One dynamic task scheduling method includes: receiving a task, wherein the task comprises a kernel and a plurality of data items to be processed by the kernel; dynamically partitioning the task into a plurality of sub-tasks, each having the kernel and a variable-sized portion of the data items; and dispatching the sub-tasks to a plurality of computing devices of a heterogeneous computing system. Another dynamic task scheduling method includes: receiving a task, wherein the task comprises a kernel and a plurality of data items to be processed by the kernel; partitioning the task into a plurality of sub-tasks, each having the kernel and a same fixed-sized portion of the data items; and dynamically dispatching the sub-tasks to a plurality of computing devices of a heterogeneous computing system.