1. * Third party brands and names are the property of their respective owners. Performance Tuning Linux* Applications LinuxWorld Conference & Expo Gary Carleton Staff SW Engineer Intel Corp.

2. 2* Third party brands and names are the property of their respective owners. Agenda Introduction Introduction –2 Performance Tuning Methodologies –CPU Execution time bottlenecks –Flow of control –Overview of the tools –Native Command Line Tool THE DEMO – Primary portion of this session THE DEMO – Primary portion of this session –Demonstration of the 2 Methodologies

3. 3* Third party brands and names are the property of their respective owners. Some Performance Tool Ideas The act of measuring performance shouldn’t change the performance of the software The act of measuring performance shouldn’t change the performance of the software –Accurate, representative results with no instrumentation –Low intrusive performance measurements –Interrupt based sampling driven by CPUs registers Programmers need to see System-wide performance Programmers need to see System-wide performance –Identify the software that is consuming most of the CPU –Application, shared objects, O.S. layer, device driver, …

4. 4* Third party brands and names are the property of their respective owners. Performance Analysis Methodologies Goal is to be able to analyze, in detail, performance issues for a Linux* application Goal is to be able to analyze, in detail, performance issues for a Linux* application Identify Performance Bottlenecks Identify Performance Bottlenecks –Interrupt based sampling using CPU registers Examine flow of control through the app Examine flow of control through the app –Which functions took the longest –Which functions were blocked the longest –Calling sequence critical path

5. 5* Third party brands and names are the property of their respective owners. 2 Methodologies: Performance Bottlenecks “Sample” the CPU’s execution context “Sample” the CPU’s execution context As program runs, gather occasional CPU context snapshots triggered by CPU’s performance monitoring registers As program runs, gather occasional CPU context snapshots triggered by CPU’s performance monitoring registers –Low intrusion –No special builds required Sample rate set to provide statisitcally meaningful data Sample rate set to provide statisitcally meaningful data –Based on CPU clock speed or can be auto-calibrated Can measure performance sensitive CPU events Can measure performance sensitive CPU events –Cache misses, branch mispredictions, …

6. 6* Third party brands and names are the property of their respective owners. 2 Methodologies: Programmatic Flow of control Instrumented technology Instrumented technology –Some performance degradation –Binary is instrumented – No special build needed Identifies function to function calling sequences Identifies function to function calling sequences Reports statistics for each called function Reports statistics for each called function –Execution time –Blocked time –Calling sequences & frequency of occurance

7. 7* Third party brands and names are the property of their respective owners. Software Performance Tools VTune™ Performance Analyzer VTune™ Performance Analyzer Intel® C++ Compiler Intel® C++ Compiler Intel Fortran Compiler Intel Fortran Compiler Intel Performance Libraries Intel Performance Libraries Intel Training Center Intel Training Center

8. 8* Third party brands and names are the property of their respective owners. VTune™ Performance Analyzer VTune Analyzer for Linux*, Command Line version VTune Analyzer for Linux*, Command Line version –Low intrusion technology –System wide analysis Runs natively on Linux* Runs natively on Linux* –Previous version required Windows system for Analysis –Port of previously existing Windows based tool –Analysis performed on Linux system

9. 9* Third party brands and names are the property of their respective owners. Demonstrations Description of Linux* app to be analyzed Description of Linux* app to be analyzed Run & Analyze the app twice: Run & Analyze the app twice: –CPU time: Identify performance bottlenecks –Flow of control through the program

10. 10* Third party brands and names are the property of their respective owners. Schedule VTune™ Analyzer for Linux*, Command Line version VTune™ Analyzer for Linux*, Command Line version –Beta is available now –www.intel.com/software/products www.intel.com/software/products Production Release Production Release –Available Q1 2003 –Purchase from Intel’s SW website –www.intel.com/software/products www.intel.com/software/products

11. 11* Third party brands and names are the property of their respective owners. VTune™ Analyzer for Linux* Future versions Future versions –Configurations –Features Demonstration in the Exhibition Hall at the Intel booth, #638 Demonstration in the Exhibition Hall at the Intel booth, #638 Intel Compiler session: Intel Compiler session: –“Using C++ Compiler Options to improve Linux- based application performance” –Thursday January 23 4-5pm www.intel.com/software/products