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Unformatted text preview: o a page table at level . Each PTE in a level- table, ½ ½, points to the base of some page table at level · ½. Each PTE in a level- table contains either the PPN of some physical page or the address of a disk block. To construct the physical address, the MMU must access PTEs before it can determine the PPN. As with a single-level hierarchy, the PPO is identical to the VPO.
n-1 VIRTUAL ADDRESS VPN 1
Level 1 Page Table p-1 0 VPN 2
Level 2 Page Table ... ... ... VPN k
Level k Page Table VPO PPN m-1 p-1 0 PPN PHYSICAL ADDRESS PPO Figure 10.19: Address translation with a -level page table. Accessing PTEs may seem expensive and impractical at ﬁrst glance. However, the TLB comes to the rescue here by caching PTEs from the page tables at the different levels. In practice, address translation with multi-level page tables is not signiﬁcantly slower than with single-level page tables. 10.6.4 Putting it Together: End-to-end Address Translation
In this section we put it all together with a concrete example o...
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- Spring '10
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