Memory Management

Page Fault Handling (2)

• If frame selected dirty, page is scheduled for transfer to disk, context switch takes place, suspending faulting process
• As soon as frame clean, operating system looks up disk address where needed page is, schedules disk operation to bring it in.
• When disk interrupt indicates page has arrived, tables updated to reflect position, and frame marked as being in normal state.

• Tanenbaum & Bos, Modern Operating Systems: 4th ed., Global Edition (c) 2015 Pearson Education Limited. All rights reserved.

Page Fault Handling (3)

• Faulting instruction backed up to state it had when it began and program counter is reset
• Faulting process is scheduled, operating system returns to routine that called it.
• Routine reloads registers and other state information, returns to user space to continue execution

• Tanenbaum & Bos, Modern Operating Systems: 4th ed., Global Edition (c) 2015 Pearson Education Limited. All rights reserved.

Instruction Backup

• Figure 3-27. An instruction causing a page fault.

• Tanenbaum & Bos, Modern Operating Systems: 4th ed., Global Edition (c) 2015 Pearson Education Limited. All rights reserved.

Backing Store

• Figure 3-28. (a) Paging to a static swap area. (b) Backing up pages dynamically.

• Tanenbaum & Bos, Modern Operating Systems: 4th ed., Global Edition (c) 2015 Pearson Education Limited. All rights reserved.

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