Re: [PATCH 2/2] cpufreq: powernv: Use PMSR to verify global and local pstate

From	Akshay Adiga <akshay.adiga@linux.vnet.ibm.com>
Newsgroups	linux.kernel
Subject	Re: [PATCH 2/2] cpufreq: powernv: Use PMSR to verify global and local pstate
Date	2016-11-07 08:40 +0100
Message-ID	<sAMH7-8iu-1@gated-at.bofh.it> (permalink)
References	<szFeF-5KK-3@gated-at.bofh.it> <szFeF-5KK-7@gated-at.bofh.it> <szGu5-6zz-21@gated-at.bofh.it>
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Thanks Viresh for taking a look at it.

I will make the mentioned changes in the next version of the patch and
will add Shilpa and Gautham to the mail chain.

Regards

Akshay Adiga


On 11/04/2016 12:11 PM, Viresh Kumar wrote:
> On 04-11-16, 10:57, Akshay Adiga wrote:
>> As fast_switch may get called in interrupt disable mode, it does not
> s/in interrupt disable mode/with interrupts disabled
> s/it does/it may
>
>> update the global_pstate_info data structure. Hence the global_pstate_info
>> has stale data whenever pstate is updated through fast_swtich().
> s/has/may have
> s/swtich/switch
>
>> So the gpstate_timer can fire after a fast_switch() call has update
> s/So the/The
> s/a fast_swtich() call has update/the fast_switch() call has updated
>
>> the pstates to a different value. Hence the timer handler cannot rely
>> on the cached values of local and global pstate and needs to read it
>> from the PMSR.
>>
>> Signed-off-by: Akshay Adiga <akshay.adiga@linux.vnet.ibm.com>
>>
>> ---
>>   drivers/cpufreq/powernv-cpufreq.c | 32 ++++++++++++++++++++++----------
>>   1 file changed, 22 insertions(+), 10 deletions(-)
> I am not the best guy to judge the code changes here. Can you please include
> Shilpa and Gautham to the mail chain and get there feedback.
>
>
>

Thread

[PATCH 1/2] cpufreq: powernv: Adding fast_switch for schedutil Akshay Adiga <akshay.adiga@linux.vnet.ibm.com> - 2016-11-04 06:30 +0100
  [PATCH 2/2] cpufreq: powernv: Use PMSR to verify global and local pstate Akshay Adiga <akshay.adiga@linux.vnet.ibm.com> - 2016-11-04 06:30 +0100
    Re: [PATCH 2/2] cpufreq: powernv: Use PMSR to verify global and  local pstate Viresh Kumar <viresh.kumar@linaro.org> - 2016-11-04 07:50 +0100
      Re: [PATCH 2/2] cpufreq: powernv: Use PMSR to verify global and local  pstate Akshay Adiga <akshay.adiga@linux.vnet.ibm.com> - 2016-11-07 08:40 +0100
  Re: [PATCH 1/2] cpufreq: powernv: Adding fast_switch for schedutil Viresh Kumar <viresh.kumar@linaro.org> - 2016-11-04 07:40 +0100
    Re: [PATCH 1/2] cpufreq: powernv: Adding fast_switch for schedutil Akshay Adiga <akshay.adiga@linux.vnet.ibm.com> - 2016-11-07 09:00 +0100

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