virtual memory(4)
Linux organizes the virtual memory as a collection of areas (also called segments ). An area is a contiguous chunk of existing (allocated) virtual memory whose pages are related in some way. Figure 9.27 highlights the kernel data structures that keep track of the virtual memory areas in a process. The kernel maintains a distinct task structure (task_ struct in the source code) for each process in the system. The elements of the task structure either contain or point to all of the information that the kernel needs to run the process (e.g., the PID , pointer to the user stack, name of the