Document Actions
HPCToolkit
Up to Table of Contents
HPCToolkit is a measurement tool for profiling application using statistical sampling of the system timer or hardware performance counters.
HPCToolkit is installed on Stallo, see http://hpctoolkit.org/
Example of basic use
On the compute-node:
module load hpctoolkit mpiexec hpcrun-flat Myprog.x
This will produce files such as "Myprog.x.hpcrun-flat.compute-24-5.local.3310.0x0" . Each process produces a separate file.
hpcstruct Myprog.x > Myprog.psxml hpcprof-flat -I '/MyPath/To/Source/Code/*' -S Myprog.psxml Myprog.x.hpcrun-flat.compute-24-5.local.3310.0x*
One or more file can be included in the profile.
The results can be looked at from the front-end (stallo-2) with:
module load hpctoolkit hpcviewer experiment-db/experiment.xml
The profiling information is given down to line numbers.
PAPI (Performance Application Programming Interface)
HPCToolkit make uses of some performance hardware counters.
You can read directly the counters if you include some calls to PAPI routines into your code.
See http://icl.cs.utk.edu/papi/ for details.
The PAPI Library is installed on the compute-nodes only.
Here is a simple fortran example to measure the number of FLOP/s using one of the high level PAPI functions:
program testpapi
real*4 :: rtime, ptime, mflops
integer*8 ::flpops
call PAPIF_flops(rtime, ptime, flpops, mflops,ierr)
call my_calc
call PAPIF_flops(rtime, ptime, flpops, mflops,ierr)
write (*,90) rtime, ptime, flpops, mflops
90 format(' Real time (secs) :', f15.3, &
/' CPU time (secs) :', f15.3,&
/'Floating point instructions :', i15,&
/' MFLOPS :', f15.3)
end program testpapi
subroutine my_calc
real :: x
x=0.5
do i=1,100000000
x=x*x-0.8
enddo
if(x==1000)write(*,*)x
end subroutine my_calc
Compile with
ifort -I/usr/include -L/usr/lib64 -lpapi papi.f90
