Intranode data communications in a parallel computer

• US 8,627,334 B2
• Filed: 12/10/2012
• Issued: 01/07/2014
• Est. Priority Date: 11/07/2011
• Status: Expired due to Fees

• Current Assignee: International Business Machines Corporation
• Original Assignee: International Business Machines Corporation
• Inventors: Archer, Charles J., Blocksome, Michael A., Miller, Douglas R., Ratterman, Joseph D., Smith, Brian E.
• Primary Examiner(s): Puente, Emerson
• Assistant Examiner(s): Verdi, Kimbleann
• Application Number:
  US13/709,305
• Publication Number:
  US 20130125135A1
• Time in Patent Office: 393 Days
• Field of Search: 719/312, 719/314
• US Class Current: 719/312
• CPC Class Codes: G06F 9/544 Buffers; Shared memory; Pipes

Abstract

Intranode data communications in a parallel computer that includes compute nodes configured to execute processes, where the data communications include: allocating, upon initialization of a first process of a compute node, a region of shared memory; establishing, by the first process, a predefined number of message buffers, each message buffer associated with a process to be initialized on the compute node; sending, to a second process on the same compute node, a data communications message without determining whether the second process has been initialized, including storing the data communications message in the message buffer of the second process; and upon initialization of the second process: retrieving, by the second process, a pointer to the second process'"'"'s message buffer; and retrieving, by the second process from the second process'"'"'s message buffer in dependence upon the pointer, the data communications message sent by the first process.

Claims

1. A method of intranode data communications in a parallel computer, the parallel computer comprising a plurality of compute nodes, each compute node of the plurality of compute nodes configured to execute a plurality of processes, the method comprising:

upon initialization of a first process of one of the plurality of compute nodes, allocating, by the first process, a region of shared memory;

establishing, by the first process within the allocated region of shared memory, a predefined number of message buffers, each message buffer associated with one of the plurality of processes to be initialized on the one of the plurality of compute nodes;

sending, by the first process to a second process of the one of the plurality of compute nodes, a data communications message without determining whether the second process has been initialized, including storing the data communications message in the message buffer of the second process;

upon initialization of the second process;

retrieving, by the second process, a pointer to the second process'"'"'s message buffer; and

retrieving, by the second process from the second process'"'"'s message buffer in dependence upon the pointer, the data communications message sent by the first process, wherein;

the parallel computer comprises a parallel active messaging interface (‘

PAMI’

) and the plurality of compute nodes execute a parallel application, the PAMI comprises data communications endpoints, each data communications endpoint comprising a specification of data communications parameters for a thread of execution on a compute node of the plurality of compute nodes, including specifications of a client, a context, and a task, the data communications endpoints coupled for data communications through the PAMI;

each process of the plurality of processes comprises one of the data communications endpoints;

each client comprises a collection of data communications resources dedicated to exclusive use of an application-level data processing entity;

each context comprises a subset of the collection of data processing resources of a client, context functions, and a work queue of data transfer instructions to be performed by use of the subset through the context functions operated by an assigned thread of execution;

each task represents a process of execution of the parallel application; and

each context carries out data communications operations independently and in parallel with other contexts.

2. The method of claim 1 wherein the establishing, by the first process within the allocated region of shared memory, the predefined number of message buffers further comprises:

establishing a single message buffer associated with the second process for which the first process intends to send the data communications message; and

establishing, by each subsequently initialized process of the plurality of processes intending to send a data communications to an uninitialized process, a message buffer for the uninitialized process.

3. The method of claim 1 wherein the establishing, by the first process within the allocated region of shared memory, a predefined number of message buffers further comprises establishing a number of message buffers equal to a maximum number of processes that may simultaneously execute.

4. The method of claim 1, further comprising:

requesting, by a process of the plurality of processes, initialization of an on-demand process to execute a task, including establishing a message buffer for the on-demand process and storing a data communications message intended for the on-demand process in the message buffer;

initializing the on-demand process, including retrieving the data communications message intended for the on-demand process from the message buffer established for the on-demand process; and

upon completion of the task, releasing, by the on-demand process, the message buffer of the on-demand process.

5. The method of claim 1 wherein each context carries out, through post and advance functions, data communications for the parallel application on data communications resources in exclusive possession of that context.