Little Alice going down the (disk) elevator

• When pdflush (or the writing process) sends Little Alice to the block device,
• she enters the block device queue,
• where everyone waits for the elevator.
• The reasons for waiting are three:
  • Supporting flow-control
  • Supporting I/O priorities
  • Optimizing (disk) device IOPS/bandwidth/latency utilization

Originally written by guy keren