VAMPIR

Visualization and Analysis of MPI Resources Commercial tool from PALLAS GmbH VAMPIRtrace - MPI profiling library VAMPIR - trace visualization tool

VAMPIRtrace Separate Installation and User’s Guide for each supported platform Works with MPICH and all vendor MPIs Instrumentation done by linking your application with the VAMPIRtrace library API for stopping and starting tracing and for inserting user-defined events into the trace file Trace files generated by MPI processes are automatically collected and merged into a single trace file

VAMPIRtrace API Used to start and stop tracing and to define application- specific activities Error to call any VAMPIRtrace API routines before MPI_Init or after MPI_Finalize To disable trace collection for the local process: –void VT_traceoff(void) –SUBROUTINE VTTRACEOFF() To re-enable trace collection for the local process: –void VT_traceon(void) –SUBROUTINE VTTRACEON()

VAMPIRtrace API (cont.) User-defined activities –Process states with start and stop times –Activitiy class can contain activities with different symbolic names –Start and stop routines identify activity by an integer code that is attached to the class/symbol pair by first calling a definition routine –Activity definitions are process local, but integer codes must be assigned in a globally consistent manner.

VAMPIRtrace Configuration File Logfile-name –Name for logfile to contain merged trace file Logfile-rank –Rank of process that will write logfile Internal-msgs [on|off] –Specifies whether communications internal to the MPI library should be traced

Configuration file (cont.) Activity [on|off] –Defines a filter for matched activity classes Symbol [on|off] –Defines a filter for matched symbol names Filter directives are evaluated in order.

Filtering Example # disable all MPI activities ACTIVITY MPI OFF # enable all send routines SYMBOL MPI_*send ON # except MPI_Bsend SYMBOL MPI_bsend OFF # enable receives SYMBOL MPI_recv ON # and all test routines SYMBOL MPI_test* ON # and all wait routines SYMBOL MPI_wait* ON # enable all activities in the Application class ACTIVITY Application ON

Default Configuration LOGFILE-RANK 0 INTERNAL-MSGS OFF ACTIVITY * ON

Limiting VAMPIRtrace Logfile Size Limit number of events to be logged by scaling down application input files, iteration count, number of processes, etc. Enable trace data collection for just a subset of the application’s runtime. Use the filtering mechanism to limit the set of logged events.

Managing VAMPIRtrace API Calls Need both instrumented and uninstrumented versions Dummy API library libVTnull.a –Maps API calls to empty subroutines –Slight overhead Use C preprocessor (or equivalent tool for Fortran) to guard calls to the VAMPIRtrace API using #ifdef directives

VAMPIR Highly configurable trace visualization tool Originally developed by Forschungszentrum Julich GmbH under name PARvis Available for all major workstations and some SMPs and MPPs Requires graphical display running X11R5 or later

VAMPIR Displays Process State Display Statistics Display Timeline Display Communications Statistics Configured by using –Pull-down menus –Configuration file

VAMPIR Control Panel

Global Timeline for entire 29-second run

Magnification near 9.87-second point

Statistics Display

Tracing off until near end of run

Selecting display options

MPI Activity Selected

Bar chart view of Statistics Display

Selecting Timeline Portion