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=-4.0 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED autolearn=ham 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 7E04AC04AB6 for ; Tue, 28 May 2019 11:59:00 +0000 (UTC) Received: from lists.ozlabs.org (lists.ozlabs.org [203.11.71.2]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id C9D722075B for ; Tue, 28 May 2019 11:58:59 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org C9D722075B Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=arm.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=linuxppc-dev-bounces+linuxppc-dev=archiver.kernel.org@lists.ozlabs.org Received: from lists.ozlabs.org (lists.ozlabs.org [IPv6:2401:3900:2:1::3]) by lists.ozlabs.org (Postfix) with ESMTP id 45CsnY3BB8zDqQZ for ; Tue, 28 May 2019 21:58:57 +1000 (AEST) Authentication-Results: lists.ozlabs.org; spf=pass (mailfrom) smtp.mailfrom=arm.com (client-ip=217.140.101.70; helo=foss.arm.com; envelope-from=vincenzo.frascino@arm.com; receiver=) Authentication-Results: lists.ozlabs.org; dmarc=none (p=none dis=none) header.from=arm.com Received: from foss.arm.com (foss.arm.com [217.140.101.70]) by lists.ozlabs.org (Postfix) with ESMTP id 45Cslw1rZ0zDqJg for ; Tue, 28 May 2019 21:57:30 +1000 (AEST) Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.72.51.249]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id C7D02341; Tue, 28 May 2019 04:57:27 -0700 (PDT) Received: from [10.1.196.72] (e119884-lin.cambridge.arm.com [10.1.196.72]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id B38783F59C; Tue, 28 May 2019 04:57:25 -0700 (PDT) Subject: Re: [PATCH v4 3/3] kselftest: Extend vDSO selftest to clock_getres To: Michael Ellerman , linux-arch@vger.kernel.org, linuxppc-dev@lists.ozlabs.org, linux-s390@vger.kernel.org, linux-kselftest@vger.kernel.org References: <20190523112116.19233-1-vincenzo.frascino@arm.com> <20190523112116.19233-4-vincenzo.frascino@arm.com> <87lfyrp0d2.fsf@concordia.ellerman.id.au> From: Vincenzo Frascino Message-ID: Date: Tue, 28 May 2019 12:57:24 +0100 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:60.0) Gecko/20100101 Thunderbird/60.6.1 MIME-Version: 1.0 In-Reply-To: <87lfyrp0d2.fsf@concordia.ellerman.id.au> Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 8bit X-BeenThere: linuxppc-dev@lists.ozlabs.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Arnd Bergmann , Heiko Carstens , Paul Mackerras , Martin Schwidefsky , Thomas Gleixner , Shuah Khan Errors-To: linuxppc-dev-bounces+linuxppc-dev=archiver.kernel.org@lists.ozlabs.org Sender: "Linuxppc-dev" Hi Michael, thank you for your reply. On 28/05/2019 07:19, Michael Ellerman wrote: > Vincenzo Frascino writes: > >> The current version of the multiarch vDSO selftest verifies only >> gettimeofday. >> >> Extend the vDSO selftest to clock_getres, to verify that the >> syscall and the vDSO library function return the same information. >> >> The extension has been used to verify the hrtimer_resoltion fix. > > This is passing for me even without patch 1 applied, shouldn't it fail > without the fix? What am I missing? > This is correct, because during the refactoring process I missed an "n" :) if·((x.tv_sec·!=·y.tv_sec)·||·(x.tv_sec·!=·y.tv_sec)) Should be: if·((x.tv_sec·!=·y.tv_sec)·||·(x.tv_nsec·!=·y.tv_nsec)) My mistake, I am going to fix the test and re-post v5 of this set. Without my patch if you pass "highres=off" to the kernel (as a command line parameter) it leads to a broken implementation of clock_getres since the value of CLOCK_REALTIME_RES does not change at runtime. Expected result (with highres=off): # uname -r 5.2.0-rc2 # ./vdso_clock_getres clock_id: CLOCK_REALTIME [FAIL] clock_id: CLOCK_BOOTTIME [PASS] clock_id: CLOCK_TAI [PASS] clock_id: CLOCK_REALTIME_COARSE [PASS] clock_id: CLOCK_MONOTONIC [FAIL] clock_id: CLOCK_MONOTONIC_RAW [PASS] clock_id: CLOCK_MONOTONIC_COARSE [PASS] The reason of this behavior is that the only clocks supported by getres on powerpc are CLOCK_REALTIME and CLOCK_MONOTONIC, the rest on the clocks use always syscalls. > # uname -r > 5.2.0-rc2-gcc-8.2.0 > > # ./vdso_clock_getres > clock_id: CLOCK_REALTIME [PASS] > clock_id: CLOCK_BOOTTIME [PASS] > clock_id: CLOCK_TAI [PASS] > clock_id: CLOCK_REALTIME_COARSE [PASS] > clock_id: CLOCK_MONOTONIC [PASS] > clock_id: CLOCK_MONOTONIC_RAW [PASS] > clock_id: CLOCK_MONOTONIC_COARSE [PASS] > > cheers > >> Cc: Shuah Khan >> Signed-off-by: Vincenzo Frascino >> --- >> >> Note: This patch is independent from the others in this series, hence it >> can be merged singularly by the kselftest maintainers. >> >> tools/testing/selftests/vDSO/Makefile | 2 + >> .../selftests/vDSO/vdso_clock_getres.c | 124 ++++++++++++++++++ >> 2 files changed, 126 insertions(+) >> create mode 100644 tools/testing/selftests/vDSO/vdso_clock_getres.c -- Regards, Vincenzo