[petsc-users] MUMPS error

Sun May 24 08:57:38 CDT 2015

I am using Matload option as in the ex7.c code given by the Slepc.
ierr = MatLoad(A,viewer);CHKERRQ(ierr);

There is no problem here right ? or any additional option is required for
very large matrices while running the eigensolver in parallel ?

cheers,
Venkatesh

On Sat, May 23, 2015 at 5:43 PM, Matthew Knepley <knepley at gmail.com> wrote:

> On Sat, May 23, 2015 at 7:09 AM, venkatesh g <venkateshgk.j at gmail.com>
> wrote:
>
>> Hi,
>> Thanks.
>> Per node it has 24 cores and each core has 4 GB RAM. And the job was
>> submitted in 10 nodes.
>>
>> So, does it mean it requires 10G for one core ? or for 1 node ?
>>
>
> The error message from MUMPS said that it tried to allocate 10G. We must
> assume each process
> tried to do the same thing. That means if you scheduled 24 processes on a
> node, it would try to
> allocate at least 240G, which is in excess of what you specify above.
>
> Note that this has nothing to do with PETSc. It is all in the
> documentation for that machine and its
> scheduling policy.
>
>   Thanks,
>
>      Matt
>
>
>> cheers,
>>
>> Venkatesh
>>
>> On Sat, May 23, 2015 at 5:17 PM, Matthew Knepley <knepley at gmail.com>
>> wrote:
>>
>>> On Sat, May 23, 2015 at 6:44 AM, venkatesh g <venkateshgk.j at gmail.com>
>>> wrote:
>>>
>>>> Hi,
>>>> The same eigenproblem runs with 120 GB RAM in a serial machine in
>>>> Matlab.
>>>>
>>>> In Cray I fired with 240*4 GB RAM in parallel. So it has to go in right
>>>> ?
>>>>
>>>
>>> I do not know how MUMPS allocates memory, but the message is
>>> unambiguous. Also,
>>> this is concerned with the memory available per node. Do you know how
>>> many processes
>>> per node were scheduled? The message below indicates that it was trying
>>> to allocate 10G
>>> for one process.
>>>
>>>
>>>> And for small matrices it is having negative scaling i.e 24 core is
>>>> running faster.
>>>>
>>>
>>> Yes, for strong scaling you always get slowdown eventually since
>>> overheads dominate
>>> work, see Amdahl's Law.
>>>
>>>   Thanks,
>>>
>>>      Matt
>>>
>>>
>>>> I have attached the submission script.
>>>>
>>>> Pls see.. Kindly let me know
>>>>
>>>> cheers,
>>>> Venkatesh
>>>>
>>>>
>>>> On Sat, May 23, 2015 at 4:58 PM, Matthew Knepley <knepley at gmail.com>
>>>> wrote:
>>>>
>>>>> On Sat, May 23, 2015 at 2:39 AM, venkatesh g <venkateshgk.j at gmail.com>
>>>>> wrote:
>>>>>
>>>>>> Hi again,
>>>>>>
>>>>>> I have installed the Petsc and Slepc in Cray with intel compilers
>>>>>> with Mumps.
>>>>>>
>>>>>> I am getting this error when I solve eigenvalue problem with large
>>>>>> matrices: [201]PETSC ERROR: Error reported by MUMPS in numerical
>>>>>> factorization phase: Cannot allocate required memory 9632 megabytes
>>>>>>
>>>>>
>>>>> It ran out of memory on the node.
>>>>>
>>>>>
>>>>>> Also it is again not scaling well for small matrices.
>>>>>>
>>>>>
>>>>> MUMPS strong scaling for small matrices is not very good. Weak scaling
>>>>> is looking at big matrices.
>>>>>
>>>>>   Thanks,
>>>>>
>>>>>      Matt
>>>>>
>>>>>
>>>>>> Kindly let me know what to do.
>>>>>>
>>>>>> cheers,
>>>>>>
>>>>>> Venkatesh
>>>>>>
>>>>>>
>>>>>> On Tue, May 19, 2015 at 3:02 PM, Matthew Knepley <knepley at gmail.com>
>>>>>> wrote:
>>>>>>
>>>>>>> On Tue, May 19, 2015 at 1:04 AM, venkatesh g <
>>>>>>> venkateshgk.j at gmail.com> wrote:
>>>>>>>
>>>>>>>> Hi,
>>>>>>>>
>>>>>>>> I have attached the log of the command which I gave in the master
>>>>>>>> node: make streams NPMAX=32
>>>>>>>>
>>>>>>>> I dont know why it says 'It appears you have only 1 node'. But
