From nobody Fri Sep 12 09:43:21 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 A9740E810DF for ; Fri, 29 Sep 2023 11:45:33 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233182AbjI2Lpd (ORCPT ); Fri, 29 Sep 2023 07:45:33 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:55580 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S233180AbjI2LpM (ORCPT ); Fri, 29 Sep 2023 07:45:12 -0400 Received: from foss.arm.com (foss.arm.com [217.140.110.172]) by lindbergh.monkeyblade.net (Postfix) with ESMTP id 88AC11B2 for ; Fri, 29 Sep 2023 04:44:58 -0700 (PDT) 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 7C4B61007; Fri, 29 Sep 2023 04:45:36 -0700 (PDT) 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 9A1783F59C; Fri, 29 Sep 2023 04:44:55 -0700 (PDT) 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 Cc: Ryan Roberts , linux-mm@kvack.org, linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org Subject: [PATCH v6 9/9] selftests/mm/cow: Add tests for small-order anon THP Date: Fri, 29 Sep 2023 12:44:20 +0100 Message-Id: <20230929114421.3761121-10-ryan.roberts@arm.com> X-Mailer: git-send-email 2.25.1 In-Reply-To: <20230929114421.3761121-1-ryan.roberts@arm.com> References: <20230929114421.3761121-1-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 THP tests, but which operate on memory backed by smaller-order, PTE-mapped THP. This reuses all the existing infrastructure. If the test suite detects that small-order THP is not supported by the kernel, the new tests are skipped. Signed-off-by: Ryan Roberts --- tools/testing/selftests/mm/cow.c | 93 ++++++++++++++++++++++++++++++++ 1 file changed, 93 insertions(+) diff --git a/tools/testing/selftests/mm/cow.c b/tools/testing/selftests/mm/= cow.c index d887ce454e34..6c5e37d8bb69 100644 --- a/tools/testing/selftests/mm/cow.c +++ b/tools/testing/selftests/mm/cow.c @@ -33,10 +33,13 @@ static size_t pagesize; static int pagemap_fd; static size_t pmdsize; +static size_t ptesize; static int nr_hugetlbsizes; static size_t hugetlbsizes[10]; static int gup_fd; static bool has_huge_zeropage; +static unsigned int orig_anon_orders; +static bool orig_anon_orders_valid; =20 static void detect_huge_zeropage(void) { @@ -1118,6 +1121,14 @@ 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); } + if (ptesize) { + run_with_pte_mapped_thp(test_case->fn, test_case->desc, ptesize); + run_with_pte_mapped_thp_swap(test_case->fn, test_case->desc, ptesize); + run_with_single_pte_of_thp(test_case->fn, test_case->desc, ptesize); + run_with_single_pte_of_thp_swap(test_case->fn, test_case->desc, ptesize); + run_with_partial_mremap_thp(test_case->fn, test_case->desc, ptesize); + run_with_partial_shared_thp(test_case->fn, test_case->desc, ptesize); + } for (i =3D 0; i < nr_hugetlbsizes; i++) run_with_hugetlb(test_case->fn, test_case->desc, hugetlbsizes[i]); @@ -1139,6 +1150,8 @@ static int tests_per_anon_test_case(void) =20 if (pmdsize) tests +=3D 8; + if (ptesize) + tests +=3D 6; return tests; } =20 @@ -1693,6 +1706,80 @@ static int tests_per_non_anon_test_case(void) return tests; } =20 +#define ANON_ORDERS_FILE "/sys/kernel/mm/transparent_hugepage/anon_orders" + +static int read_anon_orders(unsigned int *orders) +{ + ssize_t buflen =3D 80; + char buf[buflen]; + int fd; + + fd =3D open(ANON_ORDERS_FILE, O_RDONLY); + if (fd =3D=3D -1) + return -1; + + buflen =3D read(fd, buf, buflen); + close(fd); + + if (buflen < 1) + return -1; + + *orders =3D strtoul(buf, NULL, 16); + + return 0; +} + +static int write_anon_orders(unsigned int orders) +{ + ssize_t buflen =3D 80; + char buf[buflen]; + int fd; + + fd =3D open(ANON_ORDERS_FILE, O_WRONLY); + if (fd =3D=3D -1) + return -1; + + buflen =3D snprintf(buf, buflen, "0x%08x\n", orders); + buflen =3D write(fd, buf, buflen); + close(fd); + + if (buflen < 1) + return -1; + + return 0; +} + +static size_t save_thp_anon_orders(void) +{ + /* + * If the kernel supports multiple orders for anon THP (indicated by the + * presence of anon_orders file), configure it for the PMD-order and the + * PMD-order - 1, which we will report back and use as the PTE-order THP + * size. Save the original value so that it can be restored on exit. If + * the kernel does not support multiple orders, report back 0 for the + * PTE-size so those tests are skipped. + */ + + int pteorder =3D sz2ord(pmdsize) - 1; + unsigned int orders =3D (1UL << sz2ord(pmdsize)) | (1UL << pteorder); + + if (read_anon_orders(&orig_anon_orders)) + return 0; + + orig_anon_orders_valid =3D true; + + if (write_anon_orders(orders)) + return 0; + + return pagesize << pteorder; +} + +static void restore_thp_anon_orders(void) +{ + if (orig_anon_orders_valid) + write_anon_orders(orig_anon_orders); +} + int main(int argc, char **argv) { int err; @@ -1702,6 +1789,10 @@ int main(int argc, char **argv) if (pmdsize) ksft_print_msg("[INFO] detected PMD-mapped THP size: %zu KiB\n", pmdsize / 1024); + ptesize =3D save_thp_anon_orders(); + if (ptesize) + ksft_print_msg("[INFO] configured PTE-mapped THP size: %zu KiB\n", + ptesize / 1024); nr_hugetlbsizes =3D detect_hugetlb_page_sizes(hugetlbsizes, ARRAY_SIZE(hugetlbsizes)); detect_huge_zeropage(); @@ -1720,6 +1811,8 @@ int main(int argc, char **argv) run_anon_thp_test_cases(); run_non_anon_test_cases(); =20 + restore_thp_anon_orders(); + err =3D ksft_get_fail_cnt(); if (err) ksft_exit_fail_msg("%d out of %d tests failed\n", --=20 2.25.1