Virtual Memory Professional Checkpoint

1. Why can an ASID/tagged TLB keep entries across context switches?

Entries include the address-space identity All processes share the same page table The kernel disables page faults LRU becomes unnecessary

2. A process remaps VPN 5 from frame 10 to frame 20. What must happen to an old TLB entry for VPN 5 in that address space?

Invalidate it or update it Leave it forever Mark it executable Move it to disk

3. A growing working set larger than available frames usually predicts:

More page faults / cache misses Fewer misses forever No change in locality Automatic COW copies

4. In copy-on-write fork, why are shared mappings commonly marked read-only?

To trap the first write and create a private copy To prevent reads To avoid all page faults To disable address translation

5. Name one invariant a COW implementation must preserve.