The existing problem

• User-space communicates with drivers through two layers of indirection
  • Device number adds a layer
  • Larger device numbers will require a search
• Device nodes are static
  • Have thousands (need millions) of nodes
  • Choice between efficiency and ease of management (still limited)
• No generic mechanism to search for devices
• No generic mechanism to handle hot-plug
• Only one way to see the hardware
  • Usually the wrong way