HIP: hybrid interrupt-polling for the network interface

ABSTRACT

The standard way to notify the processor of a network event, such as the arrival or transmission of a packet, is through interrupts. Interrupts are more effective than polling, in terms of the per packet send/receive latency. Interrupts, however, incur a high overhead both during and after the interrupt handling, because modern superscalar processors use long pipelines, out-of-order and speculative execution, and multi-level memory systems, all of which tend to increase the interrupt overhead in terms of clock cycles. In this paper, we attempt to reduce the network interface overhead by introducing a hybrid scheme (HIP) that uses interrupts under low network load conditions and polling otherwise. Even though such hybrid schemes have been proposed in the past, the polling period in HIP is adjusted dynamically based on the rate of the arriving packet stream. In this way, the increase in the per packet latency, which occurs with polling, is quite low. This is quantified with trace-driven simulations, which also show that the per packet overhead with HIP is significantly reduced compared to the conventional interrupt-based mechanism. HIP would be beneficial for high bandwidth network interfacing in servers with a heavy WWW or streaming media workload.

REFERENCES

• 1: D. Banks and M. Prudence, "A high-performance network architecture for a PA-RISC workstation," IEEE Journal on Selected Areas in Communications, vol. 11, pp. 191-202, Feb. 1993.
• 2: C. B. S. Traw and J. M. Smith, "Hardware-software organization of a high-performance ATM host interface," IEEE Journal on Selected Areas in Communications, vol. 11, pp. 240-253, Feb. 1993.
• 3: B. Davie, "The architecture and implementation of a high-speed host interface," IEEE Journal on Selected Areas in Communications, vol. 11, pp. 228-239, Feb. 1993.
• 4: K. K. Ramakrishnan, "Performance considerations in designing network interfaces," IEEE Journal on Selected Areas in Communications, vol. 11, pp. 203-219, Feb. 1993.
• 5: Jeffrey C. Mogul , K. K. Ramakrishnan, Eliminating receive livelock in an interrupt-driven kernel, ACM Transactions on Computer Systems (TOCS), v.15 n.3, p.217-252, Aug. 1997 [doi>10.1145/263326.263335]
• 6: S. S. Mukherjee and M. D. Hill, "A survey of user-level network interfaces for system area networks," Tech. Rep. TR 1340, Computer Sciences Department, University of Wisconsin- Madison, Feb. 1997.
• 7: H. Schulzrinne, S. Casner, R. Frederick, and V. Jacobson, RTP: A Transport Protocol for Real-Time Applications, Jan. 1996. RFC 1889.
• 8: John L. Hennessy , David A. Patterson, Computer architecture (2nd ed.): a quantitative approach, Morgan Kaufmann Publishers Inc., San Francisco, CA, 1996
• 9: Uresh Vahalia, UNIX internals: the new frontiers, Prentice Hall Press, Upper Saddle River, NJ, 1995
• 10: Mohit Aron , Peter Druschel, Soft timers: efficient microsecond software timer support for network processing, ACM Transactions on Computer Systems (TOCS), v.18 n.3, p.197-228, Aug. 2000 [doi>10.1145/354871.354872]
• 11: Olivier Maquelin , Guang R. Gao , Herbert H. J. Hum , Kevin B. Theobald , Xin-Min Tian, Polling watchdog: combining polling and interrupts for efficient message handling, Proceedings of the 23rd annual international symposium on Computer architecture, p.179-188, May 22-24, 1996, Philadelphia, Pennsylvania, United States
• 12: V. Jacobson, Congestion avoidance and control, Symposium proceedings on Communications architectures and protocols, p.314-329, August 16-18, 1988, Stanford, California, United States
• 13: Walter Willinger , Murad S. Taqqu , Robert Sherman , Daniel V. Wilson, Self-similarity through high-variability: statistical analysis of ethernet LAN traffic at the source level, Proceedings of the conference on Applications, technologies, architectures, and protocols for computer communication, p.100-113, August 28-September 01, 1995, Cambridge, Massachusetts, United States
• 14: J. D. Chung, C. B. S. Traw, and J. M. Smith, "Event-signaling within higher performance network subsystems," in Proceedings, High Performance Communications Subsystems, pp. 220-225, Aug. 1995.
• 15: J. M. Smith and C. B. S. Traw, "Operating systems support for end-to-end Gbps networking," IEEE Network, vol. 7, pp. 44-52, Feb. 1993.
• 16: Mohit Aron , Peter Druschel, Soft timers: efficient microsecond software timer support for network processing, Proceedings of the seventeenth ACM symposium on Operating systems principles, p.232-246, December 12-15, 1999, Charleston, South Carolina, United States

INDEX TERMS

Primary Classification:
  C. Computer Systems Organization
  C.2 COMPUTER-COMMUNICATION NETWORKS
      C.2.1 Network Architecture and Design
          Subjects: Packet-switching networks

Additional Classification:
  D. Software
  D.4 OPERATING SYSTEMS
      D.4.4 Communications Management
          Subjects: Network communication

General Terms:
Algorithms, Design, Performance