Abstract: Performance counters may be operable to collect one or more counts of one or more selected activities, and registers may be operable to store a set of performance counter configurations. A state machine may be operable to automatically select a register from the registers for reconfiguring the one or more performance counters in response to receiving a first signal. The state machine may be further operable to reconfigure the one or more performance counters based on a configuration specified in the selected register. The state machine yet further may be operable to copy data in selected one or more of the performance counters to a memory location, or to copy data from the memory location to the counters, in response to receiving a second signal. The state machine may be operable to store or restore the counter values and state machine configuration in response to a context switch event.

Abstract: In an embodiment, a send thread receives an identifier that identifies a destination node and a pointer to data. The send thread creates a first send request in response to the receipt of the identifier and the data pointer. The send thread selects a selected channel from among a plurality of channels. The selected channel comprises a selected hand-off queue and an identification of a selected message unit. Each of the channels identifies a different message unit. The selected hand-off queue is randomly accessible. If the selected hand-off queue contains an available entry, the send thread adds the first send request to the selected hand-off queue. If the selected hand-off queue does not contain an available entry, the send thread removes a second send request from the selected hand-off queue and sends the second send request to the selected message unit.

Abstract: Hardware support for software controlled reconfiguration of performance counters may include a plurality of performance counters collecting one or more counts of one or more selected activities. A storage element stores data value representing a time interval, and a timer element reads the data value and detects expiration of the time interval based on the data value and generates a signal. A plurality of configuration registers stores a set of performance counter configurations. A state machine receives the signal and selects a configuration register from the plurality of configuration registers for reconfiguring the one or more performance counters.

Abstract: A method and system for scheduling threads on simultaneous multithreaded processors are disclosed. Hardware and operating system communicate with one another providing information relating to thread attributes for threads executing on processing elements. The operating system determines thread scheduling based on the information.

Abstract: Memory page management in a tiered memory system including a system that includes at least one page table for storing a plurality of entries, each entry associated with a page of memory and each entry including an address of the page and a memory tier of the page. The system also includes a control program configured for allocating pages associated with the entries to a software module, the allocated pages from at least two different memory tiers. The system further includes an agent of the control program capable of operating independently of the control program, the agent configured for receiving an authorization key to the allocated pages, and for migrating the allocated pages between the different memory tiers responsive to the authorization key.

Abstract: Hardware support for software controlled reconfiguration of performance counters may include a plurality of performance counters collecting one or more counts of one or more selected activities. A storage element stores data value representing a time interval, and a timer element reads the data value and detects expiration of the time interval based on the data value and generates a signal. A plurality of configuration registers stores a set of performance counter configurations. A state machine receives the signal and selects a configuration register from the plurality of configuration registers for reconfiguring the one or more performance counters.

Abstract: Performance counters may be operable to collect one or more counts of one or more selected activities, and registers may be operable to store a set of performance counter configurations. A state machine may be operable to automatically select a register from the registers for reconfiguring the one or more performance counters in response to receiving a first signal. The state machine may be further operable to reconfigure the one or more performance counters based on a configuration specified in the selected register. The state machine yet further may be operable to copy data in selected one or more of the performance counters to a memory location, or to copy data from the memory location to the counters, in response to receiving a second signal. The state machine may be operable to store or restore the counter values and state machine configuration in response to a context switch event.

Abstract: A hierarchical barrier synchronization of cores and nodes on a multiprocessor system, in one aspect, may include providing by each of a plurality of threads on a chip, input bit signal to a respective bit in a register, in response to reaching a barrier; determining whether all of the plurality of threads reached the barrier by electrically tying bits of the register together and “AND”ing the input bit signals; determining whether only on-chip synchronization is needed or whether inter-node synchronization is needed; in response to determining that all of the plurality of threads on the chip reached the barrier, notifying the plurality of threads on the chip, if it is determined that only on-chip synchronization is needed; and after all of the plurality of threads on the chip reached the barrier, communicating the synchronization signal to outside of the chip, if it is determined that inter-node synchronization is needed.

Abstract: Mechanism of efficient intra-die collective processing across the nodelets with separate shared memory coherency domains is provided. An integrated circuit die may include a hardware collective unit implemented on the integrated circuit die. A plurality of cores on the integrated circuit die is grouped into a plurality of shared memory coherence domains. Each of the plurality of shared memory coherence domains is connected to the collective unit for performing collective operations between the plurality of shared memory coherence domains.

Abstract: Performance counters may be operable to collect one or more counts of one or more selected activities, and registers may be operable to store a set of performance counter configurations. A state machine may be operable to automatically select a register from the registers for reconfiguring the one or more performance counters in response to receiving a first signal. The state machine may be further operable to reconfigure the one or more performance counters based on a configuration specified in the selected register. The state machine yet further may be operable to copy data in selected one or more of the performance counters to a memory location, or to copy data from the memory location to the counters, in response to receiving a second signal. The state machine may be operable to store or restore the counter values and state machine configuration in response to a context switch event.

