Abstract: A method, computer program product, and system are provided for dynamically routing data through the data processing system. Data is received at a first processor that is to be transmitted to a destination processor. The data that is received includes address information. A lookup is performed in routing table data structures based on the address information to identify candidate paths through which the data is routed to the destination processor. A determination is made as to whether any of the candidate paths are not able to be used to route the data to the destination processor based on a setting of at least one identifier. A path is selected from the identified candidate paths for routing of the data based on a setting of the at least one identifier. Then, the data is transmitted from the first processor along the selected path toward the destination processor.

Abstract: A system for providing a cluster-wide system clock in a multi-tiered full graph (MTFG) interconnect architecture are provided. Heartbeat signals transmitted by each of the processor chips in the computing cluster are synchronized. Internal system clock signals are generated in each of the processor chips based on the synchronized heartbeat signals. As a result, the internal system clock signals of each of the processor chips are synchronized since the heartbeat signals, that are the basis for the internal system clock signals, are synchronized. Mechanisms are provided for performing such synchronization using direct couplings of processor chips within the same processor book, different processor books in the same supernode, and different processor books in different supernodes of the MTFG interconnect architecture.

Abstract: A mechanism is provided for transmitting data in a data network. A first processor of the data network receives data to be transmitted to a second processor within the data network. A determination is made if the data has previously been routed through an indirect communication link from a source processor, the indirect communication link being a communication link that does not directly couple the source processor to a final destination processor which is to receive the data. A communication link is selected over which to transmit the data from the first processor to the second processor based on results of determining if the data has previously been routed through an indirect communication link. Finally, the data is transmitted from the first processor to the second processor using the selected communication link.

Abstract: A distributed data processing system executes multiple tasks within a parallel job, including a first local task on a local node and at least one task executing on a remote node, with a remote memory having real address (RA) locations mapped to one or more of the source effective addresses (EA) and destination EA of a data move operation initiated by a task executing on the local node. On initiation of the data move operation, remote asynchronous data move (RADM) logic identifies that the operation moves data to/from a first EA that is memory mapped to an RA of the remote memory. The local processor/RADM logic initiates a RADM operation that moves a copy of the data directly from/to the first remote memory by completing the RADM operation using the network interface cards (NICs) of the source and destination processing nodes, determined by accessing a data center for the node IDs of remote memory.

Abstract: A data processing system is programmed to provide a method for enabling user-level one-to-all message/messaging (OTAM) broadcast within a distributed parallel computing environment in which multiple threads of a single job execute on different processing nodes across a network. The method comprises: generating one or more messages for transmission to at least one other processing node accessible via a network, where the messages are generated by/for a first thread executing at the data processing system (first processing node) and the other processing node executes one or more second threads of a same parallel job as the first thread. An OTAM broadcast is transmitting via a host fabric interface (HFI) of the data processing system as a one-to-all broadcast on the network, whereby the messages are transmitted to a cluster of processing nodes across the network that execute threads of the same parallel job as the first thread.

Abstract: A method, computer program product, and system are provided performing a Message Passing Interface (MPI) job. A first processor chip receives a set of arrival signals from a set of processor chips executing tasks of the MPI job in the data processing system. The arrival signals identify when a processor chip executes a synchronization operation for synchronizing the tasks for the MPI job. Responsive to receiving the set of arrival signals from the set of processor chips, the first processor chip identifies a fastest processor chip of the set of processor chips whose arrival signal arrived first. An operation of the fastest processor chip is modified based on the identification of the fastest processor chip. The set of processor chips comprises processor chips that are in one of a same processor book or a different processor book of the data processing system.

Abstract: In a global shared memory (GSM) environment, an initiating task at a first node with a host fabric interface (HFI) uses epochs to provide reliability of transmission of packets via a network fabric to a target task. The HFI generates a packet for the initiating task addressed to the target task, and automatically inserts a current epoch of the initiating task into the packet. A copy of the current epoch is maintained by the target task, which accepts for processing only packets having the correct epoch, unless the packet is tagged for guaranteed-once delivery. When a packet delivery is accepted, the target task sends a notification to the initiating task. If the initiating task does not receive the notification of delivery for the issued packet, the initiating task updates the epoch at both the target node and the initiating node and re-transmits the packet.

Abstract: A mechanism is provided for providing reliability of communication. A first processor determines a current state of links coupled to ports of a first processor of the data processing system. Each port of the first processor comprises a plurality of links to a corresponding port on a second processor of the data processing system. The current state of the links indicates a level of error associated with each link. The first processor determines, for each link, if a level of error associated with the link exceeds a threshold. For each link whose level of error exceeds the threshold, the first processor tags the link with an error identifier in a switch associated with the ports of the first processor. The first processor reduces a level of usage for transmitting data on ports associated with links tagged with the error identifier.

Abstract: A mechanism for performing dynamic request routing based on broadcast source request information is provided. Each processor chip in the system may use a synchronized heartbeat signal it generates to provide source request information to each of the other processor chips in the system. The source request information identifies the number of active source requests sent by the processor chip that originated the heartbeat signal. The source request information from each of the processor chips in the system may be used by the processor chips in determining optimal routing paths for data from a source processor chip to a destination processor chip. As a result, the congestion of data for processing at each of the processor chips along each possible routing path may be taken into account when selecting to which processor chip to forward data.

