Abstract: Mechanisms for executing a transaction in the data processing system are provided. A transaction checkpoint data structure is generated in internal registers of a processor. The transaction checkpoint data structure stores transaction checkpoint data representing a state of program registers at a time prior to execution of a corresponding transaction. The transaction, which comprises a first portion of code that is to be executed by the processor, is executed. An interrupt of the transaction is received while executing the transaction and, as a result, the transaction checkpoint data is stored to a data structure in a memory of the data processing system. A second portion of code is then executed. A state of the program registers is restored using the data structure in the memory of the data processing system in response to an event occurring causing a switch of execution of the processor back to execution of the transaction.

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: Mechanisms for executing a transaction in the data processing system are provided. A transaction checkpoint data structure is generated in internal registers of a processor. The transaction checkpoint data structure stores transaction checkpoint data representing a state of program registers at a time prior to execution of a corresponding transaction. The transaction, which comprises a first portion of code that is to be executed by the processor, is executed. An interrupt of the transaction is received while executing the transaction and, as a result, the transaction checkpoint data is stored to a data structure in a memory of the data processing system. A second portion of code is then executed. A state of the program registers is restored using the data structure in the memory of the data processing system in response to an event occurring causing a switch of execution of the processor back to execution of the transaction.

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: Mechanisms for executing a transaction in the data processing system are provided. A transaction checkpoint data structure is generated in internal registers of a processor. The transaction checkpoint data structure stores transaction checkpoint data representing a state of program registers at a time prior to execution of a corresponding transaction. The transaction, which comprises a first portion of code that is to be executed by the processor, is executed. An interrupt of the transaction is received while executing the transaction and, as a result, the transaction checkpoint data is stored to a data structure in a memory of the data processing system. A second portion of code is then executed. A state of the program registers is restored using the data structure in the memory of the data processing system in response to an event occurring causing a switch of execution of the processor back to execution of the transaction.

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 for managing energy. A processor unit identifies a plurality of groups of virtual machines in a computer system. The processor unit allocates the energy in the computer system to the plurality of groups of virtual machines based on a policy.

Abstract: A computer implemented method to establish at least one paging partition in a data processing system. The virtualization control point (VCP) reserves up to the subset of physical memory for use in the shared memory pool. The VCP configures at least one logical partition as a shared memory partition. The VCP assigns a paging partition to the shared memory pool. The VCP determines whether a user requests a redundant assignment of the paging partition to the shared memory pool. The VCP assigns a redundant paging partition to the shared memory pool, responsive to a determination that the user requests a redundant assignment. The VCP assigns a paging device to the shared memory pool. The hypervisor may transmit at least one paging request to a virtual asynchronous services interface configured to support a paging device stream.

Abstract: A method, data processing system, and computer program product for managing energy. A processor unit identifies a plurality of groups of virtual machines in a computer system. The processor unit allocates the energy in the computer system to the plurality of groups of virtual machines based on a policy.

Abstract: A mechanism is provided for allocating energy budgets to a plurality of logical partitions. An overall energy budget for the data processing system and a total of a set of requested initial energy budgets for the plurality of partitions are determined. A determination is made as to whether the total of the set of requested initial energy budgets for the plurality of partitions is greater than the overall energy budget for the data processing system. Responsive to the total of the set of requested initial energy budgets exceeding the overall energy budget, an initial energy budget is allocated to each partition in the plurality of partitions based on at least one of priority or proportionality of each partition in the plurality of partitions such that a total of the initial energy budgets for the plurality of partitions does not exceed the overall energy budget of the data processing system.

Abstract: Mechanisms for executing a transaction in the data processing system are provided. A transaction checkpoint data structure is generated in internal registers of a processor. The transaction checkpoint data structure stores transaction checkpoint data representing a state of program registers at a time prior to execution of a corresponding transaction. The transaction, which comprises a first portion of code that is to be executed by the processor, is executed. An interrupt of the transaction is received while executing the transaction and, as a result, the transaction checkpoint data is stored to a data structure in a memory of the data processing system. A second portion of code is then executed. A state of the program registers is restored using the data structure in the memory of the data processing system in response to an event occurring causing a switch of execution of the processor back to execution of the transaction.

