From patchwork Wed Jul 14 08:56:14 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Zhansaya Bagdauletkyzy X-Patchwork-Id: 477098 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 EAE45C11F69 for ; Wed, 14 Jul 2021 08:56:21 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id D54F1613C1 for ; Wed, 14 Jul 2021 08:56:21 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S238717AbhGNI7L (ORCPT ); Wed, 14 Jul 2021 04:59:11 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:40790 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S238720AbhGNI7K (ORCPT ); Wed, 14 Jul 2021 04:59:10 -0400 Received: from mail-lj1-x236.google.com (mail-lj1-x236.google.com [IPv6:2a00:1450:4864:20::236]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id B7097C061766; Wed, 14 Jul 2021 01:56:18 -0700 (PDT) Received: by mail-lj1-x236.google.com with SMTP id r16so2264970ljk.9; Wed, 14 Jul 2021 01:56:18 -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=Dlc+fhK0S5ZoY0KI8N6iYNVFp1fJcgq3Bsfweli+I2c=; b=FQ66VKEg8om5A96sITouaGRGALw6FckhEf0aiEWEPxdTtlGGS8tapuCMdKoK2zpxyt Yf+lOFhgc5WPeXyGPH6oxUbx3ZgPbmN3ZjmixtWedHjq4eg9WCYe8fflR1tXuuYDLwC3 T/ziy1peGQNzQHh1HBCWuKLiF7leunsuRW4J0L671d+7S5nT/4CW+axQ1I4Qlt8StQKu W6AcfDQaC4EnygTJkd2sVdRUS145Rxn3/gQud3vCCtnXnPzVpFUguM1RcSgI2ke54DWv wJlCQ0IRvww3L2IM3mwLMDiFA2ARucez1CCuF9TpWqybclbxowNdl6VvcgQxx+cQaJ7d TvzA== 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=Dlc+fhK0S5ZoY0KI8N6iYNVFp1fJcgq3Bsfweli+I2c=; b=f02t0DDDwZO2KzdatkM8BraU9f3MKudz7/4ZL1DNnv1TjkDFsn/pMXLdIeckXbBqu8 bp/bWBWBgKqddLYN5W7DR7d2tQFkeKJdeRkEaQ+5dyLKAcuIal0O0t7H+M8NmY6p/4YT aoBk14Ze9Gqx6RHb/hgGRvsTmkXFFcrxLbX6NKcj+E+zSNN8665aUqTy2c6doU03Drrh VMbMSYT3jYTTtwo4cYSociCVO8UP9Uax9rErrvCW0f0j5ZjJsxHGi1tSCwnV4NzDyGYZ UUUjBcR6Yqq/E+F8GWeAMV53lEOcEdgzD2J0hZPKtoCimzjEZ1yH/FaSIN7suf62rf5U IQlQ== X-Gm-Message-State: AOAM533AQQT/S/wY0y778U/Nk7Kp7DdTs/EvTe+srBHPV5DFj9BDw4Om KFILhiBXG7c7fWLZoOKZp6A= X-Google-Smtp-Source: ABdhPJya7v51f4/5M0Ss/86YNhCuk40JictEIoevmKM4R3OtbKGBZ88XvSDsWz3xQLss4d9rSgdYSA== X-Received: by 2002:a2e:9f11:: with SMTP id u17mr8160709ljk.16.1626252977105; Wed, 14 Jul 2021 01:56:17 -0700 (PDT) Received: from asus ([93.95.240.58]) by smtp.gmail.com with ESMTPSA id t11sm112292lfe.258.2021.07.14.01.56.16 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Wed, 14 Jul 2021 01:56:16 -0700 (PDT) Date: Wed, 14 Jul 2021 14:56:14 +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 3/4] selftests: vm: add KSM zero page merging test Message-ID: <6d0caab00d4bdccf5e3791cb95cf6dfd5eb85e45.1626252248.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_zero_page_merge() function to test that empty pages are being handled properly. For this, several zero pages are allocated and merged using madvise. If use_zero_pages is enabled, the pages must be shared with the special kernel zero pages; otherwise, they are merged as usual duplicate pages. The test is run as follows: ./ksm_tests -Z Signed-off-by: Zhansaya Bagdauletkyzy Reviewed-by: Pavel Tatashin Reviewed-by: Tyler Hicks --- tools/testing/selftests/vm/ksm_tests.c | 70 ++++++++++++++++++++++- tools/testing/selftests/vm/run_vmtests.sh | 32 +++++++++++ 2 files changed, 99 insertions(+), 3 deletions(-) diff --git a/tools/testing/selftests/vm/ksm_tests.c b/tools/testing/selftests/vm/ksm_tests.c index 80302bb8f64c..5843526471e1 100644 --- a/tools/testing/selftests/vm/ksm_tests.c +++ b/tools/testing/selftests/vm/ksm_tests.c @@ -12,6 +12,7 @@ #define KSM_SCAN_LIMIT_SEC_DEFAULT 120 #define KSM_PAGE_COUNT_DEFAULT 10l #define KSM_PROT_STR_DEFAULT "rw" +#define KSM_USE_ZERO_PAGES_DEFAULT false struct ksm_sysfs { unsigned long max_page_sharing; @@ -25,7 +26,8 @@ struct ksm_sysfs { enum ksm_test_name { CHECK_KSM_MERGE, - CHECK_KSM_UNMERGE + CHECK_KSM_UNMERGE, + CHECK_KSM_ZERO_PAGE_MERGE }; static int ksm_write_sysfs(const char *file_path, unsigned long val) @@ -80,10 +82,12 @@ static int str_to_prot(char *prot_str) static void print_help(void) { - printf("usage: ksm_tests [-h] [-a prot] [-p page_count] [-l timeout]\n"); + printf("usage: ksm_tests [-h] [-a prot] [-p page_count] [-l timeout]\n" + "[-z use_zero_pages]\n"); printf("Supported :\n" " -M (page merging)\n" + " -Z (zero pages merging)\n" " -U (page unmerging)\n\n"); printf(" -a: specify the access protections of pages.\n" @@ -93,6 +97,8 @@ static void print_help(void) " 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); + printf(" -z: change use_zero_pages tunable\n" + " Default: %d\n", KSM_USE_ZERO_PAGES_DEFAULT); exit(0); } @@ -289,6 +295,50 @@ static int check_ksm_unmerge(int mapping, int prot, int timeout, size_t page_siz return KSFT_FAIL; } +static int check_ksm_zero_page_merge(int mapping, int prot, long page_count, int timeout, + bool use_zero_pages, 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; + } + + if (ksm_write_sysfs(KSM_FP("use_zero_pages"), use_zero_pages)) + return KSFT_FAIL; + + /* fill pages with zero and try to merge them */ + map_ptr = allocate_memory(NULL, prot, mapping, 0, 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: + * 1) if use_zero_pages is set to 1, empty pages are merged + * with the kernel zero page instead of with each other; + * 2) if use_zero_pages is set to 0, empty pages are not treated specially + * and merged as usual. + */ + if (use_zero_pages && !assert_ksm_pages_count(0)) + goto err_out; + else if (!use_zero_pages && !assert_ksm_pages_count(page_count)) + goto err_out; + + 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; @@ -298,8 +348,9 @@ int main(int argc, char *argv[]) size_t page_size = sysconf(_SC_PAGESIZE); struct ksm_sysfs ksm_sysfs_old; int test_name = CHECK_KSM_MERGE; + bool use_zero_pages = KSM_USE_ZERO_PAGES_DEFAULT; - while ((opt = getopt(argc, argv, "ha:p:l:MU")) != -1) { + while ((opt = getopt(argc, argv, "ha:p:l:z:MUZ")) != -1) { switch (opt) { case 'a': prot = str_to_prot(optarg); @@ -321,11 +372,20 @@ int main(int argc, char *argv[]) case 'h': print_help(); break; + case 'z': + if (strcmp(optarg, "0") == 0) + use_zero_pages = 0; + else + use_zero_pages = 1; + break; case 'M': break; case 'U': test_name = CHECK_KSM_UNMERGE; break; + case 'Z': + test_name = CHECK_KSM_ZERO_PAGE_MERGE; + break; default: return KSFT_FAIL; } @@ -359,6 +419,10 @@ int main(int argc, char *argv[]) ret = check_ksm_unmerge(MAP_PRIVATE | MAP_ANONYMOUS, prot, ksm_scan_limit_sec, page_size); break; + case CHECK_KSM_ZERO_PAGE_MERGE: + ret = check_ksm_zero_page_merge(MAP_PRIVATE | MAP_ANONYMOUS, prot, page_count, + ksm_scan_limit_sec, use_zero_pages, page_size); + break; } if (ksm_restore(&ksm_sysfs_old)) { diff --git a/tools/testing/selftests/vm/run_vmtests.sh b/tools/testing/selftests/vm/run_vmtests.sh index 3a23c6b47da2..9b4e444fc4ed 100755 --- a/tools/testing/selftests/vm/run_vmtests.sh +++ b/tools/testing/selftests/vm/run_vmtests.sh @@ -409,6 +409,38 @@ else exitcode=1 fi +echo "----------------------------------------------------------" +echo "running KSM test with 10 zero pages and use_zero_pages = 0" +echo "----------------------------------------------------------" +./ksm_tests -Z -p 10 -z 0 +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 + +echo "----------------------------------------------------------" +echo "running KSM test with 10 zero pages and use_zero_pages = 1" +echo "----------------------------------------------------------" +./ksm_tests -Z -p 10 -z 1 +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