From patchwork Wed Jul 14 08:56:06 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Zhansaya Bagdauletkyzy X-Patchwork-Id: 477099 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-12.7 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI, SPF_HELO_NONE, SPF_PASS, URIBL_BLOCKED autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 00A3AC07E9A for ; Wed, 14 Jul 2021 08:56:20 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id DF833613AB for ; Wed, 14 Jul 2021 08:56:19 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S238721AbhGNI7K (ORCPT ); Wed, 14 Jul 2021 04:59:10 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:40756 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S238522AbhGNI7D (ORCPT ); Wed, 14 Jul 2021 04:59:03 -0400 Received: from mail-lf1-x12e.google.com (mail-lf1-x12e.google.com [IPv6:2a00:1450:4864:20::12e]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 375DCC06175F; Wed, 14 Jul 2021 01:56:12 -0700 (PDT) Received: by mail-lf1-x12e.google.com with SMTP id t17so2444315lfq.0; Wed, 14 Jul 2021 01:56:12 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=date:from:to:cc:subject:message-id:references:mime-version :content-disposition:in-reply-to; bh=maZmDltJjlSNn3qTEHsM/7ThuHpuAl7iCWqDo9+ZU40=; b=jZ+Q/I+5CdQ3/y5cbpBiZ54d8rB/7KQFRvDblT8wvvFpDqZnfxE/ShAcvJPBtH6ZMi 6hPnVbBRAFhnS717XTk/TrxgTJZPSWuiQdMLLkUKai9btH8qUNpY1RR8Nv5o/tYGsewk XiarMSo9eo0LkWFGfrrcRhDJNoS4uHPazxNnRvTPqxx3tyntBt3MpyXE2VCGgKgNhZa2 jiV8rPMV4SgMlobIbGHJi3HqS7Lo6Rbk+8o2Iso//sb9lo7ND/n04RP/CRLRFLXcoJaD D47cSXbJ4ebixkRpWsR9EsRUnWcZQ2HzqYtJHygghvchEj7n6Ua4LzYimsEh/yk0/++c gNXw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:date:from:to:cc:subject:message-id:references :mime-version:content-disposition:in-reply-to; bh=maZmDltJjlSNn3qTEHsM/7ThuHpuAl7iCWqDo9+ZU40=; b=dokcifAPHi++qAinniz7GS7b3nVewE7SzQNLKa1gABoV5rg/lqyqmVR1yct+7V1lKG /Rok9ZaP4SfeVGDx+RgqomNswvlcFGTjZVmqeBvE00pUtrlCI4FTjYG/zqv7vwOLIulq ynhTVks/f+ZtsDFtN7HOB1YUounLJnmO1/aLdwobF1gqR5YvlSIcMO9bZ2Z287nmg7FC QXUnxKrbaiPbdBK+9MbNSzggU1bpORgNe4q/ruzh6QVRFgt7W/dFY7NlTAo7d993E/A9 2Gfe6DP4idzEZaDtTG8ifzl5mydWDP2a4HgIHL/GfZIlHSvUeltyu0tPYyFGZ8MCvnkb HP4Q== X-Gm-Message-State: AOAM533YkYGX3uuG7lBZ60H4cXW6deAh88VQMeW+GzoEKS3riLWC6fwR J2i7LRxqVthMO9hL9n+z6Yg= X-Google-Smtp-Source: ABdhPJyIfadpgHuSDkXYZGa93nw13wrm6Tg0c7aEIWtfyThr35xd4x4//RlHBiSJJ631m0QwQltczw== X-Received: by 2002:ac2:5312:: with SMTP id c18mr6965605lfh.649.1626252970494; Wed, 14 Jul 2021 01:56:10 -0700 (PDT) Received: from asus ([93.95.240.58]) by smtp.gmail.com with ESMTPSA id p9sm112508lfu.185.2021.07.14.01.56.08 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Wed, 14 Jul 2021 01:56:10 -0700 (PDT) Date: Wed, 14 Jul 2021 14:56:06 +0600 From: Zhansaya Bagdauletkyzy To: shuah@kernel.org, akpm@linux-foundation.org Cc: linux-kernel@vger.kernel.org, linux-kselftest@vger.kernel.org, linux-mm@kvack.org, tyhicks@linux.microsoft.com, pasha.tatashin@soleen.com Subject: [PATCH v2 1/4] selftests: vm: add KSM merge test Message-ID: <90287685c13300972ea84de93d1f3f900373f9fe.1626252248.git.zhansayabagdaulet@gmail.com> References: MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: Precedence: bulk List-ID: X-Mailing-List: linux-kselftest@vger.kernel.org Add check_ksm_merge() function to check the basic merging feature of KSM. First, some number of identical pages are allocated and the MADV_MERGEABLE advice is given to merge these pages. Then, pages_shared and pages_sharing values are compared with