Abstract: A processor is described that includes one or more processing cores. The processing core includes a memory controller to interface with a system memory having a near memory and a far memory. The processing core includes a plurality of caching levels above the memory controller. The processor includes logic circuitry to track state information of a cache line that is cached in one of the caching levels. The state information including a selected one of an inclusive state and a non inclusive state. The inclusive state indicates that a copy or version of the cache line exists in near memory. The non inclusive states indicates that a copy or version of the cache line does not exist in the near memory. The logic circuitry is to cause the memory controller to handle a write request that requests a direct write into the near memory without a read of the near memory beforehand if a system memory write request generated within the processor targets the cache line when the cache line is in the inclusive state.

Abstract: An apparatus and method for reducing or eliminating writeback operations. For example, one embodiment of a method comprises: detecting a first operation associated with a cache line at a first requestor cache; detecting that the cache line exists in a first cache in a modified (M) state; forwarding the cache line from the first cache to the first requestor cache and storing the cache line in the first requestor cache in a second modified (M?) state; detecting a second operation associated with the cache line at a second requestor; responsively forwarding the cache line from the first requestor cache to the second requestor cache and storing the cache line in the second requestor cache in an owned (O) state if the cache line has not been modified in the first requestor cache; and setting the cache line to a shared (S) state in the first requestor cache.

Abstract: Methods and apparatus relating to multiple-queue multiple-resource entry sleep and wakeup for power savings and bandwidth conservation in a retry based pipeline are described. In one embodiment, a bit indicates whether a corresponding queue entry is asleep or awake with respect to arbitration for resources in a retry based pipeline. Furthermore, multiple entries from different queues may be grouped together and multiple resources may be grouped together. Other embodiments are also disclosed.

Abstract: A starvation mode is entered and a particular dependency of a first request in a retry queue is identified. The particular dependency is determined to be acquired and the first request is retried based on acquisition of the particular dependency.

Abstract: A processor includes a cache-side address monitor unit corresponding to a first cache portion of a distributed cache that has a total number of cache-side address monitor storage locations less than a total number of logical processors of the processor. Each cache-side address monitor storage location is to store an address to be monitored. A core-side address monitor unit corresponds to a first core and has a same number of core-side address monitor storage locations as a number of logical processors of the first core. Each core-side address monitor storage location is to store an address, and a monitor state for a different corresponding logical processor of the first core. A cache-side address monitor storage overflow unit corresponds to the first cache portion, and is to enforce an address monitor storage overflow policy when no unused cache-side address monitor storage location is available to store an address to be monitored.

Abstract: Methods and apparatus relating to multiple-queue multiple-resource entry sleep and wakeup for power savings and bandwidth conservation in a retry based pipeline are described. In one embodiment, a bit indicates whether a corresponding queue entry is asleep or awake with respect to arbitration for resources in a retry based pipeline. Furthermore, multiple entries from different queues may be grouped together and multiple resources may be grouped together. Other embodiments are also disclosed.

Abstract: Methods and apparatus relating to directory based coherency to improve input/output write bandwidth in scalable systems are described. In one embodiment, a first agent receives a request to write data from a second agent via a link and logic causes the first agent to write the directory state to an Input/Output Directory Cache (IODC) of the first agent. Additionally, the logic causes the second agent to send data from a modified state to an exclusive state using write back to the first agent, while allowing the data to remain cached exclusively in the second agent and also enabling the deallocation of the IODC entry in the first agent. Other embodiments are also disclosed.

Abstract: Methods and apparatus relating to multiple-queue multiple-resource entry sleep and wakeup for power savings and bandwidth conservation in a retry based pipeline are described. In one embodiment, a bit indicates whether a corresponding queue entry is asleep or awake with respect to arbitration for resources in a retry based pipeline. Furthermore, multiple entries from different queues may be grouped together and multiple resources may be grouped together. Other embodiments are also disclosed.

Abstract: A system and method of processing a predicated instruction is disclosed. A consumer instruction and a predicated instruction are received in an reservation station of an out-order processor. The consumer instruction depends on a result of the predicated instruction. The predicated instruction is dispatched to an execution unit for execution. The executed predicate instruction is stored in a re-order buffer.

Abstract: A system and method of processing a predicated instruction is disclosed. A consumer instruction and a predicated instruction are received in an reservation station of an out-order processor. The consumer instruction depends on a result of the predicated instruction. The predicated instruction is dispatched to an execution unit for execution. The executed predicate instruction is stored in a re-order buffer.