Dynamic Soft Real Time CPU Scheduler 2.0

This is the dynamic soft real time scheduler by the Monet Group
at the Department of Computer Science, University of Illinois at Urbana-Champaign.

This release has been tested on SunOS 5.7, SGI IRIX 6.5, Linux(RedHat 6.2) , and Windows NT.

* Motivation
* General Description
* Software : DSRT CPU Scheduler, CPU Monitor, and CPU Broker
* DSRT 2.0 under Windows NTNew
* DSRT 2.0 under LinuxNew
* DSRT MonitoringNew
* Coordinating Power-Aware Adaptation of Applications and Hardware ResourcesNew
* DSRT Multi-Processor for Win2K
* Ongoing work
* People
* Publications
* Related Sites
* Mpeg Clips
* Acknowledgement


Multimedia applications such as video/audio processing, animation are time-sensitive because these applications need minimal jitter to accomplish a good viewing quality. They require that underlying systems support sufficient and constant processing time so that they can provide Quality of Service(QoS) guarantees to the users in terms of minimum throughput, maximum response time and CPU cycles. However, in current time-sharing environments, these multimedia applications do not perform well when they are scheduled concurrently with the traditional nonreal-time applications. On the other hand, allowing enough CPU to real-time applications may cause nonreal-time applications to use unfair CPU bandwidth. DSRT scheduler targets fair CPU distribution among competent applications as well as guarantee of time constraints of real-time applications. Another issue is that process scheduling has beed discussed inside OS kernel level. So in order to get new scheduling scinario, kernel source code is required to be modified and re-installed. DSRT scheduler is designed as a middleware scheduler and thus it can be used by copying executable scheduler into the target machine withoug modifying underlying kernel.

General Description

The dynamic soft real time scheduler (DSRT) 2.0 is a user-level dynamic scheduler that can schedule soft real time (RT) periodic and aperiodic tasks.  The DSRT 2.0 contains the following features

The DSRT 2.0 scheduler has the following improvements over the previously released DSRT 1.0:

Ongoing work

Currently we are taking two different approaches; adding more functionalities on DSRT scheduler and porting DSRT scheduler into Window NT and Linux based systems. The added features will be as follows.


Primary Advisor

Previous members

Current members




Ph.D Theses

M.S Theses

Technical Reports

Related Sites


This research is funded by the Air Force grant F30602-97-2-0121, the NSF CCR 96-23867, the NSF PACI grant ACU-96-19019, and in part the NSF CISE CDA 96-24396. Any opinions, findings, and conclusions or recommendations expressed in this material are those of the author(s) and do not necessarily reflect the views of the funding agencies. If you have questions or comments, send email to Klara Nahrstedt

Copyright (©) 1997-2000, Multimedia Operating Systems and Networking Group,
University of Illinois at Urbana-Champaign
Phone: (217)333-1515 (USA)
Updated at October 10, 2000