Operating Systems

Use this for “The time slice is 10 ms and a context switch takes 0.1 ms. What share of the CPU time does useful work?”

Use this for “A program calls fork() 3 times in a row. How many processes are there at the end, and how many are children?”

Use this for “Each process waits for I/O 80% of the time. With 4 processes in memory, how busy is the CPU?”

Use this for “Jobs A, B and C of 5, 3 and 1 ms share the processor with a 2 ms quantum. Find the average wait.”

Use this for “A TLB lookup takes 10 ns, memory takes 100 ns, and 90% of lookups hit. What is the effective access time?”

Use this for “Memory takes 100 ns, a page fault takes 8 ms to service, and 1 access in 100 000 faults. What is the effective access time?”

Use this for “Pages are referenced 1, 3, 1, 2, 4, 3, 1, 4 with 3 frames, all empty at the start. How many page faults does FIFO make, and LRU?”

Use this for “A disk seeks in 9 ms and spins at 7200 rpm. How long does reading 4 KiB at 100 MB/s take?”

Use this for “A 10,000-byte file is stored in 4096-byte blocks. How many blocks does it use, and how many bytes are wasted?”

Use this for “Each block holds the address of the next one. Which allocation method is it?”