主存的分配和回收的实现是与主存储器的管理方式有关的。所谓分配，就是解决多道作业或多进程如何共享主存空间的问题。所谓回收，就是当作业运行完成时将作业或进程所占的主存空间归还给系统。在可变分区管理方式下，采用最先适应算法实现主存空间的分配和回收。-Main memory allocation and recovery with the main memory to achieve management related.The so-called distribution, is to solve the job or the process how the shared memory space problem.The so-called recovery, is when the operation is completed the operation or process share the memory is returned to the system.Variable partition management mode, using the first algorithm to adapt to main memory space allocation and recovery.