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 6D691C4320E for ; Mon, 16 Aug 2021 14:00:23 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 4E6BD63305 for ; Mon, 16 Aug 2021 14:00:23 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231829AbhHPOAv (ORCPT ); Mon, 16 Aug 2021 10:00:51 -0400 Received: from linux.microsoft.com ([13.77.154.182]:43950 "EHLO linux.microsoft.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231307AbhHPN6A (ORCPT ); Mon, 16 Aug 2021 09:58:00 -0400 Received: from sequoia (162-237-133-238.lightspeed.rcsntx.sbcglobal.net [162.237.133.238]) by linux.microsoft.com (Postfix) with ESMTPSA id EB95E20C29E5; Mon, 16 Aug 2021 06:57:27 -0700 (PDT) DKIM-Filter: OpenDKIM Filter v2.11.0 linux.microsoft.com EB95E20C29E5 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux.microsoft.com; s=default; t=1629122248; bh=E/0G9tUeONPp8TeHajPXWxsLEkidxhqUtffDfnrRgbc=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=i0oXdOfeq3+icrOKxOSCzPfKLvYZUgPNvGcAfIoahe+YdkiYtVaydIGmGoKg5ZIDs KKltYF9hnKujsYDUQula21mqVfcZF/jwoC7vjgqLDlALP398qYI+4/W7MyVJGUTOnA K9qByerstchaHRfQYGFAUZmigL0MGcEsaw2wW5Sw= Date: Mon, 16 Aug 2021 08:57:24 -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 2/4] selftests: vm: add KSM unmerge test Message-ID: <20210816135724.GI5469@sequoia> References: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 2021-07-14 14:56:09, Zhansaya Bagdauletkyzy wrote: > Add check_ksm_unmerge() function to verify that KSM is properly > unmerging shared pages. For this, two duplicate pages are merged first > and then their contents are modified. Since they are not identical > anymore, the pages must be unmerged and the number of merged pages has > to be 0. The test is run as follows: ./ksm_tests -U > > Signed-off-by: Zhansaya Bagdauletkyzy Reviewed-by: Tyler Hicks Tyler > --- > tools/testing/selftests/vm/ksm_tests.c | 72 +++++++++++++++++++++-- > tools/testing/selftests/vm/run_vmtests.sh | 18 +++++- > 2 files changed, 85 insertions(+), 5 deletions(-) > > diff --git a/tools/testing/selftests/vm/ksm_tests.c b/tools/testing/selftests/vm/ksm_tests.c > index d74d5aa34b16..80302bb8f64c 100644 > --- a/tools/testing/selftests/vm/ksm_tests.c > +++ b/tools/testing/selftests/vm/ksm_tests.c > @@ -23,6 +23,11 @@ struct ksm_sysfs { > unsigned long use_zero_pages; > }; > > +enum ksm_test_name { > + CHECK_KSM_MERGE, > + CHECK_KSM_UNMERGE > +}; > + > static int ksm_write_sysfs(const char *file_path, unsigned long val) > { > FILE *f = fopen(file_path, "w"); > @@ -75,7 +80,12 @@ 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"); > + > + printf("Supported :\n" > + " -M (page merging)\n" > + " -U (page unmerging)\n\n"); > + > printf(" -a: specify the access protections of pages.\n" > " must be of the form [rwx].\n" > " Default: %s\n", KSM_PROT_STR_DEFAULT); > @@ -239,6 +249,46 @@ static int check_ksm_merge(int mapping, int prot, long page_count, int timeout, > return KSFT_FAIL; > } > > +static int check_ksm_unmerge(int mapping, int prot, int timeout, size_t page_size) > +{ > + void *map_ptr; > + struct timespec start_time; > + int page_count = 2; > + > + 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; > + > + /* change 1 byte in each of the 2 pages -- KSM must automatically unmerge them */ > + memset(map_ptr, '-', 1); > + memset(map_ptr + page_size, '+', 1); > + > + /* get at least 1 scan, so KSM can detect that the pages were modified */ > + if (ksm_do_scan(1, start_time, timeout)) > + goto err_out; > + > + /* check that unmerging was successful and 0 pages are currently merged */ > + if (assert_ksm_pages_count(0)) { > + 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; > @@ -247,8 +297,9 @@ int main(int argc, char *argv[]) > long page_count = KSM_PAGE_COUNT_DEFAULT; > size_t page_size = sysconf(_SC_PAGESIZE); > struct ksm_sysfs ksm_sysfs_old; > + int test_name = CHECK_KSM_MERGE; > > - while ((opt = getopt(argc, argv, "ha:p:l:")) != -1) { > + while ((opt = getopt(argc, argv, "ha:p:l:MU")) != -1) { > switch (opt) { > case 'a': > prot = str_to_prot(optarg); > @@ -270,6 +321,11 @@ int main(int argc, char *argv[]) > case 'h': > print_help(); > break; > + case 'M': > + break; > + case 'U': > + test_name = CHECK_KSM_UNMERGE; > + break; > default: > return KSFT_FAIL; > } > @@ -294,8 +350,16 @@ int main(int argc, char *argv[]) > 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); > + switch (test_name) { > + case CHECK_KSM_MERGE: > + ret = check_ksm_merge(MAP_PRIVATE | MAP_ANONYMOUS, prot, page_count, > + ksm_scan_limit_sec, page_size); > + break; > + case CHECK_KSM_UNMERGE: > + ret = check_ksm_unmerge(MAP_PRIVATE | MAP_ANONYMOUS, prot, ksm_scan_limit_sec, > + page_size); > + break; > + } > > if (ksm_restore(&ksm_sysfs_old)) { > printf("Cannot restore default tunables\n"); > diff --git a/tools/testing/selftests/vm/run_vmtests.sh b/tools/testing/selftests/vm/run_vmtests.sh > index 97b6f712134d..3a23c6b47da2 100755 > --- a/tools/testing/selftests/vm/run_vmtests.sh > +++ b/tools/testing/selftests/vm/run_vmtests.sh > @@ -380,7 +380,23 @@ fi > echo "-------------------------------------------------------" > echo "running KSM MADV_MERGEABLE test with 10 identical pages" > echo "-------------------------------------------------------" > -./ksm_tests -p 10 > +./ksm_tests -M -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 > + > +echo "------------------------" > +echo "running KSM unmerge test" > +echo "------------------------" > +./ksm_tests -U > ret_val=$? > > if [ $ret_val -eq 0 ]; then > -- > 2.25.1 >