Computing Accurate AVFs using ACE Analysis on Performance Models: A Rebuttal

  • Authors:
  • Arijit Biswas;Paul Racunas;Joel Emer;Shubhendu Mukherjee

  • Affiliations:
  • -;-;-;-

  • Venue:
  • IEEE Computer Architecture Letters
  • Year:
  • 2008

Quantified Score

Hi-index 0.00

Visualization

Abstract

ACE (Architecturally Correct Execution) analysis computes AVFs (architectural vulnerability factors) of hardware structures. AVF expresses the fraction of radiation-induced transient faults that result in a user-visible error. Architects usually perform this analysis on a high-level performance model to quickly compute per-structure AVFs. If, however, low-level details of a microarchitecture are not modeled appropriately in a performance model, then their effects may not be reflected in the per-structure AVFs. In this paper we refute Wang, et. al.'s claim that this detail is difficult to model and imposes a practical threshold on ACE analysis that forces its estimates to have a high error margin. We show that carefully choosing a small amount of additional detail can result in a much tighter AVF bound than Wang, et. al. were able to achieve in their refined ACE analysis. Even the inclusion of small details, such as read/write pointers and appropriate inter-structure dependencies, can increase the accuracy of the AVF computation by 40% or more. We argue that this is no different than modeling the IPC (instructions per cycle) of a microprocessor pipeline. A less detailed performance model will provide less accurate IPCs. AVFs are no different.