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=-0.6 required=3.0 tests=DKIM_INVALID,DKIM_SIGNED, 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 CD2EDC43331 for ; Tue, 31 Mar 2020 15:29:42 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 9EC7720786 for ; Tue, 31 Mar 2020 15:29:42 +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="HcYLrswa" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1730755AbgCaP3l (ORCPT ); Tue, 31 Mar 2020 11:29:41 -0400 Received: from merlin.infradead.org ([205.233.59.134]:50002 "EHLO merlin.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1730391AbgCaP3l (ORCPT ); Tue, 31 Mar 2020 11:29:41 -0400 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; bh=PQpgxNPCWWT+9PGI3Q9YA11D3XT0vA+mnCv838A5DxA=; b=HcYLrswaUl89zNBx5lBrRjvN+j zpW+u3tk5G5Pr1JffnfKGxYjX4wnwqtFMjATQ1kymjFCYX6PI7tA+g57S36MLQlVAM04RY+iLbJVM KVgqVDs721/1EWvgkZ3W2AYL5WyZo3aGL/n+upnTbqC4AScbLkvAKill1K/wfw2gs7qm9XjBv8v6J liOkNG+UrMXFbvOStKP/wtjuKOYx8xZBdNITUuzq8iJvkwtNYA5HCMzORlD91xDN/9gA5ft9atG/l DHkO2dkpGyCxWJMlHS/GaKjipvPm3iaFOBNgM+CPe8bF5EFeaUuIfDrUnlIicGs74aRZ8c97WUlge uD2wfYxQ==; Received: from j217100.upc-j.chello.nl ([24.132.217.100] helo=noisy.programming.kicks-ass.net) by merlin.infradead.org with esmtpsa (Exim 4.92.3 #3 (Red Hat Linux)) id 1jJIow-0005jf-GM; Tue, 31 Mar 2020 15:28:54 +0000 Received: from hirez.programming.kicks-ass.net (hirez.programming.kicks-ass.net [192.168.1.225]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (Client did not present a certificate) by noisy.programming.kicks-ass.net (Postfix) with ESMTPS id 6658F3060FD; Tue, 31 Mar 2020 17:28:50 +0200 (CEST) Received: by hirez.programming.kicks-ass.net (Postfix, from userid 1000) id 50D1729D75855; Tue, 31 Mar 2020 17:28:50 +0200 (CEST) Date: Tue, 31 Mar 2020 17:28:50 +0200 From: Peter Zijlstra To: Geert Uytterhoeven Cc: Sebastian Andrzej Siewior , Linux Kernel Mailing List , Ingo Molnar , Will Deacon , "Paul E . McKenney" , Joel Fernandes , Steven Rostedt , Linus Torvalds , Thomas Gleixner , Linux ARM , Russell King , Catalin Marinas , Frederic Weisbecker Subject: Re: [PATCH 6/9] lockdep: Introduce wait-type checks Message-ID: <20200331152850.GI20760@hirez.programming.kicks-ass.net> References: <20200313174701.148376-1-bigeasy@linutronix.de> <20200313174701.148376-7-bigeasy@linutronix.de> <20200331145515.GR20730@hirez.programming.kicks-ass.net> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20200331145515.GR20730@hirez.programming.kicks-ass.net> Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, Mar 31, 2020 at 04:55:15PM +0200, Peter Zijlstra wrote: > On Tue, Mar 31, 2020 at 03:25:21PM +0200, Geert Uytterhoeven wrote: > > On arm64 (e.g. R-Car H3 ES2.0): > > > > +============================= > > +[ BUG: Invalid wait context ] > > +5.6.0-salvator-x-09423-gb29514ba13a9c459-dirty #679 Not tainted > > +----------------------------- > > +swapper/5/0 is trying to lock: > > +ffffff86ff76f398 (&pool->lock){..-.}-{3:3}, at: __queue_work+0x134/0x430 > > +other info that might help us debug this: > > +1 lock held by swapper/5/0: > > + #0: ffffffc01103a4a0 (rcu_read_lock){....}-{1:3}, at: > > rcu_lock_acquire.constprop.59+0x0/0x38 > > +stack backtrace: > > +CPU: 5 PID: 0 Comm: swapper/5 Not tainted > > 5.6.0-salvator-x-09423-gb29514ba13a9c459-dirty #679 > > +Hardware name: Renesas Salvator-X 2nd version board based on r8a77951 (DT) > > +Call trace: > > + dump_backtrace+0x0/0x180 > > + show_stack+0x14/0x1c > > + dump_stack+0xdc/0x12c > > + __lock_acquire+0x37c/0xf9c > > + lock_acquire+0x258/0x288 > > + _raw_spin_lock+0x34/0x48 > > + __queue_work+0x134/0x430 > > + queue_work_on+0x48/0x8c > > + timers_update_nohz+0x24/0x2c > > + tick_nohz_activate.isra.15.part.16+0x5c/0x80 > > + tick_setup_sched_timer+0xe0/0xf0 > > + hrtimer_run_queues+0x88/0xf8 > > So this is complaining that it cannot take pool->lock, which is > WAIT_CONFIG while holding RCU, which presents a WAIT_CONFIG context. > > This seems to implicate something is amiss, because that should be > allowed. The thing it doesn't print is the context, which in the above > case is a (hrtimer) interrupt. > > I suspect this really is a hardirq context and the next patch won't cure > things. It looks nohz (full?) related. > > Frederic, can you untangle this? Sebastian is right; I completely forgot the workqueue thing was still pending.