This paper considers how two kernelized systems, Mach 3.0 with the BSD4.3 Single Server and Chorus/MiX V.4, move data to and from files under a variety of circumstances. We give an overview of the kernel abstractions and system server and describe in detail the read() and write() paths of these two systems. We then break down their read() and write() performance and compare them to two monolithic systems, Mach 2.6MSD(BSD4.3) and System V R4.0. We then describe the compromises each of the 2 kernelized systems make in order to achieve a goal of performance comparable to the monolithic systems. We conclude with a description of what techniques each system uses that could benefit both each other and traditional monolithic systems.

*Francois Armand is currently with CHORUS Systems-Cedex, France.