We propose COMDETECTIVE+, an inter-thread communication analyzer, and
REUSETRACKER+, a reuse distance analyzer, that leverage the hardware features
in AMD processors to support low-overhead profiling. Both tools employ the
instruction-based sampling (IBS) facility and debug registers in AMD processors
to detect inter-thread communication and data reuse. Different from prior arts,
COMDETECTIVE+ differentiates the communication into true and false sharing, and
REUSETRACKER+ measures reuse distance in private and shared caches by also considering cache line invalidation with low overhead. Both tools can attribute the
communications and reuses to source code lines. To our knowledge these tools are two
of the few profiling tools designed specifically for AMD x86 architectures using IBS.
Our tools are timely and relevant considering the rise in numbers of AMD processor
based data centers and HPC systems. We perform experiments to evaluate the accuracy and overheads of the proposed tools on an AMD machine with two-socket EPYC
7352 processors. COMDETECTIVE+ exhibits high accuracy while introducing 5.14×
runtime and 1.4× memory overheads. REUSETRACKER+ also displays high accuracy,
which is 95%, with 11.76×runtime and 1.46× memory overheads. These overheads are
much lower than the overheads of existing simulators and code instrumentation-based
tools. Lastly, we demonstrate the usage of the tools by having COMDETECTIVE+ and
REUSETRACKER+ facilitate the code refactoring of two data mining benchmarks to
improve their performance by up to 29%.