Abstract: A method in a data processing system is provided for processing a service request of a client partition. The method includes: obtaining by a service partition of the data processing system the service request from the client partition, wherein both the client and service partitions execute above a hypervisor of the data processing system; and processing the service request by the service partition utilizing a processor quantum assigned to the client partition and donated by the client partition to the service partition. The client partition controls scheduling of the service partition by queuing the service request at the client partition until the client partition decides to proceed with execution of the service request by the service partition. In one implementation, the service partition is a partition adjunct of the data processing system, which utilizes donated virtual address space of the client partition.

Abstract: A method, system and computer program product for managing requests for deferred updates to shared data elements while minimizing grace period detection overhead associated with determining whether pre-existing references to the data elements have been removed. Plural update requests that are eligible for grace period detection are buffered without performing grace period detection processing. One or more conditions that could warrant commencement of grace period detection processing are monitored while the update requests are buffered. If warranted by such a condition, grace period detection is performed relative to the update requests so that they can be processed. In this way, grace period detection overhead can be amortized over plural update requests while being sensitive to conditions warranting prompt grace period detection.

Abstract: A method and system for providing quality of service guarantees for 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 controls scheduling of the threads based at least partly on the information communicated and provides quality of service guarantees.

Abstract: A method and system for prefetching in computer system are provided. The method in one aspect includes using a prefetch engine to perform prefetch instructions and to translate unmapped data. Misses to address translations during the prefetch are handled and resolved. The method also includes storing the resolved translations in a respective cache translation table. A system for prefetching in one aspect includes a prefetch engine operable to receive instructions to prefetch data from the main memory. The prefetch engine is also operable to search cache address translation for prefetch data and perform address mapping translation, if the prefetch data is unmapped. The prefetch engine is further operable to prefetch the data and store the address mapping in one or more cache memory, if the data is unmapped.

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: A partition adjunct is provided for a logical partition running above a hypervisor of a data processing system. The partition adjunct, which is a separate dispatchable partition from an instantiating logical partition, provides one or more services to the logical partition. A service request received from the logical partition is processed by the partition adjunct utilizing virtual address space donated to the partition adjunct from the logical partition. The partition adjunct and the logical partition share a common virtual address to real address page table, and context switching the current state machine from the logical partition to the partition adjunct occurs without invalidating or modifying state data of selected memory management and address translation hardware of the data processing system. In a hardware multithreaded system, the partition adjunct is dispatched on a single thread, while another thread continues to run in the logical partition initiating the service request.

Abstract: A partition adjunct is provided for a logical partition running above a hypervisor of a data processing system. The partition adjunct, which is a separate dispatchable partition from an instantiating logical partition, provides one or more services to the logical partition. A service request received from the logical partition is processed by the partition adjunct utilizing virtual address space donated to the partition adjunct from the logical partition. The partition adjunct and the logical partition share a common virtual address to real address page table, and context switching the current state machine from the logical partition to the partition adjunct occurs without invalidating or modifying state data of selected memory management and address translation hardware of the data processing system. In a hardware multithreaded system, the partition adjunct is dispatched on a single thread, while another thread continues to run in the logical partition initiating the service request.

Abstract: Dedicated access is provided to a physical input/output (I/O) device which is non-configurable by an initiating logical partition. Access is established by: initiating, by the logical partition, creation of a partition adjunct; invoking a hypervisor of the data processing system to instantiate the partition adjunct with resources donated from the initiating logical partition, the donated resources including a donated virtual address space of the logical partition and the physical I/O device; creating, by the hypervisor, the partition adjunct and assigning the donated virtual address space and donated physical I/O device to the created partition adjunct; and interfacing, by the hypervisor, the logical partition and the created partition adjunct, the interfacing including providing the logical partition with a virtual I/O device which replaces the donated physical I/O device, and which is configurable by the logical partition.

Abstract: A partition adjunct is provided for a logical partition running above a hypervisor of a data processing system. The partition adjunct, which is a separate dispatchable partition from an instantiating logical partition, provides one or more services to the logical partition. A service request received from the logical partition is processed by the partition adjunct utilizing virtual address space donated to the partition adjunct from the logical partition. The partition adjunct and the logical partition share a common virtual address to real address page table, and context switching the current state machine from the logical partition to the partition adjunct occurs without invalidating or modifying state data of selected memory management and address translation hardware of the data processing system. In a hardware multithreaded system, the partition adjunct is dispatched on a single thread, while another thread continues to run in the logical partition initiating the service request.

Abstract: A method in a data processing system is provided for processing a service request of a client partition. The method includes: obtaining by a service partition of the data processing system the service request from the client partition, wherein both the client and service partitions execute above a hypervisor of the data processing system; and processing the service request by the service partition utilizing a processor quantum assigned to the client partition and donated by the client partition to the service partition. The client partition controls scheduling of the service partition by queuing the service request at the client partition until the client partition decides to proceed with execution of the service request by the service partition. In one implementation, the service partition is a partition adjunct of the data processing system, which utilizes donated virtual address space of the client partition.

