Understandable, p4est has its own minimal pseudo-mpi interface, I'll work with Satish and the other p4est devs to a simple way to keep the MPIUNI / MPIP4EST from colliding.
________________________________________
From: Barry Smith <bsmith at petsc.dev>
Sent: Friday, April 16, 2021 16:10
To: Isaac, Tobin G
Cc: petsc-dev
Subject: Re: [petsc-dev] p4est w/o MPI
Toby,
It was never our intention that MPIUNI support any other packages besides PETSc/SLEPc as an "mpi substitute". There are just so many fragile aspects to it. I think it is is best if p4est maintains its own non-MPI version (if it wants to have such as thing) and does not have it involve MPIUNI.
Barry
On Apr 16, 2021, at 12:53 PM, Isaac, Tobin G <tisaac at cc.gatech.edu<mailto:tisaac at cc.gatech.edu>> wrote:
Hmm. So if petsc always compiles mpiuni if --with-mpi=0, then it makes me think it should be possible to drop requires(MPI) from p4est, while still passing `--enable-mpi` to p4est.
Maybe: if mpiuni doesn't provide some esoteric part of MPI that p4est uses, it will break.
Toby Isaac, Assistant Professor, GTCSE
________________________________
From: Satish Balay <balay at mcs.anl.gov<mailto:balay at mcs.anl.gov>>
Sent: Friday, April 16, 2021 1:03:55 PM
To: Isaac, Tobin G <tisaac at cc.gatech.edu<mailto:tisaac at cc.gatech.edu>>
Cc: petsc-dev <petsc-dev at mcs.anl.gov<mailto:petsc-dev at mcs.anl.gov>>
Subject: Re: [petsc-dev] p4est w/o MPI
Thanks! Another issue:
mpiuni provides mpi.h. And I get the following errors when building PETSc.
/home/balay/petsc/arch-linux-c-debug/include/sc.h:87:2: error: #error "mpi.h is included. Use --enable-mpi."
87 | #error "mpi.h is included. Use --enable-mpi."
| ^~~~~
etc..
Satish
On Fri, 16 Apr 2021, Isaac, Tobin G wrote:
> Yes, `--disable-mpi` should be accepted by p4est.
>
> ________________________________________
> From: Satish Balay <balay at mcs.anl.gov<mailto:balay at mcs.anl.gov>>
> Sent: Friday, April 16, 2021 11:47
> To: Satish Balay via petsc-dev
> Cc: Isaac, Tobin G
> Subject: Re: [petsc-dev] p4est w/o MPI
>
> BTW: Is there no --disable-mpi option?
>
> Satish
>
> On Fri, 16 Apr 2021, Satish Balay via petsc-dev wrote:
>
> > MPI pacakge is a bit weird compared to others [as it does this funny thing with MPIUNI].
> >
> > For regular packages - I guess I would use 'if package.found'
> >
> > I guess I should create an MR with this diff.
> >
> > Satish
> >
> > ----
> >
> > diff --git a/config/BuildSystem/config/packages/p4est.py b/config/BuildSystem/config/packages/p4est.py
> > index e7108b0ab8..40d6797f02 100644
> > --- a/config/BuildSystem/config/packages/p4est.py
> > +++ b/config/BuildSystem/config/packages/p4est.py
> > @@ -24,14 +24,16 @@ class Configure(config.package.GNUPackage):
> > self.blasLapack = framework.require('config.packages.BlasLapack',self)
> > self.zlib = framework.require('config.packages.zlib',self)
> > self.memalign = framework.argDB['with-memalign']
> > - self.deps = [self.mpi,self.blasLapack,self.zlib]
> > + self.deps = [self.blasLapack,self.zlib]
> > + self.odeps = [self.mpi]
> > return
> >
> > def formGNUConfigureArgs(self):
> > args = config.package.GNUPackage.formGNUConfigureArgs(self)
> > if self.argDB['with-p4est-debugging']:
> > args.append('--enable-debug')
> > - args.append('--enable-mpi')
> > + if not self.mpi.usingMPIUni:
> > + args.append('--enable-mpi')
> > args.append('CPPFLAGS="'+self.headers.toStringNoDupes(self.dinclude)+'"')
> > args.append('LIBS="'+self.libraries.toString(self.dlib)+'"')
> > args.append('--enable-memalign='+self.memalign)
> >
> > On Fri, 16 Apr 2021, Isaac, Tobin G wrote:
> >
> > > Matt, this is the configure logic I would like, but I don't know how to do it:
> > > - configure p4est after MPI, but do not require MPI
> > > - if MPI is present, add the '--enable-mpi' flack in formGNUConfigureArgs(), otherwise omit it.
> > >
> > > ________________________________________
> > > From: Isaac, Tobin G <tisaac at cc.gatech.edu<mailto:tisaac at cc.gatech.edu>>
> > > Sent: Friday, April 16, 2021 11:03
> > > To: Mark Adams; For users of the development version of PETSc
> > > Subject: Re: [petsc-dev] p4est w/o MPI
> > >
> > > p4est has a mode where it can compile without MPI, I don't know if PETSc is using it, will check.
> > >
> > > ________________________________________
> > > From: petsc-dev <petsc-dev-bounces at mcs.anl.gov<mailto:petsc-dev-bounces at mcs.anl.gov>> on behalf of Mark Adams <mfadams at lbl.gov<mailto:mfadams at lbl.gov>>
> > > Sent: Friday, April 16, 2021 10:23
> > > To: For users of the development version of PETSc
> > > Subject: [petsc-dev] p4est w/o MPI
> > >
> > > I don't have MPI (Fugaku w/ gcc) and p4est seems to need it. Is there a work around?
> > > Thanks,
> > > Mark
> > >
> >
>