CSC246 Test 3 Short Answer

Paged memory eliminates one type of memory fragmentation. Which type does it eliminate?

External Fragmentation

Explain the difference between external fragmentation and internal fragmentation.

External fragmentation is unused memory that is not allocated to a process, and internal fragmentation is unused memory that is allocated to a process.

What is the purpose of the Translation Look-aside Buffer (TLB)?

It speeds up translation time in paged memory systems. It maps page numbers to frame numbers.

The Translation Look-aside Buffer (TLB) maps a page number to a frame number, which is the same thing that a Page Table does. Why is the TLB advantageous over a Page Table?

The TLB is cache memory instead of main memory so it’s faster to access, and it bypasses any hierarchy on page tables.

What is the Translation Look-aside Buffer (TLB) Hit Ratio?

It is the ratio of TLB hits to TLB misses.

What is a process’ working set?

It is the sets of pages a process is actively in the moment.

Fill in the blank (1 or more words per blank).

Address translation maps ____ to ____.

Address translation maps logical addresses to physical addresses.

Fill in the blank (1 or more words per blank).

The Translation Look-aside Buffer (TLB) maps ____ to _____.

The Translation Look-aside Buffer (TLB) maps page number to frame number.

Describe the difference in design philosophy between a CPU and a GPU.

A CPU has fewer processing elements, but each one can act independently. A GPU has more processing elements, but they must all do the same thing.

Transmission Control Protocol (TCP) is considered a reliable protocol, but User Datagram Protocol (UDP) is considered best-effort. Why are they different in that way?

When a host receives a message via TCP, it sends back an acknowledgment message so that the sender knows the message was received. With UDP, no acknowledgment message is sent back so there is no way to know if the message was received.

An IP address is used to route data to a specific machine on a network. What is the primary purpose of a port number?

A port number identifies a specific application or process running on that machine. It allows multiple applications (like a web browser and an email client) to send and receive network traffic simultaneously without mixing up their data.