摘要:
A data processing system includes a plurality of processing units, including at least a local master and a local hub, which are coupled for communication via a communication link. The local master includes a master capable of initiating an operation, a snooper capable of receiving an operation, and interconnect logic coupled to a communication link coupling the local master to the local hub. The interconnect logic includes request logic that synchronizes internal transmission of a request of the master to the snooper with transmission, via the communication link, of the request to the local hub.
摘要:
A cache coherent data processing system includes a memory and at least first and second coherency domains that each include a respective one of first and second cache memories. A master in the first coherency domain selects a scope of an initial broadcast of an operation targeting a request address allocated to the memory from among a first scope including only the first coherency domain and a second scope including both the first and second coherency domains. The master selects the scope based, at least in part, upon whether the memory belongs to the first coherency domain and performs an initial broadcast of the operation within the cache coherent data processing system utilizing the selected scope.
摘要:
A cache, system and method for reducing the number of rejected snoop requests. A “stall/reorder unit” in a cache receives a snoop request from an interconnect. Information, such as the address, of the snoop request is stored in a queue of the stall/reorder unit. The stall/reorder unit forwards the snoop request to a selector which also receives a request from a processor. An arbitration mechanism selects either the snoop request or the request from the processor. If the snoop request is denied by the arbitration mechanism, information, e.g., address, about the snoop request may be maintained in the stall/reorder unit. The request may be later resent to the selector. This process may be repeated up to “n” clock cycles. By providing the snoop request additional opportunities (n clock cycles) to be accepted by the arbitration mechanism, fewer snoop requests may ultimately be denied.
摘要:
According to a method of data processing, a predictor is maintained that indicates a historical scope of broadcast for one or more previous operations transmitted on an interconnect of a data processing system. A scope of broadcast of a subsequent operation is predictively selected by reference to the predictor.
摘要:
A cache, system and method for reducing the number of rejected snoop requests. A “stall/reorder unit” in a cache receives a snoop request from an interconnect. Information, such as the address, of the snoop request is stored in a queue of the stall/reorder unit. The stall/reorder unit forwards the snoop request to a selector which also receives a request from a processor. An arbitration mechanism selects either the snoop request or the request from the processor. If the snoop request is denied by the arbitration mechanism, information, e.g., address, about the snoop request may be maintained in the stall/reorder unit. The request may be later resent to the selector. This process may be repeated up to “n” clock cycles. By providing the snoop request additional opportunities (n clock cycles) to be accepted by the arbitration mechanism, fewer snoop requests may ultimately be denied.
摘要:
According to a method of data processing, a predictor is maintained that indicates a historical scope of broadcast for one or more previous operations transmitted on an interconnect of a data processing system. A scope of broadcast of a subsequent operation is predictively selected by reference to the predictor.
摘要:
A cache, system and method for reducing the number of rejected snoop requests. A “stall/reorder unit” in a cache receives a snoop request from an interconnect. Information, such as the address, of the snoop request is stored in a queue of the stall/reorder unit. The stall/reorder unit forwards the snoop request to a selector which also receives a request from a processor. An arbitration mechanism selects either the snoop request or the request from the processor. If the snoop request is denied by the arbitration mechanism, information, e.g., address, about the snoop request may be maintained in the stall/reorder unit. The request may be later resent to the selector. This process may be repeated up to “n” clock cycles. By providing the snoop request additional opportunities (n clock cycles) to be accepted by the arbitration mechanism, fewer snoop requests may ultimately be denied.
摘要:
A data processing system includes an interconnect fabric, a protected resource having a plurality of banks each associated with a respective one of a plurality of address sets, a snooper that controls access to the resource, one or more masters that initiate requests, and interconnect logic coupled to the one or more masters and to the interconnect fabric. The interconnect logic regulates a rate of delivery to the snooper via the interconnect fabric of requests that target any one the plurality of banks of the protected resource.
摘要:
A method and apparatus for performing data prefetch in a multiprocessor system are disclosed. The multiprocessor system includes multiple processors, each having a cache memory. The cache memory is subdivided into multiple slices. A group of prefetch requests is initially issued by a requesting processor in the multiprocessor system. Each prefetch request is intended for one of the respective slices of the cache memory of the requesting processor. In response to the prefetch requests being missed in the cache memory of the requesting processor, the prefetch requests are merged into one combined prefetch request. The combined prefetch request is then sent to the cache memories of all the non-requesting processors within the multiprocessor system. In response to a combined clean response from the cache memories of all the non-requesting processors, data are then obtained for the combined prefetch request from a system memory.
摘要:
A data processing system includes a plurality of processing units coupled by a plurality of communication links for point-to-point communication such that at least some of the communication between multiple different ones of the processing units is transmitted via intermediate processing units among the plurality of processing units. The communication includes operations having a request and a combined response representing a system response to the request. At least each intermediate processing unit includes one or more masters that initiate first operations, a snooper that receives at least second operations initiated by at least one other of the plurality of processing units, a physical queue that stores master tags of first operations initiated by the one or more masters within that processing unit, and a ticketing mechanism that assigns to second operations observed at the intermediate processing unit a ticket number indicating an order of observation with respect to other second operations observed by the intermediate processing unit. The ticketing mechanism provides the ticket number assigned to an operation to the snooper for processing with a combined response of the operation.