On Wed, Nov 25, 2009 at 3:19 PM, Barry Smith <bsmith at mcs.anl.gov> wrote: > > ?Lisandro, > > ? ? That change will certainly NOT be reverted. PETSC_ARCH_NAME! what the > heck kind of variable name is that? >
I agree the name could be messy or misleading. But so is PETSC_ARCH, which should actually be something like PETSC_CONF, right? > > ? ? I need to understand the reason for PETSC_ARCH_NAME, then we can come up > with some solution. OK. Let see. > What is the difference between > PETSC_ARCH_NAME and PETSC_ARCH? > None > Is it only needed when --prefix is used (so > PETSC_ARCH does not exist), Yes. > if so, exactly why is it needed, the whole idea > behind --prefix is to eliminate PETSC_ARCH, In the particular case of petsc4py, the Python extension module get's installed as "lib/$PETSC_ARCH/PETSc.so". Then, for --prefix installs of PETSc, I use the PETSC_ARCH_NAME (obtained from parsing makefiles, as for many other configuration stuff). > > so why is it needed? How is > PETSC_ARCH_NAME used? > I can certainly change my way of doing things in petsc4py. Perhaps I should install as "lib/PETSc.so" for --prefix PETSc builds? I said this before, but let's go one more time: I find --prefix installs of PETSc a bit useless for general-purpose installations. Supose as sysadmin "make install" PETSc in a cluster. She likely built using a C as language, double precision real scalars, 32bit integers, (dbg/opt?). Such configuration does not fit all applications. Some users may require C++, other may want complex, others may want to run her own codes with a debug version. Then I see VERY little point on --prefix builds of PETSc. Moreover, in our machines at CIMEC I maintain central installations of PETSc at /usr/local/petsc/3.0.0. This is not done at all with --prefix and "make install", instead, "/usr/local/petsc/3.0.0" is a HG clone of release-3.0.0. For all these reasons, petsc4py stills support clearly separated lib/$PETSC_ARCH/PETSc.so ext modules. For example, switching from debug to optimized is just a matter of "export PETSC_ARCH=opt-arch-name" and "python script.py". Perhaps now it is the time to change a bit this, but I certainly need some advice/discussion/comments from your side. -- Lisandro Dalc?n --------------- Centro Internacional de M?todos Computacionales en Ingenier?a (CIMEC) Instituto de Desarrollo Tecnol?gico para la Industria Qu?mica (INTEC) Consejo Nacional de Investigaciones Cient?ficas y T?cnicas (CONICET) PTLC - G?emes 3450, (3000) Santa Fe, Argentina Tel/Fax: +54-(0)342-451.1594
