From mboxrd@z Thu Jan 1 00:00:00 1970 From: Prarit Bhargava Subject: Re: [PATCH] cpufreq, store_scaling_governor requires policy->rwsem to be held for duration of changing governors [v2] Date: Thu, 31 Jul 2014 14:26:09 -0400 Message-ID: <53DA8A41.2030601@redhat.com> References: <1406634362-811-1-git-send-email-prarit@redhat.com> <2066166.pXm4lKLOID@vostro.rjw.lan> <53DA8389.80804@redhat.com> <1917362.abr2Y4p7vh@vostro.rjw.lan> Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit Return-path: Received: from mx1.redhat.com ([209.132.183.28]:2314 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751066AbaGaS0T (ORCPT ); Thu, 31 Jul 2014 14:26:19 -0400 In-Reply-To: <1917362.abr2Y4p7vh@vostro.rjw.lan> Sender: linux-pm-owner@vger.kernel.org List-Id: linux-pm@vger.kernel.org To: "Rafael J. Wysocki" Cc: Saravana Kannan , linux-kernel@vger.kernel.org, Viresh Kumar , Lenny Szubowicz , linux-pm@vger.kernel.org On 07/31/2014 02:38 PM, Rafael J. Wysocki wrote: > On Thursday, July 31, 2014 01:57:29 PM Prarit Bhargava wrote: >> >> On 07/31/2014 12:36 PM, Rafael J. Wysocki wrote: >>> On Thursday, July 31, 2014 06:23:18 AM Prarit Bhargava wrote: >>>> >>>> On 07/30/2014 10:16 PM, Rafael J. Wysocki wrote: >>>>> On Wednesday, July 30, 2014 06:36:00 PM Saravana Kannan wrote: >>>>>> On 07/30/2014 02:40 PM, Rafael J. Wysocki wrote: >>>>>>> On Wednesday, July 30, 2014 10:18:25 AM Prarit Bhargava wrote: >>>>>>>> >>>>>>>> On 07/29/2014 08:03 PM, Rafael J. Wysocki wrote: >>>>>>>>> On Tuesday, July 29, 2014 07:46:02 AM Prarit Bhargava wrote: >>>>>>> >>>>>>> [cut] >>>>>>> >>>>>>>>>> This patch effectively reverts commit 955ef483. >>>>>> >>>>>> The issue reported in this patch is valid. We are seeing that internally >>>>>> too. I believe I reported it in another thread (within the past month). >>>>>> >>>>>> However, the original patch fixes a real deadlock issue (I'm too tired >>>>>> to look it up now). We can revet the original, but it's going to bring >>>>>> back the original issue. I just want to make sure Prarit and Raphael >>>>>> realize this before proceeding. >>>>>> >>>>>> I do have plans for a proper fix for the mainline (not stable branches), >>>>>> but plan to do that after the current set of suspend/hotplug patches go >>>>>> through. The fix would be easier to make after that. >>>>>> >>>>>>>>> >>>>>>>>> OK, I'm convinced by this. >>>>>>>>> >>>>>>>>> I suppose we should push it for -stable from 3.10 through 3.15.x, right? >>>>>>>> >>>>>>>> Rafael, I think that is a good idea. I'm not sure what the protocol is for >>>>>>>> adding stable@kernel.org though ... >>>> >>>> Rafael, let me (again) re-write the patch description. I think Saravana has >>>> raised an important issue that I have not clearly identified why it is safe to >>>> remove this code in my patch description. Also, I want to clearly identify the >>>> appropriate -stable releases to push this out to. >>>> >>>> I'll submit a [v3] later today or tomorrow. >>> >>> In any case that's too late for 3.16 final, unless there's an -rc8. >>> >>> Thanks for doing that work! >> >> Ugh ... I tried this (yet another) large system and hit another panic :(. >> >> I'm investigating now, and I'm hoping this is just something "new". > > Well, I've applied your patch as is and I can push it to Linus. > > However, if you want to update the changelog, I'll not do that, but in that > case the patch will have to wait for the next week. Rafael, please let it wait for next week. I _need_ to make sure this is correct and I'd rather not pushed something half-done. Thanks, P. > > Rafael >