[petsc-users] MUMPS Stuck

[Nachiket Gokhale]

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.

Also, will -on_error_attach_debugger do the trick?

 -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
>
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