From mboxrd@z Thu Jan 1 00:00:00 1970 From: Preeti U Murthy Subject: Re: [PATCH 0/3] cpufreq: governor: Fix potential races Date: Fri, 05 Jun 2015 09:35:21 +0530 Message-ID: <55712001.8070905@linux.vnet.ibm.com> References: <556FDEA8.6090801@linux.vnet.ibm.com> <20150605030028.GB13999@linux> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Return-path: Received: from e39.co.us.ibm.com ([32.97.110.160]:34150 "EHLO e39.co.us.ibm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750705AbbFEEFb (ORCPT ); Fri, 5 Jun 2015 00:05:31 -0400 Received: from /spool/local by e39.co.us.ibm.com with IBM ESMTP SMTP Gateway: Authorized Use Only! Violators will be prosecuted for from ; Thu, 4 Jun 2015 22:05:30 -0600 Received: from b01cxnp22035.gho.pok.ibm.com (b01cxnp22035.gho.pok.ibm.com [9.57.198.25]) by d01dlp03.pok.ibm.com (Postfix) with ESMTP id B0C49C9003C for ; Thu, 4 Jun 2015 23:56:35 -0400 (EDT) Received: from d01av02.pok.ibm.com (d01av02.pok.ibm.com [9.56.224.216]) by b01cxnp22035.gho.pok.ibm.com (8.14.9/8.14.9/NCO v10.0) with ESMTP id t5545SHt45416488 for ; Fri, 5 Jun 2015 04:05:28 GMT Received: from d01av02.pok.ibm.com (localhost [127.0.0.1]) by d01av02.pok.ibm.com (8.14.4/8.14.4/NCO v10.0 AVout) with ESMTP id t5545Rff007027 for ; Fri, 5 Jun 2015 00:05:28 -0400 In-Reply-To: <20150605030028.GB13999@linux> Sender: linux-pm-owner@vger.kernel.org List-Id: linux-pm@vger.kernel.org To: Viresh Kumar , Rafael Wysocki Cc: linaro-kernel@lists.linaro.org, linux-pm@vger.kernel.org, ego@linux.vnet.ibm.com, paulus@samba.org, shilpa.bhat@linux.vnet.ibm.com, prarit@redhat.com, robert.schoene@tu-dresden.de, skannan@codeaurora.org On 06/05/2015 08:30 AM, Viresh Kumar wrote: > On 04-06-15, 10:44, Preeti U Murthy wrote: >> On 06/03/2015 03:57 PM, Viresh Kumar wrote: >>> Preeti recently highlighted [1] some issues in cpufreq core locking with >>> respect to governors. I wanted to solve them after we have simplified >>> the hotplug paths in cpufreq core with my latest patches, but now that >>> she has poked me, I have done some work in that area. >>> >>> I am trying to solve only a part of the bigger problem (in a way that I >>> feel is the right way ahead). The first patches restructures code to >>> make it more readable and the last patch does all the major changes. The >>> logs in that one should be good enough to explain why and what I am >>> doing. >>> >>> The first two shouldn't bring any functional change and so can be >>> applied early if you are confident about them. >>> >>> @Preeti: I would like you to test these patches. These should get rid of >>> the crashes you were facing but may generate a WARN() from line 447 of >>> cpufreq_governor.c, if the sequence is wrong. That has to be fixed >>> separately. >>> >>> Line 447: WARN_ON(!dbs_data && (event != CPUFREQ_GOV_POLICY_INIT)) > > Hi Preeti, > > Thanks for giving your RBY tags for all the patches, would you also > like to give Tested-by's if you have done any testing on these. > > That is just to confirm it hasn't broken things any further and that > we haven't seen any crashes in races between > INIT/EXIT/START/STOP/LIMITS. I realize that I am not currently hitting the races on my machine that this patchset is trying to solve. The races that I am hitting have been conveyed on this thread and we should be fixing that separately as Viresh pointed out. I can therefore provide only by Reviewed-bys to this patchset. Thanks Regards Preeti U Murthy >