the expected numbers using assert_ksm_pages_count() function. The number of pages can be changed using -p option. Signed-off-by: Zhansaya Bagdauletkyzy Reviewed-by: Pavel Tatashin Reviewed-by: Tyler Hicks --- tools/testing/selftests/vm/.gitignore | 1 + tools/testing/selftests/vm/Makefile | 1 + tools/testing/selftests/vm/ksm_tests.c | 306 ++++++++++++++++++++++ tools/testing/selftests/vm/run_vmtests.sh | 16 ++ 4 files changed, 324 insertions(+) create mode 100644 tools/testing/selftests/vm/ksm_tests.c diff --git a/tools/testing/selftests/vm/.gitignore b/tools/testing/selftests/vm/.gitignore index f0fd80ef17df..b02eac613fdd 100644 --- a/tools/testing/selftests/vm/.gitignore +++ b/tools/testing/selftests/vm/.gitignore @@ -27,3 +27,4 @@ hmm-tests memfd_secret local_config.* split_huge_page_test +ksm_tests diff --git a/tools/testing/selftests/vm/Makefile b/tools/testing/selftests/vm/Makefile index 521243770f26..e6f22a801b71 100644 --- a/tools/testing/selftests/vm/Makefile +++ b/tools/testing/selftests/vm/Makefile @@ -45,6 +45,7 @@ TEST_GEN_FILES += thuge-gen TEST_GEN_FILES += transhuge-stress TEST_GEN_FILES += userfaultfd TEST_GEN_FILES += split_huge_page_test +TEST_GEN_FILES += ksm_tests ifeq ($(MACHINE),x86_64) CAN_BUILD_I386 := $(shell ./../x86/check_cc.sh $(CC) ../x86/trivial_32bit_program.c -m32) diff --git a/tools/testing/selftests/vm/ksm_tests.c b/tools/testing/selftests/vm/ksm_tests.c new file mode 100644 index 000000000000..d74d5aa34b16 --- /dev/null +++ b/tools/testing/selftests/vm/ksm_tests.c @@ -0,0 +1,306 @@ +// SPDX-License-Identifier: GPL-2.0 + +#include +#include +#include +#include + +#include "../kselftest.h" + +#define KSM_SYSFS_PATH "/sys/kernel/mm/ksm/" +#define KSM_FP(s) (KSM_SYSFS_PATH s) +#define KSM_SCAN_LIMIT_SEC_DEFAULT 120 +#define KSM_PAGE_COUNT_DEFAULT 10l +#define KSM_PROT_STR_DEFAULT "rw" + +struct ksm_sysfs { + unsigned long max_page_sharing; + unsigned long merge_across_nodes; + unsigned long pages_to_scan; + unsigned long run; + unsigned long sleep_millisecs; + unsigned long stable_node_chains_prune_millisecs; + unsigned long use_zero_pages; +}; + +static int ksm_write_sysfs(const char *file_path, unsigned long val) +{ + FILE *f = fopen(file_path, "w"); + + if (!f) { + fprintf(stderr, "f %s\n", file_path); + perror("fopen"); + return 1; + } + if (fprintf(f, "%lu", val) < 0) { + perror("fprintf"); + return 1; + } + fclose(f); + + return 0; +} + +static int ksm_read_sysfs(const char *file_path, unsigned long *val) +{ + FILE *f = fopen(file_path, "r"); + + if (!f) { + fprintf(stderr, "f %s\n", file_path); + perror("fopen"); + return 1; + } + if (fscanf(f, "%lu", val) != 1) { + perror("fscanf"); + return 1; + } + fclose(f); + + return 0; +} + +static int str_to_prot(char *prot_str) +{ + int prot = 0; + + if ((strchr(prot_str, 'r')) != NULL) + prot |= PROT_READ; + if ((strchr(prot_str, 'w')) != NULL) + prot |= PROT_WRITE; + if ((strchr(prot_str, 'x')) != NULL) + prot |= PROT_EXEC; + + return prot; +} + +static void print_help(void) +{ + printf("usage: ksm_tests [-h] [-a prot] [-p page_count] [-l timeout]\n"); + printf(" -a: specify the access protections of pages.\n" + " must be of the form [rwx].\n" + " Default: %s\n", KSM_PROT_STR_DEFAULT); + printf(" -p: specify the number of pages to test.\n" + " Default: %ld\n", KSM_PAGE_COUNT_DEFAULT); + printf(" -l: limit the maximum running time (in seconds) for a test.