From mboxrd@z Thu Jan 1 00:00:00 1970 From: Viresh Kumar Subject: Re: cpufreq/ondemand: unpinning an unpinned lock. Date: Thu, 16 Jul 2015 10:41:50 +0530 Message-ID: <20150716051150.GA15404@linux> References: <20150715220422.GA13789@codemonkey.org.uk> <3682267.1lcDzeZuDs@vostro.rjw.lan> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Return-path: Received: from mail-pd0-f178.google.com ([209.85.192.178]:36191 "EHLO mail-pd0-f178.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751055AbbGPFLz (ORCPT ); Thu, 16 Jul 2015 01:11:55 -0400 Received: by pdjr16 with SMTP id r16so37715245pdj.3 for ; Wed, 15 Jul 2015 22:11:55 -0700 (PDT) Content-Disposition: inline In-Reply-To: <3682267.1lcDzeZuDs@vostro.rjw.lan> Sender: linux-pm-owner@vger.kernel.org List-Id: linux-pm@vger.kernel.org To: "Rafael J. Wysocki" Cc: Dave Jones , Linux Kernel , linux-pm@vger.kernel.org On 16-07-15, 02:13, Rafael J. Wysocki wrote: > Cc: Viresh as he's been working on governors recently. > > On Wednesday, July 15, 2015 06:04:22 PM Dave Jones wrote: > > WARNING: CPU: 1 PID: 29529 at kernel/locking/lockdep.c:3497 lock_unpin_lock+0x109/0x110() > > unpinning an unpinned lock > > CPU: 1 PID: 29529 Comm: kworker/1:1 Not tainted 4.2.0-rc2-think+ #3 > > Workqueue: events od_dbs_timer > > 0000000000000009 ffff880094d5baa8 ffffffffae7f5e6f 0000000000000007 > > ffff880094d5baf8 ffff880094d5bae8 ffffffffae07b91a 0000000000000118 > > 00000000000000e0 ffff880507bd5c58 0000000000000092 0000000000000004 > > Call Trace: > > [] dump_stack+0x4f/0x7b > > [] warn_slowpath_common+0x8a/0xc0 > > [] warn_slowpath_fmt+0x46/0x50 > > [] lock_unpin_lock+0x109/0x110 > > [] __schedule+0x3ac/0xb60 > > [] schedule+0x41/0x90 > > [] schedule_preempt_disabled+0x18/0x30 > > [] mutex_lock_nested+0x16f/0x3e0 > > [] ? gov_queue_work+0x2f/0xf0 > > [] ? od_check_cpu+0x57/0xd0 > > [] ? gov_queue_work+0x2f/0xf0 > > [] gov_queue_work+0x2f/0xf0 > > [] od_dbs_timer+0xbd/0x150 > > [] process_one_work+0x1f3/0x7a0 > > [] ? process_one_work+0x162/0x7a0 > > [] ? worker_thread+0xf9/0x470 > > [] worker_thread+0x69/0x470 > > [] ? preempt_count_sub+0xa3/0xf0 > > [] ? process_one_work+0x7a0/0x7a0 > > [] kthread+0x11f/0x140 > > [] ? kthread_create_on_node+0x250/0x250 > > [] ret_from_fork+0x3f/0x70 > > [] ? kthread_create_on_node+0x250/0x250 > > ---[ end trace 86cca931caec9193 ]--- I don't know why this will happen. Just to confirm, you are getting this over 4.2-rc(1 or 2)? And you weren't getting these on 4.1 at all? And its always reproducible? How ? There have been races in cpufreq core since sometime and what got pushed in 4.2-rc1 is just half of the fix. The other half is present here: http://marc.info/?i=cover.1434713657.git.viresh.kumar%40linaro.org Please try this and let us know if things work well or not. -- viresh