[SOLVED] grub intel_pstate

[TwiX]

Hi,

Seems that settle 'intel_pstate=disable' in /etc/default/grub is not working anymore.
However, intel_idle.max_cstate=0 processor.max_cstate=1 permit cpus to work at higher frequency but turbo still active.
In order to avoid sync issues inside vms, I'd prefer want my cpus working at constant freq. Is there a way to do it ?

Thanks in advanced !

 

[spirit]

from this bugzilla:
https://bugzilla.redhat.com/show_bug.cgi?id=1556724

can you try to add idle=pool ?

processor.max_cstate=0 intel_idle.max_cstate=0 idle=poll

 

[TwiX]

Thanks I will.

I keep you guys in touch

 

[TwiX]

Works as expected !!

Thank you so much

 

[spirit]

Works as expected !!

Thank you so much

I'm curious to see power consumption difference if you have monitoring on it.

 

[TwiX]

I don't monit power consumption sorry.

Just noticed that I tried all possibles values :
processor.max_cstate=0 intel_idle.max_cstate=0 idle=poll
processor.max_cstate=1 intel_idle.max_cstate=1 idle=poll
processor.max_cstate=0 intel_idle.max_cstate=1 idle=poll
processor.max_cstate=1 intel_idle.max_cstate=0 idle=poll

CPU runs at its maximum speed => turbo always on.

 

[TwiX]

grub with only idle=poll is enough to put CPU at its maximum speed.

 

[TwiX]

Caution : idle=poll is not compatible with hyperthreading (slow down performance)
https://software.intel.com/en-us/fo...optimization-platform-monitoring/topic/535130