Patent ID: 8495655

Claim:
A method of messaging in a parallel computer using remote direct memory access (‘RDMA’), the parallel computer including a plurality of nodes, each node including a messaging unit, the method comprising: receiving, by a kernel of the first node through an application programming interface (‘API’), a send work request, the send work request including: a local virtual address on the first node from which data is to be transferred; and a specification of a size of data to be transferred from the first node to a second node, wherein the size of data to be transferred from the first node to a second node is larger than a messaging packet size for sending data from the first node to a second node; responsive to the send work request: translating, by the kernel of the first node, the local virtual address on the first node from which data is to be transferred to a physical address on the first node from which data is to be transferred from; creating, by the kernel of the first node, a local RDMA object that includes a counter set to the size of a messaging acknowledgment field; sending, from a messaging unit in the first node to a messaging unit in a second node, a message that includes a RDMA read operation request, the physical address of the local RDMA object, and the physical address on the first node from which data is to be transferred from; and receiving, by the first node responsive to the second node's execution of the RDMA read operation request, acknowledgment data in the local RDMA object.