Analysing OpenMP Programs Inspector XE and Amplifier XE

Transcription

1 Analysing OpenMP Programs Inspector XE and Amplifier XE Berk ONAT İTÜ Bilişim Enstitüsü 22 Haziran 2012

2 Outline OpenMP Overhead Tools for analyzing OpenMP programs Print statement way!) Intel Thread Analyzing Tools Intel Inspector XE 2011 Intel VTune Amplifier XE /36

3 OpenMP Overhead Source of Overhead cost of up threads their environment the expense incurred by the of a parallel region in a separate func@on the cost of compu@ng the schedule taken to block and unblock threads OpenMP Microbenchmark: hrp://www2.epcc.ed.ac.uk/compu@ng/research_ac@vi@es/ openmpbench/download.html 3/36

4 OpenMP Overhead Source of Overhead cost of up threads their environment the expense incurred by the of a parallel region in a separate func@on the cost of compu@ng the schedule taken to block and unblock threads OpenMP Microbenchmark: hrp://www2.epcc.ed.ac.uk/compu@ng/research_ac@vi@es/ openmpbench/download.html 4/36

5 OpenMP Overhead The single library + barrier) has higher overheads than a barrier. the reduc@on clause is costly because it is implemented via a cri@cal region 5/36

6 OpenMP Overhead Overheads for the different kinds of loop schedules (scale is logarithmic) 6/36

7 Using Print Statements Advantages Can be useful for bugs Can monitor scheduling of on threads Disadvantages Slow, human intensive bug Can make the bug go away Overheads Include thread ID in messages Compute and print checksums on SMR, protect I/O with CRITICAL 7/36

8 Analysing OpenMP Programs Login to your UYBHM node using - X with ssh : bash: $ ssh - X du??@wsl- node??.uhem.itu.edu.tr or use your PuTTY program in your Windows with X11 forwarding in SSH sechon. Copy example file tar to your directory bash: $ cd workshop bash: $ cp /RS/users/bonat/workshop/YAZOKULU/ tar. bash: $ tar - xvf tar bash: $ cd /mpi- analyze/traceanalyzer 8/36

9 Analysing OpenMP Programs For Intel architecture there are two choises for analysing OpenMP codes. Intel Inspector XE 2011 (formerly Intel Thread Checker) Intel VTune Amplifier XE 2011 (formerly Intel VTune Performance Analyzer) Following lines must be added to.bashrc and.bash_profile : source /RS/progs/intel/inspector_xe_2011/inspxe- vars.sh source /RS/progs/intel/vtune_amplifier_xe_2011/amplxe- vars.sh or bash: $ co workshop bash: $ cp /RS/users/bonat/workshop/ tar. bash: $ tar - zxvf tar bash: $ cd /openmp- analyze/ bash: $./add- inspector- amplifier- to- path.sh 9/36

10 Intel Inspector XE Source Intel Inspector XE variable script file by the following command: $./ready- inspector.sh Compile yoru code and execute following commands to analyse your code in GUI based analyzer: $ icc omp_matmul.c - o omp_matmul.x - openmp - g $ inspxe- gui 10/36

11 Intel Inspector XE 2011 Compile your code and execute following commands to analyse your code with text based analyzer: $ icc omp_matmul.c - o omp_matmul.x openmp - g $ inspxe- cl - collect H3 - - omp_matmul.x Used suppression file(s): [] StarHng matrix mulhple example with 4 threads IniHalizing matrices... Thread 0 starhng matrix mulhply... Thread 3 starhng matrix mulhply... Thread 2 starhng matrix mulhply... Thread 1 starhng matrix mulhply... Thread 0 : I got 55 rows Thread 2 : I got 55 rows Thread 3 : I got 55 rows Thread 1 : I got 55 rows 1 new problem(s) found 1 Data race problem(s) detected 11/36

12 Open Inspector Main Window bash: /tmp/ $ inspxe- gui 12/36

13 Creating New Project Select New - > Project Choose a Project name which will be the project directory name. Select your /tmp/ directory path. 13/36

14 Creating New Project Select your /tmp/ directory and create projects folder and sellect. Select New - > Project Choose a Project name which will be the project directory name. 14/36

15 Creating New Project 1. Select Browse 2. And choose your OpenMP 3. 15/36

16 Setting Project Properties Set OMP_NUM_THREADS= Select Modify 16/36 5.

17 Running Analysis Select Analysis Go Inspector Go! Sellect Locate Deadlocks & Dataraces 17/36

18 Viewing Results of Analysis Detected Data race condihons Data race for write operahon Two threads detected In this operahon 18/36 Trace Analyzer & Coll.

19 Intel Amplifier XE Source Intel Amplifier XE variable script file by the following command: $ source /RS/progs/intel/vtune_amplifier_xe_2011/amplxe- vars.sh $./ready- amplifier.sh execute following commands to analyse your code in GUI based analyzer: $ amplxe- gui 19/36

20 Setting Vtune Amplifier Properties 20/36

21 Setting Vtune Amplifier Properties 21/36

22 Sellecting Analysis Type & Run 22/36

23 Sellecting Analysis Type & Run Go Amplifier Go! 23/36

24 Sellecting Analysis Type & Run 24/36

25 Hotspots by Thread Concurrency 25/36

26 Hotspots by Thread Concurrency Time consuming crihcal processes Trace analysis of OpenMP processes in Hmeline CPU usage & concurrency Trace Analyzer & Coll. 26/36

27 Analysis of Thread Concurrency HOTSPOTS Concurrency RaHo 27/36

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