Patent ID: 8255631
Filing Date: 2012-08-28
Classification: G06F

Abstract:
1. In a data processing system comprising a processor, and a memory subsystem with at least one cache and a lower level memory having stored data, a method comprising: assigning a priority to at least a first prefetch stream indicating a relative priority for scheduling a prefetch operation of the first prefetch stream; monitoring one or more activity within the data processing system relevant to a determination of changes in the priority of the first prefetch stream, said one or more activity including an availability and usage of specific system resources; dynamically updating the priority of the first prefetch stream when the monitoring indicates an occurrence of one or more activity relevant to updating the priority assigned to the first prefetch stream; scheduling the prefetch of the first prefetch stream in a scheduling sequence corresponding to the priority that is currently assigned to the first prefetch stream, relative to a next priority assigned to other prefetch streams with scheduled prefetches, wherein streams with higher priority are scheduled ahead of streams with lower priority; and issuing the prefetch of the first prefetch stream in response to the prefetch being in a first position in the scheduling sequence and a current usage level of resources being at a level below a threshold level at and above which the prefetch cannot be issued.