From mboxrd@z Thu Jan 1 00:00:00 1970 From: "Srivatsa S. Bhat" Subject: Re: [PATCH 0/8] Cpufreq, cpu hotplug, suspend/resume related fixes Date: Wed, 17 Jul 2013 10:33:06 +0530 Message-ID: <51E6258A.3050105@linux.vnet.ibm.com> References: <20130711221419.547.69781.stgit@srivatsabhat.in.ibm.com> <51DF307B.7060307@linux.vnet.ibm.com> <51E56382.3020609@gmx.de> <2829832.mz5UcF7ZkY@vostro.rjw.lan> Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: QUOTED-PRINTABLE Return-path: Received: from e23smtp02.au.ibm.com ([202.81.31.144]:60456 "EHLO e23smtp02.au.ibm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751003Ab3GQFGw (ORCPT ); Wed, 17 Jul 2013 01:06:52 -0400 Received: from /spool/local by e23smtp02.au.ibm.com with IBM ESMTP SMTP Gateway: Authorized Use Only! Violators will be prosecuted for from ; Wed, 17 Jul 2013 14:56:36 +1000 In-Reply-To: <2829832.mz5UcF7ZkY@vostro.rjw.lan> Sender: linux-pm-owner@vger.kernel.org List-Id: linux-pm@vger.kernel.org To: =?UTF-8?B?VG9yYWxmIEbDtnJzdGVy?= Cc: "Rafael J. Wysocki" , viresh.kumar@linaro.org, robert.jarzmik@intel.com, durgadoss.r@intel.com, tianyu.lan@intel.com, lantianyu1986@gmail.com, dirk.brandewie@gmail.com, stern@rowland.harvard.edu, linux-pm@vger.kernel.org, linux-kernel@vger.kernel.org On 07/17/2013 03:02 AM, Rafael J. Wysocki wrote: > On Tuesday, July 16, 2013 05:15:14 PM Toralf F=C3=B6rster wrote: >> On 07/12/2013 12:23 AM, Srivatsa S. Bhat wrote: >>> On 07/12/2013 04:03 AM, Rafael J. Wysocki wrote: >>>> On Friday, July 12, 2013 03:45:17 AM Srivatsa S. Bhat wrote: >>>>> >>>>> Hi, >>>> >>>> Hi, >>>> >>>>> Commit a66b2e (cpufreq: Preserve sysfs files across suspend/resum= e) caused >>>>> some subtle regressions in the cpufreq subsystem during suspend/r= esume. >>>>> This patchset is aimed at rectifying those problems, by fixing th= e regression >>>>> as well as achieving the original goal of that commit in a proper= way. >>>>> >>>>> Patch 1 reverts the above commit, and is CC'ed to stable. >>>>> >>>>> Patches 2 - 5 reorganize the code and have no functional impact, = and can go >>>>> in as general cleanups as well. This reorganization builds a base= that the >>>>> rest of the patches will make use of. >>>>> >>>>> Patch 6 and 7 add a mechanism to perform light-weight init/tear-d= own of CPUs >>>>> in the cpufreq subsystem and finally patch 8 uses it to preserve = sysfs files >>>>> across suspend/resume. >>>>> >>>>> All the patches apply on current mainline. >>>>> >>>>> >>>>> Robert, Durgadoss, it would be great if you could try it out and = see if it works >>>>> well for your usecase. I tested it locally and cpufreq related fi= les did retain >>>>> their permissions across suspend/resume. Let me know if it works = fine in your >>>>> setup too. >>>>> >>>>> And I'd of course appreciate to hear from Dirk, Tianyu and Toralf= to know >>>>> whether their systems work fine after: >>>>> a. applying only the first commit (this is what gets backported t= o stable) >>>>> b. applying all the commits >>>>> >>>>> (Note: I had to use Michael's fix[1] to avoid CPU hotplug deadloc= k while >>>>> testing this patchset. Though that patch also touches cpufreq sub= system, it >>>>> doesn't affect this patchset in any way and there is absolutely n= o dependency >>>>> between the two in terms of code. That fix just makes basic CPU h= otplug work >>>>> without locking up on current mainline). >>>>> >>>>> [1]. https://lkml.org/lkml/2013/7/10/611 >>>>> >>>>> >>>>> Thank you very much! >>>> >>>> Thanks Srivatsa! >>>> >>>> I'm going to take [1/8] for 3.11 and queue up the rest for 3.12 if= people don't >>>> hate them. This way we'll have some more testing coverage before = they reach >>>> the mainline hopefully. >>>> >> >> On 07/16/2013 01:25 AM, Rafael J. Wysocki wrote:> On Monday, July 15= , 2013 07:38:02 PM Toralf F=C3=B6rster wrote: >>> Sorry, I have no idea what 1#8 means. >> >> sry - here again with full quote of the email : >> >> I applied patch [1/8] on top of v3.11-rc1-8-g47188d3 passes two s2ra= m/wakeup >> cycles fine and crashed the system at the 3rd attempt / one times ju= st at >> the 4th (blinking power led, no sysrq, ...). >> >> Applying patch 1-8 on top of that tree differs in that way that it >> crashes now the system even at the 1st attempt or at least at the 2n= d >> >> My hardware is a ThinkPad T420 with latest BIOS and a 32 bit stable >> Gentoo Linux - FWIW .config attached. >=20 > I think you'll need the fixes first, basically [1/8] from this series= and > this: https://patchwork.kernel.org/patch/2827512/ . >=20 > Please try to run with these two things applied only and see how that= goes. >=20 In addition to what Rafael suggested above, also try running your kerne= l with cpufreq completely turned off (CONFIG_CPU_FREQ=3Dn). My patches to= uch only cpufreq, so this experiment will tell us if your suspend/resume issues = are really related to cpufreq or not. If turning off cpufreq also breaks yo= ur suspend/resume, then a fresh git-bisect might be the only way to go. =20 Regards, Srivatsa S. Bhat