International Business Machines Corporation

Christopher Michael Richardson

Frank Eliot Levine

Robert John Urquhart

Jimmie Earl DeWitt, Jr

Chester Charles John, Jr

Robert Francis Berry

Enio Manuel Pineda

Robert J Urguhart

Riaz Yousuf Hussain

Edward John Silha

William Preston Alexander, Iii

Kean G Kuiper

Donald Lawrence Mulvey

Hardware assist to autonomically patch code. The present invention provides hardware microcode to a new type of metadata to selectively identify instructions to be patched for specific performance optimization functions. The present invention also provides a new flag in the machine status register (MSR) to enable or disable a performance monitoring application or process to perform code-patching functions. If the code patching function is enabled, the application or process may patch code at run time by associating the metadata with the selected instructions. The metadata includes pointers pointing to the patch code block code. The program code may be patched autonomically without modifying original code.

Autonomic hardware assist for patching code

A data processing system for processing instructions is shown. 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.

Counting instruction execution and data accesses

A method, apparatus, and computer instructions for qualifying events by types of interrupt when interrupt occurs in the processor of a data processing system. A programmable performance monitoring unit (PMU) is used to program hardware counters that collect events associated with a type of interrupt, including nested interrupts. The performance monitoring unit may also count events that occur while servicing interrupt requests based upon the state of interrupt processing. Events that are known to the performance monitoring unit such as instruction retired, TLB misses, may be counted at the same time using a number of performance monitoring counters in the performance monitoring unit.

Qualifying collection of performance monitoring events by types of interrupt when interrupt occurs

A method, an apparatus, and a computer program product in a data processing system are presented for using hardware assistance for gathering performance information that significantly reduces the overhead in gathering such information. Performance indicators are associated with instructions or memory locations, and processing of the performance indicators enables counting of events associated with execution of those instructions or events associated with accesses to those memory locations. The performance information that has been dynamically gathered from the assisting hardware is available to the software application during runtime in order to autonomically affect the behavior of the software application, particularly to enhance its performance. For example, the counted events may be used to autonomically control an execution-path selection within the software application.

Method and system for autonomic execution path selection in an application

Illustrative embodiments cover a data processing system for processing instructions and monitoring accesses to memory location ranges. An instruction for execution is identified. A determination is made as to whether the instruction is within a contiguous range of instructions. Execution information relating to the instruction is identified if the instruction is within the contiguous range of instructions. With memory location accesses, an access to a memory location is identified. A determination of whether the memory location is within a contiguous range of memory locations is made. Access information is identified if the memory location is within the contiguous range of memory locations.

Counting instruction and memory location ranges

A method and apparatus in a data processing system for measuring events associated with the execution of 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, the performance indicators, counters, thresholds, and other performance monitoring structures may be stored in a page table that is used to translate virtual addresses into physical storage addresses. A standard page table is augmented with additional fields for storing the performance monitoring structures. These structures may be set by the performance monitoring application and may be queried and modified as events occur that require access to physical storage.

Method and apparatus for maintaining performance monitoring structures in a page table for use in monitoring performance of a computer program

Autonomic method and apparatus for hardware assist for patching code

A method, an apparatus, and a computer program product in a data processing system are presented for using hardware assistance for gathering performance information that significantly reduces the overhead in gathering such information. Performance indicators are associated with instructions or memory locations, and processing of the performance indicators enables counting of events associated with execution of those instructions or events associated with accesses to those memory locations. The performance information that has been dynamically gathered from the assisting hardware is available to the software application during runtime in order to autonomically affect the behavior of the software application, particularly to enhance its performance. For example, the counted events may be used to autonomically collecting statistical information about the ability of a software application to successfully acquire a semaphore.

Method and system for autonomic monitoring of semaphore operations in an application

A method, apparatus, and computer instructions for determining computer flows autonomically using hardware assisted thread stack and cataloged symbolic data. When a new thread is spawned during execution of a computer program, new thread work area is allocated by the operating system in memory for storage of call stack information for the new thread. Hardware registers are set with values corresponding to the new thread work area. Upon context switch, values of the registers are saved in a context save area for future restoration. When call stack data is post-processed, the operating system or a device driver copies call stack data from the thread work areas to a consolidated buffer and each thread is mapped to a process. Symbolic data may be obtained based on the process identifier and address of the method/routine that was called/returned in the thread. Corresponding program flow is determined using retrieved symbolic data and call stack data.

Method and apparatus for determining computer program flows autonomically using hardware assisted thread stack tracking and cataloged symbolic data

A method, apparatus, and computer instructions in a data processing system for monitoring the execution of instructions and accesses to memory locations. If an instruction is associated with a indicator, a counter associated with the instruction is incremented in response to detecting execution of the instruction. The indicator may be associated with a memory location with a counter associated with the memory location being incremented in response to an access of the memory location.

Method and apparatus for counting execution of specific instructions and accesses to specific data locations

Method and apparatus for qualifying collection of performance monitoring events by types of interrupt when interrupt occurs

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.

Method and apparatus for autonomically initiating measurement of secondary metrics based on hardware counter values for primary metrics

A method, a system, an apparatus, and a computer program product are presented for loading LDIF ((Lightweight Directory Access Protocol (LDAP) Data Interchange Format) data into a directory. A single reader thread reads entries from an LDIF file; each entry is associated with a priority value, e.g., the priority value for an entry may be based on the number of delimiters in the distinguished name within the entry. Multiple loading threads concurrently add the entries into an LDAP directory in accordance with their associated priority values. The entries are added to the LDAP directory in an order of highest indicated priority to lowest indicated priority; entries that are associated with priority values that indicate equal priority are considered to be equivalent for the purposes of ordering the entries, so entries that have equal priority may be added to the LDAP directory in any order.

Method and system for maintaining consistency during multi-threaded processing of LDIF data

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.

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Austin, TX, United States of America

Christopher Michael Richardson