摘要:
A cache controller stores pre-set variables for pre-fetch block size and stride value. A cache controller receives an access request for the main memory from the processor, and generates a pre-fetch request based an the access request and the variables. The cache controller reads data from main memory based on the generated pre-fetch request and writes this data to the cache memory.
摘要:
An information processing system that transfers transactions between a plurality of system modules. A request side interface unit in a request side module has a request ID queue in which issued request transactions are stored in order of issuance. A request side queue pointer points to an entry in this request ID queue corresponding to a response transaction to be accepted next. A response side interface unit in a response side module has a response queue in which accepted request transactions are stored in order of acceptance. A response side queue pointer points to an entry in this response queue corresponding to a response transaction to be issued next. Therefore, a request transaction and the corresponding response transaction are transferred between the request side interface unit and the response side interface unit without transferring transaction IDs. When the response order is changed, the response side interface unit issues a command, which changes the value of the request side queue pointer, to inform the request side interface unit of the change in the order.
摘要:
Multiprocessor system, having a translation lookaside buffer (TLB) in each processor, and having a structure for avoiding TLB purge overhead. Each processor node is provided with a partial main memory and a physical page map table (PPT). The PPT stores mapping between physical page number of main memory and virtual page number. Every memory access transaction for other node specifies physical address and virtual page number. Instead of strictly maintaining TLB coherency by broadcasting TLB purge transaction, an access destination node checks the coincidence between the virtual page number specified in the memory access transaction and the virtual page number mapped in the PPT when the transaction is received. If both are coincident, the memory access is executed. If not coincident, an error message is transferred to an access requesting source.
摘要:
Each node includes a node controller for decoding the control information and the address information for the access request issued by a processor or an I/O device, generating, based on the result of decoding, the cache coherence control information indicating whether the cache coherence control is required or not, the node information and the unit information for the transfer destination, and adding these information to the access request. An intra-node connection circuit for connecting the units in the node controller holds the cache coherence control information, the node information and the unit information added to the access request. When the cache coherence control information indicates that the cache coherence control is not required and the node information indicates the local node, then the intra-node connection circuit transfers the access request not to the inter-node connection circuit inter-connecting the node but directly to the unit designated by the unit information.
摘要:
In a multiprocessor arranged in accordance with either NUMA or UMA in which a plurality of processor nodes containing a plurality of processor units are coupled to each other via a network, a cache snoop operation executed in connection with a memory access operation is performed at two stages, namely, local snoop operation executed within a node, and global snoop operation among nodes. Before executing the local snoop operation, an ACTV command for specifying only an RAS of a memory is issued to a target node having a memory to be accessed, and the memory access is activated in advance. A CAS of a memory is additionally specified and a memory access is newly executed after the ACTV command has been issued and then a memory access command has been issued. When there is such a possibility that a memory to be accessed is cached in a processor node except for a source node, this memory access command is issued to be distributed to all nodes so as to execute the global snoop operation. On the other hand, when there is no possibility that the memory to be accessed is cached, this memory access command is transferred only to the target node in yan one-to-one correspondence.
摘要:
A parallel processor system controls access to a distributed shared memory and to plural cache memories to prevent frequently-used local data from being flushed out of a cache memory. The parallel processor system includes a plurality of nodes each including a processor and a shared memory in a distributed shared memory arrangement, and a local-remote divided cache memory system, wherein local data and remote data are controlled separately. Each local-remote divided cache memory system includes a local data area, a remote data area, and a cache memory controller by which either the local data area or the remote data area is accessed according to the contents of an access request.
摘要:
An instruction processor is employed which performs a cache coherence control according to a request from the storage controller. The storage controller is provided with a cache coherence control processing circuit, which performs the cache coherence control for the addresses which are the destinations of main memory accesses occurring with a data transfer. At the same time, the cache coherence control processing circuit performs the cache coherence control processing once for each cache line in the process of data transfer. The cache coherence control processing performed by software in connection with data transfer is obviated, improving the data transfer efficiency including the cache memory control and reducing limitations on program.
摘要:
A cache system comprising a cache tag buffer 270 for storing a part of a cache tag memory 260. When a memory processing request is issued from a processor 10, a cache control means 280 retrieves both of the cache tag memory 260 and the cache tag buffer 270. If a target cache block is present in the cache tag buffer 270, then, without waiting for a retrieval result of the cache tag memory 260, the cache control circuit 280 accesses the cache data memory 250 using information of the cache block.
摘要:
In a multiprocessor system of a main memory shared type having a plurality of nodes connected each other through signal lines; each of the plurality of nodes includes CPUs having caches therein, a main memory, and a node controller for performing communication control between the CPUs, main memory and ones of the nodes other than its own node. The node controller has a communication controller for controlling communication interface between the plurality of nodes, a crossbar for determining a processing sequence of memory access issued from at least one of the plurality of nodes to be directed to the main memories of the plurality of nodes, and crossbar controller for making valid or invalid the crossbar.
摘要:
Each node includes a node controller for decoding the control information and the address information for the access request issued by a processor or an I/O device, generating, based on the result of decoding, the cache coherence control information indicating whether the cache coherence control is required or not, the node information and the unit information for the transfer destination, and adding these information to the access request. An intra-node connection circuit for connecting the units in the node controller holds the cache coherence control information, the node information and the unit information added to the access request. When the cache coherence control information indicates that the cache coherence control is not required and the node information indicates the local node, then the intra-node connection circuit transfers the access request not to the inter-node connection circuit interconnecting the nodes but directly to the unit designated by the unit information.