Re: IPC drop down on AMD epyc 7702P

[Jean-Baptiste Roquefere <jb.roquefere@ateme.com>]

Hello Vincent,

> As said previously, I don't see an obvious connection between commit
> 16b0a7a1a0af  ("sched/fair: Ensure tasks spreading in LLC during LB")
> which mainly ensures a better usage of CPUs inside a LLC. Do you have
> cpufreq and freq scaling enabled ? The only link that I could think
> of, is that the spread of task inside a llc favors inter LLC newly
> idle load balance
# lsmod | grep cpufreq
cpufreq_userspace      16384  0
cpufreq_conservative    16384  0
cpufreq_powersave      16384  0


but I'm not sure cpufreq is well loaded :

# cpupower frequency-info
analyzing CPU 0:
   no or unknown cpufreq driver is active on this CPU
   CPUs which run at the same hardware frequency: Not Available
   CPUs which need to have their frequency coordinated by software: Not 
Available
   maximum transition latency:  Cannot determine or is not supported.
Not Available
   available cpufreq governors: Not Available
   Unable to determine current policy
   current CPU frequency: Unable to call hardware
   current CPU frequency:  Unable to call to kernel
   boost state support:
     Supported: yes
     Active: yes
     Boost States: 0
     Total States: 3
     Pstate-P0:  2000MHz
     Pstate-P1:  1800MHz
     Pstate-P2:  1500MHz

And I cant find cpufreq/ under /sys/devices/system/cpu/cpu*/


Thanks for your help,

jb