153 results about "Cache consistency" patented technology

The invention discloses a multi-core processor supporting cache consistency, a data reading method and apparatus based on the multi-core processor, a data writing method and apparatus based on the multi-core processor, a memory allocation method and apparatus based on the multi-core processor, and a device. The multi-core processor supporting cache consistency comprises a plurality of processor cores and local caches corresponding to the processor cores respectively, wherein the local caches of different processor cores are used for caching data in memory spaces of different address ranges respectively; and each processor core accesses the data in the local caches of other processor cores through an interconnection bus. According to the technical scheme provided by the invention, a new thought of removing a cache directory and shared caches from a conventional multi-core processor framework is provided, so that the cache consistency is realized, private caches are shared, and the overall performance of the processor is improved while the conflicts between the private caches and the shared caches are eliminated.

An apparatus and method for expediting the processing of requests in a multiprocessor shared memory system. In a multiprocessor shared memory system, requests can be processed in any order provided two rules are followed. First, no request that grants access rights to a processor can be processed before an older request that revokes access rights from the processor. Second, all requests that reference the same cache line are processed in the order in which they arrive. In this manner, requests can be processed out-of-order to allow cache-to-cache transfers to be accelerated. In particular, foreign requests that require a processor to provide data can be processed by that processor before older local requests that are awaiting data. In addition, newer local requests can be processed before older local requests. As a result, the apparatus and method described herein may advantageously increase performance in multiprocessor shared memory systems by reducing latencies associated with a cache consistency protocol.

The invention provides a multiprocessor system which accords with an AXI protocol. The system comprises at least two processor cores including a first-level cache, and at least two second-level caches, the processor cores are connected with the second-level caches by a bus; the bus comprises a read address channel, a read data channel, a write address channel, a write data channel and a write response channel; the lines in the channels are divided into regions according to the transmitted contents, and the channels comprise the regions which are defined according to the AXI protocol; wherein, the write address channel further comprises an AWDID region for identifying a target ID of the write address request, and an AWSTATE region for transmitting state information of a cache block in the first-level cache in write operation; the write data channel further comprises a WDID region for identifying the target ID of the write data request; the read address channel further comprises an ARDID region for identifying the target ID of the write address request and an ARCMD region for representing a read command; and the read data channel further comprises an RSTATE region for representing a read data response.

The invention provides a routing forwarding method of a content-based data center network, wherein the method comprises the following steps of: initializing a switchboard; and forwarding a message. On the basis of the content-based data center network, the switchboard selects a cached host with relatively short distance preferentially to carry out routing forwarding without the participation of an integrated controller through content and position mixed type routing forwarding strategy. A routing strategy utilizes the characteristics of a data center topological structure, so that the switchboard can judge the length of a route just through the direction of a port. The cache consistency is finished through simple content version number matching query during the routing forwarding of the switchboard. The load balancing is finished during the content-based forwarding of the switchboard. The content-based hash operation is carried out on an upward port during the position-based forwarding of the switchboard, so that redundant storage content forwarding tables are reduced.

The invention relates to a method for establishing an access by fusing multiple levels of cache directories, and a graded fused hierarchical cache directory mechanism is established. The method comprising the steps that multiple CPU and GPU processors form a Quart computing element, a Cuckoo directory is established in a graded way in caches built in the CPU or GPU processors, an area directory and an area directory controller are established outside the Quart computing element, thus the bus communication bandwidth is effectively reduced, the arbitration conflict frequency is lowered, a data block directory of a three-level fusion Cache can be cached, and thus the access hit rate of the three-level fusion Cache is improved. Therefore a graded fused hierarchical Cache directory mechanism inside and outside the Quart is constructed, the Cache failure rate is lowered, the on-chip bus bandwidth is reduced, the power consumption of the system is lowered, the new status of the Cache block does not need to be added, the very good compatibility with the Cache consistency protocol is realized, and a new train of thought is provided for constructing a heterogeneous monolithic multi-core processor system with extensibility and high performance.

The invention discloses a layering system for achieving the caching consistency protocol and a method of the layering system. According to the scheme, the bus monitoring protocol is adopted in the first layer of the layering system to enable the first layer of the layering system to adapt to a sharing bus framework of the first layer of the layering system, the caching consistency protocol based on a catalog is adopted in the second layer of the layering system to enable the second layer of the layering system to adapt to an internet framework on an NoC of the second layer of the layering system, the two frameworks transmit consistency maintenance signals sent by the two protocols through a node controller of each node, the two protocols can be mutually communicated, and then the mixed consistency protocol can maintain the caching consistency of the whole system. The method has the advantages of being high in performance, good in real-time performance, high in expandability and low in design complexity, solving the bus bandwidth problem of the sharing bus framework, solving the problem that the catalog in the consistency protocol based on the catalog is excessively large in occupied storage space, and enabling the consistency protocol to better adapt to lager-scale multi-core processors.

