title: Why using hierarchical page tables?
body: <p>I'm learning the Linux kernel and reading the book <em>The Linux Kernel</em>.</p>
  
  <p>Can anybody explain why can't we just use the table which maps directly between logical and physical memory instead of the tree-like multilevel structure?</p>
  
  <p>Added:</p>
  
  <p>The total number of entries needed is fixed, so I assume that it's more space wasting to store a complicated structure than a simple one.</p>