[petsc-users] About Configuring PETSc

[Balay, Satish]

On Thu, 21 Mar 2019, Maahi Talukder via petsc-users wrote:

> Thank you for your reply.
> 
> So do I need to set the value of PETSC_ARCH as needed in .bashrc  as I did
> in case of PETSC_DIR ?

You can specify PETSC_ARCH as an option to make. You can have a default value set in .bashrc - and change to a different value on command line.

For ex: in .bashrc

export PETSC_ARCH=arch-debug

Now if you want to build with debug libraries:

make wholetest1

Now If you want to build with optimized libraries:

make PETSC_ARCH=arch-opt wholetest1


>  And by PETSC_ARCH=arch-opt, do you mean the
> non-debugging mode?

Yes. You can use whatever name you think is appropriate here.

./configure PETSC_ARCH=a-name-i-can-easily-associate-with-this-build [other configure options.]

> 
> And I am using the following makefile with my code-
> 
> CFLAGS =
> FFLAGS =-I/home/maahi/petsc/include
> -I/home/maahi/petsc/arch-linux2-c-debug/include -cpp -mcmodel=large

Hm - you shouldn't be needing these options here. You should switch your source files from .f to .F and .f90 to .F90 - and remove the above FFLAGS

Satish

> CPPFLAGS =
> FPPFLAGS =
> 
> 
> include ${PETSC_DIR}/lib/petsc/conf/variables
> include ${PETSC_DIR}/lib/petsc/conf/rules
> 
> wholetest1: wholetest1.o
> -${FLINKER} -o wholetest1 wholetest1.o ${PETSC_LIB}
> ${RM} wholetest1.o
> 
> So where do I add that PETSC_ARCH?
> 
> Thanks,
> Maahi Talukder
> 
> On Thu, Mar 21, 2019 at 10:14 PM Balay, Satish <balay at mcs.anl.gov> wrote:
> 
> > PETSc uses the concept of PETSC_ARCH to enable multiple in-place
> > builds.
> >
> > So you can have a debug build with PETSC_ARCH=arch-debug, and a
> > optimized build with PETSC_ARCH=arch-opt etc.
> >
> > And if you are using a petsc formatted makefile with your code - you
> > can switch between these builds by just switching PETSC_ARCH.
> >
> > Satish
> >
> > On Thu, 21 Mar 2019, Maahi Talukder via petsc-users wrote:
> >
> > > Dear All,
> > >
> > > Currently, I am running PETSc with debugging option. And it says that if
> > I
> > > run ./configure --with-debugging=no, the performance would be faster. My
> > > question is: what would I do if I want to go back to debugging mode, and
> > If
> > > I configure it now with no debugging option, would it make any changes to
> > > my current setting?
> > >
> > > Regards,
> > > Maahi Talukder
> > >
> >
> >
>