OpenMP Region Efficiency

OpenMP Region Efficiency indicates inefficiencies within threads, and can be computed as follows:

$\begin{eqnarray*}OpenMP\; Region\; Efficiency=\frac{max(runtime) - avg(time\; in\; OpenMP) + avg(time\; in\; useful\; computation\; within\; OpenMP)}{max(runtime)} \end{eqnarray*}$

Where average time in OpenMP is computed as weighted arithmetic mean. If number of threads is equal across processes average time in OpenMP can be computed as ordinary arithmetic mean.