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=-2.8 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, USER_AGENT_SANE_1 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 B6497C2D0EE for ; Tue, 31 Mar 2020 15:37:40 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 85D2A208E0 for ; Tue, 31 Mar 2020 15:37:40 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1585669060; bh=ggMm14KxXbY1mqecFv6pjM06I08zLyhqEuowrT/NApQ=; h=Date:From:To:Cc:Subject:References:In-Reply-To:List-ID:From; b=ujvuBCl5/vWiz2qPiy2vnr4nWotZUxAYjIhDgwonLqnbbkLhSnjvYlbrVk32/G+lI H4tyCjZHrz0AeU10EzqR7rtdaszzNkFVkUFruOfyXqq6CrFWb4dNIelONeQqyiYeOq XWJ6SLB2t7g4UGK1CrGQaAyKCUJHzpMswF9a+utw= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1730946AbgCaPhj (ORCPT ); Tue, 31 Mar 2020 11:37:39 -0400 Received: from mail.kernel.org ([198.145.29.99]:43140 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727703AbgCaPhj (ORCPT ); Tue, 31 Mar 2020 11:37:39 -0400 Received: from localhost (lfbn-ncy-1-985-231.w90-101.abo.wanadoo.fr [90.101.63.231]) (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 5BB6420848; Tue, 31 Mar 2020 15:37:37 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1585669057; bh=ggMm14KxXbY1mqecFv6pjM06I08zLyhqEuowrT/NApQ=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=mGxhCt07fuJo88YbZTobkEe3mxir9Y88c89S+a3IWrsUceux7kjcXqDx/3NZydT5G 5vFmczVbdKf8IpGOlX3+Mm/NEAHVaIG0ejNjlPjvue8c4zRqmyOm0Q+d4Jj2hUanFA yd7KuK/Vq2D2O7Ll3dGhk4HpgSSLabTT2hKfbZuA= Date: Tue, 31 Mar 2020 17:37:35 +0200 From: Frederic Weisbecker To: Peter Zijlstra Cc: Geert Uytterhoeven , 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: <20200331153734.GA6979@lenoir> References: <20200313174701.148376-1-bigeasy@linutronix.de> <20200313174701.148376-7-bigeasy@linutronix.de> <20200331145515.GR20730@hirez.programming.kicks-ass.net> <20200331152850.GI20760@hirez.programming.kicks-ass.net> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20200331152850.GI20760@hirez.programming.kicks-ass.net> User-Agent: Mutt/1.9.4 (2018-02-28) 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 05:28:50PM +0200, Peter Zijlstra wrote: > 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. > Ok good, because I had no better answer :)