Configuration based cache coherency protocol selection
AssigneeInternational Business Machines Corporation
InventorsEkaterina M. Ambroladze, Deanna P. Berger, Michael F. Fee, Arthur J. O'Neill, Robert J. Sonnelitter, III
Life of this patent
Estimating the term…
Abstract
Topology of clusters of processors of a computer configuration, configured to support any of a plurality of cache coherency protocols, is discovered at initialization time to determine which one of the plurality of cache coherency protocols is to be used to handle coherency requests of the configuration
Claims24
A modular computer system for determining configuration topology of one or more active computer elements, the computer system comprising:
- a node of a configuration, the node consisting of a first plurality of communicatively coupled computer elements, each element comprising a respective second plurality of first interfaces, each pair of elements of the first plurality of elements communicatively coupled by way of respective first interfaces by way of a respective point-to-point active interconnection, the respective active interconnection interconnecting only the respective pair of elements, each element being separately packaged, the second plurality of first interfaces being greater-than or equal-to the first plurality of communicatively coupled active computer elements, the node configured to perform a method, said method comprising:
- during system initialization of the computer system, performing, by each respective element of the node, an operation to identify which other elements are active in the node, the operation comprising:
- determining, by each element, which first interfaces of the respective element are valid first interfaces, wherein each valid first interface of an element has only one active interconnection to only one other element of the node, wherein each active interconnection is a point-to-point interconnection, wherein each first interface of the respective element not having an active interconnection to another element of the node is not a valid first interface;
- and
- based on the determining, by each element, which first interfaces of the respective element are valid first interfaces, storing a coherency value by each respective element, the coherency value indicating which first interfaces of the respective element are valid interfaces and which first interfaces of the respective element are not valid interfaces;
- and
- after system initialization, during normal operation, using by each element the respective stored coherency value, of the respective element, to determine which other elements of the node are to be accessed in the node.
A computer program product for determining configuration topology of one or more active computer elements in a modular computer system comprising a node of a configuration, the node consisting of a first plurality of communicatively coupled computer elements, each element comprising a respective second plurality of first interfaces, each pair of elements of the first plurality of elements communicatively coupled by way of respective first interfaces by way of a respective point-to-point active interconnection, the respective active interconnection interconnecting only the respective pair of elements, each element being separately packaged, the second plurality of first interfaces being greater-than or equal-to the first plurality of communicatively coupled active computer elements, the computer program product comprising:
- a computer readable storage medium readable by a processing circuit and storing instructions for execution by the processing circuit for performing a method comprising:
- during system initialization of the computer system, performing, by each respective element of the node, an operation to identify which other elements are active in the node, the operation comprising:
- determining, by each element, which first interfaces of the respective element are valid first interfaces, wherein each valid first interface of an element has only one active interconnection to only one other element of the node, wherein each active interconnection is a point-to-point interconnection, wherein each first interface of the respective element not having an active interconnection to another element of the node is not a valid first interface;
- and
- based on the determining, by each element, which first interfaces of the respective element are valid first interfaces, storing a coherency value by each respective element, the coherency value indicating which first interfaces of the respective element are valid interfaces and which first interfaces of the respective element are not valid interfaces;
- and
- after system initialization, during normal operation, using by each element the respective stored coherency value, of the respective element, to determine which other elements of the node are to be accessed in the node.
Dependencies are inferred from the claim text.