Windows 2000 Performance Guide

Thread Scheduling Tuning

As we have seen, Windows 2000 provides an extensive set of facilities to set the dispatching priority of an application’s executing threads. Applications like Internet Explorer, RAS, System Monitor, and SQL Server take full advantage of Windows 2000 thread scheduling priority internally. For applications that do not take full advantage of these facilities, the Windows 2000 thread Scheduler adjusts thread priorities dynamically to increase the system’s responsiveness, maximize throughput, and prevent thread starvation. Applications like SQL Server and Exchange expose external tuning parameters that allow the administrator to configure the number of threads started and their priority, and system applications like the Windows 2000 Spooler and the file server component also have tuning parameters that control the number and priority of threads the process initiates. Windows 2000 itself also exposes some tuning options for adjusting the number of worker threads it creates and runs.

Clearly, the inside of a specific application is not the best vantage point from which to make tuning decisions that can impact system performance globally. In this area, Windows 2000 provides very little support to a system administrator who needs to adjust the relative priorities of different applications running on the same system, When sufficient processing capacity is available and the Ready Queue never backs up, an external mechanism to adjust dispatch priority is not necessary. ...