COMP: L4 nanokernel

Eugene Leitl (
Sun, 29 Dec 1996 21:01:35 +0100 (MET)

A short addendum on the L4 nanokernel: it contains merely

- task/thread management
- memory management
- device driver support

Its keystone is inter-process communication (IPC). Page faults,
preemption and interrupts are reduced to IPC. Cycle overhead for short
messages: 250 cycles (Mach takes 5750 cycles). Kernel size: 12 kBytes, 1
kByte for optimized IPC path.

More URLs:

Jochen Liedtke; On ukernel construction, in 15. ACM Symposium on
Operating System Principles (SOSP), pp. 237-250

Jochen Liedtke, L4 Reference Manual (Intel 486, Pentium, Pentium Pro)


Another thing to watch for might be the Exokernel.