Abstract: The configuration of the logical processors of a logical partition is managed dynamically. A logical partition is initially configured with one or more logical processors. Thereafter, the configuration can be dynamically adjusted. This dynamic adjustment may be in response to workload of the logical partition.

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: A method and apparatus for use in a computing environment to run a variety of applications in logical partitions. The apparatus includes one or more logical processors (LPs), one or more logical partitions (LPARs) configured to each access a share of processing resources of the LPs in accordance with predefined instructions, and an LPAR manager configured to determine an operational mode of each of the LPARs and any available amount of an excess of the share of the processing resources of the LPs and to dispatch the processing resources of at least a subset of the LPs to the LPARs in accordance with the respective predetermined shares and with respect to the determined operational mode of the respective LPARs and the amount, if any, of the excess share.

Abstract: In a logically partitioned host computer system comprising host processors (host CPUs) partitioned into a plurality of guest processors (guest CPUs) of a guest configuration, a perform topology function instruction is executed by a guest processor specifying a topology change of the guest configuration. The topology change preferably changes the polarization of quest CPUs, the polarization related to the amount of a host CPU resource is provided to a guest CPU.

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: In a logically partitioned host computer system comprising host processors (host CPUs) partitioned into a plurality of guest processors (guest CPUs) of a guest configuration, a perform topology function instruction is executed by a guest processor specifying a topology change of the guest configuration. The topology change preferably changes the polarization of quest CPUs, the polarization related to the amount of a host CPU resource is provided to a guest CPU.

Abstract: In a logically partitioned host computer system comprising host processors (host CPUs), a facility and instruction for discovering topology of one or more guest processors (guest CPUs) of a guest configuration comprises a guest processor of the guest configuration fetching and executing a STORE SYSTEM INFORMATION instruction that obtains topology information of the computer configuration. The topology information comprising nesting information of processors of the configuration and the degree of dedication a host processor provides to a corresponding guest processor. The information is preferably stored in a single table in memory.

Abstract: In a logically partitioned host computer system comprising host processors (host CPUs) partitioned into a plurality of guest processors (guest CPUs) of a guest configuration, a perform topology function instruction is executed by a guest processor specifying a topology change of the guest configuration. The topology change preferably changes the polarization of guest CPUs, the polarization related to the amount of a host CPU resource is provided to a guest CPU.

Abstract: In a logically partitioned host computer system comprising host processors (host CPUs), a facility and instruction for discovering topology of one or more guest processors (guest CPUs) of a guest configuration comprises a guest processor of the guest configuration fetching and executing a STORE SYSTEM INFORMATION instruction that obtains topology information of the computer configuration. The topology information comprising nesting information of processors of the configuration and the degree of dedication a host processor provides to a corresponding guest processor. The information is preferably stored in a single table in memory.

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: In a logically partitioned host computer system comprising host processors (host CPUs), a facility and instruction for discovering topology of one or more guest processors (guest CPUs) of a guest configuration comprises a guest processor of the guest configuration fetching and executing a STORE SYSTEM INFORMATION instruction that obtains topology information of the computer configuration. The topology information comprising nesting information of processors of the configuration and the degree of dedication a host processor provides to a corresponding guest processor. The information is preferably stored in a single table in memory.

Abstract: In a logically partitioned host computer system comprising host processors (host CPUs) partitioned into a plurality of guest processors (guest CPUs) of a guest configuration, a perform topology function instruction is executed by a guest processor specifying a topology change of the guest configuration. The topology change preferably changes the polarization of guest CPUs, the polarization related to the amount of a host CPU resource is provided to a guest CPU.

Abstract: In a logically partitioned host computer system comprising host processors (host CPUs), a facility and instruction for discovering topology of one or more guest processors (guest CPUs) of a guest configuration comprises a guest processor of the guest configuration fetching and executing a STORE SYSTEM INFORMATION instruction that obtains topology information of the computer configuration. The topology information comprising nesting information of processors of the configuration and the degree of dedication a host processor provides to a corresponding guest processor. The information is preferably stored in a single table in memory.

Abstract: In a logically partitioned host computer system comprising host processors (host CPUs) partitioned into a plurality of guest processors (guest CPUs) of a guest configuration, a perform topology function instruction is executed by a guest processor specifying a topology change of the guest configuration. The topology change preferably changes the polarization of guest CPUs, the polarization related to the amount of a host CPU resource is provided to a guest CPU.

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: An input/output subsystem is configured as a plurality of input/output subsystem images, each of which appears to a program as an independent input/output subsystem. An input/output subsystem image is identified by an input/output subsystem image identifier, which is used by various programs to designate the particular input/output subsystem image for which an I/O operation is to be performed. An input/output subsystem image includes, for instance, one or more input/output paths. An input/output path of an input/output subsystem image is identified by an input/output path identifier, as well as a physical input/output path identifier.

Abstract: A method and apparatus for use in a computing environment to run a variety of applications in logical partitions. The apparatus includes one or more logical processors (LPs), one or more logical partitions (LPARs) configured to each access a share of processing resources of the LPs in accordance with predefined instructions, and an LPAR manager configured to determine an operational mode of each of the LPARs and any available amount of an excess of the share of the processing resources of the LPs and to dispatch the processing resources of at least a subset of the LPs to the LPARs in accordance with the respective predetermined shares and with respect to the determined operational mode of the respective LPARs and the amount, if any, of the excess share.

Abstract: In a logically partitioned host computer system comprising host processors (host CPUs), a facility and instruction for discovering topology of one or more guest processors (guest CPUs) of a guest configuration comprises a guest processor of the guest configuration fetching and executing a STORE SYSTEM INFORMATION instruction that obtains topology information of the computer configuration. The topology information comprising nesting information of processors of the configuration and the degree of dedication a host processor provides to a corresponding guest processor. The information is preferably stored in a single table in memory.