We present techniques for analyzing the effect of "copy-on-write" page management stra- tegies on the performance of UNIX fork) opera- tions. The analysis techniques are applied on two workstations, the AT&T 3B2l3l0 and the Hewlett- Packard HP9000/350 in order to determine the rela- tionships between the amount of memory in the parent's data segment, the fraction of this memory which is written by the child, and the improvement in execution time due to "copy-on-write." Since the implementation of "copy-on-write" is straightfor- ward with modern MMUs, our results for these workstations are readily generalized to other workstations. The results show that the size of the parent's allo- cated memory has little direct effect on perfor- mance, due to the fact that only page table entries are copied during the fork) operations. The execu- tion time is most influenced by the amount of
['Jonathan M. Smith', 'Gerald Q. Maguire']
Effects of Copy-on-Write Memory Management on the Response Time of UNIX Fork Operations