Subject: IEEE-CS TC-RTS Newsletter for Sun Nov 07, 1993 _______________________________________________________________________________ __ _ __ ___ ___ __ __ I E E E Technical Committee |\ | |_ | | (_' | |_ | | |_ |_) C S on Real-Time Systems | \| |__ |/\| ,_) |__ |__ | | |__ | \ _______________________________________________________________________________ Table of Contents Line ----------------- ---- 1. Azer Bestavros (13 lines) Notice ............................................................ 3 2. Frank Mueller (44 lines) Technical Report Available......................................... 16 3. welch@vienna.njit.edu (Lonnie Welch) (124 lines) The Second Workshop on Parallel and Distributed Real-Time Systems.. 60 4. ken@minster.york.ac.uk (57 lines) Source code for Real-Time tools available.......................... 184 5. soapy@cs.utexas.edu (Nandit R. Soparkar) (20 lines) Real-time Transaction Management (available via FTP) .............. 241 ------------------------------------------------------------------------------ <<<<<<<<<<<<<<<<<<* START OF THE IEEE-CS TC-RTS NEWSLETTER *>>>>>>>>>>>>>>>>>> ------------------------------------------------------------------------------ Message 1; Postmarked Sun Nov 7 09:34:17 1993 From: Azer Bestavros Subject: Notice Please be advised that due to a disk crash that our mailer at Boston University suffered on the third week of October, some mail messages, which were sent to this Newsletter were lost and therefore did not appear in the last issue (sent on November 2). This issue of the Newsletter contains some of these messages. --Azer ------------------------------------------------------------------------------ Message 2; Postmarked Wed Nov 3 08:54:57 1993 From: Frank Mueller Subject: Technical Report Available The technical report "Predicting Instruction Cache Behavior" is available via anonymous ftp. Please edit the file before printing or previewing: The ASCII abstract precedes the postscript and has to be cut out. ftp-site: ftp.cs.fsu.edu internet#: 128.186.121.27 directory: /pub/techrpts file: whalley_93_091.ps.Z Authors: Frank Mueller, David Whalley, Marion Harmon. Title: Predicting Instruction Cache Behavior Abstract: It has been claimed in the past that the execution time of a task can often be predicted more accurately on an uncached system than on a system with cache memory. This work shows that instruction caching can be exploited to gain execution speed without sacrificing predictability. Assume a non-preemptive system where a task corresponds to the code executed between context switch points and cannot be interrupted. A new method called Static Cache Simulation is introduced that statically predicts the caching behavior of a portion of the instruction cache references of the task. This method can be used to show that the execution time of a task in the presence of instruction caches (and in the absence of data caches) is faster than that of an uncached system, independent of the input data. But at the same time, the execution time of a task may become less predicatable in a cached system. This problem can be resolved by adding a fetch-from-memory bit into the instruction encoding which indicates whether an instruction shall be fetched from the instruction cache or from main memory. This bit-encoding approach provides a portion of the speedup in execution time of conventional caches without sacrificing predictability. The ability to predict the caching behavior of a large percentage of the instruction references can potentially be very useful for predicting the execution time of large code segments on machines with instruction caches. Frank mueller@cs.fsu.edu ------------------------------------------------------------------------------ Message 3; Postmarked Wed Nov 3 08:55:51 1993 From: welch@vienna.njit.edu (Lonnie Welch) Subject: The Second Workshop on Parallel and Distributed Real-Time Systems Call for Papers The Second Workshop on Parallel and Distributed Real-Time Systems April 28-29, 1994 Cancun, Mexico Program Co-Chairs: Dieter K. Hammer, Technische Universiteit Eindhoven Lonnie R. Welch, New Jersey Institute of Technology Program Committee: Giovanni Cantone, University of Rome at Tor Vergata Klaus Ecker, Technical University of Clausthal Loe Feijs, Philips Research Prabha Gopinath, Honeywell Robert Harrison, Naval Surface Warfare Center Mathai Joseph, University of Warwick Joerg Kaiser, GMD Jan van Katwijk, Delft University of Technology Gerard Le Lann, INRIA Jane W. S. Liu, University of Illinois Mike Rodd, University of Wales Kang G. Shin, University of Michigan Behrooz Shirazi, University of Texas Sang Son, University of Virginia John A. Stankovic, University of Massachusetts Robert Steigerwald, U. S. Air Force Academy Alexander D. Stoyenko, New Jersey Institute of Technology Kenji Toda, MITI Electrotechnical Laboratory Jan Vytopil, University of Nijmegen There is an increasing requirement for real-time systems to exploit parallel and distributed computer platforms, to meet timing constraints and to increase fault tolerance. Unfortunately, it is often the case that researchers focus on problems relevant to parallel processing only, optimizing average case behavior, while overlooking the guarantee of timeliness and reliability. A similar phenomenon also occurs often in real-time research, wherein techniques are developed that apply only to single processor systems. Thus, we perceive a need for collaboration between researchers in the field of parallel and distributed processing, and the field of real-time and reliable systems. To encourage discussion of research results from these fields