摘要:
In a multinode data processing system in which nodes exchange information over a network or through a switch, a structure and mechanism is provided within the realm of Remote Direct Memory Access (RDMA) operations in which DMA operations are present on one side of the transfer but not the other. On the side in which the transfer is not carried out in DMA fashion, transfer processing is carried out under program control; this is in contrast to the transfer on the DMA side which is characteristically carried out in hardware. Usage of these combination processes is useful in programming situations where RDMA is carried out to or from contiguous locations in memory on one side and where memory locations on the other side is noncontiguous. This split mode of transfer is provided both for read and for write operations.
摘要:
A remote direct memory access (RDMA) system is provided in which data is transferred over a network by DMA between from a memory of a first node of a multi-processor system having a plurality of nodes connected by a network and a memory of a second node of the multi-processor system. The system includes a first network adapter at the first node, operable to transmit data stored in the memory of the first node to a second node in a plurality of portions in fulfillment of a DMA request. The first network adapter is operable to transmit each portion together with identifying information and information identifying a location for storing the transmitted portion in the memory of the second node, such that each portion is capable of being received independently by the second node according to the identifying information. Each portion is further capable of being stored in the memory of the second node at the location identified by the location identifying information.
摘要:
In order to solve the problem of the detection of the arrival of duplicate data packets in an interconnected, multinode data processing system, each data packet is provided with a field of r bits that are randomly generated for each data packet. However, one of the packets is provided with a field that is computed from the other randomly generated field entries in a checksum computation which yields a selected nonzero checksum value. A running checksum at the receiver is used to determine whether or not, after the receipt of the specified number, k, of data packets, a duplicate packet has been received.
摘要:
A dedicated collective offload engine provides collective processing of data from processing nodes in a distributed computing environment. The dedicated collective offload engine and the processing nodes are coupled to a switch fabric. A result is produced by the collective offload engine based on the collective processing of the data, and is forwarded to at least one processing node. Collective processing is facilitated by communication among a plurality of dedicated collective offload engines via the switch fabric or via a private channel disposed between the collective offload engines.
摘要:
A method and system of storing and retrieving data in a computer system are disclosed. In an embodiment, the method comprises storing a data object at a specified location in a first data store, storing in a second data store first information identifying said specified location, retrieving the data object from a defined location in the first data store, obtaining second information identifying the defined location in the first data store, and comparing the second information to the first information to determine if the first information and the second information identify a same location in the first data store. In embodiments of the invention, the method further comprises when the second information and the first information identify different locations in the first data store, generating a fault signal to indicate that the location of the data object in the first data store has changed.