[petsc-users] [petsc-maint #107932] run a simple example ex19 in src/snes/examples/tutorials

[Paul Mullowney]

Sorry.

You are asking for Jacobi, and not BJacobi.

D'oh!

-Paul
> In bjacobi.c, the following comments are given for PCCreate_BJacobi.
>
> Developer Notes: This preconditioner does not currently work with 
> CUDA/CUSP for a couple of reasons.
> (1) It creates seq vectors as work vectors that should be cusp
> (2) The use of VecPlaceArray() is not handled properly by CUSP (that 
> is it will not know where the ownership of the vector is so may use 
> wrong values) even if it did know the ownership it may induce extra 
> copy ups and downs. Satish suggests a VecTransplantArray() to handle 
> two vectors sharing the same pointer and handling the CUSP side as 
> well instead of VecGetArray()/VecPlaceArray().
>
>
> I've had some success with comment (2) above in regards to Singleblock 
> BJacobi. I haven't yet tried it for Multiblock or Multiproc.
>
> -Paul
>
>> On Tue, Mar 13, 2012 at 10:18, Paul Mullowney <paulm at txcorp.com 
>> <mailto:paulm at txcorp.com>> wrote:
>>
>>     I don't think PCJACOBI is working on the GPU yet.
>>
>>
>> It damn well better be.
>>
>> (It only calls MatGetDiagonal(), everything else is just a Vec 
>> operation and the VecType will be set so that it runs on the GPU.)
>>
>>
>>     I have some local fixes to make it work efficiently (without
>>     extra copies), but changes won't be pushed too soon because the
>>     design is not sufficiently general.
>>
>>
>

-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.mcs.anl.gov/pipermail/petsc-users/attachments/20120313/42ffb2ae/attachment.htm>