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=-10.1 required=3.0 tests=DKIM_INVALID,DKIM_SIGNED, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,MENTIONS_GIT_HOSTING, SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_1 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 C0407C432C1 for ; Wed, 25 Sep 2019 01:31:38 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 8506520874 for ; Wed, 25 Sep 2019 01:31:38 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (2048-bit key) header.d=infradead.org header.i=@infradead.org header.b="E+PDCQ/+" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2411362AbfIYBbh (ORCPT ); Tue, 24 Sep 2019 21:31:37 -0400 Received: from bombadil.infradead.org ([198.137.202.133]:33740 "EHLO bombadil.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2392412AbfIYBbh (ORCPT ); Tue, 24 Sep 2019 21:31:37 -0400 DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=bombadil.20170209; h=Content-Transfer-Encoding: Content-Type:In-Reply-To:MIME-Version:Date:Message-ID:From:References:Cc:To: Subject:Sender:Reply-To:Content-ID:Content-Description:Resent-Date: Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Id: List-Help:List-Unsubscribe:List-Subscribe:List-Post:List-Owner:List-Archive; bh=FPS6+J7Nf2Nso+6mXxRnwR+JEsJSOlRfKzBQGp9VVII=; b=E+PDCQ/+6vSLblFeljTHrstwJ /F4xvnlUwsdU4cmtVvqWHmVqIcwl2KkoBNID62jJU2dDYg9fUm0Kpfn7ar/82fEHjbgeNNn/SobIh 18hl4W6A763vX0S0XLnIeAzufSUqaQCJd0ae6k2F4YiIYTZwAGqczm3D/eD3yQpAxQRuOr2yKjYZ2 BfEZCBhX3xX/qLD5yFAJESYXasfCZ+THioYaR0afCvRYNIM40GW0AE50LLl7CxNoYrdIplb+bqKGi GXnhSw59dIP2ZYgHg3VZfVQyoA1DGrmjRBNhAlKX04OaGLXzLZNvQaowuXf5zfylUhnWTVQ2aMo9N 8ID9QSKJg==; Received: from [2601:1c0:6280:3f0::9a1f] by bombadil.infradead.org with esmtpsa (Exim 4.92.2 #3 (Red Hat Linux)) id 1iCw9X-0003Ku-EF; Wed, 25 Sep 2019 01:31:35 +0000 Subject: Re: linux-next: Tree for Sep 16 (kernel/sched/core.c) To: Patrick Bellasi , Ingo Molnar Cc: Mark Brown , Linux Next Mailing List , Linux Kernel Mailing List , Ingo Molnar , Peter Zijlstra References: <20190916223850.GQ4352@sirena.co.uk> <1898d3c9-1997-17ce-a022-a5e28c8dc115@infradead.org> <20190917075242.GB49590@gmail.com> <8736gv2gbv.fsf@arm.com> <30eb4c83-a90d-21aa-3f9e-4da8e66769ef@infradead.org> <20190918060553.GA21173@gmail.com> <87y2yl2a7d.fsf@arm.com> From: Randy Dunlap Message-ID: <3e6cd315-9588-f90c-867c-92830f68197e@infradead.org> Date: Tue, 24 Sep 2019 18:31:34 -0700 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:60.0) Gecko/20100101 Thunderbird/60.8.0 MIME-Version: 1.0 In-Reply-To: <87y2yl2a7d.fsf@arm.com> Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 9/18/19 3:03 AM, Patrick Bellasi wrote: > > On Wed, Sep 18, 2019 at 07:05:53 +0100, Ingo Molnar wrote... > >> * Randy Dunlap wrote: >> >>> On 9/17/19 6:38 AM, Patrick Bellasi wrote: >>>> >>>> On Tue, Sep 17, 2019 at 08:52:42 +0100, Ingo Molnar wrote... >>>> >>>>> * Randy Dunlap wrote: >>>>> >>>>>> On 9/16/19 3:38 PM, Mark Brown wrote: >>>>>>> Hi all, >>>>>>> >>>>>>> Changes since 20190915: >>>>>>> >>>>>> >>>>>> on x86_64: >>>>>> >>>>>> when CONFIG_CGROUPS is not set: >>>> >>>> Hi Randy, >>>> thanks for the report. >>>> >>>>>> CC kernel/sched/core.o >>>>>> ../kernel/sched/core.c: In function ‘uclamp_update_active_tasks’: >>>>>> ../kernel/sched/core.c:1081:23: error: storage size of ‘it’ isn’t known >>>>>> struct css_task_iter it; >>>>>> ^~ >>>>>> CC kernel/printk/printk_safe.o >>>>>> ../kernel/sched/core.c:1084:2: error: implicit declaration of function ‘css_task_iter_start’; did you mean ‘__sg_page_iter_start’? [-Werror=implicit-function-declaration] >>>>>> css_task_iter_start(css, 0, &it); >>>>>> ^~~~~~~~~~~~~~~~~~~ >>>>>> __sg_page_iter_start >>>>>> ../kernel/sched/core.c:1085:14: error: implicit declaration of function ‘css_task_iter_next’; did you mean ‘__sg_page_iter_next’? [-Werror=implicit-function-declaration] >>>>>> while ((p = css_task_iter_next(&it))) { >>>>>> ^~~~~~~~~~~~~~~~~~ >>>>>> __sg_page_iter_next >>>>>> ../kernel/sched/core.c:1091:2: error: implicit declaration of function ‘css_task_iter_end’; did you mean ‘get_task_cred’? [-Werror=implicit-function-declaration] >>>>>> css_task_iter_end(&it); >>>>>> ^~~~~~~~~~~~~~~~~ >>>>>> get_task_cred >>>>>> ../kernel/sched/core.c:1081:23: warning: unused variable ‘it’ [-Wunused-variable] >>>>>> struct css_task_iter it; >>>>>> ^~ >>>>>> >>>>> >>>>> I cannot reproduce this build failue: I took Linus's latest which has all >>>>> the -next scheduler commits included (ad062195731b), and an x86-64 "make >>>>> defconfig" and a disabling of CONFIG_CGROUPS still resuls in a kernel >>>>> that builds fine. >>>> >>>> Same here Ingo, I cannot reproduce on arm64 and !CONFIG_CGROUPS and >>>> testing on tip/sched/core. >>>> >>>> However, if you like, the following patch can make that code a >>>> bit more "robust". >>>> >>>> Best, >>>> Patrick >>>> >>>> ---8<--- >>>> From 7e17b7bb08dd8dfc57e01c2a7b6875439eb47cbe Mon Sep 17 00:00:00 2001 >>>> From: Patrick Bellasi >>>> Date: Tue, 17 Sep 2019 14:12:10 +0100 >>>> Subject: [PATCH 1/1] sched/core: uclamp: Fix compile error on !CONFIG_CGROUPS >>>> >>>> Randy reported a compiler error on x86_64 and !CONFIG_CGROUPS which is due >>>> to uclamp_update_active_tasks() using the undefined css_task_iter(). >>>> >>>> Since uclamp_update_active_tasks() is used only when cgroup support is >>>> enabled, fix that by properly guarding that function at compile time. >>>> >>>> Signed-off-by: Patrick Bellasi >>>> Link: https://lore.kernel.org/lkml/1898d3c9-1997-17ce-a022-a5e28c8dc115@infradead.org/ >>>> Fixes: commit babbe170e05 ("sched/uclamp: Update CPU's refcount on TG's clamp changes") >>> >>> Acked-by: Randy Dunlap # build-tested >>> >>> Thanks. >> >> Build failures like this one shouldn't depend on the compiler version - >> and it's still a mystery how and why this build bug triggered - we cannot >> apply the fix without knowing the answer to those questions. > > Right, but it's also quite strange it's not triggering without the > guarding above. The only definition of struct css_task_iter I can see is > the one > provided in: > > include/linux/cgroup.h:50 > https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/tree/include/linux/cgroup.h?h=35f7a95266153b1cf0caca3aa9661cb721864527#n50 > > which is CONFIG_CGROUPS guarded. > >> Can you reproduce the build bug with Linus's latest tree? If not, which >> part of -next triggers the build failure? > > I tried again using this morning's Linus tree headed at: > > commit 35f7a9526615 ("Merge tag 'devprop-5.4-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm") > > and compilation actually fails for me too. and linux-next of 20190924 still fails also... > Everything is fine in v5.3 with !CONFIG_CGROUPS and a git bisect > between v5.3 and Linus master points to: > > commit babbe170e053c ("sched/uclamp: Update CPU's refcount on TG's clamp changes") > > So, I think it's really my fault not properly testing !CONFIG_CGROUP, > which is enforced by default from CONFIG_SCHED_AUTOGROUP. > > The patch above fixes the compilation error, hope this helps. > > Cheers, > Patrick -- ~Randy