[petsc-dev] SuiteSparse 4.0

Jed Brown jedbrown at mcs.anl.gov
Wed Jun 13 08:41:05 CDT 2012

You can't use cublas everywhere because it's better to do small sizes on
the CPU and different threads need to be able to operate independently
(without multiple devices).

Yes, try a PETSc example before your own code. Did petsc build without any
changes to the cholmod interface? ALWAYS send the error message/stack
trace---even if we don't have an answer, it usually tells us how difficult
the problem is likely to be to fix.
On Jun 13, 2012 8:09 AM, "Dave Nystrom" <dnystrom1 at comcast.net> wrote:

> Well, I tried it last night but without success.  I got a memory corruption
> error when I tried running my app.  I suppose I should try first to get it
> working with a petsc example.  I'm building SuiteSparse but only using
> cholmod out of that package.  Several of the SuiteSparse packages use blas
> but cholmod is the only one so far that has the option to use cublas.  Tim
> gets about a 10x speedup over the single core result when using cublas on
> an
> example problem that spends a lot of time in blas.  So seems worth trying.
> Anyway, I think I must be doing something wrong so far.  But for the same
> problem, Tim gets about a 20+ percent speedup over using multi-threaded
> Goto
> blas.
> Probably a better solution for petsc would be support for using cublas for
> all of the petsc blas needs.  Why should just one petsc blas client have
> access to cublas?  But not sure how much work is involved for that - I see
> it
> is on the petsc ToDo list.  I will try again tonight but would welcome
> advice
> or experiences from anyone else who has tried the new cholmod.
> Dave
> Jed Brown writes:
>  > Nope, why don't you try it and send us a patch if you get it working.
>  >
>  > On Wed, Jun 13, 2012 at 12:49 AM, Dave Nystrom <dnystrom1 at comcast.net
> >wrote:
>  >
>  > > Has anyone tried building petsc-dev to use cholmod-2.0 which is part
> of
>  > > SuiteSparse-4.0 with the cholmod support for using cublas enabled?  I
> am
>  > > interested in trying the cublas support for cholmod to see how it
> compares
>  > > with mkl and goto for my solves.
>  > >
>  > > Thanks,
>  > >
>  > > Dave
>  > >
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.mcs.anl.gov/pipermail/petsc-dev/attachments/20120613/f27ba3e9/attachment.html>

More information about the petsc-dev mailing list