Abstract: A method, apparatus, and computer program product in a shared processor data processing system are disclosed for dynamically tuning an amount of physical processor capacity that is allocated to each one of multiple logical partitions. A physical processor is shared among the logical partitions. A service window is allocated to each logical partition during each dispatch time slice. Processes that are defined by a first one of the logical partitions are executed during a first service window that was allocated to the first logical partition. A determination is made dynamically during runtime as to whether a length of the first service window should be increased to optimize interrupt processing and reduce interrupt latency. If it is determined that the length should be increased, the length of the first service window is dynamically increased during runtime.

Abstract: A power level monitor and performance tracking tool are provided for correlating system performance with processor management events. When power management requires a change to the state of a microprocessor, software will be notified. Multiple layers of software may be notified, including a firmware level, an operating system, as well as applications. The performance tracking tool tracks the times of the power management events as well as their impact to the microprocessor performance. The performance tracking tool may then display or record the state changes to processor performance. These changes may be correlated against other system events to aid in determining system performance problems with respect to power management.

Abstract: A method, apparatus, and computer program product are disclosed for dynamically determining when to yield a processor that is assigned to perform particular work but that is currently idle. A particular processor is assigned to perform work. A determination is made regarding whether the processor is currently idle. If the processor is currently idle, a determination is made of a length of time the processor has been idle. If this determined length of time exceeds a self-tunable threshold, the processor is yielded to make the processor available to perform other work. The threshold can be dynamically tuned during runtime.

Abstract: A method, apparatus, and computer program product are disclosed for a simultaneous multithreading (SMT) data processing system for modifying the processing of software threads that acquire a contentious software lock. The system includes a processor that is capable of concurrently executing multiple different threads on the processor. The processor is also capable of utilizing hardware thread priorities assigned to each thread the processor is processing by granting a greater, disparate amount of resources to the highest priority thread. A hardware priority is assigned to each one of the SMT threads. A contentious lock is identified. Ones of the multiple threads are identified that attempt to acquire the contentious lock. These threads are dynamically redirected to special code for handling contentious locks. The hardware priority of a thread acquiring a contentious lock is then boosted.

Abstract: According to a method of operating a data processing system, software communicates to a processing unit a classification each of at least one schedulable software entity that the processing unit executes. A resource manager within the processing unit dynamically allocates hardware resources within the processing unit to the schedulable software entity during execution in accordance with the classification of the at least one schedulable software entity. The classification may be retrieved by the software from in data storage, and operating system software may schedule the schedulable software entity for execution by reference to the classification. The processing unit may also monitor, in hardware, execution of each of a plurality of schedulable software entities within the processing unit in accordance with a monitoring parameter set among one or more monitoring parameter sets.

Abstract: According to a method of operating a data processing system, one or more monitoring parameter sets are established in a processing unit within the data processing system. The processing unit monitors, in hardware, execution of each of a plurality of schedulable software entities within the processing unit in accordance with a monitoring parameter set among the one or more monitoring parameter sets. The processing unit then reports to software executing in the data processing system utilization of hardware resources by each of the plurality of schedulable software entities. The hardware utilization information reported by the processing unit may be stored and utilized by software to schedulable execution of the schedulable software entities reported by the processing unit.