Configuration: Number of vCPU's do not match host CPU count when set to -1

Open mcastelino opened this issue 7 years ago • 5 comments

Description of problem

default_vcpus = -1

On a machine with large number of CPUs the maximum number of CPU's the maximum CPU's visible to the VM is set to 8.

The number of vCPU's is equal to host pCPUs

The VM is launched with the correct number of vCPU

-smp 16,cores=16,threads=1,sockets=1

So this looks like an issue with our kernel configuration.

Oct 26 '17 00:10 mcastelino

/cc @miguelinux @jcvenegas did you set the max CPU count in the CC Kernel to be 8?

/cc @sameo

Oct 26 '17 00:10 mcastelino

Kernel used

linux-container-4.9.58-79.1.x86_64

Oct 26 '17 00:10 mcastelino

/cc @jcvenegas @miguelinux can we choose a higher number here. I know it comes at a slightly higher memory cost. But 8 seems too low.

https://github.com/clearcontainers/linux/blob/v4.9.58.79-clearcontainers/arch/x86/configs/clear_containers_defconfig#L405

Oct 26 '17 00:10 mcastelino

Nice find btw @mcastelino - can't believe we've not noticed that before! ;-)

Oct 26 '17 13:10 grahamwhaley

@mcastelino, yes CC Kernel was setted to 8 CPU since beging of CC.

Currently looks like we we need to increase this number.

Oct 26 '17 14:10 miguelinux