International Business Machines Corporation

Chester Charles John, Jr

Frank Eliot Levine

Robert Francis Berry

Robert John Urquhart

Riaz Yousuf Hussain

Christopher Michael Richardson

Robert J Urguhart

William Preston Alexander, Iii

Donald Lawrence Mulvey

Enio Manuel Pineda

John Day Howard

An apparatus and method for cataloging symbolic data for use in performance analysis of computer programs is provided. The apparatus and method stores symbolic data for loaded modules during or shortly after a performance trace and utilizes the stored symbolic data when performing a performance analysis at a later time. A merged symbol file is generated for a computer program, or application, under trace. The merged symbol file contains information useful in performing symbolic resolution of address information in trace files for each instance of a module. During post processing of the trace information generated by a performance trace of a computer program, symbolic information stored in the merged symbol file is compared to the trace information stored in the trace file. The correct symbolic information in the merged symbol file for loaded modules is identified based a number of validating criteria. The correct symbolic information for the loaded modules may then be stored as an indexed database that is used to resolve address information into corresponding symbolic information when providing the trace information to a display for use by a user.

Apparatus and method for cataloging symbolic data for use in performance analysis of computer programs

Apparatus and method for performing symbolic resolution of modules using static representations of a trace

A user may specify a vector of metrics to be used while profiling a program. The vector of metrics may optionally be thread-relative. In response to a notification of an occurrence of the current event, a thread-relative elapsed metric is computed by: determining a current thread; retrieving a stored reference metric for the preceding event of the current thread; obtaining a current reference metric; and computing the thread-relative elapsed metric as a difference between the current reference metric and the stored reference metric. In order to prevent the generation of redundant metric information, the information associated with the vector of metrics maybe placed into the trace records in several different space-saving formats.

Processing events during profiling of an instrumented program

Apparatus and method for generating a merged symbol file for verifying symbolic data

An apparatus and method for cataloging symbolic data for use in performance analysis of computer programs is provided. The apparatus and method stores symbolic data for loaded modules during or shortly after a performance trace and utilizes the stored symbolic data when performing a performance analysis at a later time. A merged symbol file is generated for a computer program, or application, under trace. The merged symbol file contains information useful in performing symbolic resolution of address information in trace files for each instance of a module. During post processing of the trace information generated by a performance trace of a computer program, symbolic information stored in the merged symbol file is compared to the trace information stored in the trace file. The correct symbolic information in the merged symbol file for loaded modules is identified based on a number of validating criteria. The correct symbolic information for the loaded modules may then be stored as an indexed database that is used to resolve address information into corresponding symbolic information when providing the trace information to a display for use by a user.

Apparatus and method for creating a trace file for a trace of a computer program based on loaded module information

Apparatus and method for creating an indexed database of symbolic data for use with trace data of a computer program

A process and system for profiling code executing on a data processing system is provided. Event-based trace data is recorded in response to selected events, and the event-based trace data includes an indication of which code is being interrupted. The trace data may be processed to identify a thread or method that was executing during the event. A periodically occurring event is also detected, and a stack associated with the profiled code is identified in response to detection of the periodically occurring event, such as a timer interrupt. The stack is examined to identify each routine that is currently executing during the periodically occurring event.

Process and system for merging trace data for primarily interpreted methods

The present invention is a system, method, and computer readable medium for representing program event trace information in a way which is very compact and efficient, and yet supports a wide variety of queries regarding system performance. The tracing and reduction of the present invention may be dynamic, in which case information is obtained and added to the trace representation in real-time. Alternately, the tracing and reduction may be static, in which case a trace text file or binary file is obtained from a trace buffer, and the reduction takes place using the trace file as input. The trace information, whether obtained statically or dynamically, is represented as a tree of events. The present invention may be used to present many types of trace information in a compact manner which supports performance queries. For example, the tree structure of the present invention may reflect the call stacks observed during a program's execution, and statistics regarding the memory allocated/deallocated in the various routines and call stacks may be stored at each node of the tree. The tree structure may be used to store performance information regarding Java bytecodes executed, memory allocated, or other types of performance information. The trace information is presented in a manner which is compact and efficient, and may be used to quickly and easily answer a variety of performance queries. Further, a system may be traced for long periods of time without losing useful performance information due to a limited buffer space.

System and method for providing trace information

During the recording of events occurring within the operation of a data processing system, a user-selected metric of interest is recorded along with the trace data for each recorded event. The metric of interest is a monotonically increasing variable that provides a non-time relationship between the recorded events. This relationship may be time or non-time based.

General event stamping scheme

A method and apparatus in a data processing system for profiling code for processes executing in a data processing system. Trace data is recorded in response to a selected interrupt, wherein the trace data includes an indication of which code is being interrupted. The trace data is processed to identify whether the interrupted code is interpreted code.

Method and apparatus for profiling processes in a data processing system background of the invention

When building an image for a JavaOS client, a date/time stamp is inserted into the symbolic image produced. When a trace program is initiated against this image, the same Build Identifier is inserted into the produced trace data. A comparison is made between the Build Identifiers to ensure that the trace file is analyzed using the correct symbolic image.

System and method for trace verification

General polygons are broken into trapezoids and/or triangles and exported to a graphics adapter for rendering. Intersecting line segments are broken at the point of inter-section. Simple polygons are then derived from the general polygon by starting at an outside corner and selecting line segments defining the general polygon utilizing criteria which will identify closed paths bounding a single area (e.g., always selecting the line segment which extends in a direction identical to or clockwise from the direction of the last selected line segment). Selected line segments are added to a current polygon definition. Each time an inter-section point is entered twice, the selected line segments from the first exit to the second entry of that intersection point are segregated into a separate polygon definition in the polygon list. Once all simple polygons have been identified, each polygon is broken into trapezoids and/or triangles. A base connection point or line segment having the lowest y-coordinate value is identified, together with adjoining line segments. A trapezoid or triangle is then delimited including at least one adjoining line segment, and the process in repeated until all line segments bounding the simple polygon have been added to at least one primitive definition in a primitive list. The primitives may then be exported to the graphics adapter for rendering. Although processor cycles are required to break the general polygon into primitives, in most cases the work required should be significantly less than that involves in breaking the general polygon into scan lines and generating pixel information for the graphics adapter.

Algorithm to transform generalized polygons to trapezoids

The present invention is directed to a system and method for tracing operations in an information handling system without changing the operating system code. Certain machine registers are shadowed during critical machine state transitions (e.g., taking and returning from interrupts), so that the tracing program does not lose control of the system. The system is interrupted before each instruction is executed, and a tracing program determines if a change in program flow has occurred. If a change in program flow has occured, a record is written to a trace log. The record contains the number of consecutive instructions executed before the program flow change, along with a displacement field indicating the number of bytes from the end of the record to the beginning of the next record. Executed instructions are also embedded in the trace log, allowing for high compression ratios and less complex post-processing of the trace data.

Growing community of inventors

Round Rock, TX, United States of America

Chester Charles John, Jr