International Business Machines Corporation

Raytheon Company

L-3 Communications Integrated Systems L.p.

Praveen S Reddy

Benjiman L Goodman

William John Starke

Charles Francis Marino

James Stephen Fields, Jr

Guy L Guthrie

Ravi Kumar Arimilli

Sanjeev Ghai

Jeffrey A Stuecheli

David John Krolak

John Thomas Hollaway, Jr

Michael Steven Siegel

William T Jennings

B Scott Darnell

Bradley D Lengel

Lakshminarayana Baba Arimilli

Paul Frank Lecocq

Paul Allen Ganfield

Sanjay Raghunath Deshpande

Vicente Enrique Chung

Daniel C Howe

John Thomas Holloway, Jr

Jason Raymond Baumgartner

Michael Stephen Floyd

Viresh Paruthi

David Mui

Manuel Joseph Alvarez, Ii

Peter Dau Geiger

Joel Roger Davidson

Lawrence Joseph Powell, Jr

Bradley Donald Bingham

A symmetric multiprocessor includes with a hierarchical ring-based interconnection network is disclosed. The symmetric processor includes a plurality of buses comprised on the symmetric multiprocessor, wherein each of the buses are configured in a circular topology. The symmetric multiprocessor also includes a plurality of multi-processing nodes interconnected by the buses to make a hierarchical ring-based interconnection network for conveying commands between the multi-processing nodes. The interconnection network includes a command network configured to transport commands based on command tokens, wherein the tokens dictate a destination of the command, a partial response network configured to transport partial responses generated by the multi-processing nodes, and a combined response network configured to combine the partial responses generated by the multi-processing nodes using combined response tokens.

Hierarchical ring-based interconnection network for symmetric multiprocessors

A method, a computer system, and a computer program product for detection of unintended dependencies between hardware design signals from pseudo-random number generator (PRNG) taps is provided. Embodiments of the present invention may include identifying one or more tap points in a design as an execution sequence. Embodiments of the present invention may include sampling the tap points by propagating the tap points in the design with different delays. Embodiments of the present invention may include defining observation points to identify tap collisions based on the tap points. Embodiments of the present invention may include identifying tap collisions. Embodiments of the present invention may include identifying one or more sources of the tap collisions in the design. Embodiments of the present invention may include eliminating the one or more sources of uninteresting tap collisions out of the tap collisions and filtering one or more of the tap collisions.

Detection of unintended dependencies in hardware designs with pseudo-random number generators

A technique for operating a data processing system includes determining, by an arbiter of a processing unit of the data processing system, whether an over-commit has occurred. In response to determining that the over-commit has occurred, the arbiter selects a broadcast command to be dropped based on a number of hops traversed through the data processing system by the broadcast command.

Techniques for command arbitation in symmetric multiprocessor systems

A technique for operating a data processing system includes detecting that a processing unit within a first group of processing units in the data processing system has a hang condition. In response to detecting that the processing unit has a hang condition, a command issue rate for the first group of processing units is reduced. One or more other groups of processing units in the data processing system are notified that the first group of processing units has reduced the command issue rate for the first group of processing units. In response to the notifying, respective command issue rates of the other groups of processing units are reduced to reduce a number of commands received by the first group of processing units from the other groups of processing units.

Techniques for managing a hang condition in a data processing system with shared memory

In one or more embodiments, one or more systems, devices, methods, and/or processes described can continually increase a command rate of an interconnect if one or more requests to lower the command rate are not received within one or more periods of time. In one example, the command rate can be set to a fastest level. In another example, the command rate can be incrementally increased over periods of time. If a request to lower the command rate is received, the command rate can be set to a reference level or can be decremented to one slower rate level. In one or more embodiments, the one or more requests to lower the command rate can be based on at least one of an issue rate of speculative commands and a number of overcommit failures, among others.

Command rate configuration in data processing system

In one or more embodiments, one or more systems, devices, methods, and/or processes described can send, via an interconnect, a rate master command to at least one of multiple processing nodes; determine that a message indicating a dropped command, associated with the rate master command, is received; determine that a count, associated with dropped commands, satisfies a threshold; and provide, to the processing nodes via the interconnect, a signal indicating a command rate, in response to determining that the count satisfies the threshold. Moreover, the count can be incremented in response to determining that the message is received. The at least one of multiple processing nodes can receive, via the interconnect, the signal indicating the command rate and can utilize the command rate in issuing speculative commands, via the interconnect.