>>>>>>>> other codes run in parallel with good scaling on 8 nodes.
>>>>>>>>
>>>>>>>
>>>>>>> If you look at the STREAMS numbers, you can see that your system is
>>>>>>> only able to support about 2 cores with the
>>>>>>> available memory bandwidth. Thus for bandwidth constrained
>>>>>>> operations (almost everything in sparse linear algebra
>>>>>>> and solvers), your speedup will not be bigger than 2.
>>>>>>>
>>>>>>> Other codes may do well on this machine, but they would be compute
>>>>>>> constrained, using things like DGEMM.
>>>>>>>
>>>>>>>   Thanks,
>>>>>>>
>>>>>>>      Matt
>>>>>>>
>>>>>>>
>>>>>>>> Kindly let me know.
>>>>>>>>
>>>>>>>> Venkatesh
>>>>>>>>
>>>>>>>>
>>>>>>>>
>>>>>>>> On Mon, May 18, 2015 at 11:21 PM, Barry Smith <bsmith at mcs.anl.gov>
>>>>>>>> wrote:
>>>>>>>>
>>>>>>>>>
>>>>>>>>>    Run the streams benchmark on this system and send the results.
>>>>>>>>> http://www.mcs.anl.gov/petsc/documentation/faq.html#computers
>>>>>>>>>
>>>>>>>>>
>>>>>>>>> > On May 18, 2015, at 11:14 AM, venkatesh g <
>>>>>>>>> venkateshgk.j at gmail.com> wrote:
>>>>>>>>> >
>>>>>>>>> > Hi,
>>>>>>>>> > I have emailed the mumps-user list.
>>>>>>>>> > Actually the cluster has 8 nodes with 16 cores, and other codes
>>>>>>>>> scale well.
>>>>>>>>> > I wanted to ask if this job takes much time, then if I submit on
>>>>>>>>> more cores, I have to increase the icntl(14).. which would again take long
>>>>>>>>> time.
>>>>>>>>> >
>>>>>>>>> > So is there another way ?
>>>>>>>>> >
>>>>>>>>> > cheers,
>>>>>>>>> > Venkatesh
>>>>>>>>> >
>>>>>>>>> > On Mon, May 18, 2015 at 7:16 PM, Matthew Knepley <
>>>>>>>>> knepley at gmail.com> wrote:
>>>>>>>>> > On Mon, May 18, 2015 at 8:29 AM, venkatesh g <
>>>>>>>>> venkateshgk.j at gmail.com> wrote:
>>>>>>>>> > Hi I have attached the performance logs for 2 jobs on different
>>>>>>>>> processors. I had to increase the workspace icntl(14) when I submit on more
>>>>>>>>> cores since it is failing with small value of icntl(14).
>>>>>>>>> >
>>>>>>>>> > 1. performance_log1.txt is run on 8 cores (option given
>>>>>>>>> -mat_mumps_icntl_14 200)
>>>>>>>>> > 2. performance_log2.txt is run on 2 cores (option given
>>>>>>>>> -mat_mumps_icntl_14 85  )
>>>>>>>>> >
>>>>>>>>> > 1) Your number of iterates increased from 7600 to 9600, but that
>>>>>>>>> is a relatively small effect
>>>>>>>>> >
>>>>>>>>> > 2) MUMPS is just taking a lot longer to do forward/backward
>>>>>>>>> solve. You might try emailing
>>>>>>>>> > the list for them. However, I would bet that your system has
>>>>>>>>> enough bandwidth for 2 procs
>>>>>>>>> > and not much more.
>>>>>>>>> >
>>>>>>>>> >   Thanks,
>>>>>>>>> >
>>>>>>>>> >      Matt
>>>>>>>>> >
>>>>>>>>> > Venkatesh
>>>>>>>>> >
>>>>>>>>> > On Sun, May 17, 2015 at 6:13 PM, Matthew Knepley <
>>>>>>>>> knepley at gmail.com> wrote:
>>>>>>>>> > On Sun, May 17, 2015 at 1:38 AM, venkatesh g <
>>>>>>>>> venkateshgk.j at gmail.com> wrote:
>>>>>>>>> > Hi, Thanks for the information. I now increased the workspace by
>>>>>>>>> adding '-mat_mumps_icntl_14 100'
>>>>>>>>> >
>>>>>>>>> > It works. However, the problem is, if I submit in 1 core I get
>>>>>>>>> the answer in 200 secs, but with 4 cores and '-mat_mumps_icntl_14 100' it
>>>>>>>>> takes 3500secs.
>>>>>>>>> >
>>>>>>>>> > Send the output of -log_summary for all performance queries.
>>>>>>>>> Otherwise we are just guessing.
>>>>>>>>> >
>>>>>>>>> >     Matt
>>>>>>>>> >
>>>>>>>>> > My command line is: 'mpiexec -np 4 ./ex7 -f1 a2 -f2 b2 -eps_nev
>>>>>>>>> 1 -st_type sinvert -eps_max_it 5000 -st_ksp_type preonly -st_pc_type lu
