Re: [powerpc]WARN : arch/powerpc/platforms/powernv/smp.c:160

On 26-Aug-2019, at 3:42 PM, Sachin Sant [off-list ref] wrote:

quoted

On 26-Aug-2019, at 8:59 AM, Michael Ellerman [off-list ref] wrote:

Sachin Sant [off-list ref] writes:

quoted

linux-next is currently broken on POWER8 non virtualized. Kernel
fails to reach login prompt with following kernel warning
repeatedly shown during boot.

I don't see it on my test systems.

The backtrace makes it look like you're doing CPU hot_un_plug during
boot, which seems a bit odd.

There is no explicit hot un plug operation being done. This happens
during boot.

For some reason cpu’s are being off lined.  

So this machine was configured as a KVM host. Hence the SMT=1
configuration at boot. Removing QEMU/libvirt packages and unloading
kvm module gets me to SMT 8 config.

Disabling kvm also allows me to boot next kernels without the warning.
The warning is only seen with kvm configured.

Thanks
-Sachin