Determining command rate based on dropped commands

One or more systems, devices, methods, and/or processes described can determine a maximum cache command rate of a processor unit. For example, an interface of the processor unit is configured to be coupled to an interconnect of a multiprocessor system and is configured such that a first portion of the interface provides a signal to a second portion of the interface, where the first portion of the interface operates utilizing a known frequency and the second portion of the interface operates utilizing a cache frequency of the processor unit; the second portion of the interface circulates the signal; the first portion of the interface receives the signal from the second portion of the interface; the first portion of the interface determines a cache command rate based on the known frequency, the frequency of the cache, and the signal; and the interface provides information indicating the cache command rate to the interconnect.

Frequency determination across an interface of a data processing system

One or more systems, devices, methods, and/or processes described can determine a maximum cache command rate of a processor unit. For example, an interface of the processor unit configured to be coupled to an interconnect of a multiprocessor system and configured such that a first portion of the interface provides a signal to a second portion of the interface, where the first portion of the interface operates utilizing a known frequency and the second portion of the interface operates utilizing a cache frequency of the processor unit; the second portion of the interface circulates the signal; the first portion of the interface receives the signal from the second portion of the interface; the first portion of the interface determines a cache command rate based on the known frequency, the frequency of the cache, and the signal; and the interface provides information indicating the cache command rate to the interconnect.

A data processing system includes a first processing node and a second processing node coupled by an interconnect fabric. The first processing node includes a plurality of first processing units coupled to each other for communication, and the second processing node includes a plurality of second processing units coupled to each other for communication. A first processing unit in the first processing node includes interconnect logic that processes a plurality of concurrently pending broadcast operations of differing broadcast scope. At least a first of the plurality of concurrently pending broadcast operations has a first scope limited to the first processing node, and at least a second of the plurality of concurrently pending broadcast operations has a second scope including the first processing node and the second processing node.

Data processing system, method and interconnect fabric supporting concurrent operations of varying broadcast scope

A data processing system includes a plurality of processing units, including at least a local master and a local hub, which are coupled for communication via a communication link. The local master includes a master capable of initiating an operation, a snooper capable of receiving an operation, and interconnect logic coupled to a communication link coupling the local master to the local hub. The interconnect logic includes request logic that synchronizes internal transmission of a request of the master to the snooper with transmission, via the communication link, of the request to the local hub.

Synchronized communication in a data processing system

A multi-chip processor apparatus includes multiple processor chips on a substrate. At least one of the multiple processor chips includes a die with a primary interconnect trunk that communicates information between multiple compute elements situated along the primary interconnect trunk. That multiple processor chip includes a secondary interconnected trunk that may be oriented perpendicular with respect to the primary interconnect trunk. The secondary interconnect trunk communicates information off-chip via a number of I/O interfaces at the perimeter of that multiple processor chip. The secondary interconnect trunk intersects the primary interconnect trunk at an intersection at which a bus control element is located. The bus control element includes a primary trunk interface that couples to the primary interconnect trunk at the intersection to enable the bus control element to control on-chip communication among the compute elements via coherency signals on the primary interconnect trunk. The bus control element includes a secondary trunk interface coupled to the secondary interconnect trunk.

Processor chip with multiple computing elements and external i/o interfaces connected to perpendicular interconnection trunks communicating coherency signals via intersection bus controller

A data processing system, method, and computer-usable medium for recovering from a hang condition in a data processing system. The data processing system includes a collection of coupled processing units. The processing units include a collection of processing unit components such as, two or more processing cores, and a cache array, a processor core master, a cache snooper, and a local hang manager. The local hang manager determines whether at least one component out of the collection of processing unit components has entered into a hang condition. If the local hang manager determines at least one component has entered into a hang condition, a throttling manager throttles the performance of the processing unit in an attempt to break the at least one component out of the hang condition.

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Austin, TX, United States of America

Praveen S Reddy