06. Multitasking

(previous topic chore: how does cache strategies works anyway?)

The task of multitasking

Effectively run a number of tasks over a certain time period

Rationale:

Problems:

Less evident problems:

Virtual memory

Virtual memory

mapping single continuous 0…LIMIT memory of each process to the real physical memory. See Virtual memory

Features:

virtual_memory.png

Swapping

Paging

keeping and (some/LRU/excessive) memory pages on disk and restoring it on demand

Swapping

keeping (LRU/excessive) full process memory on disk

Problems:

Multicore

Practical: it's easy to insert another CPU (and redesign system board), rather then develop a new processor, that is two times faster

But:

Modern processors are all multi-core (many cores on one chip).

Virtualization

Practical: run a number of operating systems on one computer

Hardware requirements

HSE/ProgrammingOS/06_MultiTasking (last edited 2020-02-13 08:02:11 by FrBrGeorge)