[MITgcm-devel] Beaufort experiment on mac os x

[Jean-Michel Campin]

Hi Martin,

Thanks for looking a this.
It's interesting to know where the optimisation break.
But I would prefer not to change this routine (if the compiler does
a wrong optimisation, this is the compiler problem after all,
and I prefer to see this in the NOOPTFILES list).

Cheers,
Jean-Michel

On Thu, Mar 15, 2012 at 10:21:32AM +0100, Martin Losch wrote:
> Alternatively, we could replace
>         DO j=1-Oly,sNy+Oly
>          DO i=1-Olx,sNx+Olx
>           R_low(i,j,bi,bj) = rF(1)
>           DO k=Nr,1,-1
>            R_low(i,j,bi,bj) = R_low(i,j,bi,bj)
>      &                      - drF(k)*hFacC(i,j,k,bi,bj)
>           ENDDO
>          ENDDO
>         ENDDO
> 
> with
>         DO j=1-Oly,sNy+Oly
>          DO i=1-Olx,sNx+Olx
>           R_low(i,j,bi,bj) = rF(1)
>          ENDDO
>         ENDDO
>         DO k=Nr,1,-1
>          DO j=1-Oly,sNy+Oly
>           DO i=1-Olx,sNx+Olx
>            R_low(i,j,bi,bj) = R_low(i,j,bi,bj)
>      &                      - drF(k)*hFacC(i,j,k,bi,bj)
>           ENDDO
>          ENDDO
>         ENDDO
> That does work too (and makes sense, if you care about vectoriziation, although in this initialisation routine, performance is not an issue).
> 
> M.
> 
> On Mar 15, 2012, at 10:15 AM, Martin Losch wrote:
> 
> > Hi there I compiled with "-g -ftraceback" (and -O3) and used gdb and found that ini_masks_etc.F (line 120) is  the problematic rountine, I don't see why. Anyway, I put this into the list of NOOPTFILES and removed (had to!!!) the -ftree-vectorize option and it works with
> >> top
> > PID    COMMAND      %CPU  TIME     #TH  #WQ  #POR #MREG RPRVT  RSHRD  RSIZE
> > 75875  mitgcmuv     98.7  00:13.07 1/1  0    14   34    98M    240K   101M
> > so the approximate 100MB core memory that Dimitris was talking about.
> > 
> > I can check in this change, but incidentally, do we need the two gad_*.F routines in the NOOPTFILES list? If not, I'll remove them.
> > 
> > Martin
> > 
> > 
> > On Mar 14, 2012, at 7:37 PM, Torge Martin wrote:
> > 
> >> Hi Dimitris,
> >> 
> >> just updated MITgcm and beaufort. I also don't use the -ieee option with genamke2 anymore. 
> >> With -O3 I get the segmentation fault, with -O2 it runs just fine.
> >> 
> >> Torge
> >> 
> >> On Wed, Mar 14, 2012 at 10:15 AM, Menemenlis, Dimitris (3248) <Dimitris.Menemenlis at jpl.nasa.gov> wrote:
> >> Torge, maybe try "-O2".  It will be a bit faster.
> >> 
> >> Martin, since "-O3" in darwin_amd64_gfortran is problematic,
> >> should we downgrade to "-O2" in the CVS repository,
> >> until compiler bug is fixed ... or until someone takes the time to
> >> locate particular subroutine that causes optimization crash?
> >> 
> >> Cheers
> >> 
> >> Dimitris Menemenlis
> >> 
> >> On Mar 14, 2012, at 10:08 AM, Torge Martin wrote:
> >> 
> >>> Hi Dimitris, Martin,
> >>> 
> >>> looks like Martin is right. I just found that using the -ieee option with genmake2 sets FOPTIM=-O0. This helps to get pass the Segmentation Fault.
> >>> 
> >>> Now, I the Beaufort set up is running with this option on my MacPro, OS X 10.5.8 (Snow Leopard), 2 x 3 GHz Dual-Core, 4 GB Memory, using gcc version 4.0.1 (Apple Inc. build 5465) and MITgcm/tools/build_options/darwin_ia32_gfortran.
> >>> 
> >>> Torge
> >>> 
> >>> P.S. Haven't tried running with MPI using both processors, yet.
> >> 
> >> 
> >> _______________________________________________
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> >> http://mitgcm.org/mailman/listinfo/mitgcm-devel
> > 
> > 
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> 
> 
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