Abstract: A computer implemented method for avoiding false activation of hang avoidance mechanisms of a system is provided. The computer implemented method includes receiving, by a nest of the system, rejects from a processor core of the system. The rejects are issued based on a cache line being locked by the processor core. The computer implemented method includes accumulating the rejects by the nest. The computer implemented method includes determining, by the nest, when an amount of the rejects accumulated by the nest has met or exceeded a programmable threshold. The computer implemented method also includes triggering, by the nest, a global reset to counters of the hang avoidance mechanisms of a system in response to the amount meeting or exceeding the programmable threshold.

Abstract: 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.

Abstract: A computer-implemented method for managing cache memory in a distributed symmetric multiprocessing computer is described. The method may include receiving, at a first central processor (CP) chip, a fetch request from a first chip. The method may further include determining via address compare mechanisms on the first CP chip whether one or more of a second CP chip and a third CP chip is requesting access to a target line. The first chip, the second chip, and the third chip are within the same chip cluster. The method further includes providing access to the target line if both of the second CP chip and the third CP chip have accessed the target line at least one time since the first CP chip has accessed the target line.

Abstract: Embodiments include methods, systems and computer program products method for maintaining ordered memory access with parallel access data streams associated with a distributed shared memory system. The computer-implemented method includes performing, by a first cache, a key check, the key check being associated with a first ordered data store. A first memory node signals that the first memory node is ready to begin pipelining of a second ordered data store into the first memory node to an input/output (I/O) controller. A second cache returns a key response to the first cache indicating that the pipelining of the second ordered data store can proceed. The first memory node sends a ready signal indicating that the first memory node is ready to continue pipelining of the second ordered data store into the first memory node to the I/O controller, wherein the ready signal is triggered by receipt of the key response.

Abstract: A system and method to transfer an ordered partial store of data from a controller to a memory subsystem receives the ordered partial store of data into a buffer of the controller. The method also includes issuing a preinstall command to the memory subsystem, wherein the preinstall command indicates that data from a number of addresses of memory corresponding with a target memory location be obtained in local memory of the memory subsystem along with ownership of the data for subsequent use. A query command is issued to the memory subsystem. The query command requests an indication from the memory subsystem that the memory subsystem is ready to receive and correctly serialize the ordered partial store of data. The ordered partial store of data is transferred from the controller to the memory subsystem.

Abstract: Methods, systems, and computer program products for managing broadcasts in a distributed symmetric multiprocessing computer are provided. Aspects include defining a default broadcast rate for a plurality of processors in the distributed symmetric multiprocessing computer, wherein the default broadcast rate is a rate at which a processor broadcasts a request for a resource. The one or more broadcasted requests by a first processor are monitored and related responses are utilized to determine a state of the one or more broadcasted requests. The default broadcast rate is adjusted based at least in part on the state of the one or more broadcasted requests.

Abstract: 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.

Abstract: 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.

Abstract: An aspect includes interlocking operations in an address-sliced cache system. A computer-implemented method includes determining whether a dynamic memory relocation operation is in process in the address-sliced cache system. Based on determining that the dynamic memory relocation operation is in process, a key operation is serialized to maintain a sequenced order of completion of the key operation across a plurality of slices and pipes in the address-sliced cache system. Based on determining that the dynamic memory relocation operation is not in process, a plurality of key operation requests is allowed to launch across two or more of the slices and pipes in parallel in the address-sliced cache system while ensuring that only one instance of the key operations is in process across all of the slices and pipes at a same time.

Abstract: A computer implemented method for avoiding false activation of hang avoidance mechanisms of a system is provided. The computer implemented method includes receiving, by a nest of the system, rejects from a processor core of the system. The rejects are issued based on a cache line being locked by the processor core. The computer implemented method includes accumulating the rejects by the nest. The computer implemented method includes determining, by the nest, when an amount of the rejects accumulated by the nest has met or exceeded a programmable threshold. The computer implemented method also includes triggering, by the nest, a global reset to counters of the hang avoidance mechanisms of a system in response to the amount meeting or exceeding the programmable threshold.

Abstract: 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.

Abstract: 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.

Abstract: A computer-implemented method for managing cache memory in a distributed symmetric multiprocessing computer is described. The method may include receiving, at a first central processor (CP) chip, a fetch request from a first chip. The method may further include determining via address compare mechanisms on the first CP chip whether one or more of a second CP chip and a third CP chip is requesting access to a target line. The first chip, the second chip, and the third chip are within the same chip cluster. The method further includes providing access to the target line if both of the second CP chip and the third CP chip have accessed the target line at least one time since the first CP chip has accessed the target line.

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

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

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.

Abstract: A computer system comprising multiple nodes, each node comprising a plurality of processors and a local cache hierarchy, suppresses local cache coherency of a node operations or global cache coherency operations between nodes based on the coherency request being a global or local request, and the state of the cache line at the node.

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.

Abstract: Maintaining store order with high throughput in a distributed shared memory system. A request is received for a first ordered data store and a coherency check is initiated. A signal is sent that pipelining of a second ordered data store can be initiated. If a delay condition is encountered during the coherency check for the first ordered data store, rejection of the first ordered data store is signaled. If a delay condition is not encountered during the coherency check for the first ordered data store, a signal is sent indicating a readiness to continue pipelining of the second ordered data store.

Abstract: Various embodiments mitigate busy time in a hierarchical store-through memory cache structure including a cache directory associated with a memory cache. The cache directory is divided into a plurality of portions each associated with a portion of memory cache. A determination is made that a first subpipe of a shared cache pipeline comprises a non-store request. The shared pipeline is communicatively coupled to the plurality of portions of the cache directory. A store command is prevented from being placed in a second subpipe of the shared cache pipeline based on determining that a first subpipe of the shared cache pipeline comprises a non-store request. Simultaneous cache lookup operations are supported between the plurality of portions of the cache directory and cache write operations. Two or more store commands simultaneously processed in a shared cache pipeline communicatively coupled to the plurality of portions of the cache directory.