From patchwork Mon Jul 24 08:25:16 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Ryan Roberts X-Patchwork-Id: 13323519 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 AEABEC41513 for ; Mon, 24 Jul 2023 08:25:40 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231441AbjGXIZk (ORCPT ); Mon, 24 Jul 2023 04:25:40 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:53830 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231429AbjGXIZi (ORCPT ); Mon, 24 Jul 2023 04:25:38 -0400 Received: from foss.arm.com (foss.arm.com [217.140.110.172]) by lindbergh.monkeyblade.net (Postfix) with ESMTP id 1E5031BE; Mon, 24 Jul 2023 01:25:36 -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 D18A411FB; Mon, 24 Jul 2023 01:26:19 -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 F0D383F67D; Mon, 24 Jul 2023 01:25:34 -0700 (PDT) From: Ryan Roberts To: "Andrew Morton" , "Shuah Khan" , =?utf-8?b?SsOpcsO0bWUgR2xpc3Nl?= , "David Hildenbrand" , "Mark Brown" , "John Hubbard" , "Florent Revest" , "Peter Xu" Cc: Ryan Roberts , linux-kernel@vger.kernel.org, linux-mm@kvack.org, linux-kselftest@vger.kernel.org Subject: [PATCH v3 2/8] selftests/mm: Skip soft-dirty tests on arm64 Date: Mon, 24 Jul 2023 09:25:16 +0100 Message-Id: <20230724082522.1202616-3-ryan.roberts@arm.com> X-Mailer: git-send-email 2.25.1 In-Reply-To: <20230724082522.1202616-1-ryan.roberts@arm.com> References: <20230724082522.1202616-1-ryan.roberts@arm.com> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-kselftest@vger.kernel.org arm64 does not support the soft-dirty PTE bit. However, the `soft-dirty` test suite is currently run unconditionally and therefore generates spurious test failures on arm64. There are also some tests in `madv_populate` which assume it is supported. For `soft-dirty` lets disable the whole suite for arm64; it is no longer built and run_vmtests.sh will skip it if its not present. For `madv_populate`, we need a runtime mechanism so that the remaining tests continue to be run. Unfortunately, the only way to determine if the soft-dirty dirty bit is supported is to write to a page, then see if the bit is set in /proc/self/pagemap. But the tests that we want to conditionally execute are testing precicesly this. So if we introduced this feature check, we could accedentally turn a real failure (on a system that claims to support soft-dirty) into a skip. So instead, do the check based on architecture; for arm64, we report that soft-dirty is not supported. Acked-by: David Hildenbrand Signed-off-by: Ryan Roberts --- tools/testing/selftests/mm/Makefile | 5 ++++- tools/testing/selftests/mm/madv_populate.c | 26 ++++++++++++++++++++-- tools/testing/selftests/mm/run_vmtests.sh | 5 ++++- 3 files changed, 32 insertions(+), 4 deletions(-) diff --git a/tools/testing/selftests/mm/Makefile b/tools/testing/selftests/mm/Makefile index 66d7c07dc177..3514697fc2db 100644 --- a/tools/testing/selftests/mm/Makefile +++ b/tools/testing/selftests/mm/Makefile @@ -63,12 +63,15 @@ TEST_GEN_PROGS += thuge-gen TEST_GEN_PROGS += transhuge-stress TEST_GEN_PROGS += uffd-stress TEST_GEN_PROGS += uffd-unit-tests -TEST_GEN_PROGS += soft-dirty TEST_GEN_PROGS += split_huge_page_test TEST_GEN_PROGS += ksm_tests TEST_GEN_PROGS += ksm_functional_tests TEST_GEN_PROGS += mdwe_test +ifneq ($(ARCH),arm64) +TEST_GEN_PROGS += soft-dirty +endif + ifeq ($(ARCH),x86_64) CAN_BUILD_I386 := $(shell ./../x86/check_cc.sh "$(CC)" ../x86/trivial_32bit_program.c -m32) CAN_BUILD_X86_64 := $(shell ./../x86/check_cc.sh "$(CC)" ../x86/trivial_64bit_program.c) diff --git a/tools/testing/selftests/mm/madv_populate.c b/tools/testing/selftests/mm/madv_populate.c index 60547245e479..17bcb07f19f3 100644 --- a/tools/testing/selftests/mm/madv_populate.c +++ b/tools/testing/selftests/mm/madv_populate.c @@ -264,14 +264,35 @@ static void test_softdirty(void) munmap(addr, SIZE); } +static int system_has_softdirty(void) +{ + /* + * There is no way to check if the kernel supports soft-dirty, other + * than by writing to a page and seeing if the bit was set. But the + * tests are intended to check that the bit gets set when it should, so + * doing that check would turn a potentially legitimate fail into a + * skip. Fortunately, we know for sure that arm64 does not support + * soft-dirty. So for now, let's just use the arch as a corse guide. + */ +#if defined(__aarch64__) + return 0; +#else + return 1; +#endif +} + int main(int argc, char **argv) { + int nr_tests = 16; int err; pagesize = getpagesize(); + if (system_has_softdirty()) + nr_tests += 5; + ksft_print_header(); - ksft_set_plan(21); + ksft_set_plan(nr_tests); sense_support(); test_prot_read(); @@ -279,7 +300,8 @@ int main(int argc, char **argv) test_holes(); test_populate_read(); test_populate_write(); - test_softdirty(); + if (system_has_softdirty()) + test_softdirty(); err = ksft_get_fail_cnt(); if (err) diff --git a/tools/testing/selftests/mm/run_vmtests.sh b/tools/testing/selftests/mm/run_vmtests.sh index 3f26f6e15b2a..9e4338aa5e09 100755 --- a/tools/testing/selftests/mm/run_vmtests.sh +++ b/tools/testing/selftests/mm/run_vmtests.sh @@ -290,7 +290,10 @@ then CATEGORY="pkey" run_test ./protection_keys_64 fi -CATEGORY="soft_dirty" run_test ./soft-dirty +if [ -x ./soft-dirty ] +then + CATEGORY="soft_dirty" run_test ./soft-dirty +fi # COW tests CATEGORY="cow" run_test ./cow