Abstract: In one set of embodiments, a hardware module of a computer system can receive a stream of addresses corresponding to memory units being accessed by a central processing unit (CPU) of the computer system. The hardware module can further generate a frequency estimate for each address in the stream of addresses, the frequency estimate being indicative of a number of times a memory unit identified by the address has been accessed by the CPU, and can determine, based on the generated frequency estimates, a set of n most frequently accessed memory units.

Abstract: The state of cache lines transferred into an out of caches of processing hardware is tracked by monitoring hardware. The method of tracking includes monitoring the processing hardware for cache coherence events on a coherence interconnect between the processing hardware and monitoring hardware, determining that the state of a cache line has changed, and updating a hierarchical data structure to indicate the change in the state of said cache line. The hierarchical data structure includes a first level data structure including first bits, and a second level data structure including second bits, each of the first bits associated with a group of second bits. The step of updating includes setting one of the first bits and one of the second bits in the group corresponding to the first bit that is being set, according to an address of said cache line.

Abstract: In one set of embodiments, a hardware module of a computer system can receive a stream of addresses corresponding to memory units being accessed by a central processing unit (CPU) of the computer system. The hardware module can further generate a frequency estimate for each address in the stream of addresses, the frequency estimate being indicative of a number of times a memory unit identified by the address has been accessed by the CPU, and can determine, based on the generated frequency estimates, a set of n most frequently accessed memory units.

Abstract: In a computer system, a processor and an I/O device controller communicate with each other via a coherence interconnect and according to a cache coherence protocol. Registers of the I/O device controllers are mapped to the cache coherent memory space to allow the processor to treat the registers as cacheable memory. As a result, latency of processor commands executed by the I/O device controller is decreased, and size of data stored in the I/O device controller that can be accessed by the processor is increased from the size of a single register to the size of an entire cache line.

Abstract: In a multi-node system, each node includes tiles. Each tile includes a cache controller, a local cache, and a snoop filter cache (SFC). The cache controller responsive to a memory access request by the tile checks the local cache to determine whether the data associated with the request has been cached by the local cache of the tile. The cached data from the local cache is returned responsive to a cache-hit. The SFC is checked to determine whether any other tile of a remote node has cached the data associated with the memory access request. If it is determined that the data has been cached by another tile of a remote node and if there is a cache-miss by the local cache, then the memory access request is transmitted to the global coherency unit (GCU) and the snoop filter to fetch the cached data. Otherwise an interconnected memory is accessed.

Abstract: In a computer system, a processor and an I/O device controller communicate with each other via a coherence interconnect and according to a cache coherence protocol. Registers of the I/O device controllers are mapped to the cache coherent memory space to allow the processor to treat the registers as cacheable memory. As a result, latency of processor commands executed by the I/O device controller is decreased, and size of data stored in the I/O device controller that can be accessed by the processor is increased from the size of a single register to the size of an entire cache line.

Abstract: Memory pages of a local application program are prefetched from a memory of a remote host. A method of prefetching the memory pages from the remote memory includes detecting that a cache-line access made by a processor executing the local application program is an access to a cache line containing page table data of the local application program, identifying data pages that are referenced by the page table data, and fetching the identified data pages from the remote memory and storing the fetched data pages in a local memory.

Abstract: A method of prefetching memory pages from remote memory includes detecting that a cache-line access made by a processor executing an application program is an access to a cache line containing page table data of the application program, identifying data pages that are referenced by the page table data, initiating a fetch of a data page, which is one of the identified data pages, and starting a timer. If the fetch completes prior to expiration of the timer, the data page is stored in a local memory. On the other hand, if the fetch does not complete prior to expiration of timer, a presence bit of the data page in the page table data is set to indicate that the data page is not present.

Abstract: Memory pages of a local application program are prefetched from a memory of a remote host. A method of prefetching the memory pages from the remote memory includes detecting that a cache-line access made by a processor executing the local application program is an access to a cache line containing page table data of the local application program, identifying data pages that are referenced by the page table data, and fetching the identified data pages from the remote memory and storing the fetched data pages in a local memory.

Abstract: The state of cache lines transferred into an out of caches of processing hardware is tracked by monitoring hardware. The method of tracking includes monitoring the processing hardware for cache coherence events on a coherence interconnect between the processing hardware and monitoring hardware, determining that the state of a cache line has changed, and updating a hierarchical data structure to indicate the change in the state of said cache line. The hierarchical data structure includes a first level data structure including first bits, and a second level data structure including second bits, each of the first bits associated with a group of second bits. The step of updating includes setting one of the first bits and one of the second bits in the group corresponding to the first bit that is being set, according to an address of said cache line.

Abstract: A method of prefetching memory pages from remote memory includes detecting that a cache-line access made by a processor executing an application program is an access to a cache line containing page table data of the application program, identifying data pages that are referenced by the page table data, initiating a fetch of a data page, which is one of the identified data pages, and starting a timer. If the fetch completes prior to expiration of the timer, the data page is stored in a local memory. On the other hand, if the fetch does not complete prior to expiration of timer, a presence bit of the data page in the page table data is set to indicate that the data page is not present.

