Linux Kernel in a Nutshell

Name

FLATMEM_MANUAL — Flat memory

This option allows you to change some of the ways that Linux manages its memory internally. Most users will see only have one option here: FLATMEM. This is normal and a correct option.

Some users of more advanced features, such as NUMA and memory hotplug, may have different options here. DISCONTIGMEM is a more mature, better tested system, but is incompatible with memory hotplug and may suffer decreased performance over SPARSEMEM. If unsure between Sparse Memory and Discontiguous Memory, choose Discontiguous Memory.

If unsure, choose this option, Flat Memory.