Intel Corporation

Silicon Graphics International Corporation

Silicon Graphics, Incorporated

Other

Donglai Dai

Randal Steven Passint

Gregory Michael Thorson

Akhilesh Kumar

Joseph Martin Placek

John B Carter

Russell Leonard Nicol

Gaspar Mora Porta

Andres Mejia

Dongkook Park

Paul R Frank

Lixin Zhang

Liqun Cheng

Zhen Fang

Russell L Nicol

Techniques for power gating. A first on-die router has an output port to receive data from a switching fabric. The output port is placed in a power-gated state if there is no activity in the output port for a current cycle and no messages are to be received by the output port during a subsequent cycle. A second on-die router has an input port coupled with the output port of the first on-die router. The input port is placed in a power-gated state if an input port buffer is empty and the output port is not active. Power-gating of the input port and the output port are independent of each other.

Reduced wake up delay for on-die routers

Methods and apparatus relating to techniques for controlling resource utilization with adaptive routing are described. In one embodiment, an output port for transmission of an incoming message that is to be received at an input port is determined at routing logic. The routing logic selects the output port from a first output port and a second output port based on congestion information that is detected at one or more other routing logic communicatively coupled to the routing logic. The first output port provides a deterministic route for the incoming message and the second output port provides an adaptive route for the incoming message. Other embodiments are also disclosed.

Mechanism to control resource utilization with adaptive routing

An apparatus that includes input ports, input buffers coupled with respective input ports, output ports, and routing control circuitry coupled with the input ports, the input buffers and/or the output ports. The plurality of input buffers and the plurality of output ports, the routing control circuitry to maintain a two-tier priority scheme having at least two queues for prioritizing requests stored in the plurality of input buffers.

Managing starvation and congestion in a two-dimensional network having flow control

A method for maintaining data coherency in a shared-memory computer system having a plurality of nodes divides the local memory of a given node into one or more blocks and stores a data record for each block indicating a plurality of node groups and a selection of the node groups. Each selected node group represents a number of nodes, and selected node groups represent at least one node that has requested access to the block. In response to receiving an access request from a requesting node that may or may not be in a selected node group, the method and system update the data record to indicate the correct selection. If the requesting node is not in any node group, the data record is adjusted to have new node groups, one of which represents the requesting node.

Data coherence method and apparatus for multi-node computer system

A system for establishing a primary master node in a computer system includes a plurality of nodes, each node configured with an update interval, a hierarchy of master nodes selected from the plurality of nodes, wherein the master nodes are configured to synchronize the plurality of nodes with a clock value by sending out its clock value when its update interval has expired, wherein each node resets its update interval when it receives the clock value, a primary master node selected from the hierarchy of master nodes based on its update interval, and at least one backup master node selected from the hierarchy of master nodes based on its update interval, the backup master node configured to become the primary master node when the plurality of nodes do not receive the clock value after a predetermined period of time has elapsed.

System and method of synchronizing real time clock values in arbitrary distributed systems

A method and apparatus for maintaining data coherency in a computer system having a plurality of nodes forms a directory by grouping the nodes into a plurality of hierarchical groups of two or more levels. The method and apparatus also 1) set the directory to have data relating to a first set of groups within a first level, and 2) determine if a requesting node requesting data is a member of one of the first set of groups. The directory then is set to have data relating to a second group of nodes if the requesting node is determined not to be a member of the first set of groups within the first level. The second group of nodes is in a higher level than the first level.

A system and method of determining a master node in a computer system having a plurality of nodes includes establishing a hierarchy of master nodes from the plurality of nodes, wherein the master node synchronizes the plurality of nodes in the computer system with a clock value and determining the master node from the hierarchy of master nodes. A system and method of synchronizing a plurality of nodes in a computer system includes determining a master node from the plurality of nodes, sending a clock value from the master node to neighbor nodes of the master node, synchronizing a node clock in each node receiving the clock value if a predetermined period of time has elapsed in each receiving node, distributing a node clock value from each synchronized node to neighbor nodes of the synchronized node, and repeating synchronizing and distributing, wherein synchronizing a node clock in each node receiving the clock value includes each node receiving the node clock value.

A method and apparatus for controlling access by a set of accessing nodes to memory of a home node (in a multimode computer system) determines that each node in the set of nodes has accessed the memory, and forwards a completion message to each node in the set of nodes after it is determined that each node has accessed the memory. The completion message has data indicating that each node in the set of nodes has accessed the memory of the home node.

Node synchronization for multi-processor computer systems

An apparatus and method of controlling data sharing in a shared memory computer system transfers control of a cache coherency directory (entry) to a node having control of the data. Specifically, the plurality of nodes includes a home node and a second node. The home node has given data in a cache line in its memory, and also has a directory identifying the state of the cache line. The method and apparatus thus detect a request for ownership of the cache line from the second node, and enable the second node to control the directory after receipt of the request.

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Pleasanton, CA, United States of America

Donglai Dai