Abstract: Execution of instructions in a transactional environment is selectively controlled. A TRANSACTION BEGIN instruction initiates a transaction and includes controls that selectively indicate whether certain types of instructions are permitted to execute within the transaction. The controls include one or more of an allow access register modification control and an allow floating point operation control.

Abstract: Execution of instructions in a transactional environment is selectively controlled. A TRANSACTION BEGIN instruction initiates a transaction and includes controls that selectively indicate whether certain types of instructions are permitted to execute within the transaction. The controls include one or more of an allow access register modification control and an allow floating point operation control.

Abstract: A monitoring facility that is operable in two modes allowing compatibility with prior existing monitoring facilities. In one mode, in response to encountering a monitored event, an interrupt is generated. In another mode, in response to encountering a monitored event, one or more associated counters are incremented without causing an interrupt.

Abstract: A program (e.g., an operating system) is provided a warning that it has a grace period in which to perform a function, such as cleanup (e.g., complete, stop and/or move a dispatchable unit). The program is being warned, in one example, that it is losing access to its shared resources. For instance, in a virtual environment, a guest program is warned that it is about to lose its central processing unit resources, and therefore, it is to perform a function, such as cleanup.

Abstract: A monitoring facility that is operable in two modes allowing compatibility with prior existing monitoring facilities. In one mode, in response to encountering a monitored event, an interrupt is generated. In another mode, in response to encountering a monitored event, one or more associated counters are incremented without causing an interrupt.

Abstract: An embodiment provides for operating an information processing system. An aspect of the invention includes allocating an execution interval to a first logical processor of a plurality of logical processors of the information processing system. The execution interval is allocated for use by the first logical processor in executing instructions on a physical processor of the information processing system. The first logical processor determines that a resource required for execution by the first logical processor is locked by another one of the other logical processors. An instruction is issued by the first logical processor to determine whether a lock-holding logical processor is currently running. The lock-holding logical processor waits to release the lock if it is currently running. A command is issued by the first logical processor to a super-privileged process for relinquishing the allocated execution interval by the first logical processor if the locking holding processor is not running.

Abstract: Exemplary embodiments include a system and storage medium for managing computer processing functions in a multi-processor computer environment. The system includes a physical processor, a standard logical processor, an assist logical processor sharing a same logical partition as the standard logical processor, and a single operating system instance associated with the logical partition, the single operating system instance including a switch-to service and a switch-from service. The system also includes a dispatch component managed by the single operating system instance. Upon invoking the switch-to service by standard code, the switch-to service checks to see if an assist logical processor is online and, if so, it updates an integrated assist field of a work element block associated with the task for indicating the task is eligible to be executed on the assist logical processor. The switch-to service also assigns a work queue to the work element block.

Abstract: Exemplary embodiments include a system and storage medium for managing computer processing functions in a multi-processor computer environment. The system includes a physical processor, a standard logical processor, an assist logical processor sharing a same logical partition as the standard logical processor, and a single operating system instance associated with the logical partition, the single operating system instance including a switch-to service and a switch-from service. The system also includes a dispatch component managed by the single operating system instance. Upon invoking the switch-to service by standard code, the switch-to service checks to see if an assist logical processor is online and, if so, it updates an integrated assist field of a work element block associated with the task for indicating the task is eligible to be executed on the assist logical processor. The switch-to service also assigns a work queue to the work element block.

Abstract: A method is provided for a first logical processor to determine a running status of a target logical processor of an information processing system. In such method, an instruction is issued by the first logical processor running on the information processing system for determining whether the target logical processor is running. In response to issuing the instruction, a state descriptor belonging to the target logical processor is queried to determine whether the target logical processor is currently running. A result is then returned to the first logical processor, the result indicating whether or not the target logical processor is currently running.

Abstract: A monitoring facility that is operable in two modes allowing compatibility with prior existing monitoring facilities. In one mode, in response to encountering a monitored event, an interrupt is generated. In another mode, in response to encountering a monitored event, one or more associated counters are incremented without causing an interrupt.

Abstract: Exemplary embodiments include a system and storage medium for managing computer processing functions in a multi-processor computer environment. The system includes a physical processor, a standard logical processor, an assist logical processor sharing a same logical partition as the standard logical processor, and a single operating system instance associated with the logical partition, the single operating system instance including a switch-to service and a switch-from service. The system also includes a dispatch component managed by the single operating system instance. Upon invoking the switch-to service by standard code, the switch-to service checks to see if an assist logical processor is online and, if so, it updates an integrated assist field of a work element block associated with the task for indicating the task is eligible to be executed on the assist logical processor. The switch-to service also assigns a work queue to the work element block.

