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=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, USER_AGENT_SANE_2 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 6E29AC433E1 for ; Thu, 20 Aug 2020 14:36:50 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 50CAB2076E for ; Thu, 20 Aug 2020 14:36:50 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728177AbgHTOgt (ORCPT ); Thu, 20 Aug 2020 10:36:49 -0400 Received: from mail.kernel.org ([198.145.29.99]:34244 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726957AbgHTOgq (ORCPT ); Thu, 20 Aug 2020 10:36:46 -0400 Received: from oasis.local.home (cpe-66-24-58-225.stny.res.rr.com [66.24.58.225]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id BE66D2076E; Thu, 20 Aug 2020 14:36:44 +0000 (UTC) Date: Thu, 20 Aug 2020 10:36:43 -0400 From: Steven Rostedt To: Peter Zijlstra Cc: linux-kernel@vger.kernel.org, mingo@kernel.org, will@kernel.org, npiggin@gmail.com, elver@google.com, jgross@suse.com, paulmck@kernel.org, rjw@rjwysocki.net, joel@joelfernandes.org, svens@linux.ibm.com, tglx@linutronix.de Subject: Re: [PATCH 0/9] TRACE_IRQFLAGS wreckage Message-ID: <20200820103643.1b9abe88@oasis.local.home> In-Reply-To: <20200820073031.886217423@infradead.org> References: <20200820073031.886217423@infradead.org> X-Mailer: Claws Mail 3.17.3 (GTK+ 2.24.32; x86_64-pc-linux-gnu) MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org I tested this series on top of tip/master and triggered the below warning when running the irqsoff tracer boot up test (config attached). -- Steve Testing tracer irqsoff: ============================= WARNING: suspicious RCU usage 5.9.0-rc1-test+ #92 Not tainted ----------------------------- include/trace/events/lock.h:13 suspicious rcu_dereference_check() usage! other info that might help us debug this: rcu_scheduler_active = 2, debug_locks = 1 RCU used illegally from extended quiescent state! no locks held by swapper/2/0. stack backtrace: CPU: 2 PID: 0 Comm: swapper/2 Not tainted 5.9.0-rc1-test+ #92 Hardware name: Hewlett-Packard HP Compaq Pro 6300 SFF/339A, BIOS K01 v03.03 07/14/2016 Call Trace: dump_stack+0x8d/0xc0 lock_acquire.cold+0x23/0x2c ? default_idle_call+0x4d/0x210 _raw_spin_lock_irqsave+0x50/0xa0 ? check_critical_timing+0x69/0x160 check_critical_timing+0x69/0x160 ? default_idle_call+0x4d/0x210 stop_critical_timings+0xdd/0xf0 default_idle_call+0x4d/0x210 do_idle+0x1f6/0x260 cpu_startup_entry+0x19/0x20 start_secondary+0x110/0x140 secondary_startup_64+0xb6/0xc0