Patent application number | Description | Published |
20080320226 | Apparatus and Method for Improved Data Persistence within a Multi-node System - Improved access to retained data useful to a system is accomplished by managing data flow through cache associated with the processor(s) of a multi-node system. A data management facility operable with the processors and memory array directs the flow of data from the processors to the memory array by determining the path along which data evicted from a level of cache close to one of the processors is to return to a main memory and directing evicted data to be stored, if possible, in a horizontally associated cache. | 12-25-2008 |
20090006693 | Apparatus and Method for Fairness Arbitration for a Shared Pipeline in a Large SMP Computer System - A modification of rank priority arbitration for access to computer system resources through a shared pipeline that provides more equitable arbitration by allowing a higher ranked request access to the shared resource ahead of a lower ranked requester only one time. If multiple requests are active at the same time, the rank priority will first select the highest priority active request and grant it access to the resource. It will also set a ‘blocking latch’ to prevent that higher priority request from re-gaining access to the resource until the rest of the outstanding lower priority active requesters have had a chance to access the resource. | 01-01-2009 |
20090193194 | Method for Expediting Return of Line Exclusivity to a Given Processor in a Symmetric Multiprocessing Data Processing System - A method and apparatus for eliminating, in a multi-nodes data handling system, contention for exclusivity of lines in cache memory through improved management of system buses, processor cross-invalidate stacks, and the system operations that can lead to these requested cache operations being rejected. | 07-30-2009 |
20090204767 | METHOD, SYSTEM AND COMPUTER PROGRAM PRODUCT FOR GENERALIZED LRU IN CACHE AND MEMORY PERFORMANCE ANALYSIS AND MODELING - The exemplary embodiment of the present invention relates to a generalized LRU algorithm is provided that is associated with a specified cache associativity line set value that is determined by a system user. As configured, the LRU algorithm as presented can comprise n-levels for an LRU tree, each specified tree being individually analyzed within the LRU algorithm. Within each LRU tree level comprises the associativity line value can be further broken down into sub-analysis groups of any desired configuration, however, the total sub-analysis group configuration must equal the specified cache associativity line value. | 08-13-2009 |
20090216933 | METHOD, SYSTEM, AND COMPUTER PROGRAM PRODUCT FOR PIPELINE ARBITRATION - A method for pipeline arbitration including receiving a first request for a shared chip interface from a first pipeline, determining whether a response bus of the shared chip interface is needed by the first request, and if it is determined that the response bus is not needed by the first request, concluding that the first request needs just an address bus of the shared chip interface, arbitrating the first request with a second request for the shared chip interface received from a second pipeline for access to the address bus, sending the first request to the address bus if the first request wins the arbitration over the second request, and rejecting the first request if the second request wins the arbitration over the first request. A corresponding system and computer program product. | 08-27-2009 |
20110314227 | Horizontal Cache Persistence In A Multi-Compute Node, Symmetric Multiprocessing Computer - Horizontal cache persistence in a multi-compute node, SMP computer, including, responsive to a determination to evict a cache line on a first one of the compute nodes, broadcasting by a first compute node an eviction notice for the cache line; transmitting the state of the cache line receiving compute nodes, including, if the cache line is missing from a compute node, an indication whether that compute node has cache storage space available for the cache line; determining by the first compute node, according to the states of the cache line and space available, whether the first compute node can evict the cache line without writing the cache line to main memory; and updating by each compute node the state of the cache line in each compute node, in dependence upon one or more of the states of the cache line in all the compute nodes. | 12-22-2011 |
20110320657 | CONTROLLING DATA STREAM INTERRUPTIONS ON A SHARED INTERFACE - A mechanism for controlling data stream interruptions on a shared bus is provided. A first request is received to transfer data. High priority data components and low priority data components are determined for the first request. The high priority data components are transferred without interruptions. In response to receiving requests when transferring the high priority data components, the received requests are rejected. | 12-29-2011 |
