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. >>>>>>>> >>>>>>>> >>>>>> >>>>> >
