Heterogeneous I/O Contention in a Single-Bus Multiprocessor

Abstract

In this article we describe an approach to measuring the performance degradation produced by contention for a single I/O bus by accesses to multiple heterogeneous I/O device types on a multiprocessor system. By heterogeneous we mean device types that have widely different characteristics, such as video, network, and disk devices, as opposed to systems with multiple devices of the same type, such as multiple disks, which we will call homogeneous. We use a correlation analysis to characterize the contention and then quantify the loss in performance by approximating the overhead time of contention using actual trace data.