1. A method for providing dynamic cache extension in a multi-cluster heterogeneous processor architecture in a portable computing device, the method comprising: receiving a processor workload input and a cache workload input for a first processor cluster and an associated first cache in a multi-cluster heterogeneous processor architecture comprising the first processor cluster and a second processor cluster having an associated second cache; based on the processor workload input and the cache workload input, determining whether a current task associated with the first processor cluster is limited by a size threshold of the first cache or a performance threshold of the first processor cluster; and if the current task is limited by the size threshold of the first cache, using at least a portion of the second cache associated with the second processor cluster as an extension of the first cache.