The research on network optimization in InfiniBand (IB) networks has been evolved in several directions, e.g. increasing network utilization, fault-tolerance, congestion control, and energy-aware systems. However, for efficient HPC clouds based on IB, the optimization problem becomes both complex and multi-dimensional, while individually proposed solutions often yield contradictory management decisions. We believe that a holistic closed-loop control system is required to effectively incorporate multidimensional objective function in future IB systems. Based on control theory, a self-adaptive model for the IB subnet system, may help acheiving better network utilization while effectively keeping user level SLAs in HPC clouds.