International Business Machines Corporation

Michael Andrew Blake

Pak-kin Mak

Timothy Carl Bronson

Ekaterina M Ambroladze

Vesselina K Papazova

Hieu Trong Huynh

Robert J Sonnelitter, Iii

Garrett M Drapala

Kenneth Douglas Klapproth

Michael F Fee

Craig Raymond Walters

Arthur J O'Neill

Guy G Tracy

Adrian Eric Seigler

Tim Bronson

Gary A Van Huben

Arthur J O'Neill, Jr

Gary E Strait

Deanna P D Berger

Chad G Wilson

Ashraf ElSharif

Arun Kwangil Iyengar

Jason D Kohl

Gary A VanHuben

Patrick James Meaney

Christine Comins Jones

Deanna P Berger

Lawrence D Curley

Rebecca S Wisniewski

Carl B Ford, Iii

Craig R Waters

Timothy John Slegel

Christian Jacobi

Mark S Farrell

Matthias Klein

Gregory William Alexander

Markus Kaltenbach

Aaron Tsai

Deanna Postles Dunn Berger

Tu-An T Nguyen

Rebecca Marie Gott

Harmony Lynn Helterhoff

Richard Joseph Branciforte

Steven Mark German

Taylor J Pritchard

Kevin Lopes

James F Driftmyer

Edward J Kaminski

Derrin M Berger

Poornima P Sulibele

Timothy W Steele

Arthur o'Neill

Gary Alan Vanhuben

Pak-Kin Mak

Castout handling in a distributed cache topology, including: detecting, by a first cache of a plurality of caches, a cache miss; providing, by the first cache to each other cache of the plurality of caches, a message comprising: data indicating a cache address corresponding to the cache miss; and data indicating a cache line to be evicted.

Castout handling in a distributed cache topology

A computer system includes a processor core and a memory system in signal communication with the processor core. The memory system includes a first cache and a second cache. The first cache is arranged at a first level of a hierarchy in the memory system and is configured to store a plurality of first-cache entries. The second cache is arranged at a second level of the hierarchy that is lower than the first level, and stores a plurality of second-cache entries. The first cache maintains a directory that contains information for each of the first-cache entries. The second cache maintains a shadow pointer directory (SPD) that includes one or more SPD entries that maps each of the first-cache entries to a corresponding second cache entry at a lower-level cache location.

Shadow pointer directory in an inclusive hierarchical cache

Embodiments are provided for implementing efficient resource allocation maintaining fairness between operation types. Embodiments include receiving an operation, and determining a number of resources that are required for the received operation. Embodiments also include determining a number of available resources, comparing the number of required resources and the number of available resources, and allocating the available resources in a first mode or a second mode based at least in part on the comparison and a number of queued operations.

Efficient remote resource allocation within an SMP broadcast scope maintaining fairness between operation types

Methods, systems and computer program products for evacuating memory from a drawer in a live multi-node system are provided. Aspects include placing a first drawer into an evacuation mode. The evacuation mode includes a cessation of non-evacuation operations and provides for a transfer of data stored by memory of the first drawer to a destination drawer using dynamic memory reallocation (DMR). Aspects also include transmitting a store request by the first drawer to the destination drawer. The store request represents a request to transfer the data stored by the memory of the first drawer to the destination drawer for storage by the destination drawer. Aspects also include transmitting the data stored by the memory of the first drawer to the destination drawer. The data is transmitted by the first drawer using a local pool of fetch/store controllers.

Evacuation of memory from a drawer in a live multi-node system

Embodiments includes a computer-implemented method, a system and computer-program product for modifying central serialization of requests in multiprocessor systems. Some embodiments includes receiving an operation requiring resources from a pool of resources, determining an availability of the pool of resources required by the operation, and selecting a queue of a plurality of queues to queue the operation based at least in part on the availability of the pool of resources. Some embodiments also include setting a resource needs register and needs register for the selected queue, and setting a take-two bit for the selected queue.

