On powerpc systems with shared configurations of CPUs and memory and
memoryless nodes at boot, an event ordering problem was observed on a
SLES12 build platforms with the hot-add of CPUs to the memoryless
nodes.
* The most common error occurred when the memory SLAB driver attempted
to reference the memoryless node to which a CPU was being added
before the kernel had finished initializing all of the data
structures for the CPU and exited 'device_online' under
DLPAR/hot-add.
Normally the memoryless node would be initialized through the call
path device_online ... arch_update_cpu_topology ... find_cpu_nid ...
try_online_node. This patch ensures that the powerpc node will be
initialized as early as possible, even if it was memoryless and
CPU-less at the point when we are trying to hot-add a new CPU to it.
Signed-off-by: Michael Bringmann <mwb@linux.vnet.ibm.com>
Reviewed-by: Nathan Fontenot <nfont@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
e67e02a544