Re: gfortran 4.3.2 running out of memory on a file

[Tom Epperly <tepperly at llnl dot gov>]

Steve Kargl wrote:
> On Fri, Nov 07, 2008 at 04:14:35PM -0800, Tom Epperly wrote:
>   
> > Steve Kargl wrote:
> >     
> > > On Fri, Nov 07, 2008 at 03:57:15PM -0800, Tom Epperly wrote:
> > >  
> > >       
> > > > I've got a situation where gfortran is running out of memory, and I am 
> > > > wondering if there are any guidelines that would help me change my 
> > > > source file to get it compiling. I am working with code produced by 
> > > > source code generators, Babel http://  www.  llnl.gov/CASC/components/ and 
> > > > Forthon. I am attaching a reproducer.
> > > >
> > > > f951: out of memory allocating 1352 bytes after a total of 2766893056 
> > > > bytes
> > > >
> > > >    
> > > >         
> > > What does ulimit show and how much memory does the machine have?
> > >
> > >  
> > >       
> > I am normally a tcsh user, so here is the tcsh equivalent followed by 
> > ulimit. I assume that cat /proc/meminfo will provide enough details 
> > about the machine's memory situation.
> >     
>
> Well, I killed the compile with top(1) showing
>
>   PID USERNAME    THR PRI NICE   SIZE    RES STATE  C    TIME   WCPU COMMAND
>  5612 sgk           1 119    0  7923M  7184M CPU1    0   7:50 98.63% f951
>
> A quick look shows
>
> troutmask:sgk[228] grep -i "  use " bbb_Mod_Impl.F90 | wc -l
>    20194
> troutmask:sgk[229] wc -l *.mod
>    86254 total
>
> gfortran does not currently cache a read module. So it will faithly
> read and store whatever information appears in the *.mod each time
> it hits a USE statement.  The autogenerators prolific use of modules
> and the 138k LOC are too much unless you have a real big system. 
>
>   
Is there any likelihood that gfortran will start caching read modules in 
the near future?  If I have "use sidl" 700 times in the source file, 
will gfortran dutifully store 700 copies of the internal presentation 
corresponding to the contents of sidl.mod? If yes, I have no prayer of 
getting this thing to compile unless I can dramatically reduce the 
absolute number of "use" statements. It seems to me that caching read 
modules would have benefits to normal Fortran files in additional to 
abnormal ones like bbb_Mod_Impl.F90

Tom