What is NUMA? It is an architecture where the memory access times for different regions of memory from a given processor varies according to the "distance" of the memory region from the processor. Each region of memory to which access times are the same from any cpu, is called a node. On such architectures, it is beneficial if the kernel tries to minimize inter node communications. Schemes for this range from kernel text and read-only data replication across nodes, and trying to house all the data structures that key components of the kernel need on memory on that node.

Read "Linux® Scalability for Large NUMA Systems" paper presented at the Ottowa Linux Symposium 2003.

Read more about or participate in NUMA development via the NUMA project at sourceforge.net.