International Business Machines Corporation

Other

Globalfoundries Inc.

Michael Steven Siegel

Brian Mitchell Bass

Marco C Heddes

Jean Louis Calvignac

Fabrice Jean Verplanken

Guy L Guthrie

William John Starke

Jeffrey A Stuecheli

Bartholomew Blaner

Derek E Williams

Clark Debs Jeffries

Anthony Matteo Gallo

Charles Francis Marino

Jeff A Stuecheli

David W Cummings

Gordon Taylor Davis

David John Krolak

John David Irish

Piyush Chunilal Patel

Lakshminarayana Baba Arimilli

Kenneth Michael Valk

Norman Clark Strole

Michael Raymond Trombley

Mark Anthony Rinaldi

James Johnson Allen, Jr

Ross Boyd Leavens

Florian Alexander Auernhammer

Praveen S Reddy

Robert Allen Drehmel

Wayne Melvin Barrett

Steven Kenneth Jenkins

Brahmanand Kumar Gorti

Paul Allen Ganfield

Andreas Kind

Ravinder Kumar Sabhikhi

Sridhar Rao

Santosh Prasad Gaur

Brian Alan Youngman

Bernard Charles Drerup

Phillip G Williams

Ronald Nick Kalla

Joseph Gerald McDonald

Alvan Wing Ng

George William Daly, Jr

Kenneth J Christensen

John Thomas Hollaway, Jr

Jody B Joyner

Gary A Van Huben

Eric Eugene Retter

Mohammad Peyravian

Richard Loise Arndt

Kevin Franklin Reick

Brian King Flachs

Joseph Franklin Logan

Charles David Wait

Timothy Hume Heil

Curtis Carl Wollbrink

Tolga Ozguner

Kenneth Anthony Lauricella

Kerry Christopher Imming

Lonny Lambrecht

Robert Brian Likovich, Jr

Kevin Neal Magill

Jeffrey Richard Summers

Joseph Lawrence Mueller

Darryl Jonathan Rumph

Bryan Keith Bullis

Steven Paul VanderWiel

Frederick Jacob Ziegler

Thomas E Stammely

Max Robert Povse

Ravi Kumar Arimilli

Daniel Mark Dreps

Colin Beaton Verrilli

Thomas Andrew Sartorius

Hugh Shen

Leah Shalev

Jeffrey Todd Bridges

Ganesh Balakrishnan

Albert James Van Norstrand, Jr

Gregory Scott Still

Julian Satran

Zorik Machulsky

James Xenidis

Hien Le

Juan Guillermo Revilla

Kenneth James Barker

Dongming Hwang

Everett Arthur Corl, Jr

James Francis Mikos

Kenneth Harvey Potter, Jr

Jeffrey James Lynch

Sonia Kiang Rovner

Yiftach Benjamini

Edward Hau-chun Ku

Chad Everett Winemiller

James Charles Gregerson

Douglas Ray Henderson

Peter Irma August Barri

Raj Kumar Singh

A coherent data processing system includes a system fabric communicatively coupling a plurality of nodes arranged in a plurality of groups. A plurality of coherence agents are distributed among the nodes and are assigned responsibility for certain addresses. A topology data structure indicates by group and node differing physical locations within the data processing system of the plurality of coherence agents. A master accesses the topology data structure utilizing a request address to obtain a particular group and node of a particular coherence agent uniquely assigned the request address. The master initially issues, on the system fabric, a memory access request specifying the request address and utilizing a remote scope of broadcast that includes the particular node and excludes at least one other node in the particular group, where the particular node is a different one of the plurality of nodes than a home node containing the master.

Broadcast scope selection in a data processing system utilizing a memory topology data structure

A multiprocessor data processing system includes multiple vertical cache hierarchies supporting a plurality of processor cores, a system memory, and an interconnect fabric coupled to the system memory and the multiple vertical cache hierarchies. Based on a request of a requesting processor core among the plurality of processor cores, a master in the multiprocessor data processing system issues, via the interconnect fabric, a read-type memory access request. The master receives via the interconnect fabric at least one beat of conditional data issued speculatively on the interconnect fabric by a controller of the system memory prior to receipt by the controller of a systemwide coherence response for the read-type memory access request. The master forwards the at least one beat of conditional data to the requesting processor core.

