[petsc-dev] I just removed Fortran support from my development build

Smith, Barry F. bsmith at mcs.anl.gov
Mon Oct 22 12:28:34 CDT 2018



> On Oct 22, 2018, at 12:17 PM, Jed Brown <jed at jedbrown.org> wrote:
> 
> "Smith, Barry F." <bsmith at mcs.anl.gov> writes:
> 
>>  Jed,
>> 
>>  Why are the modules always built last? 
>> 
>>         .....
>>         FC arch-basic/obj/sys/objects/f2003-src/fsrc/optionenum.o
>>          FC arch-basic/obj/sys/classes/bag/f2003-src/fsrc/bagenum.o
>>          FC arch-basic/obj/mat/f90-mod/petscmatmod.o
>>          FC arch-basic/obj/dm/f90-mod/petscdmmod.o
>>          FC arch-basic/obj/dm/f90-mod/petscdmplexmod.o
>>          FC arch-basic/obj/ksp/f90-mod/petsckspmod.o
>>          FC arch-basic/obj/snes/f90-mod/petscsnesmod.o
>>          FC arch-basic/obj/ts/f90-mod/petsctsmod.o
>>          FC arch-basic/obj/tao/f90-mod/petsctaomod.o
>> 
>> I don't think they have any dependency on the compiled C code so couldn't each module (still build sequentially within the list of modules) run in parallel with a bunch of C compilers? Why are they always scheduled last, forcing sequential?
> 
> The Fortran modules depend on each other so build sequentially.  Look
> way up in your compilation history and you'll see lines for
> petscsysmod.o and later petscvecmod.o.  Compiling those modules is just
> that slow compared to the hundreds of C compilations that run in
> parallel.

  Ok. 

  



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