Abstract: According to one aspect of the present disclosure a method and technique for monitoring memory access is disclosed. The method includes monitoring, by a plurality of memory controllers, access to a memory unit, wherein each memory controller is associated with a different range of memory addresses of the memory unit, and wherein each memory controller monitors access for its associated range of memory addresses. The method also includes updating an incrementor with access data corresponding to accesses to the memory unit, wherein each memory controller updates the access data based on access of its associated range of memory addresses. The method further includes storing, by each respective memory controller, the updated access data in a cache corresponding to the respective range of memory addresses and, responsive to the updated access data for a respective range of memory addresses exceeding a threshold, storing the access data for the respective range of memory addresses in memory unit.

Abstract: A method and data processing system enables scheduling of atomic operations within a Peripheral Component Interconnect Express (PCIe) architecture during page migration. In at least one embodiment, firmware detects the activation of a page migration operation and sets a migration bit in the page table. When the PCIe Host Bridge (PHB) receives an atomic operation, the PHB checks the migration bit associated with the memory page targeted by the atomic operation and if the migration bit is set, the PHB buffers the atomic operation and sets an atomic operation stall (AOS) bit associated with the buffer. The atomic operation is stalled until the migration bit is reset, at which time the PHB resets the AOS bit of the buffer. The atomic operations are permitted to continue when the migration bit of the target memory page is not set, and along with DMA operations, may bypass other stalled atomic operations.

Abstract: A computer implemented method, data processing system, and computer program product for detecting circular buffer overflow. When an entry in the circular buffer is read, a valid mark bit in the entry is set to an inactive state and the location of the entry is stored as an entry previously processed. A valid mark bit of a next entry and the valid mark bit in the entry previously processed are read. Responsive to determining that the valid mark bit in the entry previously processed is in the inactive state and the valid mark bit in the next entry is in an active state, the next entry is read, the valid mark bit in the next entry is set to an incactive state, and the location of the next entry is stored as the entry previously processed. Responsive to determining that the valid mark bit in the entry previously processed is in the active state, a determination is made that a circular buffer overflow has occurred.

Abstract: Performance counters are provided for virtualized network interfaces of communications networks, while minimizing the use of hardware resources. A virtualized network interface includes physical resources, as well as logical resources. Dedicated performance counters are provided for the physical resources of the virtualized network interface, as well as for logical partitions coupled to that interface, while non-dedicated performance counters are provided for the logical resources. This enables the provision of performance counters for virtualized network interfaces, while minimizing hardware resources consumed by those interfaces.

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: Methods, apparatus, and products are disclosed for controlling an operational mode for a logical partition on a computing system that include: receiving, in a hypervisor installed on the computing system, a processor compatibility mode for the logical partition and a firmware compatibility mode for the logical partition, the processor compatibility mode specifying a processor architecture version configured for the logical partition, and the firmware compatibility mode specifying a firmware architecture version configured for the logical partition; providing, by the hypervisor for the logical partition, a firmware interface in dependence upon the firmware compatibility mode; and providing, by the hypervisor for the logical partition, a processor interface in dependence upon the processor compatibility mode.

Abstract: A method, computer program product, and distributed data processing system that allows a system image within a multiple system image virtual server to directly expose a portion, or all, of its associated system memory to a shared PCI adapter without having to go through a trusted component, such as a Hypervisor. Specifically, the present invention is directed to a mechanism for sharing conventional PCI I/O adapters, PCI-X I/O Adapters, PCI-Express I/O Adapters, and, in general, any I/O adapter that uses a memory mapped I/O interface for communications.

Abstract: Registering memory space within a data processing system is performed. One or more open calls are received from an application to access one or more input/output (I/O) devices. Responsive to receiving the one or more open calls, one or more I/O map and pin calls are sent in order to register memory space for the one or more I/O devices within at least one storage area that will be accessed by the application. At least one virtual I/O bus address is received for each registered memory space of the one or more I/O devices. At least one I/O command is executed using the at least one virtual I/O bus address without intervention by an operating system or operating system image.