Speculative delivery of data from a lower level of a memory hierarchy in a data processing system

A technique for operating a data processing system that implements a split transaction coherency protocol that has an address tenure and a data tenure includes receiving, at a data source, a command (that includes an address tenure for requested data) that is issued from a data sink. The data source issues a response that indicates data associated with the address tenure is available to be transferred to the data sink during a data tenure. In response to determining that the data is available subsequent to issuing the response, the data source issues a first data packet to the data sink that includes the data during the data tenure. In response to determining that the data is not available subsequent to issuing the response, the data source issues a second data packet to the data sink that includes a data header that indicates the data is unavailable.

Split transaction coherency protocol in a data processing system

In a data processing environment, a communication interface of a second host data processing system receives, from a first host data processing system, a host command in a first command set. The host command specifies a memory access to a memory coupled to the second host data processing system. The communication interface translates the host command into a command in a different second command set emulating coupling of an attached functional unit to the communication interface. The communication interface presents the second command to a host bus protocol interface of the second host data processing system. Based on receipt of the second command, the host bus protocol interface initiates, on a system fabric of the second host data processing system, a host bus protocol memory access request specifying the memory access.

Multifunction communication interface supporting memory sharing among data processing systems

An integrated circuit includes a first communication interface for communicatively coupling the integrated circuit with a coherent data processing system, a second communication interface for communicatively coupling the integrated circuit with an accelerator unit including an accelerator functional unit and an effective address-based accelerator cache for buffering copies of data from the system memory of the coherent data processing system, and a real address-based directory inclusive of contents of the accelerator cache. The real address-based directory assigns entries based on real addresses utilized to identify storage locations in the system memory. The integrated circuit includes request logic that, responsive to receipt on the first communication interface of a translation entry invalidation request, issues to the accelerator unit via the second communication interface an invalidation request that identifies an entry in the effective address-based accelerator cache to be invalidated utilizing a host tag identifying a storage location in the real address-based directory.

Translation invalidation in a translation cache serving an accelerator

A snooper of a processing unit connected to processing units via a system fabric receives a first single bus command in a bus protocol that allows sampling over the system fabric of the capability of snoopers to handle an interrupt and returns a first response indicating the capability of the snooper to handle the interrupt. The snooper, in response to receiving a second single bus command in the bus protocol to poll a first selection of snoopers for an availability status to service a criteria specified in the second single bus command, returns a second response indicating the availability of the snooper to service the criteria. The snooper, in response to receiving a third single bus command in the bus protocol to direct the snooper to handle the interrupt, assigns the interrupt to a particular processor thread of a respective selection of the one or more separate selections of processors threads distributed in the processing unit.

Managing efficient selection of a particular processor thread for handling an interrupt

An integrated circuit includes a first communication interface for communicatively coupling the integrated circuit with a coherent data processing system, a second communication interface for communicatively coupling the integrated circuit with an accelerator unit including an effective address-based accelerator cache for buffering copies of data from a system memory, and a real address-based directory inclusive of contents of the accelerator cache. The real address-based directory assigns entries based on real addresses utilized to identify storage locations in the system memory. The integrated circuit further includes request logic that communicates memory access requests and request responses with the accelerator unit. The request logic, responsive to receipt from the accelerator unit of a read-type request specifying an aliased second effective address of a target cache line, provides a request response including a host tag indicating that the accelerator unit has associated a different first effective address with the target cache line.

Integrated circuit and data processing system supporting address aliasing in an accelerator

An integrated circuit for a coherent data processing system includes a first communication interface for communicatively coupling the integrated circuit with the coherent data processing system, a second communication interface for communicatively coupling the integrated circuit with an accelerator unit including an effective address-based accelerator cache for buffering copies of data from a system memory of the coherent data processing system, and a real address-based directory inclusive of contents of the accelerator cache. The real address-based directory assigns entries based on real addresses utilized to identify storage locations in the system memory. The integrated circuit further includes request logic that communicates memory access requests and request responses with the accelerator unit via the second communication interface. A request response identifies a target of a corresponding memory access request utilizing a host tag specifying an entry associated with the target in the real address-based directory.

