DPETSC_USE_FORTRAN_KERNELS-warning

[Satish Balay]

This message is outofdate. I'll fix it in petsc-dev.

The way to enable this feature is to rerun configure with the
additional option

--with-fortran-kernels=generic

You can use additonal option PETSC_ARCH with configure so that a new
set of configuraton [with new set of libraries are created] - this way
the old set is also useable. You can then check if the above option
improves performance or not [and then stick with the higher perfoming
version]

For eg: if your current PETSC_ARCH is linux-gnu - you can do:

./bmake/linux-gnu/configure --with-fortran-kernels=generic PETSC_ARCH=linux-gnu-ftn-kernels
make PETSC_ARCH=linux-gnu-ftn-kernels all
make PETSC_ARCH=linux-gnu-ftn-kernels test

Satish



On Mon, 28 Aug 2006, Patrick Lechner wrote:

> Dear all,
> 
> I currently have the following problem and would be very grateful for any
> useful advice:
> 
> I have written a Fortran code that uses PETSc for the solution of various
> linear systems with complex entries (both in the stiffness matrix and in the
> load vector). When I use the PETSc-Log to check the times for my runs, I get
> the following warning:
> 
>      ##########################################################
> 
> #
> #
>      #                          WARNING!!!
>                     #
>      #
>                             #
>      #   The code for various complex numbers numerical
> #
>      #   kernels uses C++, which generally is not well
>     #
>      #   optimized.  For performance that is about 4-5 times
>    #
>      #   faster, specify the flag -DPETSC_USE_FORTRAN_KERNELS  #
>      #   in base_variables and recompile the PETSc libraries.
> #
> 
> #
> #
>      ##########################################################
> 
> 
> My problem now is, that I can't find "base_variables" in my latest
> PETSc-version (2.3.1-p15)...
> Do I just add the flag to my cpp-flags in bmake/$PETSC_ARCH/petscconf? Or
> should I do this modification somewhere else?
> 
> Thanks a lot for any help with this!
> Best wishes,
> Patrick
> 
> 
> 
> 
> =================================
> 
> Patrick Lechner
> Numerical Analysist / Numerical Modeller
> Flat 1
> 159 Hardgate
> Aberdeen, AB11 6XQ
> 
> Phone: 07815 927333
> E-mail: patrick at lechner.com
> Homepage: http://www.patrick.lechner.com
>