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 21:19:34 +0530 Message-ID: <51E6BD0E.1020101@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> <51E6B7F7.6020901@gmx.de> Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: QUOTED-PRINTABLE Return-path: Received: from e28smtp06.in.ibm.com ([122.248.162.6]:54762 "EHLO e28smtp06.in.ibm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754456Ab3GQPxJ (ORCPT ); Wed, 17 Jul 2013 11:53:09 -0400 Received: from /spool/local by e28smtp06.in.ibm.com with IBM ESMTP SMTP Gateway: Authorized Use Only! Violators will be prosecuted for from ; Wed, 17 Jul 2013 21:14:49 +0530 In-Reply-To: <51E6B7F7.6020901@gmx.de> Sender: linux-pm-owner@vger.kernel.org List-Id: linux-pm@vger.kernel.org To: =?UTF-8?B?VG9yYWxmIEbDtnJzdGVy?= , "Rafael J. Wysocki" Cc: 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 08:57 PM, Toralf F=C3=B6rster wrote: > On 07/16/2013 11:32 PM, 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/resu= me) caused >>>>>> some subtle regressions in the cpufreq subsystem during suspend/= resume. >>>>>> This patchset is aimed at rectifying those problems, by fixing t= he regression >>>>>> as well as achieving the original goal of that commit in a prope= r 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 bas= e that the >>>>>> rest of the patches will make use of. >>>>>> >>>>>> Patch 6 and 7 add a mechanism to perform light-weight init/tear-= down 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 f= iles 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 Toral= f to know >>>>>> whether their systems work fine after: >>>>>> a. applying only the first commit (this is what gets backported = to stable) >>>>>> b. applying all the commits >>>>>> >>>>>> (Note: I had to use Michael's fix[1] to avoid CPU hotplug deadlo= ck while >>>>>> testing this patchset. Though that patch also touches cpufreq su= bsystem, it >>>>>> doesn't affect this patchset in any way and there is absolutely = no dependency >>>>>> between the two in terms of code. That fix just makes basic CPU = hotplug 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 i= f 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 1= 5, 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 s2r= am/wakeup >>> cycles fine and crashed the system at the 3rd attempt / one times j= ust 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 2= nd >>> >>> My hardware is a ThinkPad T420 with latest BIOS and a 32 bit stable >>> Gentoo Linux - FWIW .config attached. >> >> I think you'll need the fixes first, basically [1/8] from this serie= s and >> this: https://patchwork.kernel.org/patch/2827512/ . >> >> Please try to run with these two things applied only and see how tha= t goes. >> >> Thanks, >> Rafael >> >> > That was it. >=20 > Applying https://patchwork.kernel.org/patch/2827512/ and then patch > [1/8] on top of v3.11-rc1-8-g47188d3 works fine and solved the report= ed > issue. >=20 > Furthermore applying patches 2-8 works too - suspend/wakeup works fin= e > and frequencies are scaled right after wakeup at the T420. >=20 Phew! Finally :-) Thank you for all your testing efforts! =20 Regards, Srivatsa S. Bhat