Unit 2 - Processes

Question 1

What is the difference between

Cooperative multitasking & Pre-emptive multitasking?

Answer 1

Cooperative multitasking,Here applications have to be coded so that they allow other programs to run from time to time.

Pre-emptive multitasking, The operating system can require one process to give way to another to allow sharing of resources (provided that the first process is not at a critical point that would make this operation risky).

Question 2

What is Persistant Memory?

What is Volatile Memory?

Are the following examples Persistant or Volatile memory?

• Main memory,
• caches
• registers
• Disk storage

Answer 2

Persistant Memory - Retains memory when the power is switched off

Volatile Memory - Does not retain memory when the poweris switched off

• Main memory - Volatile
• caches - Volatile
• registers - Volatile
• Disk storage - Persistant