Abstract: An improved method, apparatus, and computer instructions for identifying a memory leak in a heap. Prior to the start of the observation period, all live objects in the heap are identified to form a set of live objects by altering an indicator in the live objects. After running the system for the required amount of time or until completion of the event being monitored, the system is used to obtain the list of live objects without the altered indicator. Live objects without the altered indicators form the most likely objects associated with a memory leak.

Abstract: An apparatus and method are provided for the dynamic instrumentation of code to minimize system perturbation during tracing of the execution of the code. With the apparatus and method, “hot spots” in the execution of the code are dynamically determined during tracing of the execution of the code. These “hot spots” are dynamically instrumented, i.e. an event hook is inserted, to cause control to be passed to a handler that determines a caller of the “hot spot” method. The method that called the “hot spot” method, or “caller” method, is identified from a call stack and is dynamically instrumented for an appropriate metric so that the next time the calling method is executed, the dynamically inserted hooks are executed. The execution of the hooks in the caller method is continued for a predetermined period, e.g., number of invocations, to get an understanding of the caller method's characteristics.

Abstract: A method, system, apparatus, and computer program product is presented for tracing operations. A set of related methodologies can be used within instruction tracing software, such as a tracing program, to reduce its tendency to generate interrupts that cause unwanted effects in the system that is being captured. A first methodology allows access to protected memory blocks so that instructions may be read from those memory blocks. A second methodology provides for the trace output buffer to be accessed using physical addressing. A third methodology traces only instruction addresses, which are resolved later during a post-processing phase of operation. A fourth methodology comprises multiple different methods for obtaining copies of instructions that have already executed rather than obtaining them before they are executed.

Abstract: A system and method for collecting a plurality of metrics during a single run of a computer program. The mechanism of the present invention initializes a plurality of counters to count events associated with metrics of interest. The mechanism of the present invention then counts the occurrence of events associated with metrics of interest during a single execution of a computer program. When a branch has been taken, a trace record is generated for the branch taken, wherein the generated trace record contains a count of events associated with the metrics of interest for the branch taken.

Abstract: A method, apparatus, and computer instructions in a processor for associating a data type with a memory location. The type is associated with a location by means of metadata that is generated and manipulated by hardware instructions that are typically generated by a compiler as it generates the other instructions that comprise the machine code version of a program. A determination is made as to whether a data value about to be stored is of the required data type for that location. The hardware indicates an error condition if the types do not match.

Abstract: A system and method for collecting a plurality of metrics during a single run of a computer program. The mechanism of the present invention initializes a plurality of counters to count events associated with metrics of interest. The mechanism of the present invention then counts the occurrence of events associated with metrics of interest during a single execution of a computer program. Responsive to a determination that a counter in a plurality of counters has generated an interrupt, the interrupt is rerouted to an interrupt handler, wherein the interrupt handler generates trace records comprising trace information corresponding to the interrupt. The mechanism of the present invention then generates profiles for the trace records, wherein the profiles differentiate the trace records based on the metric type associated with each trace record.

Abstract: A method, apparatus, and computer instructions for providing hardware assistance to prefetch data during execution of code by a process or in the data processing system. In response to loading of an instruction in the code into a cache, a determination is made, by the processor unit, as to whether metadata for a prefetch is present for the instruction. In response to metadata being present for the instruction, selectively prefetching data, from within a data structure using the metadata, into the cache in a processor.

Abstract: A method, apparatus, and computer instructions for providing hardware assistance to prefetch data during execution of code by a process or in the data processing system. In response to loading of an instruction in the code into a cache, a determination is made, by the processor unit, as to whether metadata for a prefetch is present for the instruction. In response to metadata being present for the instruction, selectively prefetching data, from within a data structure using the metadata, into the cache in a processor.

Abstract: A method, apparatus, and computer instructions in a data processing system for processing instructions are provided. Instructions are received at a processor in the data processing system. If a selected indicator is associated with the instruction, counting of each event associated with the execution of the instruction is enabled. Functionality may be provided in the performance monitoring application for initiating the measurement of secondary metrics with regard to identified instructions, data addresses, ranges of identified instructions, or ranges of identified data addresses, based on counter values for primary metrics. Thus, for example, when a primary metric counter, or a combination of primary metric counters, meets or exceeds a predetermined threshold value, an interrupt may be generated. In response to receiving the interrupt, counters associated with the measuring of secondary metrics of a range of instructions/data addresses may be initiated.

Abstract: A method, apparatus, and computer instructions for providing hardware assistance to prefetch data during execution of code by a process or in the data processing system. In response to loading of an instruction in the code into a cache, a determination is made, by the processor unit, as to whether metadata for a prefetch is present for the instruction. In response to metadata being present for the instruction, selectively prefetching data, from within a data structure using the metadata, into the cache in a processor.

