Abstract: A processor of a data processing system executes a controlling thread of a program and detects occurrence of a particular asynchronous event during execution of the controlling thread of the program. In response to occurrence of the particular asynchronous event during execution of the controlling thread of the program, the processor initiates execution of an assist thread of the program such that the processor simultaneously executes the assist thread and controlling thread of the program.

Abstract: During a pipeline stall in an out of order processor, until a next to complete instruction group completes, a monitoring unit receives, from a completion unit of a processor, a next to finish indicator indicating the finish of an oldest previously unfinished instruction from among a plurality of instructions of a next to complete instruction group. The monitoring unit receives, from a plurality of functional units of the processor, a plurality of finish reports including completion reasons for a plurality of separate instructions. The monitoring unit determines at least one stall reason from among multiple stall reasons for the oldest instruction from a selection of completion reasons from a selection of finish reports aligned with the next to finish indicator from among the plurality of finish reports.

Abstract: A performance projection system includes a test IHS and multiple currently existing IHSs. The performance projection system includes user application software and surrogate programs that execute on currently existing IHSs. The performance projection system measures user application software and surrogate program performance during execution on currently existing IHSs. The performance projection systems measures runtime program performance during execution of surrogate programs on a future semiconductor die IC design model or virtualized future system. Designers normalize and compare surrogate program runtime performance data with user application software performance data. Designers un-normalize the normalized runtime performance data to generate a projection of runtime performance on the future system.

Abstract: Occurrences of a particular event in an electronic device are counted by incrementing an event counter each time a variable number of the particular events have occurred, and automatically increasing that variable number as the total count increases. The variable number (prescale value) can increase geometrically according to a programmable counter base each time the count mantissa overflows. The event counter thereby provides hardware-implemented automatic prescaling while significantly reducing the number of interface bits required to support very large count ranges, and retaining high accuracy at very large event counts.

Abstract: Mechanisms are provided for a graphical user interface tool for system-wide topology and performance monitoring with per-partition views. A graphical user interface application presents a consolidated view of physical and logical information based on the received performance data. The mechanisms provide real-time performance and utilization information in a visual format relative to the physical components in a topographical layout. The user may drill down to lower levels to view more detailed performance and utilization information.

Abstract: Methods, systems, and computer program products may provide delay-identification in data processing systems. An apparatus may include a delay-identification unit having a delay counter, a threshold register, a delay register, and a delay detector. The delay detector may be configured to start the delay counter in response to detecting that one group of instructions is delayed, and stop the delay counter in response to detecting that the one group of instructions is no longer delayed. The delay detector may additionally be configured to compare the number of cycles counted by the delay counter with a threshold number of cycles in the threshold register, and store at least one effective address of one of the instructions of the one group of instructions when the number of cycles counted by the delay counter is greater than the threshold number of cycles stored in the threshold register.

Abstract: A method, system or computer usable program product for an operating system (OS) enabling an application direct control of a performance monitoring unit (PMU) including enabling the PMU to notify the application when a PMU exception occurs without interrupting the OS by controllably encoding a redirect field in an OS accessible control register, and enabling the application to reinitialize the PMU after the PMU exception.

Abstract: Occurrences of a particular event in an electronic device are counted by incrementing an event counter each time a variable number of the particular events have occurred, and automatically increasing that variable number as the total count increases. The variable number (prescale value) can increase geometrically according to a programmable counter base each time the count mantissa overflows. The event counter thereby provides hardware-implemented automatic prescaling while significantly reducing the number of interface bits required to support very large count ranges, and retaining high accuracy at very large event counts.

Abstract: During a pipeline stall in an out of order processor, until a next to complete instruction group completes, a monitoring unit receives, from a completion unit of a processor, a next to finish indicator indicating the finish of an oldest previously unfinished instruction from among a plurality of instructions of a next to complete instruction group. The monitoring unit receives, from a plurality of functional units of the processor, a plurality of finish reports including completion reasons for a plurality of separate instructions. The monitoring unit determines at least one stall reason from among multiple stall reasons for the oldest instruction from a selection of completion reasons from a selection of finish reports aligned with the next to finish indicator from among the plurality of finish reports.

Abstract: A method of data processing includes a processor of a data processing system executing a controlling thread of a program and detecting occurrence of a particular asynchronous event during execution of the controlling thread of the program. In response to occurrence of the particular asynchronous event during execution of the controlling thread of the program, the processor initiates execution of an assist thread of the program such that the processor simultaneously executes the assist thread and controlling thread of the program.

Abstract: According to one aspect of the present disclosure a method and technique for managing memory access is disclosed. The method includes setting a memory databus utilization threshold for each of a plurality of processors of a data processing system to maintain memory databus utilization of the data processing system at or below a system threshold. The method also includes monitoring memory databus utilization for the plurality of processors and, in response to determining that memory databus utilization for at least one of the processors is below its threshold, reallocating at least a portion of unused databus utilization from the at least one processor to at least one of the other processors.

