[PATCH v2 5/6] powerpc/pseries: Add CPU dlpar add functionality

[Michael Ellerman]

On Tue, 2015-10-27 at 13:27 -0500, Nathan Fontenot wrote:

> Add the ability to hotplug add cpus via rtas hotplug events by either
> specifying the drc index of the CPU to add, or providing a count of the
> number of CPUs to add.

So I just tried running this on my system, without doing anything on the HMC.

I have:

  # lsprop /proc/device-tree/cpus/ibm,drc-indexes 
  /proc/device-tree/cpus/ibm,drc-indexes
  		 00000002 10000000 10000002

So I think that says I have two cpus.

The first one is already added:

  /proc/device-tree/cpus/PowerPC,POWER6 at 0/ibm,my-drc-index
  		 10000000 (268435456)

But can I add the second one?

  # echo "cpu add count 1" > dlpar 
  RTAS: event: 34, Type: Platform Error, Severity: 2
  pseries-hotplug-cpu: Failed to acquire DRC, rc: -5, drc index: 10000002
  pseries-hotplug-cpu: CPU hot-add failed, removing any added CPUs
  -bash: echo: write error: Invalid argument


Seems not. But I'm not clear why?

Adding by index doesn't work either:

  # echo "cpu add index 10000002" > dlpar
  pseries-hotplug-cpu: Failed to acquire DRC, rc: -1, drc index: 989682
  -bash: echo: write error: Invalid argument

That's a little confusing, drc index is hex obviously.

  [root at p6-10-P5-E0 kernel]# echo "cpu add index 0x10000002" > dlpar 
  RTAS: event: 35, Type: Platform Error, Severity: 2
  pseries-hotplug-cpu: Failed to acquire DRC, rc: -5, drc index: 10000002
  -bash: echo: write error: Invalid argument


So that's probably all PEBKAC, but if we can make it more intutive that would be good.

cheers