From patchwork Wed Apr 20 08:40:35 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Muhammad Usama Anjum X-Patchwork-Id: 564602 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 35DD7C433EF for ; Wed, 20 Apr 2022 08:41:13 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1376803AbiDTIn5 (ORCPT ); Wed, 20 Apr 2022 04:43:57 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:39962 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1376792AbiDTInz (ORCPT ); Wed, 20 Apr 2022 04:43:55 -0400 Received: from bhuna.collabora.co.uk (bhuna.collabora.co.uk [46.235.227.227]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 9CC7333A14; Wed, 20 Apr 2022 01:41:07 -0700 (PDT) Received: from [127.0.0.1] (localhost [127.0.0.1]) (Authenticated sender: usama.anjum) with ESMTPSA id 6E99F1F43125 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=collabora.com; s=mail; t=1650444063; bh=im8qykLjAzYpEBohglRiXlxjTUS5oRxPNoJmH5S8HiE=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=ks/SjqCz9+U7MsH22wqPJOnvN3ahvOsS3Ugzsgi4vT1We5AbHuA0+KeIL+7ldvDpd 5NNC8xRDBnvG7IDSR6tGUdA6/IAoQr5Ivdxn6XTkMHByjaOhPoquSh718ccx/Yzd16 pIKs5y8bRc9mdRV2D3ZeoOYah5T4c+buBWNADxcN6j32V0DgNE3sjynuP7vqgtHOpp VmKIFR9pCnuU4kAHNvSfE+CjDRjoctuOlX9pi2PipKyn7sUhK8u9dnEB1obGQuNhSV 9KPj3quSW7KoUdTGSfxF694ppg9uyuPTis8bv1wFSBYL8cC0UssgrvWFBGU3xUhBdk fnFLCnQ69je8w== From: Muhammad Usama Anjum To: Andrew Morton , Shuah Khan Cc: Gabriel Krisman Bertazi , usama.anjum@collabora.com, kernel@collabora.com, Will Deacon , linux-kernel@vger.kernel.org, linux-mm@kvack.org, linux-kselftest@vger.kernel.org Subject: [PATCH v6 2/2] selftests: vm: Add test for Soft-Dirty PTE bit Date: Wed, 20 Apr 2022 13:40:35 +0500 Message-Id: <20220420084036.4101604-2-usama.anjum@collabora.com> X-Mailer: git-send-email 2.30.2 In-Reply-To: <20220420084036.4101604-1-usama.anjum@collabora.com> References: <20220420084036.4101604-1-usama.anjum@collabora.com> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-kselftest@vger.kernel.org From: Gabriel Krisman Bertazi This introduces three tests: 1) Sanity check soft dirty basic semantics: allocate area, clean, dirty, check if the SD bit is flipped. 2) Check VMA reuse: validate the VM_SOFTDIRTY usage 3) Check soft-dirty on huge pages This was motivated by Will Deacon's fix commit 912efa17e512 ("mm: proc: Invalidate TLB after clearing soft-dirty page state"). I was tracking the same issue that he fixed, and this test would have caught it. Cc: Will Deacon Signed-off-by: Gabriel Krisman Bertazi Co-developed-by: Muhammad Usama Anjum Signed-off-by: Muhammad Usama Anjum --- Changes in V6: - Update VMA reuse sub test to make it more elaborative - Minor changes in writing to the pages Output: TAP version 13 1..5 ok 1 Test test_simple ok 2 Test test_vma_reuse dirty bit of allocated page ok 3 Test test_vma_reuse dirty bit of reused address page ok 4 Test test_hugepage huge page allocation ok 5 Test test_hugepage huge page dirty bit # Totals: pass:5 fail:0 xfail:0 xpass:0 skip:0 error:0 Changes in V5: - Correct indentation of macros - Tested by reverting 912efa17e512 and one sub test failed - Updated the writing values to the memory and added a comment Changes in V4: Cosmetic changes Removed global variables Replaced ksft_print_msg with ksft_exit_fail_msg to exit the program at once Some other minor changes Correct the authorship of the patch Changes in V3: Move test to selftests/vm Use kselftest macros Minor updates to make code more maintainable Add configurations in config file V2 of this patch: https://lore.kernel.org/lkml/20210603151518.2437813-1-krisman@collabora.com/ --- tools/testing/selftests/vm/.gitignore | 1 + tools/testing/selftests/vm/Makefile | 2 + tools/testing/selftests/vm/config | 2 + tools/testing/selftests/vm/soft-dirty.c | 145 ++++++++++++++++++++++++ 4 files changed, 150 insertions(+) create mode 100644 tools/testing/selftests/vm/soft-dirty.c diff --git a/tools/testing/selftests/vm/.gitignore b/tools/testing/selftests/vm/.gitignore index d7507f3c7c76a..3cb4fa771ec2a 100644 --- a/tools/testing/selftests/vm/.gitignore +++ b/tools/testing/selftests/vm/.gitignore @@ -29,5 +29,6 @@ write_to_hugetlbfs hmm-tests memfd_secret local_config.