Modified central serialization of requests in multiprocessor systems

Embodiments of the present invention are directed to a computer-implemented method for cache eviction. The method includes detecting a first data in a shared cache and a first cache in response to a request by a first processor. The first data is determined to have a mid-level cache eviction priority. A request is detected from a second processor for a same first data as requested by the first processor. However, in this instance, the second processor has indicated that the same first data has a low-level cache eviction priority. The first data is duplicated and loaded to a second cache, however, the data has a low-level cache eviction priority at the second cache.

Multilevel cache eviction management

Processing simultaneous data requests regardless of active request in the same addressable index of a cache. In response to the cache miss in the given congruence, if the number of other compartments in the given congruence class that have an active operation is less than a predetermined threshold, setting a Do Not Cast Out (DNCO) pending indication for each of the compartments that have an active operation in order to block access to each of the other compartments that have active operations and, if the number of other compartments in the given congruence class that have an active operation is not less than a predetermined threshold, blocking another cache miss from occurring in the compartments of the given congruence class by setting a congruence class block pending indication for the given congruence class in order to block access to each of the other compartments of the given congruence class.

Coherent cache with simultaneous data requests in same addressable index

Provided are systems, methods, and media for simultaneous, non-atomic request processing of snooped operations of a broadcast scope within a SMP system. An example method includes detecting, by a first controller, based on a set of coherency resolution conditions, whether there are coherency resolution problems between two snooped operations. The method includes in response to detecting, by the first controller, that coherency resolution problems will not result, transmitting, from the first controller to a second controller, an indication signal indicating that coherency resolution problems will not result from the operation. The set of coherency resolution conditions includes: (a) detecting that a second operation of the two snooped operations operation is of a predetermined type, (b) detecting at time of snooping of the second operation that a directory state does not allow for exclusive data, and (c) detecting that the first controller has started committing to an update.

Simultaneous, non-atomic request processing within an SMP environment broadcast scope for multiply-requested data elements using real-time parallelization

In an approach for purging an address range from a cache, a processor quiesces a computing system. Cache logic issues a command to purge a section of a cache to higher level memory, wherein the command comprises a starting storage address and a range of storage addresses to be purged. Responsive to each cache of the computing system activating the command, cache logic ends the quiesce of the computing system. Subsequent to ending the quiesce of the computing system, Cache logic purges storage addresses from the cache, based on the command, to the higher level memory.

Non-disruptive clearing of varying address ranges from cache

Embodiments of the present invention are directed to managing a shared high-level cache for dual clusters of fully connected integrated circuit multiprocessors. An example of a computer-implemented method includes: providing a drawer comprising a plurality of clusters, each of the plurality of clusters comprising a plurality of processors; providing a shared cache integrated circuit to manage a shared cache memory among the plurality of clusters; receiving, by the shared cache integrated circuit, an operation of one of a plurality of operation types from one of the plurality of processors; and processing, by the shared cache integrated circuit, the operation based at least in part on the operation type of the operation according to a set of rules for processing the operation type.

Dual clusters of fully connected integrated circuit multiprocessors with shared high-level cache

Embodiments of the present invention are directed to hot cache line arbitration. An example of a computer-implemented method for hot cache line arbitration includes receiving a request for exclusive access to a cache line from a requestor of a drawer in a processing system. The method further includes bringing the cache line to a local cache of the drawer. The method further includes invalidating copies of the cache line in the processing system. The method further includes loading a remote fetch address register (RFAR) controller on other drawers in the processing system, wherein the RFAR comprises a local pending flag and a remote pending flag.

Hot cache line fairness arbitration in distributed modular SMP system

Embodiments of the present invention are directed to a computer-implemented method for ownership tracking updates across multiple simultaneous operations. A non-limiting example of the computer-implemented method includes receiving, by a cache directory control circuit, a message to update a cache directory entry. The method further includes, in response, updating, by the cache directory control circuit, the cache directory entry, and generating a reverse compare signal including an updated ownership vector of a memory line corresponding to the cache directory entry. The method further includes sending the reverse compare signal to a cache controller associated with the cache directory entry.

Ownership tracking updates across multiple simultaneous operations

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Wappingers Falls, NY, United States of America

Michael Andrew Blake