Abstract: Hardware support for software controlled reconfiguration of performance counters may include a plurality of performance counters collecting one or more counts of one or more selected activities. A storage element stores data value representing a time interval, and a timer element reads the data value and detects expiration of the time interval based on the data value and generates a signal. A plurality of configuration registers stores a set of performance counter configurations. A state machine receives the signal and selects a configuration register from the plurality of configuration registers for reconfiguring the one or more performance counters.

Abstract: Hardware support for collecting performance counters directly to memory, in one aspect, may include a plurality of performance counters operable to collect one or more counts of one or more selected activities. A first storage element may be operable to store an address of a memory location. A second storage element may be operable to store a value indicating whether the hardware should begin copying. A state machine may be operable to detect the value in the second storage element and trigger hardware copying of data in selected one or more of the plurality of performance counters to the memory location whose address is stored in the first storage element.

Abstract: A device for copying performance counter data includes hardware path that connects a direct memory access (DMA) unit to a plurality of hardware performance counters and a memory device. Software prepares an injection packet for the DMA unit to perform copying, while the software can perform other tasks. In one aspect, the software that prepares the injection packet runs on a processing core other than the core that gathers the hardware performance counter data.

Abstract: A method for checking program correctness may include executing a program on a main hardware thread in speculative execution mode on a hardware execution context on a chip having a plurality of hardware execution contexts. In this mode, the main hardware thread's state is not committed to main memory. Correctness checks by a plurality of helper threads are executed in parallel to the main hardware thread. Each helper thread runs on a separate hardware execution context on the chip in parallel with the main hardware thread. The correctness checks determine a safe point in the program up to which the operations executed by said main hardware thread are correct. Once the main hardware thread reaches the safe point, the mode of execution of the main hardware thread is switched to non-speculative. The runtime then causes the main thread to re-enter speculative mode of execution.

Abstract: A device for copying performance counter data includes hardware path that connects a direct memory access (DMA) unit to a plurality of hardware performance counters and a memory device. Software prepares an injection packet for the DMA unit to perform copying, while the software can perform other tasks. In one aspect, the software that prepares the injection packet runs on a processing core other than the core that gathers the hardware performance counter data.

Abstract: Performing a series of successive synchronizing operations by a core on data shared by a plurality of cores may include a first core indicating an upcoming synchronizing operation on shared data. A second memory layer stores the shared data and tracks the first core's ownership of the shared data. The second memory layer is shared via coherency operations among the first core and one or more second cores. The first core may perform one or more synchronization operations on the shared data without requiring interaction from the second memory layer.

Abstract: A hierarchical barrier synchronization of cores and nodes on a multiprocessor system, in one aspect, may include providing by each of a plurality of threads on a chip, input bit signal to a respective bit in a register, in response to reaching a barrier; determining whether all of the plurality of threads reached the barrier by electrically tying bits of the register together and “AND”ing the input bit signals; determining whether only on-chip synchronization is needed or whether inter-node synchronization is needed; in response to determining that all of the plurality of threads on the chip reached the barrier, notifying the plurality of threads on the chip, if it is determined that only on-chip synchronization is needed; and after all of the plurality of threads on the chip reached the barrier, communicating the synchronization signal to outside of the chip, if it is determined that inter-node synchronization is needed.

Abstract: Mechanism of efficient intra-die collective processing across the nodelets with separate shared memory coherency domains is provided. An integrated circuit die may include a hardware collective unit implemented on the integrated circuit die. A plurality of cores on the integrated circuit die is grouped into a plurality of shared memory coherence domains. Each of the plurality of shared memory coherence domains is connected to the collective unit for performing collective operations between the plurality of shared memory coherence domains.

Abstract: A method, system, and computer usable program product for local synchronization in a memory hierarchy in a multi-core data processing system are provided in the illustrative embodiments. A request to acquire a reservation for a reservation granule is received at a first core. The reservation is acquired in a first local cache associated with the first core in response to a cache line including the reservation granule being present and writable in the first local cache. A conditional store request to store at the reservation granule is received at the first core. A determination is made whether the reservation remains held at the first local cache. The store operation is performed at the first local cache responsive to reservation remaining held at the first local cache.

Abstract: A method for reconfiguring a cache memory is provided. The method in one aspect may include analyzing one or more characteristics of an execution entity accessing a cache memory and reconfiguring the cache based on the one or more characteristics analyzed. Examples of analyzed characteristic may include but are not limited to data structure used by the execution entity, expected reference pattern of the execution entity, type of an execution entity, heat and power consumption of an execution entity, etc. Examples of cache attributes that may be reconfigured may include but are not limited to associativity of the cache memory, amount of the cache memory available to store data, coherence granularity of the cache memory, line size of the cache memory, etc.