X86 OpenWRT VM in Proxmox - CPU governor

Installing and Using OpenWrt
1

I have a VM in Proxmox 8.2 running OpenWRT stock 23.05.4 (x86_64 build). However, I have noticed that the CPU (i5-8500) cores assigned to the OpenWRT VM are pegged at max frequency, so I assume OpenWRT has the CPU governor set to performance. I looked under "/sys/devices/system/cpu/cpufreq/policy0/scaling_governor" and the file doesn't exist. Actually, there is nothing under the "cpufreq" folder. I also looked in the "/sys/devices/system/cpu/cpu0" and "/sys/devices/system/cpu/cpu1" folders as well and didn't find anything of use.

This seems to suggest that the x86 OpenWRT build doesn't have a CPU governor driver installed or isn't loading it due to a Proxmox configuration issue. Perhaps I'm going about this the wrong way?

2

It lacks NOHZ on some architectures.

3

I don't notice this. But I don't run x86 - I run x86_64. And the CPU type in proxmox is set to:
x86-64-v2-AES

idles at 0 percent.

4

I apologize as I am also running OpenWRT x86_64 and I have the VM CPU in Proxmox set to "host". Do you think setting it to "x86-64-v2-AES" would help in this case?

Also, where are you measuring 0% at idle?

1 Like
5

Try any of the x86_64-v* emulators.

But run top in the VM and see what's eating your CPU to verify there first.

6

Run this in a proxmox shell to check what your host supports

/lib64/ld-linux-x86-64.so.2 --help
7

x86 has NOHZ or x86/64 has it in snapshot, quite observable with powertop.

8

My Proxmox OpenWRT x64 setup also has no CPU scaling and I have CPU type in Proxmox set to host.

Seems to be pegged at min frequency.

Also

root@pve:~# /lib/ld-linux-x86-64.so.2
-bash: /lib/ld-linux-x86-64.so.2: The file or directory does not exist
9

Unfortunately, I don't have "/lib64/ld-linux-x86-64.so.2" on my Proxmox 8.2 install.

I did see that CPU governor on the Proxmox host was set to "performance". I switched this to "powersave" and things seem to be improving a bit. Running powertop on the Proxmox host shows most of the cores are able to get to C7 now.

However, for whatever reason, OpenWRT doesn't seem to recognize and load a p-state driver. Switching the CPU type in Proxmox didn't seem to have an effect. Maybe this is normal as I don't have anything else to compare it to?

10

VM will not control CPU clock.

11

That answers my root question. Thank you!