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 representing a measure of processor workload and a cache workload input representing a measure of cache workload 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 cache workload input, determining whether a current task associated with the first processor cluster is limited by a size threshold of the first cache, based on the processor workload input and the cache workload input, determining whether the current task associated with the first processor cluster is limited by a performance threshold of the first processor cluster and not limited by the size threshold of the first cache; in response to a determination that 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; and in response to a determination that the current task is limited by the performance threshold of the first processor cluster and not limited by the size threshold of the first cache, migrating the current task from the first processor cluster to the second processor cluster.