Abstract: A method, apparatus, and computer instructions for presenting coverage data for code. The coverage data containing instruction access indicators associated with the code is obtained. Particular instruction access indicators that have been set by a processor in the data processing system in response to execution of the code by the processor are identified to form set instruction access indicators. Each set instruction access indicator is associated with a portion of the code. A presentation for the coverage data is generated. The set instruction access indicators are identified in the presentation. This presentation may be, for example, a graphical presentation.

Abstract: A method and apparatus for averaging out variations from run to run of a computer program are provided. With the apparatus and method, call trees are generated for two or more executions of a build of a computer program. The apparatus and method perform a “tree-addition” operation in which the two or more call trees generated during runs of the computer program are added to one another to thereby accumulate statistics for each call in the call trees. These statistics may then be divided by the number of runs whose tree data structures are being accumulated. In this way, an average of the tree data structures is generated. In addition, any portions of the tree data structure that are due to asynchronous events are averaged out so that their relative affect in the resulting tree data structure is minimized.

Abstract: A method, system, apparatus, and computer program product is presented for tracing operations. A set of related methodologies can be used within instruction tracing software, such as a tracing program, to reduce its tendency to generate interrupts that cause unwanted effects in the system that is being captured. A first methodology allows access to protected memory blocks so that instructions may be read from those memory blocks. A second methodology provides for the trace output buffer to be accessed using physical addressing. A third methodology traces only instruction addresses, which are resolved later during a post-processing phase of operation. A fourth methodology comprises multiple different methods for obtaining copies of instructions that have already executed rather than obtaining them before they are executed.

Abstract: A computer implemented method, apparatus, and computer usable program code to collect information for a system or processor having a transition between an idle state and a non-idle state to form collected system or processor information. The collected system or processor information is provided for analysis by an application.

Abstract: A method and apparatus for identifying differences in runs of a computer program that are due to changes in the code of the computer program. With the apparatus and method, call trees are generated for two or more builds of a computer program. The apparatus and method perform a “tree-subtract” operation in which the two or more call trees generated during runs of two or more different builds of a computer program are subtracted from one another to identify build to build differences in the execution of the computer program. From the resulting tree, portions of the runs of the different builds of the computer program where the resource utilization of the computer program has not changed are easily identifiable. Moreover, portions of the runs of the different builds of the computer program where there are improvements or regressions in resource utilization of the computer program may be easily identifiable.

Abstract: A method, apparatus, and computer instructions in a data processing system for processing instructions are provided. Instructions are received at a processor in the data processing system. If a selected indicator is associated with the instruction, counting of each event associated with the execution of the instruction is enabled. In some embodiments, a compiler may obtain performance profile data, annotated by output obtained from the use of the performance indicators and counters, along with the instructions/data of the computer program and use this information to optimize the manner by which the computer program is executed, instructions/data are stored, and the like. The optimizations may be to optimize the instruction paths, optimize the time spent in initial application load, the manner by which the cache and memory is utilized, and the like.

Abstract: A method and apparatus for automatically performing regression processing on trace data are provided. With the apparatus and method, call tree data structures are generated for two or more executions of two or more builds of a computer program. The apparatus and method perform a “tree-minimization” operation on each set of call tree data structures for each of the builds to generate minimized call tree data structures for each build of the computer program. The minimized call tree data structures are then subtracted from one another to generate a subtracted minimized call tree data structure. From this subtracted minimized call tree data structure, the portions of the computer program that are different from build to build and which appreciably and consistently affect the difference in execution of the computer program from build to build may be identified.

Abstract: A method, apparatus, and computer instructions for presenting coverage data for code. The coverage data containing instruction access indicators associated with the code is obtained. Particular instruction access indicators that have been set by a processor in the data processing system in response to execution of the code by the processor are identified to form set instruction access indicators. Each set instruction access indicator is associated with a portion of the code. A presentation for the coverage data is generated. The set instruction access indicators are identified in the presentation. This presentation may be, for example, a graphical presentation.

Abstract: A computer implemented method, apparatus, and computer usable program code to collect information for a system or processor having a transition between an idle state and a non-idle state. Idle counts occurring during execution of code are collected to form collected system or processor information. The collected system or processor information is provided to an application for analyzing why a processor becomes idle.

Abstract: A method, apparatus, and computer instructions for presenting coverage data relating to data access occurring during execution of code. The coverage data containing data access indicators associated with memory locations is obtained. The data access indicators that have been set by a processor in the data processing system in response to access of the memory locations during execution of the code by the processor are identified to form set data access indicators. Each set instruction access indicator is associated with a portion of the memory locations allocated for the code. A presentation for coverage data is generated, wherein the set data access indicators are identified in the presentation.