virtual Memory
1 Virtual Memory
Outline Multilevel page tables Different points of view Pentium/Linux Memory System Memory Mapping Suggested reading: 10.6, 10.3, 10.7, 10.8
2 Outline • Multilevel page tables • Different points of view • Pentium/Linux Memory System • Memory Mapping • Suggested reading: 10.6, 10.3, 10.7, 10.8
10.6 Address translation 10.6.3 Multi Level Page Tables
3 10.6 Address Translation 10.6.3 Multi Level Page Tables
Multi-Level Page Tables Given: 4B (212) page size 32-bit address space 4-byte pte Problem: Would need a 4 mb page table ·220*4 bytes
4 Multi-Level Page Tables • Given: – 4KB (212) page size – 32-bit address space – 4-byte PTE • Problem: – Would need a 4 MB page table! • 220 *4 bytes
Multi-Level Page Tables Level 2 Common solution Tables multi-level page tables e.g., 2-level table(P6) Level 1 Table Level 1 table: 1024 entries each of which points fo a Level 2 page table Level 2 table: 1024 entries each of which points to a page
5 Multi-Level Page Tables • Common solution – multi-level page tables – e.g., 2-level table (P6) • Level 1 table: 1024 entries, each of which points to a Level 2 page table. • Level 2 table: 1024 entries, each of which points to a page Level 1 Table ... Level 2 Tables