Barry, No, this is the same program I've used quite successfully using iterative methods within PETSc for years. Each processors portion of the matrix is constructed on the individual processors.
In fact, I downloaded and recompiled PETSc to use SUPERLU, and using the exact same program, but changing the matrix type from aijmumps to superlu_dist, and it worked just fine. So, I'm not sure why MUMPS is not working. Randy Barry Smith wrote: > > Are you sure you are not constructing the original matrix with all its > rows and columns > on the first process? > > Barry > On Aug 1, 2008, at 5:49 PM, Randall Mackie wrote: > >> In fact, during the Analysis step, the max amount of memory 300 Mbytes is >> used by one process. However, during the Factorization stage, that >> same process >> then starts to increase in memory, with all the other processes >> staying the same. >> >> I've re-run this several times using different numbers of processors, >> and I >> keep getting the same behavior. >> >> >> >> Randy >> >> >> Jean-Yves L Excellent wrote: >>> Hi, >>> Clearly in MUMPS processor 0 uses more memory during >>> the analysis step because the analysis is sequential. >>> So until we provide a parallel analysis, processor 0 >>> is gathering the graph of the matrix from all other >>> processors to perform the analysis. But that memory >>> is freed at the end of the analysis so it should >>> not affect the factorization. >>> Thanks for letting us know if you have more information. >>> Regards, >>> Jean-Yves >>> Hong Zhang wrote: >>>> >>>> Randy, >>>> The petsc interface does not create much of extra >>>> memories. >>>> The analysis phase of MUMPS solver is sequential - which might >>>> causes one process blow up with memory. >>>> I'm forwarding this email to the mumps developer >>>> for their input. >>>> >>>> Jean-Yves, >>>> What do you think about the reported problem >>>> (see attached below)? >>>> >>>> Thanks, >>>> >>>> Hong >>>> >>>> On Thu, 31 Jul 2008, Randall Mackie wrote: >>>> >>>>> Barry, >>>>> >>>>> I don't think it's the matrix - I saw the same behavior when I ran >>>>> your >>>>> ex2.c program and set m=n=5000. >>>>> >>>>> Randy >>>>> >>>>> >>>>> Barry Smith wrote: >>>>>> >>>>>> If m and n are the number of rows and columns of the sparse >>>>>> matrix (i.e. it is >>>>>> tiny problem) then please >>>>>> send us matrix so we can experiment with it to >>>>>> petsc-maint at mcs.anl.log >>>>>> >>>>>> You can send us the matrix by simply running with >>>>>> -ksp_view_binary and >>>>>> sending us the file binaryoutput. >>>>>> >>>>>> Barry >>>>>> >>>>>> On Jul 31, 2008, at 5:56 PM, Randall Mackie wrote: >>>>>> >>>>>>> When m = n = small (like 50), it works fine. When I set m=n=5000, >>>>>>> I see >>>>>>> the same thing, where one process on the localhost is taking >4 G >>>>>>> of RAM, >>>>>>> while all other processes are taking 137 M. >>>>>>> >>>>>>> Is this the standard behavior for MUMPS? It seems strange to me. >>>>>>> >>>>>>> Randy >>>>>>> >>>>>>> >>>>>>> Matthew Knepley wrote: >>>>>>>> Does it work on KSP ex2? >>>>>>>> Matt >>>>>>>> On Thu, Jul 31, 2008 at 4:35 PM, Randall Mackie >>>>>>>> <rlmackie862 at gmail.com> wrote: >>>>>>>>> I've compiled PETSc with MUMPS support, and I'm trying to run a >>>>>>>>> small test >>>>>>>>> problem, but I'm having some problems. It seems to begin just >>>>>>>>> fine, but >>>>>>>>> what I notice is that on one process (out of 64), the memory >>>>>>>>> just keeps >>>>>>>>> going up and up and up until it crashes, while on the other >>>>>>>>> processes, >>>>>>>>> the memory usage is reasonable. I'm wondering if anyone might >>>>>>>>> have any idea >>>>>>>>> why? By the way, my command file is like this: >>>>>>>>> >>>>>>>>> -ksp_type preonly >>>>>>>>> -pc_type lu >>>>>>>>> -mat_type aijmumps >>>>>>>>> -mat_mumps_cntl_4 3 >>>>>>>>> -mat_mumps_cntl_9 1 >>>>>>>>> >>>>>>>>> >>>>>>>>> Randy >>>>>>>>> >>>>>>>>> ps. This happens after the analysis stage and in the >>>>>>>>> factorization stage. >>>>>>>>> >>>>>>>>> >>>>>>> >>>>>> >> >
