[petsc-users] MUMPS error

Sat May 23 07:09:24 CDT 2015

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 ?

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
>
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