Hewlett Packard Enterprise Development LP

Silicon Graphics International Corporation

Silicon Graphics, Incorporated

Sgi International, Inc.

Thomas Edward McGee

Michael S Woodacre

Bruce Alan Strangfeld

Michael E Malewicki

Steven C Miller

Frank R Dropps

Derek Steven Schumacher

Randy Passint

Steven J Dean

Eric Carl Fromm

Randal Steven Passint

Kirill Malkin

Russell Leonard Nicol

Paul Frank

Stuart C Haden

Brian J Johnson

One aspect of the application can provide a system and method for replacing a failing node with a spare node in a non-uniform memory access (NUMA) system. During operation, in response to determining that a node-migration condition is met, the system can initialize a node controller of the spare node such that accesses to a memory local to the spare node are to be processed by the node controller, quiesce the failing node and the spare node to allow state information of processors on the failing node to be migrated to processors on the spare node, and subsequent to unquiescing the failing node and the spare node, migrate data from the failing node to the spare node while maintaining cache coherence in the NUMA system and while the NUMA system remains in operation, thereby facilitating continuous execution of processes previously executed on the failing node.

Chassis servicing and migration in a scale-up NUMA system

Example implementations relate to cache coherency protocols as applied to a memory block range. Exclusive ownership of a range of blocks of memory in a default shared state may be tracked by a directory. The directory may be associated with a first processor of a set of processors. When a request is received from a second processor of the set of processors to read one or more blocks of memory absent from the directory, one or more blocks may be transmitted in the default shared state to the second processor. The blocks absent from the directory may not be tracked in the directory.

Application of a default shared state cache coherency protocol

One embodiment can provide a node controller in a multiprocessor system. The node controller can include a processor interface to interface with a processor, a memory interface to interface with a fabric-attached memory, a node-controller interface to interface with a remote node controller, and a cache-coherence logic to operate in a first mode or a second mode. The cache-coherence logic manages cache coherence for a local memory of the processor coupled to the processor interface when operating in the first mode, and the cache-coherence logic manages cache coherence for the fabric-attached memory coupled to the memory interface when operating in the second mode.

System and method for scalable hardware-coherent memory nodes

A node controller is provided to include a first interface to interface with one or more processors, a second interface including a plurality of ports to interface with node controllers within a base node and other nodes in the cache-coherent interconnect network. The node controller can further include a third interface to interface with a first plurality of memory devices and a cache coherence management logic. The cache coherence management logic can maintain, based on a first circuitry, hardware-managed cache coherency in the cache-coherent interconnect network. The cache coherence management logic can further facilitate, based on a second circuitry, software-managed cache coherency in the cache-coherent interconnect network.

System and method for facilitating hybrid hardware-managed and software-managed cache coherency for distributed computing

In exemplary aspects of cache coherency management, a first request is received and includes an address of a first memory block in a shared memory. The shared memory includes memory blocks of memory devices associated with respective processors. Each of the memory blocks are associated with one of a plurality of memory categories indicating a protocol for managing cache coherency for the respective memory block. A memory category associated with the first memory block is determined and a response to the first request is based on the memory category of the first memory block. The first memory block and a second memory block are included in one of the same memory devices, and the memory category of the first memory block is different than the memory category of the second memory block.

Cache coherency management for multi-category memories

To reduce latency and bandwidth consumption in systems, systems and methods are provided for grouping multiple cache line request messages in a related and speculative manner. That is, multiple cache lines are likely to have the same state and ownership characteristics, and therefore, requests for multiple cache lines can be grouped. Information received in response can be directed to the requesting processor socket, and those speculatively received (not actually requested, but likely to be requested) can be maintained in queue or other memory until a request is received for that information, or until discarded to free up tracking space for new requests.

System and method for efficient cache coherency protocol processing

Systems and methods are provided for addressing die are inefficiencies associated with the use of redundant ternary content-addressable memory (TCAM) for facilitating error detection and correction. Only a portion of redundant TCAMs (or portions of the same TCAM) are reserved for modified coherency directory cache entries, while remaining portions are available for unmodified coherency directory cache entries. The amount of space reserved for redundant, modified coherency directory cache entries can be programmable and adaptable.

System and method for cache directory TCAM error detection and correction

An apparatus, system, and method of enforcing cache coherency in a multiprocessor shared memory system are disclosed. A request is received from a node controller, to process a cache coherent operation on a memory block in a shared memory. Based on the information included in the request, a determination is made as to whether the request was transmitted from a processor that is remote relative to the memory that includes the memory block referenced in the request. If the request is from a remote processor, a hardware-based cache coherency of the system is disabled, and request is processed according to software-based cache coherency protocols and mechanisms. A coherent read request may be translated to a non-coherent request, such as an immediate read request, which does not trigger tracking or storing state and ownership information of the requested memory block, or trigger communications with processors other than those involved with request. Processing a coherent write request may include transmitting an exclusive read request, which is a request for ownership of the memory block identified in the coherent write request, and transmitting a write acknowledgment to the node controller.

Selective disabling of hardware-based cache coherency and enforcement of software-based cache coherency

A high performance computing (HPC) system has an architecture that separates data paths used by compute nodes exchanging computational data from the data paths used by compute nodes to obtain computational work units and save completed computations. The system enables an improved method of saving checkpoint data, and an improved method of using an analysis of the saved data to assign particular computational work units to particular compute nodes. The system includes a compute fabric and compute nodes that cooperatively perform a computation by mutual communication using the compute fabric. The system also includes a local data fabric that is coupled to the compute nodes, a memory, and a data node. The data node is configured to retrieve data for the computation from an external bulk data storage, and to store its work units in the memory for access by the compute nodes.

Workload management system and process

A method for modifying an address in a multi-processor system may include performing a first transaction to modify an address between a first processor and an interconnect agent associated with the first processor and storing data for the address on the interconnect agent. The method may further include performing a second transaction to modify an address between the interconnect agent and a memory associated with a second processor and storing the data in the memory.

Interconnect agent

A system and method for conveying data include the capability to determine whether a transaction request credit has been received at a computer module, the transaction request credit indicating that at least a portion of a transaction request message may be sent. The system and method also include the capability to determine, of a transaction request message is to be sent, whether at least a portion of the transaction request message may be sent and to send the at least a portion of the transaction request message if it may be sent.

System and method for conveying information

A high performance computing system is provided with an ASIC that communicates with another device in the system according to a protocol defined by the other device. The ASIC is coupled to a reconfigurable protocol table, in the form of a high speed content-addressable memory ('CAM'). The CAM includes instructions to control the execution of the protocol by the ASIC. The CAM may include instructions to control the ASIC in the event that unanticipated signals or other errors are encountered while executing the protocol. Internal ASIC state data may be routed to the CAM to permit the ASIC to generate a reasonable response to errors either in the design or fabrication of the ASIC or the device with which it is communicating.

High performance system that includes reconfigurable protocol tables within an ASIC wherein a first protocol block implements an inter-ASIC communications protocol and a second block implements an intra-ASIC function

Growing community of inventors

Eau Claire, WI, United States of America

Thomas Edward McGee