Abstract: Methods, apparatus, and products are disclosed for providing policy-based operating system services in an operating system on a computing system. The computing system includes at least one compute node. The compute node includes an operating system that includes a kernel and a plurality of operating system services of a service type. Providing policy-based operating system services in an operating system on a computing system includes establishing, on the compute node, a kernel policy specifying one of the operating system services of the service type for use in the operating system, and accessing, by the kernel, the specified operating system service. The computing system may also be implemented as a distributed computing system that includes one or more operating system service nodes. One or more of the operating system services may be distributed among the operating system service nodes.

Abstract: Performing a local barrier operation with parallel tasks executing on a compute node including, for each task: retrieving a present value of a counter; calculating, in dependence upon the present value of the counter and a total number of tasks performing the local barrier operation, a base value, the base value representing the counter's value prior to any task joining the local barrier; calculating, in dependence upon the base value and the total number of tasks performing the local barrier operation, a target value of the counter, the target value representing the counter's value when all tasks have joined the local barrier; joining the local barrier, including atomically incrementing the value of the counter; and repetitively, until the present value of the counter is no less than the target value of the counter: retrieving the present value of the counter and determining whether the present value equals the target value.

Abstract: Performing a local barrier operation with parallel tasks executing on a compute node including, for each task: retrieving a present value of a counter; calculating, in dependence upon the present value of the counter and a total number of tasks performing the local barrier operation, a base value of the counter, the base value representing the counter's value prior to any task joining the local barrier; calculating, in dependence upon the base value and the total number of tasks performing the local barrier operation, a target value, the target value representing the counter's value when all tasks have joined the local barrier; joining the local barrier, including atomically incrementing the value of the counter; and repetitively, until the present value of the counter is no less than the target value of the counter: retrieving the present value of the counter and determining whether the present value equals the target value.

Abstract: Methods, apparatus, products are disclosed for providing policy-based application services to an application running on a computing system. The computing system includes at least one compute node. The compute node includes an application and a plurality of application services of a service type. Providing policy-based application services to an application running on a computing system includes establishing, on the compute node, a service policy specifying one of the application services of the service type for use by the application, establishing a performance ruleset, the performance ruleset specifying rules for analyzing the performance of the computing system, measuring performance of the computing system, and adjusting the service policy in dependence upon the performance ruleset and the measured performance. Providing policy-based application services to an application running on a computing system may also include accessing, by the application, the specified application service.

Abstract: Methods, apparatuses, and computer program products for utilizing a kernel administration hardware thread of a multi-threaded, multi-core compute node of a parallel computer are provided. Embodiments include a kernel assigning a memory space of a hardware thread of an application processing core to a kernel administration hardware thread of a kernel processing core. A kernel administration hardware thread is configured to advance the hardware thread to a next memory space associated with the hardware thread in response to the assignment of the kernel administration hardware thread to the memory space of the hardware thread. Embodiments also include the kernel administration hardware thread executing an instruction within the assigned memory space.

Abstract: Methods, apparatuses, and computer program products for optimizing collective communications within a parallel computer comprising a plurality of hardware threads for executing software threads of a parallel application are provided. Embodiments include a processor of a parallel computer determining for each software thread, an affinity of the software thread to a particular hardware thread. Each affinity indicates an assignment of a software thread to a particular hardware thread. The processor also generates one or more affinity domains based on the affinities of the software threads. Embodiments also include a processor generating, for each affinity domain, a topology of the affinity domain based on the affinities of the software threads to the hardware threads. According to embodiments of the present application, a processor also performs, based on the generated topologies of the affinity domains, a collective operation on one or more software threads.

Abstract: Data communications in a parallel active messaging interface (‘PAMI’) of a parallel computer, the parallel computer including a plurality of compute nodes that execute a parallel application, the PAMI composed of data communications endpoints, each endpoint including a specification of data communications parameters for a thread of execution on a compute node, including specifications of a client, a context, and a task, the compute nodes and the endpoints coupled for data communications through the PAMI and through data communications resources, including receiving in an origin endpoint of the PAMI a data communications instruction, the instruction characterized by an instruction type, the instruction specifying a transmission of transfer data from the origin endpoint to a target endpoint and transmitting, in accordance with the instruction type, the transfer data from the origin endpoint to the target endpoint.

Abstract: Endpoint-based parallel data processing in a parallel active messaging interface (‘PAMI’) of a parallel computer, the PAMI composed of data communications endpoints, each endpoint including a specification of data communications parameters for a thread of execution on a compute node, including specifications of a client, a context, and a task, the compute nodes coupled for data communications through the PAMI, including establishing a data communications geometry, the geometry specifying, for tasks representing processes of execution of the parallel application, a set of endpoints that are used in collective operations of the PAMI including a plurality of endpoints for one of the tasks; receiving in endpoints of the geometry an instruction for a collective operation; and executing the instruction for a collective operation through the endpoints in dependence upon the geometry, including dividing data communications operations among the plurality of endpoints for one of the tasks.

Abstract: Internode data communications in a parallel computer that includes compute nodes that each include main memory and a messaging unit, the messaging unit including computer memory and coupling compute nodes for data communications, in which, for each compute node at compute node boot time: a messaging unit allocates, in the messaging unit's computer memory, a predefined number of message buffers, each message buffer associated with a process to be initialized on the compute node; receives, prior to initialization of a particular process on the compute node, a data communications message intended for the particular process; and stores the data communications message in the message buffer associated with the particular process. Upon initialization of the particular process, the process establishes a messaging buffer in main memory of the compute node and copies the data communications message from the message buffer of the messaging unit into the message buffer of main memory.

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.

