From patchwork Tue Mar 2 12:57:48 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Yanan Wang X-Patchwork-Id: 12111853 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=-16.7 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_GIT 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 5EEFDC43331 for ; Tue, 2 Mar 2021 16:23:50 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 2C24464F11 for ; Tue, 2 Mar 2021 16:23:50 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1449133AbhCBQP2 (ORCPT ); Tue, 2 Mar 2021 11:15:28 -0500 Received: from szxga07-in.huawei.com ([45.249.212.35]:13838 "EHLO szxga07-in.huawei.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1350927AbhCBM7O (ORCPT ); Tue, 2 Mar 2021 07:59:14 -0500 Received: from DGGEMS412-HUB.china.huawei.com (unknown [172.30.72.58]) by szxga07-in.huawei.com (SkyGuard) with ESMTP id 4DqcZk2wKFz7sRB; Tue, 2 Mar 2021 20:56:30 +0800 (CST) Received: from DESKTOP-TMVL5KK.china.huawei.com (10.174.187.128) by DGGEMS412-HUB.china.huawei.com (10.3.19.212) with Microsoft SMTP Server id 14.3.498.0; Tue, 2 Mar 2021 20:58:01 +0800 From: Yanan Wang To: , , CC: Paolo Bonzini , Ben Gardon , "Sean Christopherson" , Vitaly Kuznetsov , Andrew Jones , Peter Xu , Marc Zyngier , Ingo Molnar , Adrian Hunter , Jiri Olsa , "Arnaldo Carvalho de Melo" , Arnd Bergmann , Michael Kerrisk , Thomas Gleixner , , , , Yanan Wang Subject: [RFC PATCH v4 6/9] KVM: selftests: Add a helper to get system default hugetlb page size Date: Tue, 2 Mar 2021 20:57:48 +0800 Message-ID: <20210302125751.19080-7-wangyanan55@huawei.com> X-Mailer: git-send-email 2.8.4.windows.1 In-Reply-To: <20210302125751.19080-1-wangyanan55@huawei.com> References: <20210302125751.19080-1-wangyanan55@huawei.com> MIME-Version: 1.0 X-Originating-IP: [10.174.187.128] X-CFilter-Loop: Reflected Precedence: bulk List-ID: X-Mailing-List: kvm@vger.kernel.org If HUGETLB is configured in the host kernel, then we can know the system default hugetlb page size through *cat /proc/meminfo*. Otherwise, we will not see the information of hugetlb pages in file /proc/meminfo if it's not configured. So add a helper to determine whether HUGETLB is configured and then get the default page size by reading /proc/meminfo. This helper can be useful when a program wants to use the default hugetlb pages of the system and doesn't know the default page size. Signed-off-by: Yanan Wang Reviewed-by: Andrew Jones --- .../testing/selftests/kvm/include/test_util.h | 1 + tools/testing/selftests/kvm/lib/test_util.c | 27 +++++++++++++++++++ 2 files changed, 28 insertions(+) diff --git a/tools/testing/selftests/kvm/include/test_util.h b/tools/testing/selftests/kvm/include/test_util.h index ef24c76ba89a..e087174eefe5 100644 --- a/tools/testing/selftests/kvm/include/test_util.h +++ b/tools/testing/selftests/kvm/include/test_util.h @@ -80,6 +80,7 @@ struct vm_mem_backing_src_alias { bool thp_configured(void); size_t get_trans_hugepagesz(void); +size_t get_def_hugetlb_pagesz(void); void backing_src_help(void); enum vm_mem_backing_src_type parse_backing_src_type(const char *type_name); diff --git a/tools/testing/selftests/kvm/lib/test_util.c b/tools/testing/selftests/kvm/lib/test_util.c index f2d133f76c67..80d68dbd72d2 100644 --- a/tools/testing/selftests/kvm/lib/test_util.c +++ b/tools/testing/selftests/kvm/lib/test_util.c @@ -153,6 +153,33 @@ size_t get_trans_hugepagesz(void) return size; } +size_t get_def_hugetlb_pagesz(void) +{ + char buf[64]; + const char *tag = "Hugepagesize:"; + FILE *f; + + f = fopen("/proc/meminfo", "r"); + TEST_ASSERT(f != NULL, "Error in opening /proc/meminfo: %d", errno); + + while (fgets(buf, sizeof(buf), f) != NULL) { + if (strstr(buf, tag) == buf) { + fclose(f); + return strtoull(buf + strlen(tag), NULL, 10) << 10; + } + } + + if (feof(f)) { + fclose(f); + TEST_FAIL("HUGETLB is not configured in host kernel"); + } else { + fclose(f); + TEST_FAIL("Error in reading /proc/meminfo: %d", errno); + } + + return 0; +} + void backing_src_help(void) { int i;