CentOS 7.4 No CPU Driver

[Nerigal]

Hi,

ive been trying to test some tuned-adm profile on a virtual machine ( CentOS 7.4 ) on hyper-v
and i noticed that every time i reboot the VM, the CPU frequency is diffrent and lower than what it should be from the host

so i tried to set the governor to performance and i ran into a problem where there is no such kernel module to do so

after that i tried many things to figure why and what package is missing but could never find decent answer

here is some command i tried

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# 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.
  hardware limits: 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: no
    Active: no

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# lsmod | grep cpuf
#

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# modprobe acpi-cpufreq
modprobe: ERROR: could not insert 'acpi_cpufreq': No such device

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# modprobe pcc-cpufreq
modprobe: ERROR: could not insert 'pcc_cpufreq': No such device

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# ls /lib/modules/`uname -r`/kernel/arch/x86/kernel/cpu/cpufreq/
ls: cannot access /lib/modules/3.10.0-693.21.1.el7.x86_64/kernel/arch/x86/kernel/cpu/cpufreq/: No such file or directory

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# locate cpufreq
/etc/selinux/targeted/active/modules/100/cpufreqselector
/etc/selinux/targeted/active/modules/100/cpufreqselector/cil
/etc/selinux/targeted/active/modules/100/cpufreqselector/hll
/etc/selinux/targeted/active/modules/100/cpufreqselector/lang_ext
/etc/selinux/targeted/tmp/modules/100/cpufreqselector
/etc/selinux/targeted/tmp/modules/100/cpufreqselector/cil
/etc/selinux/targeted/tmp/modules/100/cpufreqselector/hll
/etc/selinux/targeted/tmp/modules/100/cpufreqselector/lang_ext
/usr/include/cpufreq.h
/usr/lib/modules/3.10.0-514.el7.x86_64/kernel/drivers/cpufreq
/usr/lib/modules/3.10.0-514.el7.x86_64/kernel/drivers/cpufreq/acpi-cpufreq.ko
/usr/lib/modules/3.10.0-514.el7.x86_64/kernel/drivers/cpufreq/amd_freq_sensitivity.ko
/usr/lib/modules/3.10.0-514.el7.x86_64/kernel/drivers/cpufreq/cpufreq_stats.ko
/usr/lib/modules/3.10.0-514.el7.x86_64/kernel/drivers/cpufreq/p4-clockmod.ko
/usr/lib/modules/3.10.0-514.el7.x86_64/kernel/drivers/cpufreq/pcc-cpufreq.ko
/usr/lib/modules/3.10.0-514.el7.x86_64/kernel/drivers/cpufreq/powernow-k8.ko
/usr/lib/modules/3.10.0-514.el7.x86_64/kernel/drivers/cpufreq/speedstep-lib.ko
/usr/lib/modules/3.10.0-693.17.1.el7.x86_64/kernel/drivers/cpufreq
/usr/lib/modules/3.10.0-693.17.1.el7.x86_64/kernel/drivers/cpufreq/acpi-cpufreq.ko.xz
/usr/lib/modules/3.10.0-693.17.1.el7.x86_64/kernel/drivers/cpufreq/amd_freq_sensitivity.ko.xz
/usr/lib/modules/3.10.0-693.17.1.el7.x86_64/kernel/drivers/cpufreq/cpufreq_stats.ko.xz
/usr/lib/modules/3.10.0-693.17.1.el7.x86_64/kernel/drivers/cpufreq/p4-clockmod.ko.xz
/usr/lib/modules/3.10.0-693.17.1.el7.x86_64/kernel/drivers/cpufreq/pcc-cpufreq.ko.xz
/usr/lib/modules/3.10.0-693.17.1.el7.x86_64/kernel/drivers/cpufreq/powernow-k8.ko.xz
/usr/lib/modules/3.10.0-693.17.1.el7.x86_64/kernel/drivers/cpufreq/speedstep-lib.ko.xz

[avij]

I don't think you can select the CPU frequency from within a virtual machine. This would need to be done on the host.

[Nerigal]

I don't think you can select the CPU frequency from within a virtual machine. This would need to be done on the host.

what ?! this has nothing to do with selecting CPU frequency but missing CPU drivers

[avij]

Your description sounded like you were interested in the CPU frequency.

and i noticed that every time i reboot the VM, the CPU frequency is diffrent and lower than what it should be from the host
so i tried to set the governor to performance and i ran into a problem where there is no such kernel module to do so

Maybe I was mistaken then. Perhaps you should clarify what your actual goal is.

In any case, the kernel modules you were looking for can be found from /lib/modules/3.10.0-693.21.1.el7.x86_64/kernel/drivers/cpufreq/ , not from /lib/modules/3.10.0-693.21.1.el7.x86_64/kernel/arch/x86/kernel/cpu/cpufreq/ as you tried.

[Nerigal]

if the module is present why modprobe fail to load the module then ?

[avij]

Perhaps because you are trying to do this in a virtual machine? Note that the error message is "No such device" instead of "No such file", suggesting that the kernel does not see a suitable device for the kernel module.

For comparison, this is what happens when I try to load a random sound card kernel module and the acpi-cpufreq kernel module on a bare metal server:

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# ls -l /lib/modules/3.10.0-693.21.1.el7.x86_64/kernel/sound/drivers/mpu401
total 16
-rw-r--r--. 1 root root 4376 Mar  7 21:57 snd-mpu401.ko.xz
-rw-r--r--. 1 root root 4748 Mar  7 21:57 snd-mpu401-uart.ko.xz
# modprobe snd-mpu401
modprobe: ERROR: could not insert 'snd_mpu401': No such device
# modprobe acpi-cpufreq
#

Please consider running your CPU governor tests outside a virtual machine.

[Nerigal]

Ok

im a bit surprise even for a virtual machine to not see any cpu drivers
i would expect drivers from the hyper visor or any generic drivers anyway

Thank you

[reallyrex]

I'm seeing the same behavior on bare metal, anyone know how to get acpi-cpufreq on centos 7.4?

[TrevorH]

That module is shipped as part of the standard CentOS kernel. Either you're not running that or there is some problem that stops it from loading when requested. To find that out you need to look in your dmesg output for errors when it's loaded or maybe in /var/log/messages.

/usr/lib/modules/3.10.0-693.21.1.el7.x86_64/kernel/drivers/cpufreq/acpi-cpufreq.ko.xz
/usr/lib/modules/3.10.0-862.el7.x86_64/kernel/drivers/cpufreq/acpi-cpufreq.ko.xz

First one is the latest 7.4 kernel, second is the one from the new 7.5 kernel from the CR repo.

[reallyrex]

I'm seeing the same behavior on bare metal, anyone know how to get acpi-cpufreq on centos 7.4?

Lenovo's newest servers are coming with a BIOS setting that does not allow the OS to modify the cpu speed. I've changed this and all is well. reference:

https://lenovopress.com/lp0870.pdf