[petsc-dev] [Fortran] MatLoad() error: MatLoad is not supported for type: mpiaij!

Mon Sep 6 10:54:12 CDT 2010

Hello Barry, Matt,
About this error I am having:

[2]PETSC ERROR: Nonconforming object sizes!
[2]PETSC ERROR: Mat mat,Vec y: local dim 700536 697068!

I am creating my RHS and initial vector from the same DA as the matrix is
from (see below). I even tried with setting RHS==1 instead of loading from
file, to no avail. I found out the error occurs when #PROC=3,5,7,...,8+ but
NOT when #PROC=2,4,8. It might have something to do with differences in
partitioning strategies of Mat and Vec? As you know my gridsize has a rather
unusual value (number of gridpoints is 2101608).

Leo

**

      call DACreateGlobalVector(da,x,ierr)
      call VecDuplicate(x,b,ierr)
(...)
      call DAGetMatrix(da,MATMPIAIJ,A,ierr)
(...)
      call VecSet(b,one,ierr)
      call KSPCreate(MPI_COMM_WORLD,ksp,ierr)
      call KSPSetOperators(ksp,A,A,SAME_NONZERO_PATTERN,ierr)
(...)
      call KSPSolve(ksp,b,x,ierr)

2010/9/3 Barry Smith <bsmith at mcs.anl.gov>

>
>     You initial vectors must be created with the same DA that is associated
> with the Matrix for the layout to be automatically correct. Use
> DACreateGlobalVector() instead of VecCreate(). You may already be doing this
> and then the problem is more subtle. Let us know.
>
>    Barry
>
>     Something may be going wrong with the copy header
>
> On Sep 3, 2010, at 11:35 AM, Matthew Knepley wrote:
>
> On Fri, Sep 3, 2010 at 5:50 PM, Leo van Kampenhout <
> lvankampenhout at gmail.com> wrote:
>
>> Thanks. Following this conversation closely, i have already built petsc
>> with --with-debugging=0 and found that then thing work better there. Until
>> there is a ultimate fix I'm perfectly happy with that.
>>
>> Even on my cluster, I can now run the program for 2,4,8 cores. But there
>> is always a catch... with 10 cores, GMRES breaks down! (see below) Sorry to
>> bother you with this, it seems unrelated at first sight. Should I issue a
>> new thread for this?
>>
>
> This is almost certainly somewhere you are not careful about constructing
> a Vec with the proper layout (as the message says). In fact, from the trace
> it looks like the rhs Vec passed in is not compatible with the matrix.
>
>   Matt
>
>
>> Regards, Leo
>>
>> [5]PETSC ERROR: --------------------- Error Message
>> ------------------------------------
>> [5]PETSC ERROR: Nonconforming object sizes!
>> [5]PETSC ERROR: Mat mat,Vec y: local dim 210161 213282!
>> [5]PETSC ERROR:
>> ------------------------------------------------------------------------
>> [5]PETSC ERROR: Petsc Development HG revision:
>> 6da7d8c5aaa81099861622f4e6bf1087652253a7  HG Date: Fri Sep 03 15:06:40 2010
>> +0200
>> [5]PETSC ERROR: See docs/changes/index.html for recent updates.
>> [5]PETSC ERROR: See docs/faq.html for hints about trouble shooting.
>> [5]PETSC ERROR: See docs/index.html for manual pages.
>> [5]PETSC ERROR:
>> ------------------------------------------------------------------------
>> [5]PETSC ERROR: ./main on a linux-opt named node164 by s1459295    Fri
>> Sep  3 17:44:26 2010
>> [5]PETSC ERROR: Libraries linked from
>> /home/s1459295/install/petsc-dev/linux-optimized/lib
>> [5]PETSC ERROR: Configure run at Fri Sep  3 15:28:20 2010
>> [5]PETSC ERROR: Configure options --with-debugging=0
>> [5]PETSC ERROR:
>> ------------------------------------------------------------------------
>> [5]PETSC ERROR: MatMult() line 1976 in src/mat/interface/matrix.c
>> [5]PETSC ERROR: KSPInitialResidual() line 55 in
>> src/ksp/ksp/interface/itres.c
>> [5]PETSC ERROR: KSPSolve_GMRES() line 236 in
>> src/ksp/ksp/impls/gmres/gmres.c
>> [5]PETSC ERROR: KSPSolve() line 427 in src/ksp/ksp/interface/itfunc.c
>>
>>
>>
>>
>>
>> 2010/9/3 Jed Brown <jed at 59a2.org>
>>
>> On Fri, 3 Sep 2010 09:15:09 -0600 (GMT-06:00), Shri <abhyshr at mcs.anl.gov>
>>> wrote:
>>> > Leo,
>>> >     Jed and I both tried running a MatLoad example (see
>>> src/dm/da/examples/tests/ex35.c) with petsc configured in debug mode and had
>>> issues running it with your grid size 202 X 102 X 102. This example runs in
>>> a reasonable amount of time with the optimized petsc build.
>>> > I suggest running your code on a smaller grid (100 X100 X 100 seems to
>>> work fine in the debug mode) for now, get it working and then using the
>>> optimized petsc build (--debugging=0) for the large grid size.
>>>
>>> I wrote an improved sort that doesn't have this bad behavior, but I'm
>>> trying to figure out why the old one is okay in optimized mode.  See
>>> here:
>>>
>>>  http://gist.github.com/563948
>>>
>>> The MEDIAN macro chooses the median of the first, last, and middle
>>> element in the segment.  Performance looks like
>>>
>>>  FAST -O1: 2.0 seconds
>>>  FAST -O0: 5 seconds
>>>  SLOW -O1: 2.3 seconds
>>>  SLOW -O0: more than an hour
>>>
>>> SLOW, which is basically the old implementation does a lot of shuffling
>>> with the array and ends up hitting a bad case for quicksort (even with
>>> the median choice).  What I don't understand, is that apparently
>>> building SLOW with -O1 transforms the algorithm into something
>>> asymptotically faster.  The assembly is a few hundred lines, and it's
>>> not obvious to me what this transform would be.
>>>
>>> Jed
>>>
>>
>>
>
>
> --
> 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
>
>
>
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