Re: [FLASH-BUGS] hangups on IBM regatta

From: Mike Zingale (zingale@flash.uchicago.edu)
Date: Wed Sep 18 2002 - 12:54:27 CDT

  • Next message: ywrhv@hotbot.com: "[FLASH-BUGS] Program caivv"

    I've never tried 32-bit ABI on an IBM.

    The -O3 usually does not work -- runtime_parameters.F90 is the problem
    (bug #66). The amr_redist_blks hang may be a symptom of this. As best as
    I can tell, we do not have a bug in our code. A pointer just magically
    become dissociated at some point. Things work fine for me if this routine
    is compiled with -O2.

    Mike

    On Wed, 18 Sep 2002, Andrew Siegel wrote:

    > ---------- Forwarded message ----------
    >
    >
    > Date: Thu, 12 Sep 2002 10:30:02 -0500 (CDT)
    > From: Andrew Siegel <siegela@sunspot.uchicago.edu>
    > To: Sebastian Heinz <heinzs@mpa-garching.mpg.de>
    > Cc: flash-bugs@flash.uchicago.edu
    > Subject: Re: [FLASH-BUGS] hangups on IBM regatta
    >
    >
    > Hi Sebastian: Have you tried running with -O2?
    >
    > On Thu, 12 Sep 2002, Sebastian Heinz wrote:
    >
    > > Dear FLASH team,
    > >
    > >
    > > I am having problems getting FLASH to run on the new IBM regatta system at
    > > the IPP in Garching, Germany. A description can be found at
    > >
    > > http://www.rzg.mpg.de/computing/IBM_P/
    > >
    > > Here's a brief description of the problem:
    > >
    > > Currently I am running a 2D hydro simulation in cylindrical coordinates at
    > > relatively high resolution (but the same problem occurs also in cartesian
    > > 3D simulations).
    > >
    > > After running for a while, the system simply hangs up without producing
    > > any errors. This only happens when I run the process on more than two
    > > processors, while it runs fine on one or two processors (i.e., this is not
    > > a maxblocks problem: I compiled using maxblocks=12000 and at the
    > > corresponding timestep the simulation has 4478 blocks). After some
    > > back-tracking, I found that the system hangs in the routine
    > >
    > > amr_redist_blk.F90
    > >
    > > at the MPI_ALLREDUCE call in line 102. Some processors make it past this
    > > call, while the others don't.
    > >
    > > I compiled using the flags
    > >
    > > ABI = -q32 -qmaxmem=-1
    > > OPT1 = -O3 -qstrict -bmaxdata:0x80000000
    > > OPT2 = -qfloat=nomaf -bloadmap:makelog
    > > OPT3 = -qcache=auto -qtune=auto -qarch=auto -qthreaded -qnosave
    > > OPTS = $(OPT1) $(OPT2) $(OPT3)
    > >
    > > Any ideas what this could be? (From what I read on the FLASH website, I
    > > don't seem to be the only one with problems on IBM systems).
    > >
    > > I tried to compile the code with 64 bits, but I couldn't get that to work
    > > - any input on what compiler options to use for 64 bits (and which
    > > libraries I need to link) would also be highly welcome.
    > >
    > >
    > > Thanks for your help,
    > >
    > > Best regards,
    > >
    > > Sebastian
    > >
    > >
    > > P.S.: I also found a small bug in MarkRefLib.F90, which I will send you in
    > > a separate E-mail
    > >
    >



    This archive was generated by hypermail 2b30 : Wed Sep 18 2002 - 12:54:32 CDT