From mboxrd@z Thu Jan 1 00:00:00 1970 From: Viresh Kumar Subject: Re: [PATCH V2 0/7] cpufreq: governors: Fix ABBA lockups Date: Fri, 5 Feb 2016 08:19:26 +0530 Message-ID: <20160205024926.GD3068@vireshk> References: <20160203155428.GY3947@e106622-lin> <20160203161059.GH3469@vireshk> <20160204062439.GZ3469@vireshk> <20160204121727.GH3469@vireshk> <56B3B9B0.4010401@linux.vnet.ibm.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Return-path: Received: from mail-pa0-f46.google.com ([209.85.220.46]:34106 "EHLO mail-pa0-f46.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751621AbcBECta (ORCPT ); Thu, 4 Feb 2016 21:49:30 -0500 Received: by mail-pa0-f46.google.com with SMTP id uo6so26405066pac.1 for ; Thu, 04 Feb 2016 18:49:29 -0800 (PST) Content-Disposition: inline In-Reply-To: <56B3B9B0.4010401@linux.vnet.ibm.com> Sender: linux-pm-owner@vger.kernel.org List-Id: linux-pm@vger.kernel.org To: Shilpasri G Bhat Cc: Juri Lelli , Rafael Wysocki , linaro-kernel@lists.linaro.org, linux-pm@vger.kernel.org, skannan@codeaurora.org, peterz@infradead.org, mturquette@baylibre.com, steve.muckle@linaro.org, vincent.guittot@linaro.org, morten.rasmussen@arm.com, dietmar.eggemann@arm.com, linux-kernel@vger.kernel.org On 05-02-16, 02:20, Shilpasri G Bhat wrote: > I could see the previous lockdep warnings on pm/next and on top of patch[4]. > On Patch[5-7] I see the below lockdep trace on running './runme' on a Power8 box. > [ 710.336130] Chain exists of: > s_active#91 --> &dbs_data->mutex --> od_dbs_cdata.mutex > > [ 710.336376] Possible unsafe locking scenario: > > [ 710.336488] CPU0 CPU1 > [ 710.336577] ---- ---- > [ 710.336666] lock(od_dbs_cdata.mutex); > [ 710.336778] lock(&dbs_data->mutex); > [ 710.336911] lock(od_dbs_cdata.mutex); > [ 710.337064] lock(s_active#91); > [ 710.337176] This is the same lockdep, just that we have added another mutex (dbs_data->mutex) to it. Have you tried if all the lockdeps go away with the 8th patch that I provided yesterday ? -- viresh