>>>>>>>>> -st_pc_factor_mat_solver_package mumps -mat_mumps_icntl_14 100'
>>>>>>>>> >
>>>>>>>>> > Kindly let me know.
>>>>>>>>> >
>>>>>>>>> > Venkatesh
>>>>>>>>> >
>>>>>>>>> >
>>>>>>>>> >
>>>>>>>>> > On Sat, May 16, 2015 at 7:10 PM, David Knezevic <
>>>>>>>>> david.knezevic at akselos.com> wrote:
>>>>>>>>> > On Sat, May 16, 2015 at 8:08 AM, venkatesh g <
>>>>>>>>> venkateshgk.j at gmail.com> wrote:
>>>>>>>>> > Hi,
>>>>>>>>> > I am trying to solving AX=lambda BX eigenvalue problem.
>>>>>>>>> >
>>>>>>>>> > A and B are of sizes 3600x3600
>>>>>>>>> >
>>>>>>>>> > I run with this command :
>>>>>>>>> >
>>>>>>>>> > 'mpiexec -np 4 ./ex7 -f1 a2 -f2 b2 -eps_nev 1 -st_type sinvert
>>>>>>>>> -eps_max_it 5000 -st_ksp_type preonly -st_pc_type lu
>>>>>>>>> -st_pc_factor_mat_solver_package mumps'
>>>>>>>>> >
>>>>>>>>> > I get this error: (I get result only when I give 1 or 2
>>>>>>>>> processors)
>>>>>>>>> > Reading COMPLEX matrices from binary files...
>>>>>>>>> > [0]PETSC ERROR: --------------------- Error Message
>>>>>>>>> ------------------------------------
>>>>>>>>> > [0]PETSC ERROR: Error in external library!
>>>>>>>>> > [0]PETSC ERROR: Error reported by MUMPS in numerical
>>>>>>>>> factorization phase: INFO(1)=-9, INFO(2)=2024
>>>>>>>>> >
>>>>>>>>> >
>>>>>>>>> > The MUMPS error types are described in Chapter 7 of the MUMPS
>>>>>>>>> manual. In this case you have INFO(1)=-9, which is explained in the manual
>>>>>>>>> as:
>>>>>>>>> >
>>>>>>>>> > "–9 Main internal real/complex workarray S too small. If INFO(2)
>>>>>>>>> is positive, then the number of entries that are missing in S at the moment
>>>>>>>>> when the error is raised is available in INFO(2). If INFO(2) is negative,
>>>>>>>>> then its absolute value should be multiplied by 1 million. If an error –9
>>>>>>>>> occurs, the user should increase the value of ICNTL(14) before calling the
>>>>>>>>> factorization (JOB=2) again, except if ICNTL(23) is provided, in which case
>>>>>>>>> ICNTL(23) should be increased."
>>>>>>>>> >
>>>>>>>>> > This says that you should use ICTNL(14) to increase the working
>>>>>>>>> space size:
>>>>>>>>> >
>>>>>>>>> > "ICNTL(14) is accessed by the host both during the analysis and
>>>>>>>>> the factorization phases. It corresponds to the percentage increase in the
>>>>>>>>> estimated working space. When significant extra fill-in is caused by
>>>>>>>>> numerical pivoting, increasing ICNTL(14) may help. Except in special cases,
>>>>>>>>> the default value is 20 (which corresponds to a 20 % increase)."
>>>>>>>>> >
>>>>>>>>> > So, for example, you can avoid this error via the following
>>>>>>>>> command line argument to PETSc: "-mat_mumps_icntl_14 30", where 30
>>>>>>>>> indicates that we allow a 30% increase in the workspace instead of the
>>>>>>>>> default 20%.
>>>>>>>>> >
>>>>>>>>> > David
>>>>>>>>> >
>>>>>>>>> >
>>>>>>>>> >
>>>>>>>>> >
>>>>>>>>> >
>>>>>>>>> >
>>>>>>>>> > --
>>>>>>>>> > 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
>>>>>>>>> >
>>>>>>>>> >
>>>>>>>>> >
>>>>>>>>> >
>>>>>>>>> > --
>>>>>>>>> > 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
>>>>>>>>> >
>>>>>>>>>
>>>>>>>>>
>>>>>>>>
>>>>>>>
>>>>>>>
>>>>>>> --
>>>>>>> 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
>>>>>>>
>>>>>>
>>>>>>
>>>>>
>>>>>
>>>>> --
>>>>> 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
>>>>>
>>>>
>>>>
>>>
>>>
>>> --
>>> 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
>>>
>>
>>
>
>
> --
> 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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