Abstract: A method in a data processing system is provided for processing a service request of a client partition. The method includes: obtaining by a service partition of the data processing system the service request from the client partition, wherein both the client and service partitions execute above a hypervisor of the data processing system; and processing the service request by the service partition utilizing a processor quantum assigned to the client partition and donated by the client partition to the service partition. The client partition controls scheduling of the service partition by queuing the service request at the client partition until the client partition decides to proceed with execution of the service request by the service partition. In one implementation, the service partition is a partition adjunct of the data processing system, which utilizes donated virtual address space of the client partition.

Abstract: A method and system for thread scheduling for optimal heat dissipation are provided. Temperature sensors measure temperature throughout various parts of a processor chip. The temperatures detected are reported to an operating system or the like for scheduling threads. In one aspect, the observed temperature values are recorded on registers. An operating system or the like reads the registers and schedules threads based on the temperature values.

Abstract: Access control to shared virtual address space within a single logical partition is provided. The access control includes: associating, by a hypervisor of the data processing system, a memory protection key with a portion of a single logical partition's virtual address space being shared by multiple entities, the key preventing access by one of the multiple entities to that portion of the virtual address space, and allowing access by another of the entities to that portion of the virtual address space; and locking by the hypervisor the memory protection key from modification by the one entity, wherein the locking prevents the one entity from modifying the key and thereby gaining access to the portion of the single logical partition's virtual address space with the associated memory protection key. In one embodiment, the one entity is the single logical partition itself, and the another entity is a partition adjunct.

Abstract: A method and apparatus for restricting access of an application to computer hardware. The apparatus includes both an authentication module and a validation module. The authentication module is within the trusted firmware layer. The purpose of the authentication module is to verify a cryptographic key presented by an application. The validation module is responsive to the authentication module and limits access of the application to the computer hardware. The authentication modules may be implemented in software through a firmware call, or through a hardware register of the computer.

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: A system, method and computer program product for atomically moving a shared list element from a first list location to a second list location includes inserting a placeholder element at the second list location to signify to readers that a move operation is underway, removing the shared list element from the first list location, re-identifying the list element to reflect its move from the first list location to the second list location, inserting it at the second list location and unlinking the placeholder element. A deferred removal of the placeholder element is performed following a period in which readers can no longer maintain references thereto. A method, system and computer program product are additionally provided for performing a lookup of a target list element that is subject to being atomically moved from a first list to a second list.

Abstract: A system, method and computer program product for efficient sharing of memory between first and second applications running under first and second operating systems on a shared hardware system. The hardware system runs a hypervisor that supports concurrent execution of the first and second operating systems, and further includes a region of shared memory managed on behalf of the first and second applications. Techniques are used to avoid preemption when the first application is accessing the shared memory region. In this way, the second application will not be unduly delayed when attempting to access the shared memory region due to delays stemming from the first application's access of the shared memory region. This is especially advantageous when the second application and operating system are adapted for real-time processing. Additional benefits can be obtained by taking steps to minimize memory access faults.

Abstract: A method and system for prefetching in computer system are provided. The method in one aspect includes using a prefetch engine to perform prefetch instructions and to translate unmapped data. Misses to address translations during the prefetch are handled and resolved. The method also includes storing the resolved translations in a respective cache translation table. A system for prefetching in one aspect includes a prefetch engine operable to receive instructions to prefetch data from the main memory. The prefetch engine is also operable to search cache address translation for prefetch data and perform address mapping translation, if the prefetch data is unmapped. The prefetch engine is further operable to prefetch the data and store the address mapping in one or more cache memory, if the data is unmapped.

Abstract: A system, method and computer program product for efficient sharing of memory between first and second applications running under first and second operating systems on a shared hardware system. The hardware system runs a hypervisor that supports concurrent execution of the first and second operating systems, and further includes a region of shared memory managed on behalf of the first and second applications. Techniques are used to avoid preemption when the first application is accessing the shared memory region. In this way, the second application will not be unduly delayed when attempting to access the shared memory region due to delays stemming from the first application's access of the shared memory region. This is especially advantageous when the second application and operating system are adapted for real-time processing. Additional benefits can be obtained by taking steps to minimize memory access faults.

Abstract: A method in a data processing system is provided for processing a service request of a client partition. The method includes: obtaining by a service partition of the data processing system the service request from the client partition, wherein both the client and service partitions execute above a hypervisor of the data processing system; and processing the service request by the service partition utilizing a processor quantum assigned to the client partition and donated by the client partition to the service partition. The client partition controls scheduling of the service partition by queuing the service request at the client partition until the client partition decides to proceed with execution of the service request by the service partition. In one implementation, the service partition is a partition adjunct of the data processing system, which utilizes donated virtual address space of the client partition.