[petsc-users] CG+GAMG convergence issues in GHEP Krylov-Schur for some MPI runs

[Mark Adams]

These are the only PETSc params that I used:

-log_summary
-options_left false
-fp_trap

I last update about 3 weeks ago and I am on a branch.  I can redo this with
a current master.  My repo seems to have been polluted:

13:35 edison12 master> ~/petsc$ git status
# On branch master
# Your branch is ahead of 'origin/master' by 262 commits.
#
nothing to commit (working directory clean)

I trust this is OK but let me know if you would like me to clone a fresh
repo.

Mark



On Wed, Nov 11, 2015 at 11:21 AM, Barry Smith <bsmith at mcs.anl.gov> wrote:

>
>   Thanks
>
>    do you use a petscrc file or any file with PETSc options in it for the
> run?
>
>   Thanks please send me the exact PETSc commit you are built off so I can
> see the line numbers in our source when things go bad.
>
>    Barry
>
> > On Nov 11, 2015, at 7:36 AM, Mark Adams <mfadams at lbl.gov> wrote:
> >
> >
> >
> > On Tue, Nov 10, 2015 at 11:15 AM, Barry Smith <bsmith at mcs.anl.gov>
> wrote:
> >
> >   Please send me the full output. This is nuts and should be reported
> once we understand it better to NERSc as something to be fixed. When I pay
> $60 million in taxes to a computing center I expect something that works
> fine for free on my laptop to work also there.
> >
> >   Barry
> >
> > > On Nov 10, 2015, at 7:51 AM, Mark Adams <mfadams at lbl.gov> wrote:
> > >
> > > I ran an 8 processor job on Edison of a small code for a short run
> (just a linear solve) and got 37 Mb of output!
> > >
> > > Here is a 'Petsc' grep.
> > >
> > > Perhaps we should build an ignore file for things that we believe is a
> false positive.
> > >
> > > On Tue, Nov 3, 2015 at 11:55 AM, Barry Smith <bsmith at mcs.anl.gov>
> wrote:
> > >
> > >   I am more optimistic about valgrind than Mark. I first try valgrind
> and if that fails to be helpful then use the debugger. valgrind has the
> advantage that it finds the FIRST place that something is wrong, while in
> the debugger it is kind of late at the crash.
> > >
> > >   Valgrind should not be noisy, if it is then the
> applications/libraries should be cleaned up so that they are valgrind clean
> and then valgrind is useful.
> > >
> > >   Barry
> > >
> > >
> > >
> > > > On Nov 3, 2015, at 7:47 AM, Mark Adams <mfadams at lbl.gov> wrote:
> > > >
> > > > BTW, I think that our advice for segv is use a debugger.  DDT or
> Totalview, and gdb if need be, will get you right to the source code and
> will get 90% of bugs diagnosed.  Valgrind is noisy and cumbersome to use
> but can diagnose 90% of the other 10%.
> > > >
> > > > On Tue, Nov 3, 2015 at 7:32 AM, Denis Davydov <davydden at gmail.com>
> wrote:
> > > > Hi Jose,
> > > >
> > > > > On 3 Nov 2015, at 12:20, Jose E. Roman <jroman at dsic.upv.es> wrote:
> > > > >
> > > > > I am answering the SLEPc-related questions:
> > > > > - Having different number of iterations when changing the number
> of processes is normal.
> > > > the change in iterations i mentioned are for different
> preconditioners, but the same number of MPI processes.
> > > >
> > > >
> > > > > - Yes, if you do not destroy the EPS solver, then the
> preconditioner would be reused.
> > > > >
> > > > > Regarding the segmentation fault, I have no clue. Not sure if this
> is related to GAMG or not. Maybe running under valgrind could provide more
> information.
> > > > will try that.
> > > >
> > > > Denis.
> > > >
> > >
> > >
> > > <petsc_val.gz>
> >
> >
> > <outval.gz>
>
>
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