  This paper focuses on one of the most frequently visited multithreading
library interfaces - ParallelFor. In this study, it is inferred that
ParallelFor's end-to-end latency performance is noticeably affected by the
frequency with which fetch-add-add (FAA) is called during program execution.
This can be explained by ParallelFor's uniform semantics and the utilization of
atomic FAA. To prove this assumption, a battery of tests was designed and
conducted on diverse platforms. From the collected performance statistics and
overall trends, several conclusions were drawn and a cost model is proposed to
enhance performance by mitigating the influence of FAA.
