[petsc-users] MUMPS Stuck

[Matthew Knepley]

On Thu, Dec 13, 2012 at 1:44 PM, Nachiket Gokhale <gokhalen at gmail.com> wrote:
> Thanks - should I attached the debugger in debug mode or in optimized mode?
> I suspect it will be tremendously slow in debug mode, otoh I am not sure if
> it will yield any useful information in optimized mode.

Optimized will still give a stack trace.

> Also, will -on_error_attach_debugger do the trick?

No, either spawn one -start_in_debugger -debugger_nodes 0, or attach
using gdb -p <proc id>

   Matt

>  -Nachiket
>
> On Thu, Dec 13, 2012 at 4:29 PM, Matthew Knepley <knepley at gmail.com> wrote:
>>
>> On Thu, Dec 13, 2012 at 1:20 PM, Nachiket Gokhale <gokhalen at gmail.com>
>> wrote:
>> > I am trying to solve a complex matrix equation which was assembled using
>> > MatCompositeMerge using MUMPS and LU preconditioner. It seems to  me
>> > that
>> > the solve is stuck in the factorization phase. It is taking 20 mins or
>> > so,
>> > using 16 processes.  A problem of the same size using reals instead of
>> > complex was solved previously in approximately a minute using 4
>> > processes.
>> > Mumps output of -mat_mumps_icntl_4 1  at the end of this email.  Does
>> > anyone
>> > have any ideas about what the problem maybe ?
>>
>> Complex arithmetic is much more expensive, and you can lose some of
>> the optimizations
>> made in the code. I think you have to wait longer than this. Also, you
>> should try attaching
>> the debugger to a process to see whether it is computing or waiting.
>>
>>    Matt
>>
>> > Thanks,
>> >
>> > -Nachiket
>> >
>> >
>> >
>> > Entering ZMUMPS driver with JOB, N, NZ =   1      122370              0
>> >
>> >  ZMUMPS 4.10.0
>> > L U Solver for unsymmetric matrices
>> > Type of parallelism: Working host
>> >
>> >  ****** ANALYSIS STEP ********
>> >
>> >  ** Max-trans not allowed because matrix is distributed
>> >  ... Structural symmetry (in percent)=  100
>> >  Density: NBdense, Average, Median   =    0   42   26
>> >  Ordering based on METIS
>> >  A root of estimated size         2736  has been selected for Scalapack.
>> >
>> > Leaving analysis phase with  ...
>> > INFOG(1)                                       =               0
>> > INFOG(2)                                       =               0
>> >  -- (20) Number of entries in factors (estim.) =       563723522
>> >  --  (3) Storage of factors  (REAL, estimated) =       565185337
>> >  --  (4) Storage of factors  (INT , estimated) =         3537003
>> >  --  (5) Maximum frontal size      (estimated) =           15239
>> >  --  (6) Number of nodes in the tree           =            7914
>> >  -- (32) Type of analysis effectively used     =               1
>> >  --  (7) Ordering option effectively used      =               5
>> > ICNTL(6) Maximum transversal option            =               0
>> > ICNTL(7) Pivot order option                    =               7
>> > Percentage of memory relaxation (effective)    =              35
>> > Number of level 2 nodes                        =              35
>> > Number of split nodes                          =               8
>> > RINFOG(1) Operations during elimination (estim)=   4.877D+12
>> > Distributed matrix entry format (ICNTL(18))    =               3
>> >  ** Rank of proc needing largest memory in IC facto        :         0
>> >  ** Estimated corresponding MBYTES for IC facto            :      3661
>> >  ** Estimated avg. MBYTES per work. proc at facto (IC)     :      2018
>> >  ** TOTAL     space in MBYTES for IC factorization         :     32289
>> >  ** Rank of proc needing largest memory for OOC facto      :         0
>> >  ** Estimated corresponding MBYTES for OOC facto           :      3462
>> >  ** Estimated avg. MBYTES per work. proc at facto (OOC)    :      1787
>> >  ** TOTAL     space in MBYTES for OOC factorization        :     28599
>> > Entering ZMUMPS driver with JOB, N, NZ =   2      122370        5211070
>> >
>> >  ****** FACTORIZATION STEP ********
>> >
>> >
>> >  GLOBAL STATISTICS PRIOR NUMERICAL FACTORIZATION ...
>> >  NUMBER OF WORKING PROCESSES              =          16
>> >  OUT-OF-CORE OPTION (ICNTL(22))           =           0
>> >  REAL SPACE FOR FACTORS                   =   565185337
>> >  INTEGER SPACE FOR FACTORS                =     3537003
>> >  MAXIMUM FRONTAL SIZE (ESTIMATED)         =       15239
>> >  NUMBER OF NODES IN THE TREE              =        7914
>> >  Convergence error after scaling for ONE-NORM (option 7/8)   = 0.79D+00
>> >  Maximum effective relaxed size of S              =   199523439
>> >  Average effective relaxed size of S              =    98303057
>> >
>> >  REDISTRIB: TOTAL DATA LOCAL/SENT         =      657185    14022665
>> >  GLOBAL TIME FOR MATRIX DISTRIBUTION       =      0.4805
>> >  ** Memory relaxation parameter ( ICNTL(14)  )            :        35
>> >  ** Rank of processor needing largest memory in facto     :         0
>> >  ** Space in MBYTES used by this processor for facto      :      3661
>> >  ** Avg. Space in MBYTES per working proc during facto    :      2018
>> >
>>
>>
>>
>> --
>> 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