The invention provides a correctness verifying method of a cache consistency protocol. After a computer enters an operating system, the complexity of a core and the application of the operating system is higher; the action of a processor is not easy to control accurately; therefore, in order to keep verification correctness, a verifying program for the cache consistency protocol is necessary to embed in a systematic procedure; the program is embedded in a BIOS (basic input/output system) code; after the initialization of a memory subsystem is completed at the initialization initial stage of the system, the verifying program is started to be executed; the verifying program needs to be capable of accurately controlling actions of each processor of the system, supports a user to select a verification item to be particularly executed, and feeds back a verification result to the user; by using the method, the verification of the correctness of the cache consistency protocol is realized at a system level; all application scenes of a real system can be completely covered; the disadvantages that a conventional verifying method based on an analog way is low in efficiency and poor in verification coverage rate are made up; the design period and the verifying period of an inter-domain cache consistency chip of the processor can be shortened; the one-time taping-out mission success rate of the chip can be guaranteed effectively; and therefore, the correctness verifying method has an extremely wide development prospect and an extremely high technical value.

The invention belongs to the technical field of processors and particularly relates to a cache consistency protocol-free distributed sharing on-chip storage framework. According to the framework, a cache is only mapped to a local primary memory space based on a cluster structure, and a processor finishes reading and writing of other shared primary memory blocks in a cluster by accessing to caches of other cores, so that overlapped primary memory address spaces are no longer mapped among the caches of different cores, and the cache consistency problem of a multi-core processor is solved; and an L1 storage device of a local core is divided into two parts, i.e., a non cache storage device and the cache, so that the cache miss rate is reduced and corresponding complicated logic circuits and power consumption are avoided. Moreover, a direct memory access (DMA) operation is supported, i.e., DMA is supported in a stream application to directly perform inter-cluster large data transit on a primary memory, so that the framework is suitable for large-scale expansion.

Storage arrays, systems and methods for operating storage arrays for maintaining consistency in configuration data between processes running on an active controller and a standby controller of the storage array are provided. One example method includes executing a primary process in user space of the active controller. The primary process is configured to process request commands from one or more initiators, and the primary process has access to a volume manager for serving data input/output (I/O) requests and non-I/O requests. The primary process has primary access to the configuration data and includes a first logical unit (LU) cache for storing the configuration data. The method also includes executing a secondary process in user space of the standby controller. The secondary process is configured to process request commands from one or more of the initiators, wherein the secondary process does not have access to the volume manger. The secondary process has a second LU cache for storing the configuration data, and the second LU cache is used by the secondary process for responding to non-I/O requests. The method includes receiving, at the primary process, an update to the configuration data and sending, by the primary process, the update to the configuration data to the secondary process for updating the second LU cache. When the primary process receives an acknowledgement from the secondary process that the update to the configuration data was received, then the updates to the configuration data are committed to the first LU cache of the active controller.

A method is described of managing memory in a microprocessor system comprising two or more processors (40, 42). Each processor (40, 42) has a cache memory (44, 46) and the system has a system memory (48) divided into pages subdivided into blocks. The method is concerned with managing the system memory (48) identifying areas thereof as being "cacheable", "non-cacheable" or "free". Safeguards are provided to ensure that blocks of system memory (48) cannot be cached by two different processors (40, 42) simultaneously.

The present invention provides a cache consistency test method. The method comprises the steps of: a master process applying for a shared space; the master process creating a plurality of sub processes; dividing four shared space parts in the shared space; the master process arranging numbers of memory blocks accessed by a read operation and a write operation, so as to allow memory addresses accessed by the read operation and write operation not to overlap, and allow the plurality of sub processes to enter synchronous interfaces; after the plurality of sub processes are synchronized successfully, reading an arranged sequence, so as to allow the master process and the plurality of sub processes to perform read and write operations simultaneously; and after the master process and the plurality of sub processes finish read and write operations, each process using an exclusive OR operation to calculate the weight of a read space and a write space accessed by the process, and comparing the weight of the memory accessed by the read operation with the weight of the memory accessed by the write operation.

The invention discloses a data verification method, a data verification device and a data verification system. The data verification method comprises the following steps of: according to a current state space corresponding to n processors in a circuit and a target state space, carrying out searching in a pre-acquired excitation database to obtain at least one target excitation, wherein each target excitation is an excitation required by jumping between the current state space and the target state space; executing each target excitation, indicating a first processor to execute a command in the target excitation, and after the first processor finishes executing the command in the target excitation, judging whether the state space formed by working states of the n processors and the target state space belong to the same type of state space; and if a judgment result is Yes, continuously executing the next target excitation and obtaining a verification result that data stored in the N processor is same until all the target excitations are executed, so that the efficiency of verifying the Cache consistency of each CPU (Central Processing Unit) in the circuit is effectively improved.

