International Business Machines Corporation

Robert Tod Dimpsey

Frank Eliot Levine

Robert John Urquhart

William Preston Alexander, Iii

Phani Gopal V Achanta

Kean G Kuiper

Harshal Hemendra Shah

Phani Achanta

Michael Richard Fortin

Robert Francis Berry

Geoffrey Owen Blandy

Enio Manuel Pineda

Matthew Francis Peters

Chendong Zou

Weiming Gu

Edwin V Sapugay

Brian David Peacock

Pranta Das

William Presten Alexander, Iii

Benjamin Joseph Hoflich

Raghuram Thiagarajan

Maher Saba

A method and apparatus for identifying a minimum call tree data structure from a plurality of call tree data structures are provided. With the apparatus and method, call tree data structures are generated for two or more executions of a build of a computer program. The apparatus and method perform a 'tree-minimization' operation in which the two or more call trees generated during runs of the computer program are walked and only those nodes that are present in each of the tree data structures are maintained in a minimized tree data structure. In addition, the minimum values for these common nodes are maintained in the minimized tree data structure. In this way, asynchronous events are removed from the minimum tree data structure and analysis may focus on those areas of the computer program that are consistent between runs of the computer program.

Removal of asynchronous events in complex application performance analysis

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. Thus, the analyst's attention is directed to these areas of the computer program code which may be optimized in order to obtain better execution of the computer program.

Method for automatic detection of build regressions

Illustrative embodiments disclose 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.

Autonomic test case feedback using hardware assistance for data coverage

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 an instruction in the code into a cache, a determination is made by a processor unit as to whether a prefetch indicator is associated with the instruction. In response to the prefetch indicator being associated with the instruction, a pointer to a data structure identified by the prefetch indicator is selectively prefetched into the cache in the processor.

Method and apparatus for hardware assistance for prefetching a pointer to a data structure identified by a prefetch indicator

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.

Autonomic test case feedback using hardware assistance for code coverage

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.

Method and apparatus for determining leaks in a Java heap

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 &#x201c;hot spot&#x201d; method. The method that called the &#x201c;hot spot&#x201d; method, or &#x201c;caller&#x201d; 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. A list of callers of instrumented methods is maintained and used to determine one or more calling methods of the instrumented caller method. One or more of these calling methods may be instrumented and the hooks inserted in the instrumented caller method (called by the one or more calling methods), are removed. In this way, the call graph of the hot spots of a program execution is &#x201c;walked up&#x201d; and characterized over time.

Apparatus and method for dynamic instrumenting of code to minimize system perturbation

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.

Method and apparatus for hardware awareness of data types

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.

Method and apparatus for prefetching data from a data structure

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.

Method and apparatus for averaging out variations in run-to-run path data of a computer program

A business integration (BI) system receives business objects from a source application at an event partitioner. Event partitioner partitions received business objects into independent sets based on interdependent events, and allocates each independent group of business events to a separate event queue based a partitioning modulo reduction transformation of the independent sets to determine the correct event queue for storing a particular received business object. This transformation reduces the number of independent sets to a number of event groups equal to the number of allocated event queues. Events in different groups are delivered to an interchange server through the separate event queues so that they may be processed independently and in parallel, thus improving the overall performance of the interchange server, while guaranteeing that dependent events are processed in the correct serial order.

Efficient and scalable event partitioning in business integration applications using multiple delivery queues

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.

Method and apparatus for identifying differences in runs of a computer program due to code changes

A chunking controller within a broker layer detects a large object, where a large object is one that the size of the allocation of the large object within a memory heap exceeds a maximum contiguous free space within the Java heap. The broker layer operates atop the Java Virtual Manager to facilitate communication and business processes between heterogeneous systems. The chunking controller describes the large object by an underlying array of the large object divided into multiple pieces of a size not exceeding the maximum contiguous free space. Then, the chunking controller enables requests through the broker layer for allocation by the Java Virtual Manager of each of the pieces of the large object within the Java heap, such that the broker layer facilitates efficient allocation of large objects in the Java heap managed by the Java Virtual Manager.

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Austin, TX, United States of America

Robert Tod Dimpsey