Memory Request/Grant Daemons in Virtual Nodes for Moving Subdivided Local Memory Space from VN to VN in Nodes of a Massively Parallel Computer System

A parallel processing computer system, comprising:

• a plurality of nodes, each said node having a respective plurality of processors and a respective common physical nodal memory accessible only to processes executing on one or more of the respective processors within the respective node;
• wherein each node of said plurality of nodes is configurable as a plurality of virtual nodes for executing respective processes, each process executing in a respective said virtual node, each virtual node having a respective disjoint subset of the respective plurality of processors of the respective node, each said disjoint subset containing at least one of said plurality of processors for executing processes in the respective virtual node, and a respective discrete non-overlapping subdivision of said common physical nodal memory for use by processes executing within the respective virtual node, and wherein each said process is unable to access nodal memory outside the respective subdivision of said common physical nodal memory of the virtual node in which the process is executing;
• a respective nodal memory management mechanism resident in at least some of said plurality of nodes, each said at least some of said plurality of nodes being configured as a respective plurality of virtual nodes, each said nodal memory management mechanism comprising a respective memory regulating process executing in each said virtual node of the respective node in which the respective nodal memory management mechanism resides, each said respective nodal memory management mechanism dynamically adjusting the size of a respective discrete subdivisions of said common physical nodal memory of the respective node in which the nodal memory management mechanism resides by:
• (a) sending a request on behalf of a respective user process executing within a first virtual node of the respective plurality of virtual nodes of the respective node within the respective nodal memory management mechanism resides, said request to enlarge the size of the subdivision of the common physical nodal memory of said first virtual node for use by the respective user process, said request being sent by a first memory regulating process executing in the respective first virtual node to a second memory regulating process executing in a second virtual node of the respective plurality of virtual nodes;
• (b) responsive to sending said request, granting said request, said request being granted by said second memory regulating process;
• and
• (c) responsive to granting said request, dynamically enlarging the size of the subdivision of the common physical nodal memory of said first virtual node during execution of the respective user process for use by the respective user process, the size of the subdivision of the common physical nodal memory of said first virtual node being dynamically enlarged by said first memory regulating process.