\n" + " Default: %d seconds\n", KSM_SCAN_LIMIT_SEC_DEFAULT); + + exit(0); +} + +static void *allocate_memory(void *ptr, int prot, int mapping, char data, size_t map_size) +{ + void *map_ptr = mmap(ptr, map_size, PROT_WRITE, mapping, -1, 0); + + if (!map_ptr) { + perror("mmap"); + return NULL; + } + memset(map_ptr, data, map_size); + if (mprotect(map_ptr, map_size, prot)) { + perror("mprotect"); + munmap(map_ptr, map_size); + return NULL; + } + + return map_ptr; +} + +static int ksm_do_scan(int scan_count, struct timespec start_time, int timeout) +{ + struct timespec cur_time; + unsigned long cur_scan, init_scan; + + if (ksm_read_sysfs(KSM_FP("full_scans"), &init_scan)) + return 1; + cur_scan = init_scan; + + while (cur_scan < init_scan + scan_count) { + if (ksm_read_sysfs(KSM_FP("full_scans"), &cur_scan)) + return 1; + if (clock_gettime(CLOCK_MONOTONIC_RAW, &cur_time)) { + perror("clock_gettime"); + return 1; + } + if ((cur_time.tv_sec - start_time.tv_sec) > timeout) { + printf("Scan time limit exceeded\n"); + return 1; + } + } + + return 0; +} + +static int ksm_merge_pages(void *addr, size_t size, struct timespec start_time, int timeout) +{ + if (madvise(addr, size, MADV_MERGEABLE)) { + perror("madvise"); + return 1; + } + if (ksm_write_sysfs(KSM_FP("run"), 1)) + return 1; + + /* Since merging occurs only after 2 scans, make sure to get at least 2 full scans */ + if (ksm_do_scan(2, start_time, timeout)) + return 1; + + return 0; +} + +static bool assert_ksm_pages_count(long dupl_page_count) +{ + unsigned long max_page_sharing, pages_sharing, pages_shared; + + if (ksm_read_sysfs(KSM_FP("pages_shared"), &pages_shared) || + ksm_read_sysfs(KSM_FP("pages_sharing"), &pages_sharing) || + ksm_read_sysfs(KSM_FP("max_page_sharing"), &max_page_sharing)) + return false; + + /* + * Since there must be at least 2 pages for merging and 1 page can be + * shared with the limited number of pages (max_page_sharing), sometimes + * there are 'leftover' pages that cannot be merged. For example, if there + * are 11 pages and max_page_sharing = 10, then only 10 pages will be + * merged and the 11th page won't be affected. As a result, when the number + * of duplicate pages is divided by max_page_sharing and the remainder is 1, + * pages_shared and pages_sharing values will be equal between dupl_page_count + * and dupl_page_count - 1. + */ + if (dupl_page_count % max_page_sharing == 1 || dupl_page_count % max_page_sharing == 0) { + if (pages_shared == dupl_page_count / max_page_sharing && + pages_sharing == pages_shared * (max_page_sharing - 1)) + return true; + } else { + if (pages_shared == (dupl_page_count / max_page_sharing + 1) && + pages_sharing == dupl_page_count - pages_shared) + return true; + } + + return false; +} + +static int ksm_save_def(struct ksm_sysfs *ksm_sysfs) +{ + if (ksm_read_sysfs(KSM_FP("max_page_sharing"), &ksm_sysfs->max_page_sharing) || + ksm_read_sysfs(KSM_FP("merge_across_nodes"), &ksm_sysfs->merge_across_nodes) || + ksm_read_sysfs(KSM_FP("sleep_millisecs"), &ksm_sysfs->sleep_millisecs) || + ksm_read_sysfs(KSM_FP("pages_to_scan"), &ksm_sysfs->pages_to_scan) || + ksm_read_sysfs(KSM_FP("run"), &ksm_sysfs->run) || + ksm_read_sysfs(KSM_FP("stable_node_chains_prune_millisecs"), + &ksm_sysfs->stable_node_chains_prune_millisecs) || + ksm_read_sysfs(KSM_FP("use_zero_pages"), &ksm_sysfs->use_zero_pages)) + return 1; + + return 0; +} + +static int ksm_restore(struct ksm_sysfs *ksm_sysfs) +{ + if (ksm_write_sysfs(KSM_FP("max_page_sharing"), ksm_sysfs->max_page_sharing) || + ksm_write_sysfs(KSM_FP("merge_across_nodes"), ksm_sysfs->merge_across_nodes) || + ksm_write_sysfs(KSM_FP("pages_to_scan"), ksm_sysfs->pages_to_scan) || + ksm_write_sysfs(KSM_FP("run"), ksm_sysfs->run) || + ksm_write_sysfs(KSM_FP("sleep_millisecs"), ksm_sysfs->sleep_millisecs) || + ksm_write_sysfs(KSM_FP("stable_node_chains_prune_millisecs"), + ksm_sysfs->stable_node_chains_prune_millisecs) || + ksm_write_sysfs(KSM_FP("use_zero_pages"), ksm_sysfs->use_zero_pages)) + return 1; + + return 0; +} + +static int check_ksm_merge(int mapping, int prot, long page_count, int timeout, size_t page_size) +{ + void *map_ptr; + struct timespec start_time; + + if (clock_gettime(CLOCK_MONOTONIC_RAW, &start_time)) { + perror("clock_gettime"); + return KSFT_FAIL; + } + + /* fill pages with the same data and merge them */ + map_ptr = allocate_memory(NULL, prot, mapping, '*', page_size * page_count); + if (!map_ptr) + return KSFT_FAIL; + + if (ksm_merge_pages(map_ptr, page_size * page_count, start_time, timeout)) + goto err_out; + + /* verify that the right number of pages are merged */ + if (assert_ksm_pages_count(page_count)) { + printf("OK\n"); + munmap(map_ptr, page_size * page_count); + return KSFT_PASS; + } + +err_out: + printf("Not OK\n"); + munmap(map_ptr, page_size * page_count); + return KSFT_FAIL; +} + +int main(int argc, char *argv[]) +{ + int ret, opt; + int prot = 0; + int ksm_scan_limit_sec = KSM_SCAN_LIMIT_SEC_DEFAULT; + long page_count = KSM_PAGE_COUNT_DEFAULT; + size_t page_size = sysconf(_SC_PAGESIZE); + struct ksm_sysfs ksm_sysfs_old; + + while ((opt = getopt(argc, argv, "ha:p:l:")) != -1) { + switch (opt) { + case 'a': + prot = str_to_prot(optarg); + break; + case 'p': + page_count = atol(optarg); + if (page_count <= 0) { + printf("The number of pages must be greater than 0\n"); + return KSFT_FAIL; + } + break; + case 'l': + ksm_scan_limit_sec = atoi(optarg); + if (ksm_scan_limit_sec <= 0) { + printf("Timeout value must be greater than 0\n"); + return KSFT_FAIL; + } + break; + case 'h': + print_help(); + break; + default: + return KSFT_FAIL; + } + } + + if (prot == 0) + prot = str_to_prot(KSM_PROT_STR_DEFAULT); + + if (access(KSM_SYSFS_PATH, F_OK)) { + printf("Config KSM not enabled\n"); + return KSFT_SKIP; + } + + if (ksm_save_def(&ksm_sysfs_old)) { + printf("Cannot save default tunables\n"); + return KSFT_FAIL; + } + + if (ksm_write_sysfs(KSM_FP("run"), 2) || + ksm_write_sysfs(KSM_FP("sleep_millisecs"), 0) || + ksm_write_sysfs(KSM_FP("merge_across_nodes"), 1) || + ksm_write_sysfs(KSM_FP("pages_to_scan"), page_count)) + return KSFT_FAIL; + + ret = check_ksm_merge(MAP_PRIVATE | MAP_ANONYMOUS, prot, page_count, ksm_scan_limit_sec, + page_size); + + if (ksm_restore(&ksm_sysfs_old)) { + printf("Cannot restore default tunables\n"); + return KSFT_FAIL; + } + + return ret; +} diff --git a/tools/testing/selftests/vm/run_vmtests.sh b/tools/testing/selftests/vm/run_vmtests.sh index d09a6b71f1e9..97b6f712134d 100755 --- a/tools/testing/selftests/vm/run_vmtests.sh +++ b/tools/testing/selftests/vm/run_vmtests.sh @@ -377,6 +377,22 @@ else exitcode=1 fi +echo "-------------------------------------------------------" +echo "running KSM MADV_MERGEABLE test with 10 identical pages" +echo "-------------------------------------------------------" +./ksm_tests -p 10 +ret_val=$? + +if [ $ret_val -eq 0 ]; then + echo "[PASS]" +elif [ $ret_val -eq $ksft_skip ]; then + echo "[SKIP]" + exitcode=$ksft_skip +else + echo "[FAIL]" + exitcode=1 +fi + exit $exitcode exit $exitcode