Papers Evaluation.
Tue, 18 Apr 2000 05:18:16 EDT

Hi Geoff,

Below is Tuesday's papers evaluations.




With the appearance of the 64-bit processors, many of the fundamentals made while designing previous operating systems should be reevaluated. The single address space paper provides an operating system that meets the goals of previous systems in a simple, general and more efficient way. Since the 64-bit architecture is newly out, further evaluation was taken to maximize the performance degraded in the small address space machines.
With the introduction of protection domains supported by capabilities, the Opal system achieves better protection and sharing of data than previous systems without loss of performance. The Opal system strongly tackles the Unix design holes and tries to resolve them with the current system architecture. The paper explores many of the previous work and is very rich in information.


The Pilot paper presents an operating system for personal computers in which many of the current (at that time) system design decisions are reexamined. With the hardware becoming less expensive, demands increase for personal computers. In those personal computers, protection mechanisms are redesigned since errors are more serious problem than maliciousness. Protection mechanisms are defensive rather than absolute.
For personal computers, an operating system design should emphasize on a close user/system cooperation. Many of time-sharing system techniques are considered as an overhead to the operation in a single-user environment. Since the system is designed for a single-user, resource allocation is easier to manage than in a multi-user system, where fair distribution of resources is a serious problem.
The paper is interesting in the separation it proposes than the previous multi-user operating systems. The problem had to be reinvestigated for PC operating system design. With the current advances in the Internet and communication between several entities over the Internet, I think Pilot design requires more protection against intended attacks from hackers.