[petsc-dev] could we let "make -j N" work for PETSc and external packages?

[Satish Balay]

I hate html e-mail which doesn't add reply markers - can't figure out easily what you saying :(

> > However some older make version might not display this info properly. [it should use the user specified '-j' value though]
> 
> This confused me, and now I understood.  But it is misleading. Could we do something at the PETSc side regardless the make version? At least display the user-specified value not the default value.  I thought my "-j" did not change anything.

Thats a 'make' issue. you are specifying options to make. So we have no control on it [unless make tells us - and this mode is buggy on the OSX default make version].

The only option we have is : not print anything. I think thats a bad option.

You have alternatives:

- use a newer make with --download-make

- or use MAKE_NP

Satish

On Tue, 24 Jul 2018, Fande Kong wrote:

> 
> 
> 
> ________________________________
> From: Satish Balay <balay at mcs.anl.gov>
> Sent: Tuesday, July 24, 2018 4:06 PM
> To: Fande Kong
> Cc: Jed Brown; For users of the development version of PETSc
> Subject: Re: [petsc-dev] could we let "make -j N" work for PETSc and external packages?
> 
> PETSc configure sets up a default value that always gets used.
> 
> >>>>>>>
> balay at asterix /home/balay/tmp/petsc (maint=)
> $ make
> <snip>
> Using MAKEFLAGS: -j4 -l6.0 w -- PETSC_DIR=/home/balay/tmp/petsc PETSC_ARCH=arch-linux2-c-debug
> <<<
> 
> You can always override this default by adding a -j option. [since the
> user specified -j value comes at the end - it overrides the one that
> is specified at the begining of make command]
> 
> >>>>>>>>>>
> balay at asterix /home/balay/tmp/petsc (maint=)
> $ make -j20
> <snip>
> Using MAKEFLAGS: -j4 -l6.0 w -j20 --jobserver-auth=3,4 -- PETSC_DIR=/home/balay/tmp/petsc PETSC_ARCH=arch-linux2-c-debug
> <<<<<<<<<<
> 
> 
> However some older make version might not display this info properly. [it should use the user specified '-j' value though]
> 
> This confused me, and now I understood.  But it is misleading. Could we do something at the PETSc side regardless the make version? At least display the user-specified value not the default value.  I thought my "-j" did not change anything.
> 
> Fande,
> 
> >>>>>>>
> [petsc at ipro petsc.maint ((879a78556f...))]$ make -j2
> Using MAKEFLAGS: -j7 -l12.0 w --jobserver-fds=3,4 -j -- PETSC_DIR=/Users/petsc/petsc.maint PETSC_ARCH=arch-osx-10.6
> <<<<<<<
> 
> You can use the alternate mode - just modify the default '-j' value used MAKE_NP
> 
> >>>>>>>>
> [petsc at ipro petsc.maint ((879a78556f...))]$ make MAKE_NP=2
> Using MAKEFLAGS: -j2 -l12.0 w -- PETSC_DIR=/Users/petsc/petsc.maint PETSC_ARCH=arch-osx-10.6 MAKE_NP=2
> <<<<<<<
> 
> Or you can control this default value at configure time [this affects externalpackage builds]
> 
> ./configure --with-make-np=2
> 
> Satish
> 
> 
> On Tue, 24 Jul 2018, Fande Kong wrote:
> 
> > Thanks, Jed and Satish,
> >
> >
> > But "make -j N" does not change anything when compiling petsc.
> >
> >
> >
> > If I do something like: "make -j whatever". Then I always get:
> >
> >
> > Using MAKEFLAGS: -j8 -l36.0 w
> >
> >
> > It looks like PETSc always uses "-j something" that we can not change using the command-line.
> >
> >
> > Is it a bug?
> >
> >
> >
> > Fande,
> >
> >
> >
> > ________________________________
> > From: Jed Brown <jed at jedbrown.org>
> > Sent: Tuesday, July 24, 2018 3:44 PM
> > To: Fande Kong; For users of the development version of PETSc
> > Subject: Re: [petsc-dev] could we let "make -j N" work for PETSc and external packages?
> >
> > Fande Kong <Fande.Kong at inl.gov> writes:
> >
> > > Hi Developers,
> > >
> > >
> > > Could we somehow let "make -j N" to take multiple threads for compiling PETSc. Do we use multiple threads when compiling the external packages such as hypre, parmetis etc.?
> >
> > Yes, see self.parallelMake=0 for the few packages that don't support parallel make.
> >
> 
>