摘要:
A method for reducing memory latency in a multi-node architecture. In one embodiment, a speculative read request is issued to a home node before results of a cache coherence protocol are determined. The home node initiates a read to memory to complete the speculative read request. Results of a cache coherence protocol may be determined by a coherence agent to resolve cache coherency after the speculative read request is issued.
摘要:
A method and apparatus for a mechanism for handling explicit writeback in a cache coherent multi-node architecture is described. In one embodiment, the invention is a method. The method includes receiving a read request relating to a first line of data in a coherent memory system. The method further includes receiving a write request relating to the first line of data at about the same time as the read request is received. The method further includes detecting that the read request and the write request both relate to the first line. The method also includes determining which request of the read and write request should proceed first. Additionally, the method includes completing the request of the read and write request which should proceed first.
摘要:
A method for reducing memory latency in a multi-node architecture. In one embodiment, a speculative read request is issued to a home node before results of a cache coherence protocol are determined. The home node initiates a read to memory to complete the speculative read request. Results of a cache coherence protocol may be determined by a coherence agent to resolve cache coherency after the speculative read request is issued.
摘要:
A method and apparatus for a mechanism for handling explicit writeback in a cache coherent multi-node architecture is described. In one embodiment, the invention is a method. The method includes receiving a read request relating to a first line of data in a coherent memory system. The method further includes receiving a write request relating to the first line of data at about the same time as the read request is received. The method further includes detecting that the read request and the write request both relate to the first line. The method also includes determining which request of the read and write request should proceed first. Additionally, the method includes completing the request of the read and write request which should proceed first.
摘要:
A method of sending messages from a node to a receiving agent. In one embodiment, if a outbound message that is stored in a buffer in the node is unsuccessfully sent to the receiving agent more than a threshold number of times, outbound messages currently stored in the buffer are sent to the receiving agent. It is determined that these outbound messages have been successfully sent before any other outbound messages are sent to the receiving agent. In a further embodiment, an outbound message is successfully sent if a success confirmation message is received for the outbound message from the receiving agent. In a still further embodiment, a retry response is received from the receiving agent for an outbound message if a buffer in the receiving agent that stores incoming outbound messages does not have room for the outbound message.
摘要:
A method of invalidating a cache line in a system having a plurality of nodes that include a processor and a cache memory. A request to invalidate a cache line that is caching a particular memory block is sent from a first node. The request is a request to invalidate a cache line in another node without returning to the first node the data stored in a cache line to be invalidated. In an embodiment, the data in the cache line to be invalidated is not returned to the first node even if the cache line is in the modified state. In a further embodiment, new data is written to a cache line in the first node that is caching the particular memory block without writing old data that was stored in that cache line back to a memory.
摘要:
A method of managing requests in a multi-node system. A first request associated with a location in a memory address space is sent to a first node. A second request associated with the same location in the same location in the memory address space is received before a response is received from the first node to the first request. If the received second request had been received from the first node, a retry message is sent to the first node requesting resending of the second request.
摘要:
Embodiments of the present invention relate to methods and apparatus for managing transaction requests in a multi-node architecture. In one embodiment, a previously received ordered group request may be forwarded to a destination agent. Whether a next received ordered group request belongs to a same ordered group as the previously received ordered group request may be determined. Additionally, it may be determined whether an ordering fork is encountered if the next received ordered group request belongs to the same ordered group as the previously received ordered group request. If an ordering fork is encountered, it may be determined whether a request complete message for the previously received ordered group request has been received. If the request complete message for the previously received ordered group request has not been received and the next received ordered group request in the same ordered group is at least one of a un-ordered request and a forward-ordered request, then the next received ordered group request may be forwarded to the destination agent after the request complete message for the previously received at least one of a forward-ordered request and a sequential-ordered request issued on a different path at the ordering fork has been received.
摘要:
According to one embodiment, a method is disclosed. The method comprises receiving a read request from a first node in a multi-node computer system to read data from a memory at a second node. Subsequently, a write request from a third node is received to write data to the memory at the second node. The read request and write request is detected at conflict detection circuitry. Finally, read data from the memory at the second node is transmitted to the first node.
摘要:
A method for reducing memory latency in a multi-node architecture. In one embodiment, a speculative read request is issued to a home node before results of a cache coherence protocol are determined. The home node initiates a read to memory to complete the speculative read request. Results of a cache coherence protocol may be determined by a coherence agent to resolve cache coherency after the speculative read request is issued.