in a forum where scientists from each field are present, a two day workshop will be held at IPPS '94 (The IEEE 8th International Parallel Processing Symposium, April 26-29 1994, Cancun, Mexico). Topics of interest (as they relate to real-time) for papers to be presented at the workshop include, but are not limited to: -Scheduling, Resource Allocation, and Optimization -Fault Tolerance -Complex Systems Engineering and Reengineering -Extraction and Exploitation of Parallelism -Compiler Techniques -Object-Oriented Techniques -Architecture and Hardware -Multiprocessor and Distributed Operating Systems -Artificial Intelligence -Parallel Algorithms -Communication Systems and Protocols -Case Studies and Applications -Specification and Verification Methods -Development Techniques and Tools Submissions should not exceed 2500 words (about 10 pages) and must be received by December 15, 1993 by the program co-chair located closest to you. North American Co-Chair: Lonnie R. Welch The Real-Time Computing Laboratory Institute for Integrated Systems Resaerch Dept. of Computer and Information Science New Jersey Institute of Technology University Heights Newark, NJ 07102 Vox: (201) 596-5683 / Fax: (201) 596-5777 Internet: welch@vienna.njit.edu European Co-Chair: Dieter K. Hammer Dept. of Mathematics and Computing Science Technische Universiteit Eindhoven P. O. Box 513 NL-5600 MB Eindhoven The Netherlands Vox: 31 40 474416 / Fax: 31 40 463992 Internet: wsindh@win.tue.nl IPPS is sponsored by The IEEE Computer Society Technical Committee on Parallel Processing in cooperation with ACM SIGARCH. The workshop on Parallel and Distributed Real-Time Systems is sponsored by The U.S. Naval Surface Warfare Center, and is held in cooperation with The IEEE Computer Society Technical Committee on Parallel Processing and with The IEEE Computer Society Technical Committee on Real-Time Systems. ------------------------------------------------------------------------------ Message 4; Postmarked Thu Nov 4 05:08:26 1993 From: ken@minster.york.ac.uk Subject: Source code for Real-Time tools available The source code to three real-time tools is available via FTP from: minster.york.ac.uk (144.32.128.41) in the directories: /pub/realtime/programs/src/arbdead /pub/realtime/programs/src/disksched /pub/realtime/programs/src/holistic The tools implement analysis described in previous technical reports (YCS189, YCS197, and YCS204), available in /pub/realtime/papers. The tools are described brielfy below. Binaries for the RS6000 processor are also available in the above directories. Be sure to set binary mode when FTPing these. Queries/comments/bug reports to ken@minster.york.ac.uk. These tools are provided merely for illustrating the application of the theory developed in the Real-Time Systems Research Group at the University of York, and no responsibility is taken for errors. arbdead Contains a tool to calculate worst-case response times of tasks with arbitrary deadlines scheduled according to fixed priorities. Tool permits tasks to be bursty, sporadic or periodic, lock and unlock semaphores, and takes account of overheads when processor scheduled by a tick-scheduler. Appropriate for single processor problems only. This tool can be used in conjunction with the analysis reported in YCS189, and subsequently used as "techniques 4 and 5" of the Rate Monotonic Handbook. disksched Contains an interactive program for multi-media stream admission. A multi-media stream is assumed to be stored on a disk drive, and read back in real-time. The overheads due to moving the disk head are accounted for, and the analysis can be used as part of a negotiation of quality-of-service policy. The analysis behind the tool is described in report YCS204. holistic Contains a tool similar to "arbdead", but also addresses the distributed hard real-time problem. Tasks can send and receive messages across a network scheduled by a TDMA protocol. The overheads due to sending and receiving messages are bounded, including the cost of packet interrupts, and the processor cycles taken to copy packet data to the main memory of the CPU. The analysis behind this tool is described in report YCS197. -- Ken Tindell Internet : ken@minster.york.ac.uk Computer Science Dept., Local FTP site: minster.york.ac.uk University of York, Tel. : +44-904-433377 YO1 5DD, UK Fax. : +44-904-432708 ------------------------------------------------------------------------------ Message 5; Postmarked Thu Nov 4 20:15:26 1993 From: soapy@cs.utexas.edu (Nandit R. Soparkar) Subject: Real-time Transaction Management (available via FTP) In case someone is interested, my dissertation entitled "Time-Constrained Transaction Management" is now available for anonymous ftp from UT Austin. The files can be anonymously ftp'd from UT as follows: ftp cs.utexas.edu or 128.83.139.9 Name: anonymous Password: cd pub/avi/soapy At this point the normal ftp commands will work. There is a README file to explain how the dissertation is organized to be printed out. - Nandit Soparkar ------------------------------------------------------------------------------ <<<<<<<<<<<<<<<<<<<* END OF THE IEEE-CS TC-RTS NEWSLETTER *>>>>>>>>>>>>>>>>>>> ------------------------------------------------------------------------------ The TC-RTS repository is maintained by Azer Bestavros at Boston University Internet address for anonymous FTP to the TC-RTS repository is: cs.bu.edu Contributions to this forum should be sent via E-mail to: IEEE-RTTC@cs.bu.edu Requests / inquiries should be sent via E-mail to: IEEE-RTTC-request@cs.bu.edu ------------------------------------------------------------------------------