Abstract: Embodiments include methods, apparatus, and systems for prioritizing input/outputs (I/Os) to storage devices. One embodiment includes a method that receives an input/output (I/O) command having a group number field and a priority number field at a target device. The method then generates a new priority value based on the group number field. The I/O command is processed at the target device with the new priority value.

Abstract: In general, a system and method is provided for dynamically reallocating computer memory. A mapper receives requests to access data. The requests include bus addresses, and the mapper maps the bus addresses to memory unit addresses based on a plurality of mappings maintained by the mapper. The memory unit addresses identify a plurality of memory locations including a destination memory location and a source memory location. Data requested by the requests received by the mapper is accessed based on the memory unit addresses mapped from the bus addresses included in the requests. When desired, a data value from the source memory location is dynamically moved to the destination memory location, and the mappings are updated such that a bus address mapped to a memory unit address identifying the source memory location is instead mapped to a memory unit address identifying the destination memory location.

Abstract: A method and apparatus link translation lookaside buffer (TLB) purge operations to cache coherency transactions, thereby allowing the TLB purge operations to be performed by hardware without significant software intervention. Computer systems having cache memories associated with multiple cache modules, such as a CPU or an I/O device, typically use a cache coherency protocol to ensure that the cache memories remain consistent with each other and with main memory. Popular cache coherency protocols usually include an INVALIDATE transaction that signals cache memories to invalidate a cache line associated with the address contained in the transaction. A TLB in accordance with the present invention will observe the physical address contained in an INVALIDATE request and determine whether address lies within the page table. If it does, the physical address into the page table will be converted into a virtual page number. The TLB will then be accessed to see if the TLB contains an entry for the virtual page number.