Systems Software Flashcards
What is the memory manager?
-splits RAM into segments
- assigns different process base on needs
- handle virtual memory
What is process manager?
- multitasking and decide which order to run process
What is a file manager?
Manage file system and secondary storage devices
What is software?
Interact with OS and hardware drivers making use of the hardware
What is application software?
Software that allows the user to carry out specific tasks
What is paging?
- fixed size blocks of memory
- each page has an address
- process loaded into RAM is allocated sufficient pages but may not be next to each other
What is segmentation?
- memory divided into segments which can be different lengths
- segments relate to different parts of the program( particular subroutine or function may occupy each segment)
- each segment stored in table and will record ID, start address and length of each segment
What is virtual memory?
- move pages out of RAM onto disk
- memory manager notes which page is on the disk
- can be swapped back into memory and page table updated
- pages getting swapped in and out of memory DISK THRASHING
What are the design goals for memory management?
- allocate enough memory so each process can run
- ensure security so the other processes cannot access each others data
What is interrupts?
Electronic signals or process generated signal sent to CPU inform that devices/ process requires attention
What is interrupt priority?
Interrupts can be interrupted themselves if the new one becomes a priority
What are buffers?
Small pieces of memory in case CPU not ready to deal with the interrupt
What is processor scheduling?
Decide which take to process for how long and what order achieved through scheduling algorithms
What are the aims for processor scheduling?
- Provide acceptable response time for user
- Maximise time CPU is engaged for
- Ensure fairness on multi-user system
