virtual memory
WHAT
DEF
1. separation from physical memory
ISSUE
prepaging
page size
TLB reach
program structure
IO interlock
w
0x20. HOW — internal
0x21. memory management scheme
- demand paging
- demand segmentation
0x22. demand paging — using 'page fault'
performance?
locality!
page fault
0x23. replacement
When there is no enough free [(draft yet): page frame], ALG for choosing victim page for replacement
goal
how to minimize the #(page fault)?
FCFS; First Come First Served
policy: FCFS; First Come First Served
optimal
LRU; Least Recently Used
policy: [(draft yet): LRU; Least Recently Used]
LRU proximation ALG
[(draft yet): reference bit ALG]
[(draft yet): second chance(clock) ALG]
0x24. but, how to allocate 'frame?
thrashing
working-set model
replacement & allocation 모두 가능
[(draft yet): page-fault frequency scheme]
WHY
VALUE1. process creation
- [(draft yet): COW; Copy-on-Write]
- [(draft yet): memory-mapped file]