Abstract: A processor of an information handling system (IHS) initiates an L3 cache prefetch operation in response to a demand load during instruction processing. The processor selects an L3 cache prefetch at random for tracking as a target prefetched instruction. The processor initiates an L1 cache target prefetch operation and stores the resultant target prefetched instruction in the L1 cache. If a demand load arrives, the processor analyses the target prefetched instruction for effectiveness and determines the source of the prefetch data. If a demand does not arrive, the processor tests to determine if the particular prefetched instruction timed out in the cache and identifies the infectiveness of the prefetch operation. The processor samples multiple prefetch operations at random and generates a history of prefetch effectiveness and other useful prefetch information. The processor stores the prefetch effectiveness information to enable reduction or removal of ineffective prefetch operations.

Abstract: A filter executing on a processor monitors instructions executing on the processor to identify instructions that will benefit from performance tuning. Filtering instructions before analysis for performance tuning reduces overhead by identifying candidates for performance tuning with low cost monitoring before expending resources on analysis so that only instructions that will have performance tuning are analyzed. Reducing overhead for performance tuning makes performance tuning practical in a dynamic optimization environment in which instructions and their effective addresses change over time.

Abstract: A method of data processing includes a processor of a data processing system executing a controlling thread of a program and detecting occurrence of a particular asynchronous event during execution of the controlling thread of the program. In response to occurrence of the particular asynchronous event during execution of the controlling thread of the program, the processor initiates execution of an assist thread of the program such that the processor simultaneously executes the assist thread and controlling thread of the program.

Abstract: A method, system, and computer program product are provided for identifying instructions to obtain representative traces. A phase instruction budget is calculated for each phase in a set of phases. The phase instruction budget is based on a weight associated with each phase and a global instruction budget. A starting index and an ending index are identified for instructions within a set of intervals in each phase in order to meet the phase instruction budget for that phase, thereby forming a set of interval indices. A determination is made as to whether the instructions within the set of interval indices meet the global instruction budget. Responsive to the global instruction budget being met, the set of interval indices are output as collection points for the representative traces.

Abstract: A method and data processing system for managing running of instructions in a program. A processor of the data processing system receives a monitoring instruction of a monitoring unit. The processor determines if at least one secondary thread of a set of secondary threads is available for use as an assist thread. The processor selects the at least one secondary thread from the set of secondary threads to become the assist thread in response to a determination that the at least one secondary thread of the set of secondary threads is available for use as an assist thread. The processor changes profiling of running of instructions in the program from the main thread to the assist thread.

Abstract: A test system or simulator includes an integrated circuit (IC) benchmark software program that executes workload program software on a semiconductor die IC design model. The benchmark software program includes trace, simulation point, basic block vector (BBV) generation, cycles per instruction (CPI) error, clustering and other programs. The test system also includes CPI stack program software that generates CPI stack data that includes microarchitecture dependent information for each instruction interval of workload program software. The CPI stack data may also include an overall analysis of CPI data for the entire workload program. IC designers may utilize the benchmark software and CPI stack program to develop a reduced representative workload program that includes CPI data as well as microarchitecture dependent information.

Abstract: According to one aspect of the present disclosure a method and technique for managing memory access is disclosed. The method includes setting a memory databus utilization threshold for each of a plurality of processors of a data processing system to maintain memory databus utilization of the data processing system at or below a system threshold. The method also includes monitoring memory databus utilization for the plurality of processors and, in response to determining that memory databus utilization for at least one of the processors is below its threshold, reallocating at least a portion of unused databus utilization from the at least one processor to at least one of the other processors.

Abstract: A test system or simulator includes an IC benchmark software program that executes application software on a semiconductor die IC design model. The benchmark software includes trace, simulation point, clustering and other programs. IC designers utilize the benchmark software to evaluate the performance characteristics of IC designs with customer user software applications. The benchmark software generates basic block vectors BBVs from instruction traces of application software. The benchmark software analyzes data dependent information that it appends to BBVs to create enhanced BBVs or EBBVs. The benchmark software may graph the EBBV information in a cluster diagram and selects a subset of EBBVs as a representative sample for each program phase. Benchmarking software generates a reduced application software program from the representative EBBV samples.

Abstract: A test system or simulator includes an IC test application sampling software program that executes test application software on a semiconductor die IC design model. The test application sampling software includes trace, simulation point, CPI error, clustering and other programs. IC designers utilize the test application sampling software to evaluate the performance characteristics of IC designs with test software applications. The test application sampling software generates basic block vectors (BBVs) and fly-by vectors (FBVs) from instruction trace analysis of test application software. The test application sampling software analyzes microarchitecture dependent information that it uses to generate the FBVs. Test application sampling software generates a reduced representative test application software program from the BBV and FBV data utilizing an instruction budgeting method.