Re: [PATCH 1/2] cpufreq: serialize calls to __cpufreq_governor()

[Prarit Bhargava <prarit@redhat.com>]

On 10/14/2014 02:58 AM, Viresh Kumar wrote:
> On 10 October 2014 19:35, Robert Schöne <robert.schoene@tu-dresden.de> wrote:
>> @all:
>> I have to leave now and will not be available for a week.
>>
>> @Viresh:
>> The line you are looking for is 2c8 (260h+68h, length check passed).
>> Here it is with the surrounding instructions:
> 
> Thanks..
> 
> I now understand most of the races you and Prarit have reported.
> Finally I was able to get my multi-cluster board up and could test this
> myself :)
> 
> So you need to try my cpufreq/governor-fixes-v4 branch to confirm if
> this fixes your issues or not.
> 
> @Prarit: As Robert probably isn't around this week, would it be possible for
> you to test this stuff ?

Hi Viresh,

I've been running both my test and Robert's test for about 5 mins.  In Robert's
case I don't see any problems ... in my case I do occasionally get a system
panic because of the sysfs access race I described in the other thread (cpu 1
holds a sysfs file open, while cpu 2 changes the governor ...)

I do have some concerns about the nature of this patchset; I feel it is more of
a band-aid approach to the whole cpufreq mechanism.  Having said that, I haven't
offered an alternative yet so I can't really object too loudly :)

I'll do a more formal review when you post to the list.

P.

> 
> I will send this as a patchset so that people can review and comment.
> 
> --
> viresh
>