Scheduling issues for interfacing to high speed networks

It is shown that a straightforward design of the schedulers on the adapter and the host operating system makes a system prone to receive livelocks, significantly increases receive latency, potentially starves transmission of packets, and increases packet loss. Receive livelocks and starvation of transmission of packets can have wide-ranging consequences in the network. When viewed from an endsystem perspective, transport protocols can unnecessarily time-out, and cause retransmissions. For an intermediate system, these problems can result in control packets not being transmitted in a timely manner. Several of these problems are attributable to poor scheduling algorithms based one interrupts and priorities, which are unsuitable in an overloaded environment. That several of these problems are due to the traditional way of scheduling communications is shown by means of a measurement study on an end system. An approach to scheduling communication functions which would alleviate, if not eliminate, these problems is outlined