HPCC Mid-Morning Break Dirk Colbry, Ph.D. Research Specialist Institute for Cyber Enabled Discovery TotalView Parallel Debugger

Prerequisites for running TotalView Compiling with the –g option How to run TotalView with serial code. How to run TotalView using openmpi

Prerequisites Requires a working X11 server  s/Installing+an+X-server+on+Windows s/Installing+an+X-server+on+Windows module load totalview  already on by default on the dev nodes.

Compiling your code You need to add the –g option to either your compile command. The –g option adds links to your source code from executable. If you do not add the –g option:  TotalView will still work.  However, it will not show you your code.  Instead it will show you machine code.

Serial Totalview Use the following command to start totalview:  totalview./programname If you have input arguments  totalview./programname –a

Basic TotalView Interface

Startup Parameters

Select Replay Engine

Main Window Variable Stack Source Code Navigatio n Bar Program Stack Go Button

Main Window

Tracking Down an Error Use your mouse to select different functions in your stack.

Program Navigation Next – Move to next line Prev – Move to previous line Step – Step into a function Caller – Move back to call of function

Break Points Click on Line number to add/remove a break point. Blue Arrow Represents farthest forward the program has run. Yellow arrow represents the current line being displayed. Breakpoints are show in the bottom panel

Other interface options Right click on a function name and select “Dive” to look at the code for that function. Hover your mouse pointer over a variable to see the current values.

TotalView and openmpi Compile your code using openmpi.  module swap mvapich openmpi  Don’t forget the –g option Use totalview interface to set up your mpitest  Totalview &

MPI New Program

Process Window

MPI Interface Process Navigation

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