参考了apple的这篇官方文档。下面是我看了之后的理解，欢迎大家拍砖 先是有关三种内存空间的定义： The active list contains pages that are currently mapped into memory and have been recently accessed. The inactive list contains pages that are currently resident in physical memory but have not been accessed recently. These pages contain valid data but may be released from memory at any time. The free list contains pages read more »