An Appraisal of the Instrumentation in Berkeley UNIX 4.2BSD
Kupfer, Michael David
Technical Report Identifier: CSD-85-246
Abstract: Berkeley UNIX 4.2BSD comprises four subsystems: networking, the file system, virtual memory, and process management. We present explanations of how those subsystems work and problems with their instrumentation in 4.2BSD. We discuss inaccuracies in the reported performance indices, cases where uninteresting indices are recorded, and cases where interesting indices are not recorded. We restrict our attention mainly to tools that sites can use without special hardware and without their changing the UNIX kernel. We also suggest tools for debugging and monitoring the networking and file system subsystems. Last, we comment on general implementation issues at both the kernel and user levels of the instrumentation code.