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=-3.8 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS autolearn=no 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 1B23EC433DF for ; Tue, 25 Aug 2020 09:03:25 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id E44D22067C for ; Tue, 25 Aug 2020 09:03:24 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728080AbgHYJDT convert rfc822-to-8bit (ORCPT ); Tue, 25 Aug 2020 05:03:19 -0400 Received: from foss.arm.com ([217.140.110.172]:53808 "EHLO foss.arm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726000AbgHYJDS (ORCPT ); Tue, 25 Aug 2020 05:03:18 -0400 Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.121.207.14]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id 315FD30E; Tue, 25 Aug 2020 02:03:18 -0700 (PDT) Received: from e113632-lin (e113632-lin.cambridge.arm.com [10.1.194.46]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 4BC9D3F68F; Tue, 25 Aug 2020 02:03:17 -0700 (PDT) References: <20200824153902.57875-1-andriy.shevchenko@linux.intel.com> <20200825082636.GQ1891694@smile.fi.intel.com> User-agent: mu4e 0.9.17; emacs 26.3 From: Valentin Schneider To: Andy Shevchenko Cc: Ingo Molnar , Peter Zijlstra , Vincent Guittot , linux-kernel@vger.kernel.org, Dietmar Eggemann Subject: Re: [PATCH v1] sched/topology: Make compiler happy about unused constant definitions In-reply-to: <20200825082636.GQ1891694@smile.fi.intel.com> Date: Tue, 25 Aug 2020 10:03:12 +0100 Message-ID: MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 8BIT Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 25/08/20 09:26, Andy Shevchenko wrote: > On Mon, Aug 24, 2020 at 06:09:41PM +0100, Valentin Schneider wrote: >> On 24/08/20 16:39, Andy Shevchenko wrote: >> > Compilation of almost each file ends up with >> > >> > In file included from .../include/linux/energy_model.h:10, >> > from .../include/linux/device.h:16, >> > from .../drivers/spi/spi.c:8: >> > .../include/linux/sched/topology.h:30:27: warning: ‘SD_DEGENERATE_GROUPS_MASK’ defined but not used [-Wunused-const-variable=] >> > 30 | static const unsigned int SD_DEGENERATE_GROUPS_MASK = >> > | ^~~~~~~~~~~~~~~~~~~~~~~~~ >> > ... >> > >> > Make compiler happy by annotating the static constants with __maybwe_unused. >> > >> >> That should see some use as long as the build is for SMP. This whole region >> is guarded by #ifdef CONFIG_SMP, so an !SMP build shouldn't trigger this. > > Isn't SMP is default for most of the kernel builds? > And honestly I didn't get the purpose of this comment. > Sorry, that's what I get for trying to be too succinct; what I tried to say was that SD_DEGENERATE_GROUPS_MASK should very much be used for SMP. If the build is !SMP, it shouldn't even be defined, IOW I'm perplexed as to where this is coming from. >> With what config/kernel are you getting this? > > x86_64_defconfig from the kernel sources with some drivers added (SMP or so has > not been touched, DEBUG_SHED was enabled once to confirm that another static > const has same issue). Thanks, I'll poke around this.