[petsc-dev] boomerAmg scalability

Sat Jan 14 15:37:46 CST 2012

Ravi, this system is highly diagonally dominate.  I've fixed the code so you can pull and try again.

I've decided to basically just do a one level method with DD systems.  I don't know if that is the best semantics, I think Barry will hate it, because it gives you a one level solver when you asked for MG.  It now picks up the coarse grid solver as the solver, which is wrong, so I need to fix this if we decide to stick with the current semantics.

And again thanks for helping to pound on this code.

Mark

On Jan 13, 2012, at 6:33 PM, Ravi Kannan wrote:

> Hi Mark, Hong,
>  
> Lets make it simpler. I fixed my partitiotion bug (in metis). Now there is a equidivision of cells.
>  
> To simplify even further, lets run a much smaller case : with 6 cells (equations) in SERIAL. This one crashes. The out and the ksp_view_binary files are attached.
>  
> Thanks,
> RAvi.
>  
> From: petsc-dev-bounces at mcs.anl.gov [mailto:petsc-dev-bounces at mcs.anl.gov] On Behalf Of Mark F. Adams
> Sent: Friday, January 13, 2012 3:00 PM
> To: For users of the development version of PETSc
> Subject: Re: [petsc-dev] boomerAmg scalability
>  
> Well, we do have a bug here.  It should work with zero elements on a proc, but the code is being actively developed so you are really helping us to find these cracks.
>  
> If its not too hard it would be nice if you could give use these matrices, before you fix it, so we can fix this bug.  You can just send it to Hong and I (cc'ed).
>  
> Mark
>  
> On Jan 13, 2012, at 12:16 PM, Ravi Kannan wrote:
> 
> 
> Hi Mark,Hong
>  
> Thanks for the observation w.r.t the proc 0 having 2 equations. This is a bug from our end. We will fix it and get back to you if needed.
>  
> Thanks,
> Ravi.
>  
> From: petsc-dev-bounces at mcs.anl.gov [mailto:petsc-dev-bounces at mcs.anl.gov] On Behalf Of Mark F. Adams
> Sent: Thursday, January 12, 2012 10:03 PM
> To: Hong Zhang
> Cc: For users of the development version of PETSc
> Subject: Re: [petsc-dev] boomerAmg scalability
>  
> Ravi, can you run with -ksp_view_binary? This will produce two files.
>  
> Hong, ex10 will read in these files and solve them.  I will probably not be able to get to this until Monday.
>  
> Also, this matrix has just two equations on proc 0 and and about 11000 on proc 1 so its is strangely balanced, in case that helps ...
>  
> Mark
>  
> On Jan 12, 2012, at 10:35 PM, Hong Zhang wrote:
> 
> 
> 
> Ravi,
>  
> I need more info for debugging. Can you provide a simple stand alone code and matrices in petsc
> binary format that reproduce the error?
>  
> MatTransposeMatMult() for mpiaij is a newly developed subroutine - less than one month old 
> and not well tested yet :-(
> I used petsc-dev/src/mat/examples/tests/ex94.c for testing.
>  
> Thanks,
>  
> Hong
> 
> On Thu, Jan 12, 2012 at 9:17 PM, Mark F. Adams <mark.adams at columbia.edu> wrote:
> It looks like the problem is in MatTransposeMatMult and Hong (cc'ed) is working on it.
>  
> I'm hoping that your output will be enough for Hong to figure this out but I could not reproduce this problem with any of my tests.
>  
> If Hong can not figure this out then we will need to get the matrix from you to reproduce this.
>  
> Mark
>  
>  
> On Jan 12, 2012, at 6:25 PM, Ravi Kannan wrote:
> 
> 
> 
> Hi Mark,
>  
> Any luck with the gamg bug fix?
>  
> Thanks,
> Ravi.
>  
> From: petsc-dev-bounces at mcs.anl.gov [mailto:petsc-dev-bounces at mcs.anl.gov] On Behalf Of Mark F. Adams
> Sent: Wednesday, January 11, 2012 1:54 PM
> To: For users of the development version of PETSc
> Subject: Re: [petsc-dev] boomerAmg scalability
>  
> This seems to be dying earlier than it was last week, so it looks like a new bug in MatTransposeMatMult.
>  
> Mark
>  
> On Jan 11, 2012, at 1:59 PM, Matthew Knepley wrote:
>  
> 
> On Wed, Jan 11, 2012 at 12:23 PM, Ravi Kannan <rxk at cfdrc.com> wrote:
> Hi Mark,
>  
> I downloaded the dev version again. This time, the program crashes even earlier. Attached is the serial and parallel info outputs.
>  
> Could you kindly take a look.
>  
> It looks like this is a problem with MatMatMult(). Can you try to reproduce this using KSP ex10? You put
> your matrix in binary format and use -pc_type gamg. Then you can send us the matrix and we can track
> it down. Or are you running an example there?
>  
>   Thanks,
>  
>     Matt
>  
>  
>  
> Thanks,
> Ravi.
>  
> From: petsc-dev-bounces at mcs.anl.gov [mailto:petsc-dev-bounces at mcs.anl.gov] On Behalf Of Mark F. Adams
> Sent: Monday, January 09, 2012 3:08 PM
> 
> To: For users of the development version of PETSc
> Subject: Re: [petsc-dev] boomerAmg scalability
>  
>  
> Yes its all checked it, just pull from dev.
> Mark
>  
> On Jan 9, 2012, at 2:54 PM, Ravi Kannan wrote:
>  
> 
> Hi Mark,
>  
> Thanks for your efforts.
>  
> Do I need to do the install from scratch once again? Or some particular files (check out gamg.c for instance)?
>  
> Thanks,
> Ravi.
>  
> From: petsc-dev-bounces at mcs.anl.gov [mailto:petsc-dev-bounces at mcs.anl.gov] On Behalf Of Mark F. Adams
> Sent: Friday, January 06, 2012 10:30 AM
> To: For users of the development version of PETSc
> Subject: Re: [petsc-dev] boomerAmg scalability
>  
> I think I found the problem.  You will need to use petsc-dev to get the fix.
>  
> Mark
>  
> On Jan 6, 2012, at 8:55 AM, Mark F. Adams wrote:
>  
> 
> Ravi, I forgot but you can just use -ksp_view_binary to output the matrix data (two files).  You could run it with two procs and a Jacobi solver to get it past the solve, where it writes the matrix (I believe).
> Mark
>  
> On Jan 5, 2012, at 6:19 PM, Ravi Kannan wrote:
>  
> 
> Just send in another email with the attachment.
>  
> From: petsc-dev-bounces at mcs.anl.gov [mailto:petsc-dev-bounces at mcs.anl.gov] On Behalf Of Jed Brown
> Sent: Thursday, January 05, 2012 5:15 PM
> To: For users of the development version of PETSc
> Subject: Re: [petsc-dev] boomerAmg scalability
>  
> On Thu, Jan 5, 2012 at 17:12, Ravi Kannan <rxk at cfdrc.com> wrote:
> I have attached the verbose+info outputs for both the serial and the parallel (2 partitions). NOTE: the serial output at some location says PC=Jacobi! Is it implicitly converting the PC to a Jacobi?
>  
> Looks like you forgot the attachment.
>  
>  
>  
> 
> 
>  
> -- 
> What most experimenters take for granted before they begin their experiments is infinitely more interesting than any results to which their experiments lead.
> -- Norbert Wiener
>  
>  
>  
>  
>  
> <out><binaryoutput><binaryoutput.info>

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