20110320730 | NON-BLOCKING DATA MOVE DESIGN - A mechanism for data buffering is provided. A portion of a cache is allocated as buffer regions, and another portion of the cache is designated as random access memory (RAM). One of the buffer regions is assigned to a processor. A data block is stored to the one of the buffer regions of the cache according an instruction of the processor. The data block is stored from the one of the buffer regions of the cache to the memory. | 12-29-2011 |
20120210070 | NON-BLOCKING DATA MOVE DESIGN - A mechanism for data buffering is provided. A portion of a cache is allocated as buffer regions, and another portion of the cache is designated as random access memory (RAM). One of the buffer regions is assigned to a processor. A data block is stored to the one of the buffer regions of the cache according an instruction of the processor. The data block is stored from the one of the buffer regions of the cache to the memory. | 08-16-2012 |
20130339608 | MULTILEVEL CACHE HIERARCHY FOR FINDING A CACHE LINE ON A REMOTE NODE - Embodiments relate to accessing a cache line on a multi-level cache system having a system memory. Based on a request for exclusive ownership of a specific cache line at the local node, requests are concurrently sent to the system memory and remote nodes of the plurality of nodes for the specific cache line by the local node. The specific cache line is found in a specific remote node. The specific remote node is one of the remote nodes. The specific cache line is removed from the specific remote node for exclusive ownership by another node. Based on the specified node having the specified cache line in ghost state, any subsequent fetch request is initiated for the specific cache line from the specific node encounters the ghost state. When the ghost state is encountered, the subsequent fetch request is directed only to nodes of the plurality of nodes. | 12-19-2013 |
20130339609 | MULTILEVEL CACHE HIERARCHY FOR FINDING A CACHE LINE ON A REMOTE NODE - Embodiments relate to accessing a cache line on a multi-level cache system having a system memory. Based on a request for exclusive ownership of a specific cache line at the local node, requests are concurrently sent to the system memory and remote nodes of the plurality of nodes for the specific cache line by the local node. The specific cache line is found in a specific remote node. The specific remote node is one of the remote nodes. The specific cache line is removed from the specific remote node for exclusive ownership by another node. Based on the specified node having the specified cache line in ghost state, any subsequent fetch request is initiated for the specific cache line from the specific node encounters the ghost state. When the ghost state is encountered, the subsequent fetch request is directed only to nodes of the plurality of nodes. | 12-19-2013 |
20140258621 | NON-DATA INCLUSIVE COHERENT (NIC) DIRECTORY FOR CACHE - Embodiments relate to a non-data inclusive coherent (NIC) directory for a symmetric multiprocessor (SMP) of a computer. An aspect includes determining a first eviction entry of a highest-level cache in a multilevel caching structure of the first processor node of the SMP. Another aspect includes determining that the NIC directory is not full. Another aspect includes determining that the first eviction entry of the highest-level cache is owned by a lower-level cache in the multilevel caching structure. Another aspect includes, based on the NIC directory not being full and based on the first eviction entry of the highest-level cache being owned by the lower-level cache, installing an address of the first eviction entry of the highest-level cache in a first new entry in the NIC directory. Another aspect includes invalidating the first eviction entry in the highest-level cache. | 09-11-2014 |
20150058569 | NON-DATA INCLUSIVE COHERENT (NIC) DIRECTORY FOR CACHE - Embodiments relate to a non-data inclusive coherent (NIC) directory for a symmetric multiprocessor (SMP) of a computer. An aspect includes determining a first eviction entry of a highest-level cache in a multilevel caching structure of the first processor node of the SMP. Another aspect includes determining that the NIC directory is not full. Another aspect includes determining that the first eviction entry of the highest-level cache is owned by a lower-level cache in the multilevel caching structure. Another aspect includes, based on the NIC directory not being full and based on the first eviction entry of the highest-level cache being owned by the lower-level cache, installing an address of the first eviction entry of the highest-level cache in a first new entry in the NIC directory. Another aspect includes invalidating the first eviction entry in the highest-level cache. | 02-26-2015 |