Abstract: A method, computer program product, and system are provided for selecting, from a plurality of routes through the data processing system, an indirect route for transmitting data. Data that includes address information is received at a first processor that is to be transmitted to a destination processor. Using routing table data structures, indirect route entries are identified that correspond to indirect routes for transmitting data. An accessed priority table data structure comprises a priority entry for each entry in the routing table data structures. The priority entry specifies a priority of a corresponding entry in the routing table data structures. An indirect route entry is selected that corresponds to an indirect route from the routing table data structures, based on specified priorities. Then the data is transmitted from the first processor to the destination processor using a path corresponding to the selected indirect route entry.

Abstract: A method, computer program product, and system are provided for selecting, from a plurality of routes through the data processing system, a direct route for transmitting data. Data that includes address information is received at a first processor that is to be transmitted to a destination processor. Using routing table data structures, direct route entries are identified that correspond to direct routes for transmitting data. An accessed priority table data structure comprises a priority entry for each entry in the routing table data structures. The priority entry specifies a priority of a corresponding entry in the routing table data structures. A direct route entry is selected that corresponds to a direct route from the routing table data structures, based on specified priorities. Then the data is transmitted from the first processor to the destination processor using a path corresponding to the selected direct route entry.

Abstract: A technique for performing cache injection includes monitoring addresses on a bus in response to a cache injection instruction. Ownership of input/output data on the bus is acquired by a cache when an address on the bus (that is associated with the input/output data) corresponds to an address of a data block associated with the cache injection instruction.

Abstract: A technique for performing cache injection includes monitoring, at a cache, addresses on a bus. Ownership of input/output data on the bus is then acquired by the cache when an address on the bus (that is associated with the input/output data) corresponds to an address of a data block stored in the cache. A replacement policy position of the data block is then modified (to increase a probability that the data block is consumed prior to ejection from the cache).

Abstract: A technique for performing cache injection includes monitoring an instruction stream for a specific instruction sequence. Addresses on a bus are then monitored, at a cache, in response to detecting the specific instruction sequence a determined number of times. Ownership of input/output data on the bus is then acquired by the cache when an address on the bus (that is associated with the input/output data) corresponds to an address of a data block stored in the cache.

Abstract: A technique for performing cache injection includes monitoring addresses on a bus. Ownership of input/output data on the bus is acquired by a cache when an address on the bus (that is associated with the input/output data) corresponds to an address of a data block stored in the cache.

Abstract: A method for handling multiple memory requests within a multi-processor system is disclosed. A lock control section is initially assigned to a data block within a system memory. In response to a request for accessing the data block by a processing unit, a determination is made whether or not the lock control section of the data block has been set. If the lock control section has been set, another determination is made whether or not the requesting processing unit is located beyond a predetermined distance from a memory controller. If the requesting processing unit is located beyond a predetermined distance from the memory controller, the requesting processing unit is invited to perform other functions; otherwise, the number of the requesting processing unit is placed in a queue table. However, if the lock control section has not been set, the lock control section of the data block is set, and the access request is allowed.

Abstract: A method and data processing system for performing fence operations within a global shared memory (GSM) environment having a local task executing on a processor and providing GSM commands for processing by a host fabric interface (HFI) window that is allocated to the task. The HFI window has one or more registers for use during local fence operations. A first register tracks a first count of task-issued GSM commands, and a second register tracks a second count of GSM operations being processed by the HFI. The processing logic detects a locally-issued fence operation, and responds by performing a series of operations, including: automatically stopping the task from issuing additional GSM commands; monitoring for completion of all the task-issued GSM commands at the HFI; and triggering a resumption of issuance of GSM commands by the task when the completion of all previous task-issued GSM commands is registered by the HFI.

Abstract: A system and method for performing dynamic request routing based on broadcast depth queue information are provided. Each processor chip in the system may use a synchronized heartbeat signal it generates to provide queue depth information to each of the other processor chips in the system. The queue depth information identifies a number of requests or amount of data in each of the queues of a processor chip that originated the heartbeat signal. The queue depth information from each of the processor chips in the system may be used by the processor chips in determining optimal routing paths for data from a source processor chip to a destination processor chip. As a result, the congestion of data for processing at each of the processor chips along each possible routing path may be taken into account when selecting to which processor chip to forward data.

Abstract: According to method of data processing in a multiprocessor data processing system, in response to a processor request to modify a target granule of a target cache line of data containing multiple granules, a processing unit originates on an interconnect of the multiprocessor data processing system a data-claim-partial request that requests permission to promote only the target granule of the target cache line to a unique copy with an intent to modify the target granule. In response to a combined response to the data-claim-partial request indicating success (the combined response representing a system-wide response to the data-claim-partial-request), the processing unit promotes only the target granule of the target cache line to a unique copy by updating a coherency state of the target granule and retaining a coherency state of at least one other granule of the target cache line.

Abstract: A heterogeneous processing element model is provided where I/O devices look and act like processors. In order to be treated like a processor, an I/O processing element, or other special purpose processing element, must follow some rules and have some characteristics of a processor, such as address translation, security, interrupt handling, and exception processing, for example. The heterogeneous processing element model puts special purpose processing elements on the same playing field as processors, from a programming perspective, operating system perspective, power perspective, as the processors. The operating system can get work to a security engine, for example, in the same way it does to a processor.