Integrated circuit and data processing system supporting attachment of a real address-agnostic accelerator

An integrated circuit includes a first communication interface for communicatively coupling the integrated circuit with a coherent data processing system, a second communication interface for communicatively coupling the integrated circuit with an accelerator unit including an effective address-based accelerator cache for buffering copies of data from a system memory, and a real address-based directory inclusive of contents of the accelerator cache. The real address-based directory assigns entries based on real addresses utilized to identify storage locations in the system memory. The integrated circuit further includes directory control logic that configures at least a number of congruence classes utilized in the real address-based directory based on configuration parameters specified on behalf of or by the accelerator unit.

Integrated circuit and data processing system having a configurable cache directory for an accelerator

In response to receipt by a first coherency domain of a memory access request originating from a master in a second coherency domain and excluding from its scope a third coherency domain, coherence participants in the first coherency domain provide partial responses, and one of the coherence participants speculatively provides, to the master, data from a target memory block. The data includes a memory domain indicator indicating whether the memory block is cached, if at all, only within the first coherency domain. Based on the partial responses a combined response is generated representing a systemwide coherence response to the memory access request. In response to the combined response indicating success and the memory domain indicator indicating that a valid copy of the memory block may be cached outside the first coherence domain, the master discards the speculatively provided data and reissues the memory access request with a larger broadcast scope.

Remote node broadcast of requests in a multinode data processing system

Reducing translation latency within a memory management unit (MMU) using external caching structures including requesting, by the MMU on a node, page table entry (PTE) data and coherent ownership of the PTE data from a page table in memory; receiving, by the MMU, the PTE data, a source flag, and an indication that the MMU has coherent ownership of the PTE data, wherein the source flag identifies a source location of the PTE data; performing a lateral cast out to a local high-level cache on the node in response to determining that the source flag indicates that the source location of the PTE data is external to the node; and directing at least one subsequent request for the PTE data to the local high-level cache.

Reducing translation latency within a memory management unit using external caching structures

A claw-back request, received from an accelerator, is issued for an address line. While waiting for a response to the claw-back request, a cast-out push request with a matching address line is received. The cast-out push request is associated with a cache having a modified copy of the address line. A combined-response, associated with the cast-out push request, is received from a bus. Data associated with the modified copy of the address line is received from the cache. A claw-back response, with the data associated with the modified version of the address line, is issued to an accelerator.

Accelerator memory coherency with single state machine

A data processing system includes first and second processing nodes and response logic coupled by an interconnect fabric. A first coherence participant in the first processing node is configured to issue a memory access request specifying a target memory block, and a second coherence participant in the second processing node is configured to issue a probe request regarding a memory region tracked in a memory coherence directory. The first coherence participant is configured to, responsive to receiving the probe request after the memory access request and before receiving a systemwide coherence response for the memory access request, detect an address collision between the probe request and the memory access request and, responsive thereto, transmit a speculative coherence response. The response logic is configured to, responsive to the speculative coherence response, provide a systemwide coherence response for the probe request that prevents the probe request from succeeding.

Coherence protocol providing speculative coherence response to directory probe

A cache coherent data processing system includes at least non-overlapping first, second, and third coherency domains. A master in the first coherency domain of the cache coherent data processing system selects a scope of an initial broadcast of an interconnect operation from among a set of scopes including (1) a remote scope including both the first coherency domain and the second coherency domain, but excluding the third coherency domain that is a peer of the first coherency domain, and (2) a local scope including only the first coherency domain. The master then performs an initial broadcast of the interconnect operation within the cache coherent data processing system utilizing the selected scope, where performing the initial broadcast includes the master initiating broadcast of the interconnect operation within the first coherency domain.

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Michael Steven Siegel