[dpdk-dev] librte_power w/ intel_pstate cpufreq governor

[Hunt, David]

Hi BL,

I have always used "intel_pstate=disable" in my kernel parameters at 
boot so as to disable the intel_pstate driver, and force the kernel to 
use the acpi-cpufreq driver:

# cat /sys/devices/system/cpu/cpu0/cpufreq/scaling_driver
acpi-cpufreq

This then gives me the following options for the governor:
['conservative', 'ondemand', 'userspace', 'powersave', 'performance', 
'schedutil']

Because DPDK threads typically poll, they appear as 100% busy to the 
p_state driver, so if you want to be able to change core frequency down 
(as in l3fwd-power), you need to use the acpi-cpufreq driver.

I had a read through the docs just now, and this does not seem to be 
mentioned, so I'll do up a patch to give some information on the correct 
kernel parameters to use when using the power library.

Regards,
Dave.

On 2/3/2018 7:20 AM, longtb5 at viettel.com.vn wrote:
> Forgot to link the original thread.
>
> http://dpdk.org/ml/archives/dev/2016-January/030930.html
>
> -BL
>
>> -----Original Message-----
>> From: longtb5 at viettel.com.vn [mailto:longtb5 at viettel.com.vn]
>> Sent: Friday, March 2, 2018 2:19 PM
>> To: dev at dpdk.org
>> Cc: david.hunt at intel.com; mhall at mhcomputing.net; helin.zhang at intel.com;
>> longtb5 at viettel.com.vn
>> Subject: librte_power w/ intel_pstate cpufreq governor
>>
>> Hi everybody,
>>
>> I know this thread was from over 2 years ago but I ran into the same
> problem
>> with l3fwd-power today.
>>
>> Any updates on this?
>>
>> -BL
>