Abstract: Technologies generally described herein relate to systems and methods effective to control an operating frequency of routers in a multicore processor. Heterogeneous routers in a multicore processor with different maximum operating frequencies may be clustered together to form groups of routers with homogenous assigned operating frequencies. The groups may be used to identify paths to send packets from a first router to a second router along one or more paths.

Abstract: Technologies are generally described for methods and systems effective to implement a memory allocation accelerator. A processor may generate a request for allocation of a requested chunk of memory. The request may be received by a memory allocation accelerator configured to be in communication with the processor. The memory allocation accelerator may process the request to identify an address for a particular chunk of memory corresponding to the request and may return the address to the processor.

Abstract: Technologies are generally described for methods and systems effective to provide accelerator buffer access. An operating system may allocate a range of addresses in virtual address spaces and a range of addresses in a buffer mapped region of a physical (or main) memory. A request to read from, or write to, data by an application may be read from, or written to, the virtual address space. A memory management unit may then map the read or write requests from the virtual address space to the main or physical memory. Multiple applications may be able to operate as if each application has exclusive access to the accelerator and its buffer. Multiple accesses to the buffer by application tasks may avoid a conflict because the memory controller may be configured to fetch data based on respective application identifiers assigned to the applications. Each application may be assigned a different application identifier.

Abstract: Technologies are generally described herein for determining a profitability of direct fetching in a multicore processor. The multicore processor may include a first and a second tile. The first tile may include a first core and a first cache. The second tile may include a second core, a second cache, and a fetch location pointer register (FLPR). The multicore processor may migrate a thread executing on the first core to the second core. The multicore processor may store a location of the first cache in the FLPR. The multicore processor may execute the thread on the second core. The multicore processor may identify a cache miss for a block in the second cache. The multicore processor may determine whether a profitability of direct fetching of the block indicates direct fetching or directory-based fetching. The multicore processor may perform direct fetching or directory-based fetching based on the determination.

Abstract: Technologies are generally described for methods, systems, and devices effective to implement one-cacheable multi-core architectures. In one example, a multi-core processor that includes a first and second tile may be configured to implement a one-cacheable architecture. The second tile may be configured to generate a request for a data block. The first tile may be configured to receive the request for the data block, and determine that the requested data block is part of a group of data blocks identified as one-cacheable. The first tile may further determine that the requested data block is stored in a first cache in the first tile. The first tile may send the data block from the first cache in the first tile to the second tile, and invalidate the data blocks of the group of data blocks in the first cache in the first tile.

Abstract: Technologies are described herein generally relate to aggregation of cache eviction notifications to a directory. Some example technologies may be utilized to update an aggregation table to reflect evictions of a plurality of blocks from a plurality of block addresses of at least one cache memory. An aggregate message can be generated, where the message specifies the evictions of the plurality of blocks as reflected in the aggregation table. The aggregate message can be sent to the directory. The directory can parse the aggregate message and update a plurality of directory entries to reflect the evictions from the cache memory as specified in the aggregate message.

Abstract: Technologies generally described herein relate to cache directories in multi-core processors. Various examples may include, methods, systems, and devices. A first tile may receive a request to transfer a thread from the first tile to a second tile. An instruction may be sent from the first tile to map a virtual cache identifier to identifiers of caches of the first and second tiles. The thread may be transferred from the first tile to the second tile. Thereafter, a request may be generated for a data block. After a determination that the data block is not stored in the second tile's cache, and that the virtual cache identifier is mapped to the first and second cache identifiers, a request may be sent for the data block to the first tile.

Abstract: Technologies are described herein for improving performance and energy efficiency in a computing system while using a large memory page size. Some example technologies may configure a main memory of the computing system to include a page-to-chunk table and a data area. The page-to-chunk table may include multiple entries such as a first entry. The first entry may correspond to a page that is made up of multiple chunks. The first entry may include pointers to the multiple chunks stored in the data area.

Abstract: Technologies generally described herein relate to waved time multiplexing. In some examples, a command flit can be transmitted from a sender node of a network-on-chip (“NOC”) to a destination node of the NOC via an intermediate node along a circuit-switched path. The command flit can include an interval period and a release duration. When the command flit has been transmitted, one or more data flits can be transmitted from the sender node to the destination node via the intermediate node along the circuit-switched path. The sender node, the destination node, and the intermediate node can be configured to reserve router resources of the sender node, the destination node, and the intermediate node respectively for circuit-switched traffic during a use duration of the interval period and to release the router resources for packet-switched traffic during the release duration in a waved time multiplex arrangement.

Abstract: Technologies are generally described for a cache coherence directory in multi-processor architectures. In an example, a directory in a die may receive a request for a particular block. The directory may determine a block aging threshold relating to a likelihood that data blocks, including the particular data block, are stored in one or more caches in the die. The directory may further analyze a memory to identify a particular cache indicated as storing the particular data block and identify a number of cache misses for the particular cache. The directory may identify a time when an event occurred for the particular data block and determine whether to send the request for the particular data block to the particular cache based on the aging threshold, the time of the event, and the number of cache misses.

Abstract: Briefly stated, technologies are generally described for accessing a data block in a cache with a domain based cache coherence protocol. A first processor in a first tile and first domain can be configured to evaluate a request to access the data block. A cache in a second tile in the first domain can be configured to send the data block to the first tile when the data block is cached in the second tile. The first processor can be configured to send the request to a third tile in another domain when the cached location is outside the first processor's domain. The third processor can be configured to determine and send the request to a data domain associated with the cached location of the data block. A fourth tile can be configured to receive the request and send the data block to the first tile.

Abstract: Technologies are generally described for a method, device and architecture effective to allocate resources. In an example, the method may include associating first and second resources with first and second resource identifiers and mapping the first and resource identifiers to first and second sets of addresses in a memory, respectively. The method may include identifying that the first resource is at least partially unavailable. The method may include mapping the second resource identifier to at least one address of the first set of addresses in the memory when the first resource is identified as at least partially unavailable. The method may include receiving a request for the first resource, wherein the request identifies a particular address of the addresses in the first set of addresses. The method may include analyzing the particular address to identify a particular resource and allocating the request to the particular resource.

Abstract: Technologies are generally described that relate to processing cache coherence information and processing a request for a data block. In some examples, methods for processing cache coherence information are described that may include storing in a directory a tag identifier effective to identify a data block. The methods may further include storing a state identifier in association with the tag identifier. The state identifier may be effective to identify a coherence state of the data block. The methods may further include storing sharer information in association with the tag identifier. The sharer information may be effective to indicate one or more caches storing the data block. The methods may include storing, by the controller in the directory, replication information in association with the sharer information. The replication information may be effective to indicate a type of replication of the sharer information in the directory, and effective to indicate replicated segments.

Abstract: Technologies are described herein for conserving energy in a multicore chip via selectively refreshing memory directory entries. Some described examples may refresh a dynamic random access memory (DRAM) that stores a cache coherence directory of a multicore chip. More particularly, a directory entry may be accessed in the cache coherence directory stored in the DRAM. Some further examples may identify a cache coherence state of a block associated with the directory entry. In some examples, refresh of the directory entry stored in the DRAM may be selectively disabled based on the identified cache coherence state of the block such that energy associated with the multicore chip is conserved.

Abstract: Technologies for low power execution of one or more threads of a multithreaded program by one or more processing elements are generally disclosed.

Abstract: Technologies are described herein for providing a hardware-based accelerator adapted to manage copy-on-write. Some example technologies may identify a read request adapted to read a block at an original memory address. The technologies may utilize the hardware-based accelerator to determine whether the block is located at the original memory address. When a determination is made that the block is located in at the original memory address, the technologies may utilize the hardware-based accelerator to pass the original memory address so that the read request can be performed utilizing the original memory address. When a determination is made that the block is not located in the memory at the original memory address, the technologies may utilize the hardware-based accelerator to generate a new memory address and to pass the new memory address so that the read request can be performed utilizing the new memory address.

Abstract: Technologies are generally for maintaining cache coherency within a multi-core processor. A first cache entry to be evicted from a first cache may be identified. The first cache entry may include a block of data and a first tag indicating an owned state. An owner eviction message for the first cache entry may be broadcasted from the first cache. A second cache entry in a second cache may be identified. The second cache entry may include the block of data and a second tag indicating a shared state. The broadcasted owner eviction message may be detected with the second cache. An ownership acceptance message for the second cache entry may be broadcasted from the second cache. The broadcasted ownership acceptance message may be detected with the first cache. The second tag in the second cache entry may be transformed from the shared state to the owned state.

Abstract: Technologies for low power execution of one or more threads of a multithreaded program by one or more processing elements are generally disclosed.

Abstract: Technologies are generally described for a multi-processor core and a method for transferring threads in a multi-processor core. In an example, a multi-core processor may include a first group including a first core and a second core. A first sum of the operating frequencies of the cores in the first group corresponds to a first total operating frequency. The multi-core processor may further include a second group including a third core. A second sum of the operating frequencies of the cores in the second group may correspond to a second total operating frequency that is substantially the same as the first total operating frequency. A hardware controller may be configured in communication with the first, second and third core. A memory may be configured in communication with the hardware controller and may include an indication of at least the first group and the second group.

Abstract: Technologies are described herein for adapting a processor core on a multicore processor to achieve a quality of service target. Some example technologies may identify a target level of a resource on the computer. The technologies may identify a first utilization value and a second utilization value of the resource when the processor core operates at a first frequency and a second frequency. The technologies may generate a linear interpolation between a first point and a second point. Coordinates of the first point may include the first frequency and the first utilization value. Coordinates of the second point may include the second frequency and the second utilization value. The technologies may set the processor core to operate at a third frequency, which can be specified as one of the coordinates in an intersection point between the linear interpolation and the target level.