| address | memory |
|---|---|
| max | Stack |
| (down) | |
| (up) | |
| Heap | |
| Data | |
| 0 | Text |
- Text: code
- Data: global variables
- Heap: memory that is dynamically allocated during program run time
- Stack: temporary data storage when invoking functions (parameters, return addresses, local variables)
OS is above stack and heap
The total size of stack and heap is fixed, but they can dynamic increase or decrease.
size of an address: 1 word (8, 16, 32... bits)
A logical address is generated by CPU
- page
A physical address is generated by MMU
- frame
Page Fault
A page fault occurs when an access to a page that has not been brought into main memory takes place.
The operating system verifies the memory access, aborting the program if it is invalid. If it is valid, a free frame is located and I/O is requested to read the needed page into the free frame. Upon completion of I/O, the process table and page table are updated and the instruction is restarted.
