On Apr 15, 2013, at 5:26 PM, Jed Brown wrote: > Hui Zhang <mike.hui.zhang at hotmail.com> writes: > >> Maybe my question was unclear. From the manual >> >> http://www.mcs.anl.gov/petsc/petsc-current/docs/manualpages/AO/AOCreateBasicIS.html#AOCreateBasicIS >> >> AOCreateBasicIS(IS isapp,IS ispetsc,AO *aoout) >> >> is collective on IS so the parallel IS's must already conceptually >> contain all the indices from all the processors in the 'comm' of IS. >> Is this also what you meant? > > No, "collective" means that all processes in the communicator must call > the function together. Usually (not always, documentation should > explain), PETSc makes collective interfaces memory scalable so that each > process provides only its local part.
Ok, I see. Thanks very much!
