Cooperative I/O: a novel I/O semantics for energy-aware applications

ABSTRACT

In this paper we demonstrate the benefits of application involvement in operating system power management. We present Coop-I/O, an approach to reduce the power consumption of devices while encompassing all levels of the system---from the hardware and OS to a new interface for cooperative I/O that can be used by energy-aware applications. We assume devices which can be set to low-power operation modes if they are not accessed and where switching between modes consumes additional energy, e.g. devices with rotating components or network devices consuming energy for the establishment and shutdown of network connections. In these cases frequent mode switches should be avoided.With Coop-I/O, applications can declare open, read and write operations as deferrable and even abortable by specifying a time-out and a cancel flag. This information enables the operating system to delay and batch requests so that the number of power mode switches is reduced and the device can be kept longer in a low-power mode. We have deployed our concept to the IDE hard disk driver and Ext2 file system of Linux and to typical real-life programs so that they make use of the new cooperative I/O functions. With energy savings of up to 50%, the experimental results demonstrate the benefits of the concept. We will show that Coop-I/O even outperforms the "oracle" shutdown policy which defines the lower bound in power consumption if the timing of requests can not be influenced.

REFERENCES

• 1: American National Standards Institute. Information Technology -- AT Attachment with Packet Interface 5 (ATA/ATAPI-5). Published as ANSI/INCITS 340-2000, Dec 2000
• 2: M. Berger, S. Richter, ACPI4Linux. http://phobos.fs.tum.de/acpi/index.html
• 3: Compaq, Intel, Microsoft, Phoenix, Toshiba. Advanced Configuration and Power Interface Specification 2.0a, Mar 2002
• 4: Fred Douglis , P. Krishnan , Brian N. Bershad, Adaptive Disk Spin-down Policies for Mobile Computers, Proceedings of the 2nd Symposium on Mobile and Location-Independent Computing, p.121-137, April 10-11, 1995
• 5: F. Douglis, P. Krishnan, B Marsh. Thwarting the Power Hungry Disk. In Proceedings of the 1994 Winter USENIX Conference, Jan 1994
• 6: Jason Flinn , M. Satyanarayanan, Energy-aware adaptation for mobile applications, Proceedings of the seventeenth ACM symposium on Operating systems principles, p.48-63, December 12-15, 1999, Charleston, South Carolina, United States
• 7: Paul M. Greenawalt, Modeling Power Management for Hard Disks, Proceedings of the Second International Workshop on Modeling, Analysis, and Simulation On Computer and Telecommunication Systems, p.62-66, January 31-February 02, 1994
• 8: David P. Helmbold , Darrell D. E. Long , Bruce Sherrod, A dynamic disk spin-down technique for mobile computing, Proceedings of the 2nd annual international conference on Mobile computing and networking, p.130-142, November 1996, Rye, New York, United States [doi>10.1145/236387.236423]
• 9: IBM Corporation. Hard Disk Drive Specifications for Travelstar 48GH, 30GN & 15GN, Rev. 2.0, Jan 2002
• 10: P. Krishnan, P. Long, J. Vitter. Adaptive Disk Spin-Down via Optimal Rent-to-Buy in Probabilistic Environments. In Proceedings of the 12th International Conference on Machine Learning. pp. 332--330, July 1995
• 11: Li-K; Kumpf-R; Horton-P; Anderson-T. A Quantitative Analysis of Disk Drive Power Management in Portable Computers. In Proceedings of the USENIX Winter 1994 Conference, pp. 279--292, Jan 1994
• 12: Yung-Hsiang Lu , Luca Benini , Giovanni De Micheli, Operating-system directed power reduction, Proceedings of the 2000 international symposium on Low power electronics and design, p.37-42, July 25-27, 2000, Rapallo, Italy [doi>10.1145/344166.344189]
• 13: Yung-Hsiang Lu , Luca Benini , Giovanni De Micheli, Power-aware operating systems for interactive systems, IEEE Transactions on Very Large Scale Integration (VLSI) Systems, v.10 n.2, p.119-134, April 2002 [doi>10.1109/92.994989]
• 14: Yung-Hsiang Lu , Giovanni de Micheli, Adaptive Hard Disk Power Management on Personal Computers, Proceedings of the Ninth Great Lakes Symposium on VLSI, p.50, March 04-06, 1999
• 15: Yung-Hsiang Lu , Giovanni De Micheli, Comparing System-Level Power Management Policies, IEEE Design & Test, v.18 n.2, p.10-19, March 2001 [doi>10.1109/54.914592]
• 16: Microsoft. OnNow Power Management http://www.microsoft.com/hwdev/onnow/
• 17: Brian D. Noble , M. Satyanarayanan , Dushyanth Narayanan , James Eric Tilton , Jason Flinn , Kevin R. Walker, Agile application-aware adaptation for mobility, Proceedings of the sixteenth ACM symposium on Operating systems principles, p.276-287, October 05-08, 1997, Saint Malo, France
• 18: J. Pouwelse, K. Langendoen, H. Spis. Dynamic Voltage Scaling on a Low-power Microprocessor. In Proceedings of the International Symposium on Mobile Multimedia Systems & Applications MMSA'2000, Nov 2000
• 19: Heng Zeng , Carla S. Ellis , Alvin R. Lebeck , Amin Vahdat, ECOSystem: managing energy as a first class operating system resource, Proceedings of the 10th international conference on Architectural support for programming languages and operating systems, October 05-09, 2002, San Jose, California

INDEX TERMS

Primary Classification:
  D. Software
  D.4 OPERATING SYSTEMS
      D.4.4 Communications Management

Additional Classification:
  D. Software
  D.4 OPERATING SYSTEMS
      D.4.7 Organization and Design
          Subjects: Distributed systems
      D.4.8 Performance
          Subjects: Operational analysis

General Terms:
Design, Management, Performance