The invention provides a replacement method for a Cache row in a last level cache (LLC). If a target Cache address is lost in the LLC, the replacement priority of a Cache row which is recently called in is calculated according to the operation type, the original Cache row with the highest replacement priority is replaced according to the replacement priority orderly principle, and the Cache row which is recently called in is stored to the corresponding position of the target Cache; if the target Cache address is in the LLC, the replacement priority of the current access Cache row is updated according to the Cache consistency state and operation type, and the priority of the current access Cache row is upgraded or degraded according to the replacement priority orderly principle. Performance losses caused by inclusive victims led into the inclusive Cache in a replacement mode can be effectively reduced.

The invention relates to a block equipment write IO shaping and multi-controller synchronization system and method, and belongs to the technical field of mass data storage. According to the system and method, virtual block equipment driving, binding with bottom block equipment, write IO request shaping and synchronization among multi-controller clusters are realized at a controller. The system comprises a block equipment filter drive, an IP shaping module, a read gap module, a cache pool, a forwarding module and an IP downward brushing module. Rear-end physical block equipment is share type equipment and comprises FC equal-mapping shared disks or disks connected through SAS or other manners. Compared with the prior art, the system and method have the advantages that multi-controller data synchronization is solved without occupying double space; the write IO performance optimization and cache consistency problems in multi-controller cluster storage are solved, the bandwidth performance of block equipment is brought into full play, the time waste of repeated track seeking is avoided, and the write jitter and response delay of the bottom disk are reduced; and write cache is returned, so that the write jitter of the disk and the response delay problem of IO are solved.

The invention provides a multistage cache consistency pipeline processing method and device. The method comprises the steps that message information of currently-scheduled messages to be processed is obtained, wherein the message information comprises address information; whether the messages to be processed are effective messages is judged according to the message information, and if the messages to be processed are judged to be the effective messages, according to the address information in the message information, whether the effective messages which are unprocessed and have the same addresses as the messages to be processed exist is judged; if it is judged that the effective messages which are unprocessed and have the same addresses as the messages to be processed exist, the messages to be processed are blocked; if it is judged that the effective messages which are unprocessed and have the same addresses as the messages to be processed do not exist, cache consistency processing is carried out on the messages to be processed; by blocking the messages, to be processed, of the same addresses, when the cache consistency processing is carried out, resources are saved; moreover, timing sequence is good, and therefore the performance of a system is promoted.

The invention discloses a Cache consistency protocol verification method and system for an on-chip multi-core processor, and a medium. The method comprises the steps of loading and executing a test program for the on-chip multi-core processor executing a Cache protocol to be verified, tracking a Cache related message of an on-chip network, and recording the life cycle of a Cache transaction through a recording board file; checking whether the running result of the test program has an error or not, if so, judging that the Cache protocol verification does not pass the test, and exiting; otherwise, checking an error scene in the execution process of the record board file positioning test program, and if the error scene is found or the record board file still has an unfinished Cache transaction, judging that the Cache protocol verification does not pass the test; otherwise, judging that the Cache protocol verification passes the test. According to the invention, an error scene can be accurately positioned in a verification process, and design vulnerabilities and errors are easy to discover.

Various methods and systems for optimizing cache consistency are disclosed. For example, one method involves writing data to a file during a write transaction. The file is stored in a persistent storage device and cached in a non-volatile storage device. The method determines if an in-memory flag associated with the persistent storage device set. If the in-memory flag is not set, the method increases a generation count associated with the persistent storage device before a write transaction is performed on the file. The method then sets the in-memory flag before performing the write transaction on the file. In other examples, the method involves using a persistent flag associated with the non-volatile storage device to maintain cache consistency during a data freeze related to the taking of a snapshot by synchronizing generation counts associated with the persistent storage device and the non-volatile storage device.

Systems, apparatuses, and methods for performing efficient data transfer in a computing system are disclosed. A computing system includes multiple fabric interfaces in clients and a fabric. A packet transmitter in the fabric interface includes multiple queues, each for storing packets of a respective type, and a corresponding address history cache for each queue. Queue arbiters in the packet transmitter select candidate packets for issue and determine when address history caches on both sides of the link store the upper portion of the address. The packet transmitter sends a source identifier and a pointer for the request in the packet on the link, rather than the entire request address, which reduces the size of the packet. The queue arbiters support out-of-order issue from the queues. The queue arbiters detect conflicts with out-of-order issue and adjust the outbound packets and fields stored in the queue entries to avoid data corruption.