Advanced Micro Devices Corporation

Ati Technologies Ulc

Elizabeth Morrow Cooper

Eric Christopher Morton

Vydhyanathan Kalyanasundharam

Amit P Apte

Ganesh Balakrishnan

Kevin Michael Lepak

Eric M Rentschler

Ravindra Nath Bhargava

Philip Ng

Mark Douglas Hummel

Benjamin Charles Serebrin

Paul J Moyer

William Louie Walker

Patrick N Conway

Richard Martin Born

Douglas Benson Hunt

Steven Kommrusch

Paul C Miranda

Stephen C Ennis

Chen-Ping Yang

Ryan D Bedwell

John F Wiederhirn

Richard H Lee

Systems, apparatuses, and methods for maintaining a region-based cache directory are disclosed. A system includes multiple processing nodes, with each processing node including a cache subsystem. The system also includes a cache directory to help manage cache coherency among the different cache subsystems of the system. In order to reduce the number of entries in the cache directory, the cache directory tracks coherency on a region basis rather than on a cache line basis, wherein a region includes multiple cache lines. Accordingly, the system includes a region-based cache directory to track regions which have at least one cache line cached in any cache subsystem in the system. The cache directory includes a reference count in each entry to track the aggregate number of cache lines that are cached per region. If a reference count of a given entry goes to zero, the cache directory reclaims the given entry.

Region based directory scheme to adapt to large cache sizes

Systems, apparatuses, and methods for implementing a cancel and replay mechanism for ordered requests are disclosed. A system includes at least an ordering master, a memory controller, a coherent slave coupled to the memory controller, and an interconnect fabric coupled to the ordering master and the coherent slave. The ordering master generates a write request which is forwarded to the coherent slave on the path to memory. The coherent slave sends invalidating probes to all processing nodes and then sends an indication that the write request is globally visible to the ordering master when all cached copies of the data targeted by the write request have been invalidated. In response to receiving the globally visible indication, the ordering master starts a timer. If the timer expires before all older requests have become globally visible, then the write request is cancelled and replayed to ensure forward progress in the fabric and avoid a potential deadlock scenario.

Cancel and replay protocol scheme to improve ordered bandwidth

A device and method for providing performance information about a processing device. A stream of performance data is generated by one or more devices whose performance is reflected in the performance data. This performance data stream is then provided to a parallel port for outputting thereof.

Method and apparatus for providing performance data over a debug bus

A method for steering data for an I/O write operation includes, in response to receiving the I/O write operation, identifying, at an interconnect fabric, a cache of one of a plurality of compute complexes as a target cache for steering the data based on at least one of: a software-provided steering indicator, a steering configuration implemented at boot initialization, and coherency information for a cacheline associated with the data. The method further includes directing, via the interconnect fabric, the identified target cache to cache the data from the I/O write operation. The data is temporarily buffered at the interconnect fabric, and if the target cache attempts to fetch the data while the data is still buffered at the interconnect fabric, the interconnect fabric provides a copy of the buffered data in response to the fetch operation instead of initiating a memory access operation to obtain the data from memory.

I/O writes with cache steering

A system and method for network traffic management between multiple nodes are described. A computing system includes multiple nodes connected to one another. When a home node determines a number of nodes requesting read access for a given data block assigned to the home node exceeds a threshold and a copy of the given data block is already stored at a first node of the multiple nodes in the system, the home node sends a command to the first node. The command directs the first node to forward a copy of the given data block to the home node. The home node then maintains a copy of the given data block and forwards copies of the given data block to other requesting nodes until the home node detects a write request or a lock release request for the given data block.

Contended lock request elision scheme

A processor includes a set of processing modules, each of the processing modules including a cache and a coherency manager that keeps track of the memory addresses of data stored at the caches of other processing modules. In response to its local cache requesting access to a particular memory address or other triggering event, the coherency manager generates a coherency probe. In the event that the generated coherency probe is targeted to multiple processing modules, the coherency manager includes a set of multicast bits indicating the processing modules whose caches include copies of the data targeted by the multicast probe. A transport switch that connects the processing module to the fabric communicates the coherency probe only to subset of processing modules indicated by the multicast bits.

Coherency probe with link or domain indicator

An apparatus, processor, and method for synchronizing trace data. A processor includes multiple cores, and each core operates at a different local clock frequency. A global clock is distributed to each core, and a timestamp is generated using the global clock and the local clock. The timestamp and a local clock saturation value are included in each trace entry, and the local clock saturation value is equal to the ratio between the local clock and the global clock. The trace entries from separate cores are time-correlated in a post-processing phase based on the timestamp and local clock saturation values.

Correlating traces in a computing system

An embodiment of an electronic system includes a first electronic module, a second electronic module, a first debug circuit integrated with the first electronic module, a second debug circuit integrated with the second electronic module, and a communications interface between the first debug circuit and the second debug circuit. The first debug circuit is configured to determine that a triggering event has occurred, and to produce a first cross trigger signal on the communications interface in response to determining that the triggering event has occurred. The second debug circuit is configured to detect the first cross trigger signal on the communications interface, and to perform an action in response to detecting the first cross trigger signal.

Debug state machine cross triggering

In an embodiment, a system comprises a memory system and a guest interrupt manager. The guest interrupt manager is configured to receive an interrupt message corresponding to an interrupt that is targeted at a guest executable on the system. The guest interrupt manager is configured to record the interrupt in a data structure in the memory system to ensure that the interrupt is delivered to the guest even if the guest is not active in the system at a time that the interrupt message is received.

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Los Gatos, CA, United States of America

Elizabeth Morrow Cooper