Oracle International Corporation

Damien Walker

Paul N Loewenstein

Ali Vahidsafa

Josephus Ebergen

Matthew Cohen

Priyambada Mitra

Andrew Brock

Ramaswamy Sivaramakrishnan

Bruce E Petrick

Stephen Phillips

David Smentek

Bruce J Chang

Connie Wai Mun Cheung

Serena Wing Yee Leung

Stephen E Phillips

David Richard Smentek

A cache coherence system manages both internode and intranode cache coherence in a cluster of nodes. Each node in the cluster of nodes is either a collection of processors running an intranode coherence protocol between themselves, or a single processor. A node comprises a plurality of coherence ordering units (COUs) that are hardware circuits configured to manage intranode coherence of caches within the node and/or internode coherence with caches on other nodes in the cluster. Each node contains one or more directories which tracks the state of cache line entries managed by the particular node. Each node may also contain one or more scoreboards for managing the status of ongoing transactions. The internode cache coherence protocol implemented in the COUs may be used to detect and resolve communications errors, such as dropped message packets between nodes, late message delivery at a node, or node failure. Additionally, a transport layer manages communication between the nodes in the cluster, and can additionally be used to detect and resolve communications errors.

Fault-tolerant cache coherence over a lossy network

A method for cache coherence, including: broadcasting, by a requester cache (RC) over a partially-ordered request network (RN), a peer-to-peer (P2P) request for a cacheline to a plurality of slave caches; receiving, by the RC and over the RN while the P2P request is pending, a forwarded request for the cacheline from a gateway; receiving, by the RC and after receiving the forwarded request, a plurality of responses to the P2P request from the plurality of slave caches; setting an intra-processor state of the cacheline in the RC, wherein the intra-processor state also specifies an inter-processor state of the cacheline; and issuing, by the RC, a response to the forwarded request after setting the intra-processor state and after the P2P request is complete; and modifying, by the RC, the intra-processor state in response to issuing the response to the forwarded request.

Broadcast cache coherence on partially-ordered network

Systems and methods that allow for dynamically deconfiguring, reconfiguring and/or otherwise configuring nodes (e.g., processors) in a symmetric multiprocessing system (e.g., a symmetric multiprocessor) in a manner that avoids, or at least limits, inefficiencies such as renumbering of node IDs, system reboots, SW configuration handle changes, and the like. In one arrangement, a number of modules, tables and/or the like that are configured to generate node IDs and/or convert node IDs from one form to another form can be intelligently implemented within an SMP to allow the various processes and/or components of an SMP to utilize the node IDs in a more efficient manner. For instance, as SDs in an SMP are often configured to work with CNIDs (e.g., for use in determining at which node a particular requested cache line resides), any node GNIDs that are sent to the SD for processing can first be converted into corresponding CNIDs.

Dynamic node configuration in directory-based symmetric multiprocessing systems

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Santa Cruz, CA, United States of America

Damien Walker