kdump: A memory hotplug issue on s390

[Michael Holzheu]

Hello Simon and Vivek,

For s390 we currently use /proc/iomem for defining the memory layout in
the kexec elfcore header. Unfortunately this is not correct, when using
memory hotplug. When a memory chunk is set offline (e.g. with "echo
offline > /sys/devices/system/memory/memoryX/state") this is not
reflected in /proc/iomem.

To fix this I could parse /sys/devices/system/memory and exclude each
memory chunk that in not online from the /proc/iomem info. Do you think
that this approach is fine or is there a better solution?

Michael