On 30 March 2012 19:34, Barry Smith <bsmith at mcs.anl.gov> wrote: > > On Mar 30, 2012, at 11:07 AM, Lisandro Dalcin wrote: > >> On 30 March 2012 19:00, Lisandro Dalcin <dalcinl at gmail.com> wrote: >>> On 30 March 2012 18:20, Blaise Bourdin <bourdin at lsu.edu> wrote: >>>> >>>> On Mar 30, 2012, at 10:13 AM, Jed Brown wrote: >>>> >>>> The PetscLayout is shared. It should probably not be allowed to change >>>> block >>>> size after duplicating. >>>> >> >> Actually, reading my previous reply, I did not expressed it well. I DO >> AGREE with you that blocksizes should not be allowed to change once >> set for first time. However, I think PETSc do have some code around >> (in PC?) relying on this and unashamedly changing the bs of an INPUT >> vector! If that was fixed, then we can disable changing bs for Vec. >> But as long as we need to support this misfeature, at least let's try >> to do better around the lines of my patch (BTW, I'm not sure how to >> handle the blocked local to global mapping.... perhaps we can >> reconstruct another one?) > > > ? Let's locate all the code that changes the block size (after it is set) and > eradicate it, then we won't need this bad patch. >
I think I complained about this long, long ago: $ grep VecSetBlockSize -nR src/ksp/pc/ src/ksp/pc/impls/fieldsplit/fieldsplit.c:637: ierr = VecSetBlockSize(x,jac->bs);CHKERRQ(ierr); src/ksp/pc/impls/fieldsplit/fieldsplit.c:638: ierr = VecSetBlockSize(y,jac->bs);CHKERRQ(ierr); src/ksp/pc/impls/fieldsplit/fieldsplit.c:710: ierr = VecSetBlockSize(x,jac->bs);CHKERRQ(ierr); src/ksp/pc/impls/fieldsplit/fieldsplit.c:711: ierr = VecSetBlockSize(y,jac->bs);CHKERRQ(ierr); > > ?I think this can be done by having VecSetBlockSize() simple error out it if > the map->bs != -1 and new block size not equals current block size. > Are you sure? How are we going to support the usage below?: VecCreateSeq(comm,n,&vec) VecSetBlockSize(vec,bs) We cannot certainly have a long-living vec with bs=-1, right? -- Lisandro Dalcin --------------- CIMEC (INTEC/CONICET-UNL) Predio CONICET-Santa Fe Colectora RN 168 Km 472, Paraje El Pozo 3000 Santa Fe, Argentina Tel: +54-342-4511594 (ext 1011) Tel/Fax: +54-342-4511169
