Tutorial: Reducing Trace File Size for IntelĀ® Trace Analyzer and Collector
Insert
the MPI_Pcontrol
function call into your application to turn the trace collection on and
off.
To collect the data on the exchange function of the poisson application, do the following:
Go to <installdir>/examples/poisson/pardat.f90
Edit the pardat.f90 file:
Right after the MPI_Init call, turn the trace collection off:
MPI_Pcontrol(0);
At the beginning of the poisson_red_black subroutine, turn the trace collection on:
MPI_Pcontrol(1);
At the end of the poisson_red_black subroutine, turn the trace collection off
Save the pardat.f90 file.
Rebuild the application.
Run the application.
Linux* OS:
$ mpirun -trace -n 4 ./poisson
Windows* OS:
> mpiexec -n 4 poisson.exe
Check your work:
Open the resulting trace file poisson.stf in IntelĀ® Trace Analyzer.
In the Function Profile, right-click Group MPI and select Ungroup Group MPI from the context menu.
Go to the Load Balance tab of the Function Profile to see how the MPI_Finalize, MPI_Sendrecv and MPI_Allreduce functions are distributed among the four processes.
Go to Charts > Event Timeline to see the activities in each of the four processes individually.
You can see that the trace data was collected only for a particular part of the code. Note the VT_API group: it stands for the part of the code where trace data collection was turned off: