Abstract: A wake-and-go mechanism is provided for a microprocessor. The wake-and-go mechanism looks ahead in the instruction stream of a thread for programming idioms that indicates that the thread is waiting for an event. If a look-ahead polling operation succeeds, the look-ahead wake-and-go engine may record an instruction address for the corresponding idiom so that the wake-and-go mechanism may have the thread perform speculative execution at a time when the thread is waiting for an event. During execution, when the wake-and-go mechanism recognizes a programming idiom, the wake-and-go mechanism may store the thread state in the thread state storage. Instead of putting thread to sleep, the wake-and-go mechanism may perform speculative execution.

Abstract: A wake-and-go mechanism is provided with a central repository wake-and-go array for a multiple processor data processing system. The wake-and-go mechanism recognizes a programming idiom that indicates that a thread running on a processor within the multiple processor data processing system is waiting for an event. The wake-and-go mechanism updates a central repository wake-and-go array with a target address associated with the event. Each entry in the central repository wake-and-go array may include a thread identification (ID), a central processing unit (CPU) ID, the target address, the expected data, a comparison type, a lock bit, a priority, and a thread state pointer, which is the address at which the thread state information is stored.

Abstract: A hardware wake-and-go mechanism is provided for a data processing system. The wake-and-go mechanism looks ahead in a thread for programming idioms that indicates that the thread is waiting for an event. The wake-and-go mechanism performs a look-ahead polling operation for each of the programming idioms. If each of the look-ahead polling operations fails, then the wake-and-go mechanism updates a wake-and-go array with a target address associated with the event for each recognized programming idiom.

Abstract: A wake-and-go mechanism may be a programming idiom accelerator. As a processor fetches instructions, the programming idiom accelerator may look ahead to determine whether a programming idiom is coming up in the instruction stream. If the programming idiom accelerator recognizes a programming idiom, the programming idiom accelerator may perform an action to accelerate execution of the programming idiom. In the case of a wake-and-go programming idiom, the programming idiom accelerator may record an entry in a wake-and-go array, for example.

Abstract: A hardware private array is a thread state storage that is embedded within the processor or within logic associated with a bus or wake-and-go logic. The hardware private array and/or wake-and-go array may have a limited storage area. Therefore, each thread may have an associated priority. If there is insufficient space in the hardware private array, then the wake-and-go mechanism may compare the priority of the thread to the priorities of the threads already stored in the hardware private array and wake-and-go array. If the thread has a higher priority than at least one thread already stored in the hardware private array and wake-and-go array, then the wake-and-go mechanism may remove a lowest priority thread, meaning the thread is removed from hardware private array and wake-and-go array and converted to a flee model.

Abstract: A wake-and-go mechanism may be a programming idiom accelerator. As a processor fetches instructions, the programming idiom accelerator may look ahead to determine whether a programming idiom is coming up in the instruction stream. If the programming idiom accelerator recognizes a programming idiom, the programming idiom accelerator may perform an action to accelerate execution of the programming idiom. A compiler may recognize programming idioms and expose the programming idioms to the programming idiom accelerator within the resulting machine language instructions.

Abstract: A mechanism is provided in a logically partitioned data processing system for controlling depth and latency of exit of a virtual processor's idle state. A virtualization layer generates a cede latency setting information (CLSI) data. Responsive to booting a logical partition, the virtualization layer communicates the CLSI data to an operating system (OS) of the logical partition. The OS determines, based on the CLSI data, a particular idle state of a virtual processor under a control of the OS. Responsive to the OS calling the virtualization layer, the OS communicates the particular idle state of the virtual processor to the virtualization layer for assigning the particular idle state and wake-up characteristics to the virtual processor.

Abstract: A method, system and computer-usable medium are disclosed for managing power consumption in information processing systems. Processing resources are successively folded, allowing them to be placed into deeper and deeper power saving states while maintaining the ability to respond to new processing loads without exposing the latency of the deeper power saving states as they are unfolded. Before a deeper power saving state can be used, there must be sufficient processing resources in the prior power saving state to mask the latency of bringing a processing resource out of the deeper power saving state.

Abstract: A method, system, and computer usable program product for scaling energy use in a virtualized data processing environment are provided in the illustrative embodiments. A set of PIOAs is configured such that each PIOAs in the set of PIOAs is a functional equivalent of another PIOAs in the set of PIOAs. A utilization of each PIOA in the set of PIOAs is measured. A number of PIOAs needed to service a workload is determined. A first subset of PIOAs from the set of PIOAs is powered down if the number of PIOAs needed to service the workload is smaller than a number of operational PIOAs. The I/O operations associated with the first subset of PIOAs are transferred to a second subset of PIOAs remaining operational in the set of PIOAs.

Abstract: A wake-and-go mechanism is provided for a data processing system. The wake-and-go mechanism is configured to issue a look-ahead load command on a system bus to read a data value from a target address and perform a comparison operation to determine whether the data value at the target address indicates that an event for which a thread is waiting has occurred. In response to the comparison resulting in a determination that the event has not occurred, the wake-and-go engine populates a wake-and-go storage array with the target address and snooping the target address on the system bus without data exclusivity. In response to the comparison resulting in a determination that the event has occurred, the wake-and-go engine issues a load command on the system bus to read the data value from the target address with data exclusivity.

Abstract: A wake-and-go mechanism is configured to issue a look-ahead load command on a system bus to read a data value from a target address and perform a comparison operation to determine whether the data value at the target address indicates that an event for which a thread is waiting has occurred. In response to the comparison resulting in a determination that the event has not occurred, the wake-and-go engine populates the wake-and-go storage array with the target address. In response to the comparison resulting in a determination that the event has occurred, the wake-and-go engine issues a load command on the system bus to read the data value from the target address with data exclusivity and determines whether the wake-and-go engine obtains a lock for the target address. Responsive to obtaining the lock for the target address, the wake-and-go engine holds the lock for the thread.

Abstract: A wake-and-go mechanism is provided for a data processing system. The wake-and-go mechanism is configured to issue a look-ahead load command on a system bus to read a data value from a target address and perform a comparison operation to determine whether the data value at the target address indicates that an event for which a thread is waiting has occurred. In response to the comparison resulting in a determination that the event has not occurred, the wake-and-go engine populates the wake-and-go storage array with the target address and snoops the target address on the system bus.

Abstract: A wake-and-go mechanism is provided for a data processing system. The wake-and-go mechanism detects a thread running on a first processing unit within a plurality of processing units that is waiting for an event that modifies a data value associated with a target address. The wake-and-go mechanism creates a wake-and-go instance for the thread by populating a wake-and-go storage array with the target address. The operating system places the thread in a sleep state. Responsive to detecting the event that modifies the data value associated with the target address, the wake-and-go mechanism assigns the wake-and-go instance to a second processing unit within the plurality of processing units. The operating system on the second processing unit places the thread in a non-sleep state.

Abstract: In a NUMA-topology computer system that includes multiple nodes and multiple logical partitions, some of which may be dedicated and others of which are shared, NUMA optimizations are enabled in shared logical partitions. This is done by specifying a home node parameter in each virtual processor assigned to a logical partition. When a task is created by an operating system in a shared logical partition, a home node is assigned to the task, and the operating system attempts to assign the task to a virtual processor that has a home node that matches the home node for the task. The partition manager then attempts to assign virtual processors to their corresponding home nodes. If this can be done, NUMA optimizations may be performed without the risk of reducing the performance of the shared logical partition.

Abstract: A wake-and-go mechanism is provided for a data processing system. The wake-and-go mechanism recognizes a programming idiom that indicates that a thread is spinning on a lock. The wake-and-go mechanism updates a wake-and-go array with a target address associated with the lock and sets a lock bit in the wake-and-go array. The thread then goes to sleep until the lock frees. The wake-and-go array may be a content addressable memory (CAM). When a transaction appears on the symmetric multiprocessing (SMP) fabric that modifies the value at a target address in the CAM, the CAM returns a list of storage addresses at which the target address is stored. The wake-and-go mechanism associates these storage addresses with the threads waiting for an even at the target addresses, and may wake the thread that is spinning on the lock.

Abstract: A wake-and-go mechanism is provided for a data processing system. When a thread is waiting for an event, rather than performing a series of get-and-compare sequences, the thread updates a wake-and-go array with a target address associated with the event. The wake-and-go mechanism may save the state of the thread in a hardware private array. The hardware private array may comprise a plurality of memory cells embodied within the processor or pervasive logic associated with the bus, for example. Alternatively, the hardware private array may be embodied within logic associated with the wake-and-go storage array.

Abstract: A wake-and-go mechanism is provided for a data processing system. When a thread is waiting for an event, rather than performing a series of get-and-compare sequences, the thread updates a wake-and-go array with a target address associated with the event. The wake-and-go mechanism may save the state of the thread in a hardware private array. The hardware private array may comprise a plurality of memory cells embodied within the processor or pervasive logic associated with the bus, for example. Alternatively, the hardware private array may be embodied within logic associated with the wake-and-go storage array.

Abstract: A wake-and-go mechanism is provided for a data processing system. The wake-and-go mechanism recognizes a programming idiom, specialized instruction, operating system call, or application programming interface call that indicates that a thread is waiting for an event. The wake-and-go mechanism updates a wake-and-go array with a target address, expected data value, and comparison type associated with the event. The thread then goes to sleep until the event occurs. The wake-and-go array may be a content addressable memory (CAM). When a transaction appears on the symmetric multiprocessing (SMP) fabric that modifies the value at a target address in the CAM, logic associated with the CAM performs a comparison based on the data value being written, expected data value, and comparison type.

Abstract: Snoop response logic on a system bus is configured to detect on the system bus requests to access data at a target address with data exclusivity from at least one of a plurality of wake-and-go engines. The snoop response logic is further configured to determine a winning wake-and-go engine from the at least one wake-and-go engine that obtains a lock on the target address and generate a combined snoop response. The combined snoop response identifies the winning wake-and-go engine. The snoop response logic sends the combined snoop response to the at least one wake-and-go engine on the system bus. Each remaining wake-and-go engine within the at least one wake-and-go engine places an entry in its respective wake-and-go storage array to spin on a lock for the target address.

Abstract: A hardware wake-and-go mechanism is provided for a data processing system. The wake-and-go mechanism recognizes a programming idiom that indicates that a thread is waiting for an event. The wake-and-go mechanism updates a wake-and-go array with a target address associated with the event. The thread then goes to sleep until the event occurs. The wake-and-go array may be a content addressable memory (CAM). When a transaction appears on the symmetric multiprocessing (SMP) fabric that modifies the value at a target address in the CAM, the CAM returns a list of storage addresses at which the target address is stored. The wake-and-go mechanism associates these storage addresses with the threads waiting for an even at the target addresses, and may wake the one or more threads waiting for the event.