Re: [Powertop] [RESEND PATCH] powertop: fix erroneous C state detection on ARM

[Alexandra Yates <alexandra.yates at linux.intel.com>]

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This patch was added to the current powertop.rc1
AY

On 07/07/2015 08:04 AM, Lorenzo Pieralisi wrote:
> On Mon, Jun 15, 2015 at 10:57:29AM +0100, Lorenzo Pieralisi wrote:
>> When the kernel is configured with CONFIG_CPU_IDLE_MULTIPLE_DRIVERS,
>> the cpuidle directory contains a "driver" subdirectory that confuses
>> the current code parsing the C states on ARM platforms, ending up
>> with a C state entry corresponding to the actual driver name instead
>> of a proper C state entry.
>>
>> This patch fixes the code by stopping the parsing if the files that
>> characterise the C states (ie usage) are not found in the respective:
>>
>> /sys/devices/system/cpu/cpuX/cpuidle
>>
>> subdirectory containing C states information.
>>
>> Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi(a)arm.com>
>> Tested-by: Kevin Hilman <khilman(a)linaro.org>
>> ---
>> Alexandra, Arjan,
>>
>> previous posting here:
>>
>> https://lists.01.org/pipermail/powertop/2014-December/001724.html
>>
>> Please consider pulling this patch.
> Gentle ping.
>
> Thanks,
> Lorenzo
>
>> Thanks,
>> Lorenzo
>>
>>   src/cpu/cpu_linux.cpp | 6 ++++--
>>   1 file changed, 4 insertions(+), 2 deletions(-)
>>
>> diff --git a/src/cpu/cpu_linux.cpp b/src/cpu/cpu_linux.cpp
>> index e1ff165..78fd2d3 100644
>> --- a/src/cpu/cpu_linux.cpp
>> +++ b/src/cpu/cpu_linux.cpp
>> @@ -83,7 +83,8 @@ void cpu_linux::parse_cstates_start(void)
>>   		if (file) {
>>   			file >> usage;
>>   			file.close();
>> -		}
>> +		} else
>> +			continue;
>>   
>>   		sprintf(filename + len, "/%s/time", entry->d_name);
>>   
>> @@ -172,7 +173,8 @@ void cpu_linux::parse_cstates_end(void)
>>   		if (file) {
>>   			file >> usage;
>>   			file.close();
>> -		}
>> +		} else
>> +			continue;
>>   
>>   		sprintf(filename + len, "/%s/time", entry->d_name);
>>   
>> -- 
>> 1.9.1
>>

-- 
Thank you,
<Alexandra>