than PMD-size). */ + for (i =3D 0; i < sz2ord(pmdsize); i++) { + if (!(orders & (1UL << i))) + continue; + kb =3D (pagesize >> 10) << i; + sizes[count++] =3D kb * 1024; + ksft_print_msg("[INFO] detected small-sized THP size: %zu KiB\n", + kb); + } + + return count; +} + static void detect_huge_zeropage(void) { int fd =3D open("/sys/kernel/mm/transparent_hugepage/use_zero_page", @@ -1113,6 +1147,23 @@ static void run_anon_test_case(struct test_case cons= t *test_case) run_with_partial_mremap_thp(test_case->fn, test_case->desc, pmdsize); run_with_partial_shared_thp(test_case->fn, test_case->desc, pmdsize); } + for (i =3D 0; i < nr_thpsmallsizes; i++) { + size_t size =3D thpsmallsizes[i]; + struct thp_settings settings =3D *thp_current_settings(); + + settings.hugepages[sz2ord(pmdsize)].enabled =3D THP_NEVER; + settings.hugepages[sz2ord(size)].enabled =3D THP_ALWAYS; + thp_push_settings(&settings); + + run_with_pte_mapped_thp(test_case->fn, test_case->desc, size); + run_with_pte_mapped_thp_swap(test_case->fn, test_case->desc, size); + run_with_single_pte_of_thp(test_case->fn, test_case->desc, size); + run_with_single_pte_of_thp_swap(test_case->fn, test_case->desc, size); + run_with_partial_mremap_thp(test_case->fn, test_case->desc, size); + run_with_partial_shared_thp(test_case->fn, test_case->desc, size); + + thp_pop_settings(); + } for (i =3D 0; i < nr_hugetlbsizes; i++) run_with_hugetlb(test_case->fn, test_case->desc, hugetlbsizes[i]); @@ -1134,6 +1185,7 @@ static int tests_per_anon_test_case(void) if (pmdsize) tests +=3D 8; + tests +=3D 6 * nr_thpsmallsizes; return tests; } @@ -1691,12 +1743,24 @@ static int tests_per_non_anon_test_case(void) int main(int argc, char **argv) { int err; + struct thp_settings default_settings; pagesize =3D getpagesize(); pmdsize =3D read_pmd_pagesize(); - if (pmdsize) + if (pmdsize) { + /* Only if THP is supported. */ + thp_read_settings(&default_settings); + default_settings.hugepages[sz2ord(pmdsize)].enabled =3D THP_GLOBAL; + thp_save_settings(); + thp_push_settings(&default_settings); + ksft_print_msg("[INFO] detected PMD-mapped THP size: %zu KiB\n", pmdsize / 1024); + + nr_thpsmallsizes =3D detect_smallthp_sizes(thpsmallsizes, + ARRAY_SIZE(thpsmallsizes)); + } + nr_hugetlbsizes =3D detect_hugetlb_page_sizes(hugetlbsizes, ARRAY_SIZE(hugetlbsizes)); detect_huge_zeropage(); @@ -1715,6 +1779,11 @@ int main(int argc, char **argv) run_anon_thp_test_cases(); run_non_anon_test_cases(); + if (pmdsize) { + /* Only if THP is supported. */ + thp_restore_settings(); + } + err =3D ksft_get_fail_cnt(); if (err) ksft_exit_fail_msg("%d out of %d tests failed\n", -- 2.25.1