On Mon, Nov 16, 2009 at 10:49 AM, Jed Brown <jed at 59a2.org> wrote: > Since it is not collective, the names can get out of sync, even with > "reasonable" usage. ?Consider a case where rank 0 views a serial Vec > (say with the Matlab viewer), and then a parallel Vec (e.g. to > HDF5). The result would either be deadlock (with collective IO) or a > file where Vec_0 contains all but rank 0's part, and Vec_1 contains only > rank 0's part (and an HDF5 error once another vector is viewed because > the Vec_1 dataspace cannot be created if it already exists). > > Is it reasonable to make PetscObjectName (and necessary dependents) > collective where it performs this? > > ?MPI_Allreduce(MPI_IN_PLACE,&counter,1,MPI_INT,MPI_MAX,obj->comm); >
And what about VecView() of serial objects on two different processes? What about parallel Vec's on subcommunicators of COMM_WORLD? -- 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
