From mboxrd@z Thu Jan 1 00:00:00 1970 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=-23.3 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER, INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED, USER_IN_DEF_DKIM_WL 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 28261C432BE for ; Mon, 16 Aug 2021 14:01:34 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id F30C360F21 for ; Mon, 16 Aug 2021 14:01:33 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S237030AbhHPOCC (ORCPT ); Mon, 16 Aug 2021 10:02:02 -0400 Received: from linux.microsoft.com ([13.77.154.182]:44334 "EHLO linux.microsoft.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231151AbhHPOAl (ORCPT ); Mon, 16 Aug 2021 10:00:41 -0400 Received: from sequoia (162-237-133-238.lightspeed.rcsntx.sbcglobal.net [162.237.133.238]) by linux.microsoft.com (Postfix) with ESMTPSA id 5FCD120C29E3; Mon, 16 Aug 2021 07:00:09 -0700 (PDT) DKIM-Filter: OpenDKIM Filter v2.11.0 linux.microsoft.com 5FCD120C29E3 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux.microsoft.com; s=default; t=1629122409; bh=uVD76K1R9bqw+wIlp5GS3K0uZGhGxrkIvE6zHrAIqR4=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=kQ3ru5kDZ7G9RTxsXMLy5lkKTB3Gk6gTdzKc2jyDbfgo+qMW2driHWdTgHXvqXOmN iudGQXdbD2sAY8tbUbeNLkH1Id/MN687UsGw3vWdSUhMzlg61znONCRTT1CyN+lkIA JhBV6k8NdpwPVT6zBejyEIoXCUrYbMIPzDbjyhn4= Date: Mon, 16 Aug 2021 09:00:07 -0500 From: Tyler Hicks To: Zhansaya Bagdauletkyzy Cc: shuah@kernel.org, akpm@linux-foundation.org, linux-kernel@vger.kernel.org, linux-kselftest@vger.kernel.org, linux-mm@kvack.org, pasha.tatashin@soleen.com Subject: Re: [PATCH v2 3/4] selftests: vm: add KSM zero page merging test Message-ID: <20210816140007.GJ5469@sequoia> References: <6d0caab00d4bdccf5e3791cb95cf6dfd5eb85e45.1626252248.git.zhansayabagdaulet@gmail.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <6d0caab00d4bdccf5e3791cb95cf6dfd5eb85e45.1626252248.git.zhansayabagdaulet@gmail.com> Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 2021-07-14 14:56:14, Zhansaya Bagdauletkyzy wrote: > 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: Tyler Hicks Tyler > --- > 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 > -- > 2.25.1 >