On Fri, Jan 20, 2012 at 1:52 PM, Wen Jiang <jiangwen84 at gmail.com> wrote:
> Hi Jed, > > Could you cover it a bit more details why it will get deadlock unless the > number of elements is *exactly* the same on every process? Thanks. > The flush call is collective. Everyone has to call it the same number of times. Matt > Regards, > Wen > > Message: 5 > Date: Fri, 20 Jan 2012 11:36:17 -0600 > From: Jed Brown <jedbrown at mcs.anl.gov> > Subject: Re: [petsc-users] generate entries on 'wrong' process > To: PETSc users list <petsc-users at mcs.anl.gov> > Message-ID: > <CAM9tzSnQvEDOSTrHbbMZVOyOg2+yPA2zeYM-ouk1HGr09tE7hA at mail.gmail.com > > > Content-Type: text/plain; charset="utf-8" > > On Fri, Jan 20, 2012 at 11:31, Wen Jiang <jiangwen84 at gmail.com> wrote: > > > The serial job is running without any problems and never stalls. Actually > > the parallel jobs also running successfully on distributed-memory desktop > > or on single node of cluster. It will get stuck if it is running on more > > than one compute node(now it is running on two nodes). Both the serial > job > > and parallel job (running on distributed or cluster) I mentioned before > > have the same size(dofs). But If I ran a smaller job on cluster with two > > nodes, it might not get stuck and work fine. > > > > As you said before, I add MAT_ASSEMBLY_FLUSH after every element > stiffness > > matrix is inserted. > > > > This will deadlock unless the number of elements is *exactly* the same on > every process. > > > > I got the output like below, and it gets stuck too. > > > > > -- What most experimenters take for granted before they begin their experiments is infinitely more interesting than any results to which their experiments lead. -- Norbert Wiener -------------- next part -------------- An HTML attachment was scrubbed... URL: <http://lists.mcs.anl.gov/pipermail/petsc-users/attachments/20120120/4d384210/attachment.htm>
