摘要:
An access blocking unit (74) blocks an access to a failed segment by using tokens in hardware and a replacing unit (75) performs a process for replacing the failed segment with a replacement segment. For each segment of a shared memory (43), an application recognizing unit (71) recognizes the node numbers of nodes that are given access permission and PIDs of applications and records them in the management table (70). When a failure occurs in the shared memory (43), an access stopping unit (73) identifies applications that use the failed segment including applications of different nodes (1) by using the management table (70) and informs the applications of stop of the use of the failed segment.
摘要:
A method for building a multi-processor system with nodes having multiple cache coherency domains. In this system, a directory built in a node controller needs to include processor domain attribute information, and the information can be acquired by configuring cache coherency domain attributes of ports of the node controller connected to processors. In the disclosure herein, the node controller can support the multiple physical cache coherency domains in a node.
摘要:
A method and apparatus for supporting cache coherency in a multiprocessor computing environment having multiple processing units, each processing unit having a local cache memory associated therewith. A snoop filter device is associated with each processing unit and includes at least one snoop filter primitive implementing filtering method based on usage of stream registers sets and associated stream register comparison logic. From the plurality of stream registers sets, at least one stream register set is active, and at least one stream register set is labeled historic at any point in time. In addition, the snoop filter block is operatively coupled with cache wrap detection logic whereby the content of the active stream register set is switched into a historic stream register set upon the cache wrap condition detection, and the content of at least one active stream register set is reset. Each filter primitive implements stream register comparison logic that determines whether a received snoop request is to be forwarded to the processor or discarded.
摘要:
A method and apparatus for supporting cache coherency in a multiprocessor computing environment having multiple processing units, each processing unit having a local cache memory associated therewith. A snoop filter device is associated with each processing unit and includes at least one snoop filter primitive implementing filtering method based on usage of stream registers sets and associated stream register comparison logic. From the plurality of stream registers sets, at least one stream register set is active, and at least one stream register set is labeled historic at any point in time. In addition, the snoop filter block is operatively coupled with cache wrap detection logic whereby the content of the active stream register set is switched into a historic stream register set upon the cache wrap condition detection, and the content of at least one active stream register set is reset. Each filter primitive implements stream register comparison logic that determines whether a received snoop request is to be forwarded to the processor or discarded.
摘要:
One embodiment of the present invention provides a system that facilitates speculative load operations in a multiprocessor system. This system operates by maintaining a record at an L2 cache of speculative load operations that have returned data values through the L2 cache to associated L1 caches, wherein a speculative load operation is a load operation that is speculatively initiated before a preceding load operation has returned. In response to receiving an invalidation event, the system invalidates a target line in the L2 cache. The system also performs a lookup in the record to identify affected L1 caches that are associated with speculative load operations that may be affected by the invalidation of the target line in the L2 cache. Next, the system sends replay commands to the affected L1 caches in order to replay the affected speculative load operations, so that the affected speculative load operations take place after invalidation of the target line in the L2 cache.
摘要:
A system may include a plurality of nodes. Each node may include one or more active devices coupled to one or more memory subsystems. An active device included in one of the nodes includes a memory management unit configured to receive a virtual address generated within that active device and to responsively output a global address identifying a coherency unit. A portion of the global address identifies a translation function. A memory subsystem included in the node is configured to perform the translation function identified by the portion of the global address on an additional portion of the global address in order to obtain a local physical address of the coherency unit. Each active device included in the node is configured to use the portion of the global address identifying the translation function when determining whether a local copy of the coherency unit is currently stored in a cache associated with that active device.
摘要:
A second level cash device (200) records a part of register information of data for a first level cash device (102) (and other first level cash devices) in a second level cash tag unit (204a) corresponding to register information for a second level cash data unit (204b) while recording the register information of the data for the first level cash device (102) in a first level cash tag copying unit (204c). A coherency maintaining processing unit (203a) uses information recorded in the second level cash tag unit (204a) and the first level cash tag unit (204c) to maintain coherency between the first level cash unit (102) and the second level cash unit (200).
摘要:
A system for tracking cache coherency in multiprocessor environment includes a first cell having a multiprocessor assembly, a memory, and a coherency director including a first intermediate home agent and a first intermediate cache agent. A second cell is similarly equipped. The two cells may share lines of cache in a controlled manner. Interconnection between the two cells connect the intermediate home agent of one cell to the intermediate cache agent of the second cell. Trackers are present in the agents of the first cell and the second cell. The trackers are responsible for keeping track of cache transactions between cells and queuing up requests for lines of cache so that retry attempts may be made. The trackers thus assist in transactions involving sharing lines of cache, exchanging information and resolving conflicts.
摘要:
In a multiprocessor system, a system controller includes snoop tags which are copy information on cache tags retained by respective CPUs. If the same address is registered in S (Shared state) in the cache tag of each of the CPUs connected to the same CPU bus, the address is registered in S (Shared state) in only any one of the snoop tags corresponding to the CPUs in which the same address is registered.