This package includes tools for understanding the determinism of hardware performance counters. This work so far has been primarily on x86. Other architectures (such as ARM and Power) seem to have fewer problems with counter determinism. There are the following subdirectories: + automatic/ prototype tools for automatically finding counter determinism issues this is a work in progress (TODO) + papers/ The most recent version of the counter writeups. These often have more up-to-date results than the published versions. + spec/ holds results found when measuring determinism of the SPEC CPU 2000 and 2006 benchmarks + static/ includes a static hand-coded microbenchmark and analysis tools for finding sources of nondeterminism See the README files in the relevant subdirectories for more information.