Systems and methods for scheduling highly-parallel applications executed by high-performance computing systems. An example processing system may comprise: a control register and a processing core, communicatively coupled to the control register. The processing core may be configured to receive a node allocation request specifying an expected running time of an application and a requested number of nodes of a cluster of nodes; determine, in view of the node allocation request and a current load on the plurality of nodes, an actual number of nodes to be allocated to the application, wherein the actual number of nodes to be allocated to the application optimizes a cluster load criterion; and notify, using the control register, the application of the actual number of nodes.