Question on using MUMPS in PETSC

[Hong Zhang]

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