一个好的计算机系统不仅要有一个足够容量的、存取速度高的、稳定可靠的主存储器，而且要能合理地分配和使用这些存储空间。当用户提出申请存储器空间时，存储管理必须根据申请者的要求，按一定的策略分析主存空间的使用情况，找出足够的空闲区域分配给申请者。当作业撤离或主动归还主存资源时，则存储管理要收回作业占用的主存空间或归还部分主存空间。-A good computer system will not only have a sufficient capacity and access to high speed, stable and reliable main memory, but also to rational allocation and use of such storage space. When the user application memory space, storage management must be based on the applicant' s request, according to a certain degree of strategy analysis of the use of main memory space, and find out enough to free the regional distribution of applicants. When the operation to evacuate or take the initiative to return the main memory resources, the storage management operation to recover the space occupied by the main memory or the return of part of main memory space.