From patchwork Fri Oct 2 11:56:29 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Amit Daniel Kachhap X-Patchwork-Id: 11813167 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id C7BB36CB for ; Fri, 2 Oct 2020 11:57:14 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id B350D208B6 for ; Fri, 2 Oct 2020 11:57:14 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2387966AbgJBL5F (ORCPT ); Fri, 2 Oct 2020 07:57:05 -0400 Received: from foss.arm.com ([217.140.110.172]:33786 "EHLO foss.arm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2387813AbgJBL5C (ORCPT ); Fri, 2 Oct 2020 07:57:02 -0400 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 ACC9F1396; Fri, 2 Oct 2020 04:57:01 -0700 (PDT) Received: from a077416.blr.arm.com (unknown [172.31.20.19]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPA id A99EE3F70D; Fri, 2 Oct 2020 04:56:58 -0700 (PDT) From: Amit Daniel Kachhap To: linux-arm-kernel@lists.infradead.org, linux-kselftest@vger.kernel.org Cc: linux-kernel@vger.kernel.org, Shuah Khan , Catalin Marinas , Will Deacon , Vincenzo Frascino , Gabor Kertesz , Amit Daniel Kachhap Subject: [PATCH v2 5/6] kselftest/arm64: Verify KSM page merge for MTE pages Date: Fri, 2 Oct 2020 17:26:29 +0530 Message-Id: <20201002115630.24683-6-amit.kachhap@arm.com> X-Mailer: git-send-email 2.17.1 In-Reply-To: <20201002115630.24683-1-amit.kachhap@arm.com> References: <20201002115630.24683-1-amit.kachhap@arm.com> Precedence: bulk List-ID: X-Mailing-List: linux-kselftest@vger.kernel.org Add a testcase to check that KSM should not merge pages containing same data with same/different MTE tag values. This testcase has one positive tests and passes if page merging happens according to the above rule. It also saves and restores any modified ksm sysfs entries. Cc: Shuah Khan Cc: Catalin Marinas Cc: Will Deacon Signed-off-by: Amit Daniel Kachhap --- Changes in v2: * Moved read/write sysfs functions from global to local functions. tools/testing/selftests/arm64/mte/.gitignore | 1 + .../selftests/arm64/mte/check_ksm_options.c | 159 ++++++++++++++++++ 2 files changed, 160 insertions(+) create mode 100644 tools/testing/selftests/arm64/mte/check_ksm_options.c diff --git a/tools/testing/selftests/arm64/mte/.gitignore b/tools/testing/selftests/arm64/mte/.gitignore index 79a215d3bbd0..44e9bfdaeca6 100644 --- a/tools/testing/selftests/arm64/mte/.gitignore +++ b/tools/testing/selftests/arm64/mte/.gitignore @@ -2,3 +2,4 @@ check_buffer_fill check_tags_inclusion check_child_memory check_mmap_options +check_ksm_options diff --git a/tools/testing/selftests/arm64/mte/check_ksm_options.c b/tools/testing/selftests/arm64/mte/check_ksm_options.c new file mode 100644 index 000000000000..bc41ae630c86 --- /dev/null +++ b/tools/testing/selftests/arm64/mte/check_ksm_options.c @@ -0,0 +1,159 @@ +// SPDX-License-Identifier: GPL-2.0 +// Copyright (C) 2020 ARM Limited + +#define _GNU_SOURCE + +#include +#include +#include +#include +#include +#include +#include +#include + +#include "kselftest.h" +#include "mte_common_util.h" +#include "mte_def.h" + +#define TEST_UNIT 10 +#define PATH_KSM "/sys/kernel/mm/ksm/" +#define MAX_LOOP 4 + +static size_t page_sz; +static unsigned long ksm_sysfs[5]; + +static unsigned long read_sysfs(char *str) +{ + FILE *f; + unsigned long val = 0; + + f = fopen(str, "r"); + if (!f) { + ksft_print_msg("ERR: missing %s\n", str); + return 0; + } + fscanf(f, "%lu", &val); + fclose(f); + return val; +} + +static void write_sysfs(char *str, unsigned long val) +{ + FILE *f; + + f = fopen(str, "w"); + if (!f) { + ksft_print_msg("ERR: missing %s\n", str); + return; + } + fprintf(f, "%lu", val); + fclose(f); +} + +static void mte_ksm_setup(void) +{ + ksm_sysfs[0] = read_sysfs(PATH_KSM "merge_across_nodes"); + write_sysfs(PATH_KSM "merge_across_nodes", 1); + ksm_sysfs[1] = read_sysfs(PATH_KSM "sleep_millisecs"); + write_sysfs(PATH_KSM "sleep_millisecs", 0); + ksm_sysfs[2] = read_sysfs(PATH_KSM "run"); + write_sysfs(PATH_KSM "run", 1); + ksm_sysfs[3] = read_sysfs(PATH_KSM "max_page_sharing"); + write_sysfs(PATH_KSM "max_page_sharing", ksm_sysfs[3] + TEST_UNIT); + ksm_sysfs[4] = read_sysfs(PATH_KSM "pages_to_scan"); + write_sysfs(PATH_KSM "pages_to_scan", ksm_sysfs[4] + TEST_UNIT); +} + +static void mte_ksm_restore(void) +{ + write_sysfs(PATH_KSM "merge_across_nodes", ksm_sysfs[0]); + write_sysfs(PATH_KSM "sleep_millisecs", ksm_sysfs[1]); + write_sysfs(PATH_KSM "run", ksm_sysfs[2]); + write_sysfs(PATH_KSM "max_page_sharing", ksm_sysfs[3]); + write_sysfs(PATH_KSM "pages_to_scan", ksm_sysfs[4]); +} + +static void mte_ksm_scan(void) +{ + int cur_count = read_sysfs(PATH_KSM "full_scans"); + int scan_count = cur_count + 1; + int max_loop_count = MAX_LOOP; + + while ((cur_count < scan_count) && max_loop_count) { + sleep(1); + cur_count = read_sysfs(PATH_KSM "full_scans"); + max_loop_count--; + } +#ifdef DEBUG + ksft_print_msg("INFO: pages_shared=%lu pages_sharing=%lu\n", + read_sysfs(PATH_KSM "pages_shared"), + read_sysfs(PATH_KSM "pages_sharing")); +#endif +} + +static int check_madvise_options(int mem_type, int mode, int mapping) +{ + char *ptr; + int err, ret; + + err = KSFT_FAIL; + if (access(PATH_KSM, F_OK) == -1) { + ksft_print_msg("ERR: Kernel KSM config not enabled\n"); + return err; + } + + mte_switch_mode(mode, MTE_ALLOW_NON_ZERO_TAG); + ptr = mte_allocate_memory(TEST_UNIT * page_sz, mem_type, mapping, true); + if (check_allocated_memory(ptr, TEST_UNIT * page_sz, mem_type, false) != KSFT_PASS) + return KSFT_FAIL; + + /* Insert same data in all the pages */ + memset(ptr, 'A', TEST_UNIT * page_sz); + ret = madvise(ptr, TEST_UNIT * page_sz, MADV_MERGEABLE); + if (ret) { + ksft_print_msg("ERR: madvise failed to set MADV_UNMERGEABLE\n"); + goto madvise_err; + } + mte_ksm_scan(); + /* Tagged pages should not merge */ + if ((read_sysfs(PATH_KSM "pages_shared") < 1) || + (read_sysfs(PATH_KSM "pages_sharing") < (TEST_UNIT - 1))) + err = KSFT_PASS; +madvise_err: + mte_free_memory(ptr, TEST_UNIT * page_sz, mem_type, true); + return err; +} + +int main(int argc, char *argv[]) +{ + int err; + + err = mte_default_setup(); + if (err) + return err; + page_sz = getpagesize(); + if (!page_sz) { + ksft_print_msg("ERR: Unable to get page size\n"); + return KSFT_FAIL; + } + /* Register signal handlers */ + mte_register_signal(SIGBUS, mte_default_handler); + mte_register_signal(SIGSEGV, mte_default_handler); + /* Enable KSM */ + mte_ksm_setup(); + + evaluate_test(check_madvise_options(USE_MMAP, MTE_SYNC_ERR, MAP_PRIVATE), + "Check KSM mte page merge for private mapping, sync mode and mmap memory\n"); + evaluate_test(check_madvise_options(USE_MMAP, MTE_ASYNC_ERR, MAP_PRIVATE), + "Check KSM mte page merge for private mapping, async mode and mmap memory\n"); + evaluate_test(check_madvise_options(USE_MMAP, MTE_SYNC_ERR, MAP_SHARED), + "Check KSM mte page merge for shared mapping, sync mode and mmap memory\n"); + evaluate_test(check_madvise_options(USE_MMAP, MTE_ASYNC_ERR, MAP_SHARED), + "Check KSM mte page merge for shared mapping, async mode and mmap memory\n"); + + mte_ksm_restore(); + mte_restore_setup(); + ksft_print_cnts(); + return ksft_get_fail_cnt() == 0 ? KSFT_PASS : KSFT_FAIL; +}