Intel Corporation

Ganesh Kumar

Herbert H Hum

David Bubien

Eric R Delano

James R Vash

Eric J DeHaemer

Brinda Ganesh

Leena K Puthiyedath

Adrian C Moga

Richard Lawrence Carlson

Scott J Erlanger

Michelle M Sebot

Dheemanth Nagaraj

Gregory S Averill

Vincent R Freytag

Eric R DeLano

Robert Charles Swanson

Michael T Klinglesmith

Vedaraman Geetha

Sailesh Kottapalli

Derek T Bachand

Jeffrey D Chamberlain

Jose Niell

Luke L Chang

Bongjin Jung

Ramadass Nagarajan

Henk G Neefs

Manoj K Arora

Eric Gouldey

Mahak Gupta

Neil J Achtman

Lavanya Nama

A processor of an aspect includes a plurality of logical processors each having one or more corresponding lower level caches. A shared higher level cache is shared by the plurality of logical processors. The shared higher level cache includes a distributed cache slice for each of the logical processors. The processor includes logic to direct an access that misses in one or more lower level caches of a corresponding logical processor to a subset of the distributed cache slices in a virtual cluster that corresponds to the logical processor. Other processors, methods, and systems are also disclosed.

Processors having virtually clustered cores and cache slices

Methods and apparatus relating to improving the value of F-state by increasing a local caching agent's data forwarding are described. In one embodiment, the opportunity for forwarding from a local caching agent is improved by allowing the local caching agent to keep an F-state copy of the line while sending an S-state copy to the requestor (e.g., in response to a non-ownership read operation). Other embodiments are also disclosed.

Value of forward state by increasing local caching agent forwarding

In an example, a system-on-a-chip comprises a plurality of multi-core processors, such as four dual-core processors for eight total cores. Each of the processors connects to shared resources such as memory and peripherals via a shared uncore fabric. Because each input bus for each core can include hundreds of data lines, the number of lines into the shared uncore fabric can become prohibitive. Thus, inputs from each core are multiplexed, such as in a two-to-one configuration. The multiplexing may be a non-blocking, queued (such as FIFO) multiplexing to ensure that all packets from all cores are delivered to the uncore fabric. In certain embodiment, some smaller input lines may be provided to the uncore fabric non-multiplexed, and returns (outputs) from the uncore fabric to the cores may also be non-multiplexed.

Low overhead hierarchical connectivity of cache coherent agents to a coherent fabric

Responsive to receiving a write request for a cache line from an input/output device, a caching agent of a first processor determines that the cache line is managed by a home agent of a second processor. The caching agent sends an ownership request for the cache line to the second processor. A home agent of the second processor receives the ownership request, generates an entry in a directory cache for the cache line, the entry identifying the remote caching agent as having ownership of the cache line, and grants ownership of the cache line to the remote caching agent. Responsive to receiving the grant of ownership for the cache line from the home agent an input/output controller of the first processor adds an entry for the cache line to an input/output write cache, the entry comprising a first indicator that the cache line is managed by the home agent of the second processor.

Directory cache supporting non-atomic input/output operations

An apparatus and method are described for performing partial memory mirroring operations. For example, one embodiment of a processor comprises: a processor core for generating a read or write transaction having a system memory address; a home agent identified to service the read or write transaction based on the system memory address; one or more target address decoders (TADs) associated with the home agent to determine whether the system memory address is within a mirrored memory region or a non-mirrored memory region, wherein: if the system memory address is within a mirrored memory region, then the one or more TADs identifying multiple mirrored memory channels for the read or write transaction; and if the system memory address is not within a mirrored memory region, then the one or more TADs identifying a single memory channel for the read or write transaction.

Apparatus and method for partial memory mirroring

Methods and apparatus relating to memory mirroring and migration at a Home Agent (HA) are described. In one embodiment, a home agent may mirror its data at a slave agent. In some embodiments, a bit in a directory may indicate status of cache lines. Other embodiments are also disclosed.

Memory mirroring and migration at home agent

In one embodiment, a method includes receiving a read request from a first caching agent and if a directory entry associated with the request is in an unknown state, an invalidating snoop message is sent to at least one other caching agent to invalidate information in a cache location of the other caching agent corresponding to the location of the read request, to enable setting of the directory entry into a known state. Other embodiments are described and claimed.

Controllably exiting an unknown state of a cache coherency directory

Methods and apparatus relating to home agent data and memory management are described. In one embodiment, a scrubber logic corrects an error at a location in a memory corresponding to a target address by writing back the corrected version of data to the target location. In an embodiment, a map out logic maps out an index or way of a directory cache in response to a number of errors, corresponding to the directory cache, exceeding a threshold value. Other embodiments are also disclosed.

Home agent data and memory management

Growing community of inventors

Fort Collins, CO, United States of America

Ganesh Kumar