Fujitsu Corporation

Naohiro Kiyota

Toshio Yoshida

Tsuyoshi Motokurumada

Masaki Ukai

Iwao Yamazaki

Shuji Yamamura

Ryuji Kan

Masaharu Maruyama

Mikio Hondo

Hayato Koike

Hiroyuki Imai

An arithmetic processing device having an allocation unit configured to reserve a memory allocation area in a memory and register address range information indicating an address range of the memory allocation area in an address range table, in response to an execution of a memory area allocation function requesting memory area allocation, and a determination unit configured to refer to the address range table and perform determination processing as to whether or not an access destination address of a memory access instruction is within an address range indicated by the address range information registered in the address range table, in response to an execution of the memory access instruction relating to the memory allocation area.

Arithmetic processing device, information processing device, control method for information processing device, and control program for information processing device

A processor includes: a primary cache memory; an instruction control unit that issues a store request to the primary cache memory; a pipeline processing unit that, upon receiving the store request, writes data to the primary cache memory; a buffer unit that obtains an address output to the primary cache memory from the pipeline processing unit during an output period of the store request regarding certain data to hold the obtained address in an entry, and when the output period ends, issues a write-back request for writing the data indicated by the address held in the entry to a memory; and a secondary cache memory that, upon receiving the write-back request from the buffer unit, writes the data of the primary cache memory to the memory, the certain data is quickly written back to the memory from the primary cache memory.

Processor, information processing apparatus, and control method of processor

An arithmetic processing apparatus includes a plurality of processors, each of the processors having an arithmetic unit and a cache memory. The processor includes an instruction port that holds a plurality of instructions accessing data of the cache memory, a first determination unit that validates a first flag when receiving an invalidation request for data in the cache memory, a cache index of a target address and a way ID of the received request match with a cache index of a designated address and a way ID of the load instruction, a second determination unit that validates a second flag when target data is transmitted due to a cache miss, and an instruction re-execution determination unit that instructs re-execution of an instruction subsequent to the load instruction when both the first flag and the second flag are validated at the time of completion of an instruction in the instruction port.

Arithmetic processing apparatus, and cache memory control device and cache memory control method

A cache memory apparatus is configured to include a data holding unit comprising a plurality of ways that has a plurality of cache lines; an alternation data register to hold data in one line of the cache lines or in a part of the cache lines; an alternation address register to hold an index address that indicates a faulty cache line and a part in which the fault has occurred in the faulty cache line; an alternation way register to hold information of a way including the part having a fault; an address match circuit comparing, when an access is performed to the data holding unit, an index address and the index address held by the alternation address register; and a way match circuit comparing, when an access is performed to the data holding unit, way information used for the access and way information held by the alternation way register.

Cache memory apparatus, execution processing apparatus and control method thereof

According to an aspect of the embodiment, an FP includes a plurality of entries which holds requests to be processed, and each of the plurality of entries includes a requested flag indicating that data transfer is once requested. An FP-TOQ holds information indicating an entry holding the oldest request. A data transfer request prevention determination circuit checks the requested flag of a request to be processed and the FP-TOQ, and when a transfer request of data as a target of the request to be processed has already been issued and the entry holding the request to be processed is not the entry indicated by the FP-TOQ, transmits a signal which prevents the transfer request of the data to a data transfer request control circuit. Even when a cache miss occurs in a primary cache RAM, the data transfer request control circuit does not issue a data transfer request when the signal which prevents the transfer request is received.

Cache memory control apparatus and cache memory control method

An information processor includes processing units each processes an out-of-order memory access and includes a cache memory, an instruction port that holds instructions for accessing data in the cache memory, a first determinator that validates a first flag when a request for invalidating cache data is received after a target data of a load instruction is transferred from the cache memory and a load instruction having a cache index identical to that of a target address of the received invalidating instruction exists, a second determinator that validates a second flag when the target data of the load instruction in the instruction port is transferred after a cache miss of the target data occurred, and a re-execution determinator that instructs to re-execute an instruction that follows the load instruction if the first and the second flags are valid when a load instruction in the instruction port has been completed.

