Re: [PATCH 0/8] Cpufreq, cpu hotplug, suspend/resume related fixes

From: "Toralf Förster" <toralf.foerster@gmx.de>
To: "Srivatsa S. Bhat" <srivatsa.bhat@linux.vnet.ibm.com>
Cc: "Rafael J. Wysocki" <rjw@sisk.pl>,
	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
Subject: Re: [PATCH 0/8] Cpufreq, cpu hotplug, suspend/resume related fixes
Date: Tue, 16 Jul 2013 17:15:14 +0200	[thread overview]
Message-ID: <51E56382.3020609@gmx.de> (raw)
In-Reply-To: <51DF307B.7060307@linux.vnet.ibm.com>

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/resume) caused
>>> some subtle regressions in the cpufreq subsystem during suspend/resume.
>>> This patchset is aimed at rectifying those problems, by fixing the 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-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 files 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 to stable)
>>> b. applying all the commits
>>>
>>> (Note: I had to use Michael's fix[1] to avoid CPU hotplug deadlock while
>>> testing this patchset. Though that patch also touches cpufreq subsystem, 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 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 Förster 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 s2ram/wakeup
cycles fine and crashed the system at the 3rd attempt / one times just 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 2nd

My hardware is a ThinkPad T420 with latest BIOS and a 32 bit stable
Gentoo Linux - FWIW .config attached.

> 
> Sounds great! Thanks a lot Rafael!
>  
> Regards,
> Srivatsa S. Bhat
> 
> 

-- 
MfG/Sincerely
Toralf Förster
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