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=-3.9 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_PASS 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 DD6A8C04EB8 for ; Mon, 10 Dec 2018 14:19:58 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id A247820855 for ; Mon, 10 Dec 2018 14:19:58 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org A247820855 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=arm.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727782AbeLJOT5 (ORCPT ); Mon, 10 Dec 2018 09:19:57 -0500 Received: from usa-sjc-mx-foss1.foss.arm.com ([217.140.101.70]:54924 "EHLO foss.arm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727396AbeLJOT5 (ORCPT ); Mon, 10 Dec 2018 09:19:57 -0500 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 DB69C1596; Mon, 10 Dec 2018 06:19:56 -0800 (PST) Received: from [10.1.194.37] (e113632-lin.cambridge.arm.com [10.1.194.37]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 18FB33F575; Mon, 10 Dec 2018 06:19:54 -0800 (PST) Subject: Re: [RESEND PATCH v2] clocksource/arm_arch_timer: fix a lockdep warning To: Peter Zijlstra , Qian Cai Cc: akpm@linux-foundation.org, mark.rutland@arm.com, marc.zyngier@arm.com, daniel.lezcano@linaro.org, tglx@linutronix.de, mingo@kernel.org, longman@redhat.com, linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org References: <1543877121-4098-1-git-send-email-cai@gmx.us> <20181210135228.49751-1-cai@lca.pw> <20181210140703.GM5289@hirez.programming.kicks-ass.net> From: Valentin Schneider Message-ID: <9303a6cf-24af-2f31-9fbd-8c1ecdd5e4f4@arm.com> Date: Mon, 10 Dec 2018 14:19:53 +0000 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:60.0) Gecko/20100101 Thunderbird/60.2.1 MIME-Version: 1.0 In-Reply-To: <20181210140703.GM5289@hirez.programming.kicks-ass.net> Content-Type: text/plain; charset=utf-8 Content-Language: en-GB Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi, On 10/12/2018 14:07, Peter Zijlstra wrote: [...] > --- > kernel/cpu.c | 2 ++ > 1 file changed, 2 insertions(+) > > diff --git a/kernel/cpu.c b/kernel/cpu.c > index 91d5c38eb7e5..e1ee8caf28b5 100644 > --- a/kernel/cpu.c > +++ b/kernel/cpu.c > @@ -313,6 +313,8 @@ void cpus_write_unlock(void) > > void lockdep_assert_cpus_held(void) > { > + if (system_state < SYSTEM_RUNNING) > + return; > percpu_rwsem_assert_held(&cpu_hotplug_lock); > } > Kinda hijacking the thread here - is that something we'd want to replace 40fa3780bac2 ("sched/core: Take the hotplug lock in sched_init_smp()") with?