Operating Systems: Concurrent and Distributed Software Design

5.6. Combining segmentation and paging

The arguments for having several segments per process (for protection and sharing) still hold in a system which uses paging for physical storage management. The two concepts can be combined so that each segment of a process is divided into pages. This means that the virtual address space of a process is logically divided into segments but it is no longer necessary for each segment to be contiguous in physical memory. Figure 5.11 illustrates the idea for the simple case of two segments per process. Figure 5.12 shows how a virtual address may be interpreted when both segmentation and paging hardware are used.

Figure 5.11. Paged segments illustrated for two segments per process.

Figure 5.12. A virtual address ...