Abstract: Compiling software for a hierarchical distributed processing system including providing to one or more compiling nodes software to be compiled, wherein at least a portion of the software to be compiled is to be executed by one or more other nodes; compiling, by the compiling node, the software; maintaining, by the compiling node, any compiled software to be executed on the compiling node; selecting, by the compiling node, one or more nodes in a next tier of the hierarchy of the distributed processing system in dependence upon whether any compiled software is for the selected node or the selected node's descendants; sending to the selected node only the compiled software to be executed by the selected node or selected node's descendant.

Abstract: A system and method for enhancing barrier collective synchronization on a computer system comprises a computer system including a data storage device. The computer system includes a program stored in the data storage device and steps of the program being executed by a processor. The system includes providing a plurality of communicators for storing state information for a barrier algorithm. Each communicator designates a master core in a multi-processor environment of the computer system. The system allocates or designates one counter for each of a plurality of threads. The system configures a table with a number of entries equal to the maximum number of threads. The system sets a table entry with an ID associated with a communicator when a process thread initiates a collective. The system determines an allocated or designated counter by searching entries in the table.

Abstract: Distributed administration of a lock for an operational group of compute nodes in a hierarchical tree structured network including assigning the root node of the operational group to send acknowledgments for lock requests, the root lock administration module comprising a module of automated computing machinery; receiving a lock request assigned to a particular node from a child node; determining whether another request from another child is directly ahead in an acknowledgement queue; if a request from another child is directly ahead in the acknowledgement queue, putting the lock request for the particular node in the acknowledgement queue until the lock request directly ahead in the acknowledgement queue is satisfied and when the lock request ahead in the queue is satisfied, sending the particular node for whom the lock request is assigned a message acknowledging the particular node has the lock; and if a request from another child is not directly ahead in a queue, sending to the particular node for whom the

Abstract: Performing a deterministic reduction operation in a parallel computer that includes compute nodes, each of which includes computer processors and a CAU (Collectives Acceleration Unit) that couples computer processors to one another for data communications, including organizing processors and a CAU into a branched tree topology in which the CAU is a root and the processors are children; receiving, from each of the processors in any order, dummy contribution data, where each processor is restricted from sending any other data to the root CAU prior to receiving an acknowledgement of receipt from the root CAU; sending, by the root CAU to the processors in the branched tree topology, in a predefined order, acknowledgements of receipt of the dummy contribution data; receiving, by the root CAU from the processors in the predefined order, the processors' contribution data to the reduction operation; and reducing, by the root CAU, the processors' contribution data.

Abstract: Processing posted receive commands in a parallel computer, including: posting, by a parallel process of a compute node, a receive command, the receive command including a set of parameters excluding the receive command from being directed among parallel posted receive queues; flattening the parallel unexpected message queues into a single unexpected message queue; determining whether the posted receive command is satisfied by an entry in the single unexpected message queue; if the posted receive command is satisfied by an entry in the single unexpected message queue, processing the posted receive command; if the posted receive command is not satisfied by an entry in the single unexpected message queue: flattening the parallel posted receive queues into a single posted receive queue; and storing the posted receive command in the single posted receive queue.

Abstract: Processing posted receive commands in a parallel computer, including: posting, by a parallel process of a compute node, a receive command, the receive command including a set of parameters excluding the receive command from being directed among parallel posted receive queues; flattening the parallel unexpected message queues into a single unexpected message queue; determining whether the posted receive command is satisfied by an entry in the single unexpected message queue; if the posted receive command is satisfied by an entry in the single unexpected message queue, processing the posted receive command; if the posted receive command is not satisfied by an entry in the single unexpected message queue: flattening the parallel posted receive queues into a single posted receive queue; and storing the posted receive command in the single posted receive queue.

Abstract: Systems, methods and articles of manufacture are disclosed for effecting a desired collective operation on a parallel computing system that includes multiple compute nodes. The compute nodes may pipeline multiple collective operations to effect the desired collective operation. To select protocols suitable for the multiple collective operations, the compute nodes may also perform additional collective operations. The compute nodes may pipeline the multiple collective operations and/or the additional collective operations to effect the desired collective operation more efficiently.

Abstract: Methods, apparatuses, and computer program products for scheduling synchronization in association with collective operations in a parallel computer that includes a shared memory and a plurality of compute nodes that execute a parallel application utilizing the shared memory are provided. Embodiments include acquiring an available channel of the shared memory; posting to the acquired channel of the shared memory one or more collective operations and a synchronization point; determining that processing within the acquired channel has reached the synchronization point; and posting to the acquired channel, in response to determining that processing within the acquired channel has reached the synchronization point, a background synchronization operation corresponding to the one or more collective operations.

Abstract: Data communications in a parallel active messaging interface (‘PAMI’) of a parallel computer composed of compute nodes that execute a parallel application, each compute node including application processors that execute the parallel application and at least one management processor dedicated to gathering information regarding data communications. The PAMI is composed of data communications endpoints, each endpoint composed of a specification of data communications parameters for a thread of execution on a compute node, including specifications of a client, a context, and a task, the compute nodes and the endpoints coupled for data communications through the PAMI and through data communications resources.

Abstract: Direct injection of a data to be transferred in a hybrid computing environment that includes a host computer and a plurality of accelerators, the host computer and the accelerators adapted to one another for data communications by a system level message passing module. Each accelerator includes a Power Processing Element (‘PPE’) and a plurality of Synergistic Processing Elements (‘SPEs’). Direct injection includes reserving, by each SPE, a slot in a shared memory region accessible by the host computer; loading, by each SPE into local memory of the SPE, a portion of data to be transferred to the host computer; executing, by each SPE in parallel, a data processing operation on the portion of the data loaded in local memory of each SPE; and writing, by each SPE, the processed data to the SPE's reserved slot in the shared memory region accessible by the host computer.