* +soft-dirty split_huge_page_test ksm_tests diff --git a/tools/testing/selftests/vm/Makefile b/tools/testing/selftests/vm/Makefile index 4e68edb26d6b6..f25eb30b5f0cb 100644 --- a/tools/testing/selftests/vm/Makefile +++ b/tools/testing/selftests/vm/Makefile @@ -47,6 +47,7 @@ TEST_GEN_FILES += on-fault-limit TEST_GEN_FILES += thuge-gen TEST_GEN_FILES += transhuge-stress TEST_GEN_FILES += userfaultfd +TEST_GEN_PROGS += soft-dirty TEST_GEN_PROGS += split_huge_page_test TEST_GEN_FILES += ksm_tests @@ -92,6 +93,7 @@ KSFT_KHDR_INSTALL := 1 include ../lib.mk $(OUTPUT)/madv_populate: vm_util.c +$(OUTPUT)/soft-dirty: vm_util.c $(OUTPUT)/split_huge_page_test: vm_util.c ifeq ($(MACHINE),x86_64) diff --git a/tools/testing/selftests/vm/config b/tools/testing/selftests/vm/config index 60e82da0de850..be087c4bc3961 100644 --- a/tools/testing/selftests/vm/config +++ b/tools/testing/selftests/vm/config @@ -4,3 +4,5 @@ CONFIG_TEST_VMALLOC=m CONFIG_DEVICE_PRIVATE=y CONFIG_TEST_HMM=m CONFIG_GUP_TEST=y +CONFIG_TRANSPARENT_HUGEPAGE=y +CONFIG_MEM_SOFT_DIRTY=y diff --git a/tools/testing/selftests/vm/soft-dirty.c b/tools/testing/selftests/vm/soft-dirty.c new file mode 100644 index 0000000000000..08ab62a4a9d07 --- /dev/null +++ b/tools/testing/selftests/vm/soft-dirty.c @@ -0,0 +1,145 @@ +// SPDX-License-Identifier: GPL-2.0 +#include +#include +#include +#include +#include +#include +#include +#include "../kselftest.h" +#include "vm_util.h" + +#define PAGEMAP_FILE_PATH "/proc/self/pagemap" +#define TEST_ITERATIONS 10000 + +static void test_simple(int pagemap_fd, int pagesize) +{ + int i; + char *map; + + map = aligned_alloc(pagesize, pagesize); + if (!map) + ksft_exit_fail_msg("mmap failed\n"); + + clear_softdirty(); + + for (i = 0 ; i < TEST_ITERATIONS; i++) { + if (pagemap_is_softdirty(pagemap_fd, map) == 1) { + ksft_print_msg("dirty bit was 1, but should be 0 (i=%d)\n", i); + break; + } + + clear_softdirty(); + // Write something to the page to get the dirty bit enabled on the page + map[0]++; + + if (pagemap_is_softdirty(pagemap_fd, map) == 0) { + ksft_print_msg("dirty bit was 0, but should be 1 (i=%d)\n", i); + break; + } + + clear_softdirty(); + } + free(map); + + ksft_test_result(i == TEST_ITERATIONS, "Test %s\n", __func__); +} + +static void test_vma_reuse(int pagemap_fd, int pagesize) +{ + char *map, *map2; + + map = mmap(NULL, pagesize, (PROT_READ | PROT_WRITE), (MAP_PRIVATE | MAP_ANON), -1, 0); + if (map == MAP_FAILED) + ksft_exit_fail_msg("mmap failed"); + + // The kernel always marks new regions as soft dirty + ksft_test_result(pagemap_is_softdirty(pagemap_fd, map) == 1, + "Test %s dirty bit of allocated page\n", __func__); + + clear_softdirty(); + munmap(map, pagesize); + + map2 = mmap(NULL, pagesize, (PROT_READ | PROT_WRITE), (MAP_PRIVATE | MAP_ANON), -1, 0); + if (map2 == MAP_FAILED) + ksft_exit_fail_msg("mmap failed"); + + // Dirty bit is set for new regions even if they are reused + if (map == map2) + ksft_test_result(pagemap_is_softdirty(pagemap_fd, map2) == 1, + "Test %s dirty bit of reused address page\n", __func__); + else + ksft_test_result_skip("Test %s dirty bit of reused address page\n", __func__); + + munmap(map2, pagesize); +} + +static void test_hugepage(int pagemap_fd, int pagesize) +{ + char *map; + int i, ret; + size_t hpage_len = read_pmd_pagesize(); + + map = memalign(hpage_len, hpage_len); + if (!map) + ksft_exit_fail_msg("memalign failed\n"); + + ret = madvise(map, hpage_len, MADV_HUGEPAGE); + if (ret) + ksft_exit_fail_msg("madvise failed %d\n", ret); + + for (i = 0; i < hpage_len; i++) + map[i] = (char)i; + + if (check_huge(map)) { + ksft_test_result_pass("Test %s huge page allocation\n", __func__); + + clear_softdirty(); + for (i = 0 ; i < TEST_ITERATIONS ; i++) { + if (pagemap_is_softdirty(pagemap_fd, map) == 1) { + ksft_print_msg("dirty bit was 1, but should be 0 (i=%d)\n", i); + break; + } + + clear_softdirty(); + // Write something to the page to get the dirty bit enabled on the page + map[0]++; + + if (pagemap_is_softdirty(pagemap_fd, map) == 0) { + ksft_print_msg("dirty bit was 0, but should be 1 (i=%d)\n", i); + break; + } + clear_softdirty(); + } + + ksft_test_result(i == TEST_ITERATIONS, "Test %s huge page dirty bit\n", __func__); + } else { + // hugepage allocation failed. skip these tests + ksft_test_result_skip("Test %s huge page allocation\n", __func__); + ksft_test_result_skip("Test %s huge page dirty bit\n", __func__); + } + free(map); +} + +int main(int argc, char **argv) +{ + int pagemap_fd; + int pagesize; + + ksft_print_header(); + ksft_set_plan(5); + + pagemap_fd = open(PAGEMAP_FILE_PATH, O_RDONLY); + if (pagemap_fd < 0) + ksft_exit_fail_msg("Failed to open %s\n", PAGEMAP_FILE_PATH); + + pagesize = getpagesize(); + + test_simple(pagemap_fd, pagesize); + test_vma_reuse(pagemap_fd, pagesize); + test_hugepage(pagemap_fd, pagesize); + + close(pagemap_fd); + + return ksft_exit_pass(); +}