Asking for PAGE_SIZE + 1 bytes of memory is about the worst thing you can do to the heap allocator: the system reserves two pages, of which nearly half will ultimately be wasted.

• 请求页大小+1字节的内存大概是你能够使用堆分配器的最坏的事情：系统预留两个页面，基本上几乎其中的一半都被浪费了。