Zero copy

• Ways to do zero-copy
  • forward, skip, write_zeros, copy
  • io-array's read_at skips intervening data
  • create an I/O Array and pass around a handle
• read is not zero-copy
  • shared pages require protocols, synchronization
    • not virtualizable
• What can we do instead?
  • Avoid bringing data into an instance that doesn't need it
  • Use direct calls instead of shared-memory protocols where appropriate