CNK operating system

Compute Node Kernel (CNK) is the node level operating system for the IBM Blue Gene series of supercomputers.

To maximize operating efficiency, the design of CNK was kept simple and minimal.

[1] Physical memory is statically mapped and the CNK neither needs nor provides scheduling or context switching, given that at each point it runs one application for one user.

[1] By not allowing virtual memory or multi-tasking, the design of CNK aimed to devote as many cycles as possible to application processing.

[2] CNK delegates file input/output (I/O) to dedicated I/O nodes which run the INK (I/O Node Kernel) operating system, based on a modified Linux kernel.