Paper
J. Kelly Flanagan, Brent E. Nelson, James K. Archibald, and Knut Grimsrud.
BACH: BYU Address Collection Hardware, the collection of complete traces.
In Proc. of the 6th Int. Conf. on Modelling Techniques and Tools for
Computer Performance Evaluation, pages 128-137, 1992.
Abstract
Trace driven simulation is an important tool for computer systems
performance analysis and prediction, but its accuracy decreases when
incomplete or inaccurate traces are used for input. Nevertheless, many
memory hierarchy simulation studies have been published which rely on such
traces. In this paper we describe BACH, a hardware monitor developed to
captures long, accurate, and complete traces on a variety of hardware and
software platforms. BACH traces are long-- traces containing over 200
million contiguous references have been collected to date. BACH traces
are accurate-- in contrast to other techniques such as inlining they
contain almost no time and space dilation effects. BACH traces are
complete-- they contain all references generated by the CPU during
tracing, including prefetches and demand fetches from user code, system
calls, exceptions, interrupts, and other system code. Finally, the traces
produced using BACH are available to members of the general community. In
addition, we demonstrate the usefulness of the traces acquired using BACH
through a cache simulation study. The miss rates obtained using BACH
traces are shown to be as much as 50 times higher than those obtained
using other traces. It is also shown that with a memory access time of
30, predictions of effective access time can be off by as much as a factor
of 2 when using inaccurate or incomplete trace data.