Memory hotplug
You can dynamically increase or decrease the memory for your running Linux® instance.
To make memory available as hotplug memory, you must define it to your LPAR or z/VM®. Hotplug memory is supported by z/VM 5.4 with the PTF for APAR VM64524 and by later z/VM versions.
For more information about memory hotplug, see Documentation/memory-hotplug.txt in the Linux source tree.