Information processing device and cache memory control device

In such a configuration that a port unit is provided which takes a form being shared among threads and has a plurality of entries for holding access requests, and the access requests for a cache shared by a plurality of threads being executed at the same time are controlled using the port unit, the access request issued from each tread is registered on a port section of the port unit which is assigned to the tread, thereby controlling the port unit to be divided for use in accordance with the thread configuration. In selecting the access request, the access requests are selected for each thread based on the specified priority control from among the access requests issued from the threads held in the port unit, thereafter a final access request is selected in accordance with a thread selection signal from among those selected access requests. In accordance with such a configuration, the cache access processing can be carried out while reducing the amount of resources of the port unit and assuring effective use of such resources.

Cache controller and control method for controlling access requests to a cache shared by plural threads that are simultaneously executed

In order to control an access request to the cache shared between a plurality of threads, a storage unit for storing a flag provided in association with each of the threads is included. If the threads enter the execution of an atomic instruction, a defined value is written to the flags stored in the storage unit. Furthermore, if the atomic instruction is completed, a defined value different from the above defined value is written, thereby displaying whether or not the threads are executing the atomic instruction. If an access request is issued from a certain thread, it is judged whether or not a thread different from the certain thread is executing the atomic instruction by referencing the flag values in the storage unit. If it is judged that another thread is executing the atomic instruction, the access request is kept standby. This makes it possible to realize the exclusive control processing necessary for processing the atomic instruction according to simple configuration.

Cache control device and control method

According to an aspect of the embodiment, when data on a cache RAM is rewritten in a storage processing of one thread, an determination unit searches a fetch port which holds a request of another thread, checks whether a request exists whose processing is completed, whose instruction is a load type instruction, and whose target address corresponds to a target address in a storage processing. When the corresponding request is detected, the determination unit sets a re-execution request flag to all the entries of the fetch port from the next entry of the entry which holds the oldest request to the entry which holds the detected request. When the processing of the oldest request is executed, a re-execution request unit transfers a re-execution request of an instruction to an instruction control unit for the request held in the entry in which the re-execution request flag is set.

Information processing apparatus, cache memory controlling apparatus, and memory access order assuring method

A multiprocessor system includes processors each having a primary cache and a secondary cache shared by the processors. The processors each include a read unit that reads data from the primary cache, a request unit that makes a write request when the data to be read is not stored in the primary cache, a measuring unit that measures an elapsed time since the write request is made, a receiving unit that receives a read command from an external device, a comparing unit that compares specific information for specifying data, for which the read command has been received, with specific information for specifying data, for which the write request has been made, and a controller that suspends reading of the data according to the read command, when pieces of specific information are the same, and the elapsed time measured is less than a predetermined time.

Multiprocessor system, processor, and cache control method

A multithread control apparatus and control method to switch a plurality of threads in a multithread processor, which includes a plurality of thread processors to execute the plurality of threads, by executing a synchronization lock control by considering release of exclusive access right to a relevant thread processor when a particular block in caches is updated with another processor or another thread processor during execution of a certain thread processor.

Multithread controller and control method

The present invention relates to a multithread processor. In the multithread processor, when a cache miss occurs on a request related to an instruction in, of a plurality of caches arranged hierarchically, a cache at the lowest place in the hierarchy, with respect to the request suffering the cache miss, a cache control unit notifies an instruction identifier and a thread identifier, which are related to the instruction, to a multithread control unit. When a cache miss occurs on an instruction to be next completed, the multithread control unit makes the switching between threads on the basis of the instruction identifier and thread identifier notified from the cache control unit. This enables effective thread switching, thus enhancing the processing speed.

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Kawasaki, Japan

Naohiro Kiyota