The watermark-based lazy buddy system for dynamic memory management uses lazy coalescing rules controlled by watermark parameters to achieve low operational costs. The correctness of the watermark-based lazy buddy system is shown by defining a space of legal states called the lazy space and proving that the watermark-based lazy coalescing rules always keep the memory state within that space. In this paper we describe a different lazy coalescing policy, called the DELAY-2 algorithm, that focuses directly on keeping the memory state within the lazy space. The resulting implementation is simpler, and experimental data shows it to be up to 12% faster than the watermark-based buddy system and about 33% faster than the standard buddy system. Inexpensive operations make the DELAY-2 algorithm attractive as a memory manager for an operating system.

In this paper, we describe an experiment to evaluate a distributed architecture via functional database workload decomposition. A workload in a circuit pack assembly environment was decomposed and mapped onto a frontend/backend distributed computer architecture. To evaluate this distributed architecture, an operational model for capacity planning was devised, and performance and cost-effectiveness measures were chosen. Model parameters were estimated through benchmark experiments in a distributed system consisting of various super-microcomputers connected by a CSMA/CD local area network with INGRES as the database management system.