Chapter 15: Scheduling, Thread Context, and IRQL

Overview

Thread context and the current IRQL for each processor have important effects on how kernel-mode drivers work. Microsoft Windows Internals provides a thorough description of thread scheduling and quantums. This chapter covers the basics of thread scheduling, thread context, and IRQL. It also explains how a driver can use a work item to launch a PASSIVE_LEVEL function from code that runs at DISPATCH_LEVEL.

For this chapter, you need …	From …
Samples
Usbsamp	%wdk%\src\kmdf\usbsamp
Toastmon	%wdk%\src\kmdf\Toaster\Toastmon
WDK documentation
Do Waiting Threads Receive Alerts and APCs?	http://go.microsoft.com/fwlink/?LinkId=80071
Specifying Priority Boosts When Completing I/O Requests	http://go.microsoft.com/fwlink/?LinkId=81582
Locking Pageable Code or Data	http://go.microsoft.com/fwlink/?LinkId=82719
Other
"Interrupt Architecture Enhancements in Windows" on the WHDC Web site	http://go.microsoft.com/fwlink/?LinkId=81584
Microsoft Windows Internals	http://go.microsoft.com/fwlink/?LinkId=82721