Abstract: In a multi-node system, each node includes tiles. Each tile includes a cache controller, a local cache, and a snoop filter cache (SFC). The cache controller responsive to a memory access request by the tile checks the local cache to determine whether the data associated with the request has been cached by the local cache of the tile. The cached data from the local cache is returned responsive to a cache-hit. The SFC is checked to determine whether any other tile of a remote node has cached the data associated with the memory access request. If it is determined that the data has been cached by another tile of a remote node and if there is a cache-miss by the local cache, then the memory access request is transmitted to the global coherency unit (GCU) and the snoop filter to fetch the cached data. Otherwise an interconnected memory is accessed.

Abstract: Managing instructions on a processor includes: identifying selected instructions as being associated with operations from a stored library of operations. The identifying includes, for instructions included in a particular thread executing on the processor, identifying first/second subsets of the instructions as being associated with a lock/unlock operation based on predetermined characteristics of the instructions. Managing lock/unlock operations associated with the selected instructions that are issued on a first processor core includes, for each instruction included in a first thread and identified as being associated with a lock operation corresponding to a particular lock, in response to determining that the particular lock has already been acquired, continuing to attempt to acquire the particular lock for multiple attempts using a lock operation different from the lock operation in the stored library.

Abstract: Managing lock and unlock operations for a first thread executing on a first processor core includes, for each instruction included in the first thread and identified as being associated with: (1) a lock operation corresponding to a particular lock, in response to determining that the particular lock has already been acquired, continuing to perform the lock operation for multiple attempts during which the first processor core is not able to execute threads other than the first thread, or (2) an unlock operation corresponding to a particular lock, releasing the particular lock from the first thread. Prioritization of selected messages sent over interconnection circuitry configured to connect each processor core to a memory system of the processor is preserved. The selected messages associated with instructions identified as being associated with an unlock operation are prioritized over messages associated with instructions identified as being associated with a lock operation.

Abstract: Managing lock and unlock operations for a first thread executing on a first processor core includes, for each instruction included in the first thread and identified as being associated with: (1) a lock operation corresponding to a particular lock stored in a particular memory location, in response to determining that the particular lock has already been acquired, continuing to perform the lock operation for multiple attempts using associated operation messages for accessing the particular memory location, or (2) an unlock operation corresponding to a particular lock stored in a particular memory location, releasing the particular lock from the first thread using an associated operation message for accessing the particular memory location. Selected operation messages associated with an unlock operation are prioritized over operation messages associated with a lock operation.

Abstract: Managing instructions on a processor includes: executing threads having access to a stored library of operations. For a first thread executing on the first processor core, for each instruction included in the first thread and identified as being associated with a lock operation corresponding to a particular lock, the managing includes determining if the particular lock has already been acquired for another thread executing on a processor core other than the first processor core, and if so, continuing to perform the lock operation for multiple attempts using a hardware lock operation different from the lock operation in the stored library, and if not, acquiring the particular lock for the first thread. The hardware lock operation performs a modified atomic operation that changes a result of the hardware lock operation for failed attempts to acquire the particular lock relative to a result of the lock operation in the stored library.

Abstract: Managing instructions on a processor includes: executing threads having access to a stored library of operations. For a first thread executing on the first processor core, for each instruction included in the first thread and identified as being associated with a lock operation corresponding to a particular lock, the managing includes determining if the particular lock has already been acquired for another thread executing on a processor core other than the first processor core, and if so, continuing to perform the lock operation for multiple attempts using a hardware lock operation different from the lock operation in the stored library, and if not, acquiring the particular lock for the first thread. The hardware lock operation performs a modified atomic operation that changes a result of the hardware lock operation for failed attempts to acquire the particular lock relative to a result of the lock operation in the stored library.

Abstract: Managing lock and unlock operations for a first thread executing on a first processor core includes, for each instruction included in the first thread and identified as being associated with: (1) a lock operation corresponding to a particular lock stored in a particular memory location, in response to determining that the particular lock has already been acquired, continuing to perform the lock operation for multiple attempts using associated operation messages for accessing the particular memory location, or (2) an unlock operation corresponding to a particular lock stored in a particular memory location, releasing the particular lock from the first thread using an associated operation message for accessing the particular memory location. Selected operation messages associated with an unlock operation are prioritized over operation messages associated with a lock operation.

Abstract: Managing instructions on a processor includes: identifying selected instructions as being associated with operations from a stored library of operations. The identifying includes, for instructions included in a particular thread executing on the processor, identifying first/second subsets of the instructions as being associated with a lock/unlock operation based on predetermined characteristics of the instructions. Managing lock/unlock operations associated with the selected instructions that are issued on a first processor core includes, for each instruction included in a first thread and identified as being associated with a lock operation corresponding to a particular lock, in response to determining that the particular lock has already been acquired, continuing to attempt to acquire the particular lock for multiple attempts using a lock operation different from the lock operation in the stored library.

Abstract: Managing lock and unlock operations for a first thread executing on a first processor core includes, for each instruction included in the first thread and identified as being associated with: (1) a lock operation corresponding to a particular lock, in response to determining that the particular lock has already been acquired, continuing to perform the lock operation for multiple attempts during which the first processor core is not able to execute threads other than the first thread, or (2) an unlock operation corresponding to a particular lock, releasing the particular lock from the first thread. Prioritization of selected messages sent over interconnection circuitry configured to connect each processor core to a memory system of the processor is preserved. The selected messages associated with instructions identified as being associated with an unlock operation are prioritized over messages associated with instructions identified as being associated with a lock operation.