Long description

The figure shows a rectangular block labeled main memory which is divided into two layers. The first layer is labeled user space and consists of two circles labeled user process and external pager. The second layer is labeled kernel space and consists of two circles labeled fault handler and M M U handler. A cylinder labeled disk is shown next to the block. The steps are given as follows:

1. An arrow labeled page fault points downward from the user process.

2. An arrow labeled needed page points from the fault handler to the external pager.

3. An arrow labeled request page points from external page to disk.

4. Another arrow labeled page arrives points from the disk to the external pager.

5. An arrow labeled here is page points from the external page to the fault reminder.

6. An arrow labeled map page in points from fault handler to M M U handler.