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=-5.2 required=3.0 tests=DKIM_INVALID,DKIM_SIGNED, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_PASS, USER_AGENT_MUTT 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 A3A1FC04EB8 for ; Mon, 10 Dec 2018 14:07:20 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 681D320855 for ; Mon, 10 Dec 2018 14:07:20 +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="17FX2thS" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 681D320855 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=infradead.org 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 S1727642AbeLJOHT (ORCPT ); Mon, 10 Dec 2018 09:07:19 -0500 Received: from merlin.infradead.org ([205.233.59.134]:58836 "EHLO merlin.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727197AbeLJOHS (ORCPT ); Mon, 10 Dec 2018 09:07:18 -0500 DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=merlin.20170209; h=In-Reply-To:Content-Type:MIME-Version: References:Message-ID:Subject:Cc:To:From:Date:Sender:Reply-To: Content-Transfer-Encoding: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=GkAUqUKQu/1gTgqSH3aCvVxy7YJVnyUJfvfSRt4Y3YI=; b=17FX2thSO5MJC/nachnhmUXwq Uh2bS4ja8aMSb3EhKDf32Mu0n8n0EXqzOwMlMCOHFs+GKoJxaOFXb5rAUzrrBGecaXH7yXJiWWqV/ +nk/w+mOG+9HU45cLassdpHYKUiSK/kUv8dkkqWjBpMJOL9N0t7oyqBL8X6SFfiZ+lFbB3sKlN+3s D5VoG19fTPc/u+2zj+p2e//TaCsqh6UXeCBAJslG011HlWaVY/zTlleCGn7Cd/Ca8ricTt8CpdwCR 8rcGqBz5JUYkJy0M3gkQ2BdwJ8qO9Br7iiw+epQ2j7ogVWz9zCmgca2zHIrvmNPw0FULVwKzvl+ci 8DoMWMIXQ==; Received: from j217100.upc-j.chello.nl ([24.132.217.100] helo=hirez.programming.kicks-ass.net) by merlin.infradead.org with esmtpsa (Exim 4.90_1 #2 (Red Hat Linux)) id 1gWMDB-0004IE-Nu; Mon, 10 Dec 2018 14:07:06 +0000 Received: by hirez.programming.kicks-ass.net (Postfix, from userid 1000) id 2CFE82075BCE5; Mon, 10 Dec 2018 15:07:03 +0100 (CET) Date: Mon, 10 Dec 2018 15:07:03 +0100 From: Peter Zijlstra To: 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 Subject: Re: [RESEND PATCH v2] clocksource/arm_arch_timer: fix a lockdep warning Message-ID: <20181210140703.GM5289@hirez.programming.kicks-ass.net> References: <1543877121-4098-1-git-send-email-cai@gmx.us> <20181210135228.49751-1-cai@lca.pw> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20181210135228.49751-1-cai@lca.pw> User-Agent: Mutt/1.10.1 (2018-07-13) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, Dec 10, 2018 at 08:52:28AM -0500, Qian Cai wrote: > Booting this Huawei TaiShan 2280 arm64 server generated this lockdep > warning. > > [ 0.000000] lockdep_assert_cpus_held+0x50/0x60 > [ 0.000000] static_key_enable_cpuslocked+0x30/0xe8 > [ 0.000000] arch_timer_check_ool_workaround+0x128/0x2d0 > [ 0.000000] arch_timer_acpi_init+0x274/0x6ac > [ 0.000000] acpi_table_parse+0x1ac/0x218 > [ 0.000000] __acpi_probe_device_table+0x164/0x1ec > [ 0.000000] timer_probe+0x1bc/0x254 > [ 0.000000] time_init+0x44/0x98 > [ 0.000000] start_kernel+0x4ec/0x7d4 It seems to me we want something like: --- 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); }