The same is done for your target point within its own cluster (finding paths from all its border points to your actual destination).
清晨6点半，路边小摊前，格雷格从摊主手中接过刚出炉的煎饼果子，金黄酥脆、香气扑鼻。“听说天津人早餐爱吃这个，我特意来排队。”他边吃边说，“天津人很热情。煎饼摊主告诉我，他每天凌晨三四点起床，20多年来靠这门手艺养家，虽然辛苦，但日子过得踏实。这让我体会到中国人的勤劳乐观。”
。爱思助手下载最新版本对此有专业解读
Segmentation maps a logical address (a 16-bit selector plus a 32-bit offset) to a 32-bit linear address, enforcing privilege and limit checks along the way. Paging then translates that linear address to a physical address, adding a second layer of User/Supervisor and Read/Write protection. The two layers are independent: segmentation is always active in protected mode, while paging is optional (controlled by CR0.PG).
Authors:Ryan Gibb, Patrick Ferris, David Allsopp, Thomas Gazagnaire, Anil Madhavapeddy