[PATCH] makedumpfile: ppc64: do page traversal if vmemmap_list not populated

[Aditya Gupta]

To be able to test this on a system with Radix MMU, the kernel needs to be
patched with given kernel patch, since makedumpfile requires
'cpu_features.mmu_features' to check if MMU was Radix MMU:

https://lore.kernel.org/linuxppc-dev/20230911091409.415662-1-adityag@linux.ibm.com/T/#u

Or, the vmlinux can be provided to makedumpfile, so that it finds the
'cur_cpu_spec.mmu_features' symbol, run makedumpfile with '-x' flag similar to
this:

makedumpfile -l -d 31 -x VMLINUX /proc/vmcore /var/crash/vmcore.kdump

Thanks,
Aditya Gupta