Abstract: A monitoring facility that is operable in two modes allowing compatibility with prior existing monitoring facilities. In one mode, in response to encountering a monitored event, an interrupt is generated. In another mode, in response to encountering a monitored event, one or more associated counters are incremented without causing an interrupt.

Abstract: A method of searching for work elements for processing in a computing system having a primary queue of work elements and at least one secondary queue of work elements. A numerical priority value is associated with each of the work elements. The method includes setting an initial priority bar and processing work elements from the primary queue until reaching a work element having a priority less than the initial priority bar. A priority bar is set equal to a minimum of a priority limit and a priority on the at least one secondary queue. If the primary queue contains a work element having a priority greater than or equal to the priority bar, then the work element is processed. If the primary queue contains a work element having a priority less than the priority bar, then a work element from the at least one secondary queue is processed.

Abstract: A method is provided for determining whether a logical processor of an information processing system has access to an address space of the information processing system. An instruction is issued by a first processor, the instruction referencing a target logical processor and a target address space. In response to the instruction, first information is checked to determine whether the target logical processor is running. When it is determined that the target logical processor is not running, second information is checked by a host program to determine whether the target logical processor has access to the target address space.

Abstract: Two forms of TOD Clock instructions are provided, Store Clock and Store Clock Fast. Execution of the Store Clock Fast instruction may produce a time of day (TOD) result that is exactly the same as a previous TOD result, however execution of Store Clock Fast instructions while the clock is running always produce unique TOD results.

Abstract: Exemplary embodiments include a system and storage medium for managing computer processing functions in a multi-processor computer environment. The system includes a physical processor, a standard logical processor, an assist logical processor sharing a same logical partition as the standard logical processor, and a single operating system instance associated with the logical partition, the single operating system instance including a switch-to service and a switch-from service. The system also includes a dispatch component managed by the single operating system instance. Upon invoking the switch-to service by standard code, the switch-to service checks to see if an assist logical processor is online and, if so, it updates an integrated assist field of a work element block associated with the task for indicating the task is eligible to be executed on the assist logical processor. The switch-to service also assigns a work queue to the work element block.

Abstract: Exemplary embodiments include a method, system, and storage medium for managing computer processing functions in a multi-processor computer environment that includes a standard logical processor and an assist logical processor, each of which share the same operating system instance within a logical partition. The method includes invoking a switch-to service by standard code. The standard code is running on a standard logical processor and is executing a task. The switch-to service checks to see if an assist logical processor is online, and it if finds one, the switch-to service updates an integrated assist field of a work element block associated with the task and assigns a queue to the work element block. The task is dispatched, in accordance with business rules identified in a system control block, on either of said assist logical processor or said standard logical processor.

Abstract: A method is provided for obtaining time-of-day (“TOD”) clock records on an information processing system. In accordance with such method, a first instruction is issued for recording a TOD clock value. In response to issuing the first instruction, a truncated version of a first current TOD clock value is obtained and recorded as a first TOD clock record, the first TOD clock value being a first current TOD clock value produced by a TOD clock running continuously on the information processing system. Thereafter, a second instruction is issued. In response to issuing the second instruction, a truncated version of a second current TOD clock value is obtained and recorded as a second TOD clock record, the second current TOD clock value being produced by the TOD clock, and the second TOD clock record being permitted to have the same value as the first TOD clock record.

Abstract: A method is provided for determining whether a logical processor of an information processing system has access to an address space of the information processing system. An instruction is issued by a first processor, the instruction referencing a target logical processor and a target address space. In response to the instruction, first information is checked to determine whether the target logical processor is running. When it is determined that the target logical processor is not running, second information is checked by a host program to determine whether the target logical processor has access to the target address space.

Abstract: A method is provided for a first logical processor to determine a running status of a target logical processor of an information processing system. In such method, an instruction is issued by the first logical processor running on the information processing system for determining whether the target logical processor is running. In response to issuing the instruction, a state descriptor belonging to the target logical processor is queried to determine whether the target logical processor is currently running. A result is then returned to the first logical processor, the result indicating whether or not the target logical processor is currently running.