Hi Ashwin,
I pushed a function for obtaining the CUDA pointer from a CUSP vector here:
https://bitbucket.org/petsc/petsc/commits/d831094ec27070ea54a249045841367f8aab0976
It currently resides in branch
karlrupp/feature-gpu-handle-access-for-vec
The respective function for ViennaCL will be pushed later.
Please let me know if this works for you, then I'll start the
integration process.
Best regards,
Karli
On 10/19/2014 04:12 PM, Ashwin Srinath wrote:
Thanks Karl!
Ashwin
On Sun, Oct 19, 2014 at 9:45 AM, Karl Rupp <[email protected]
<mailto:[email protected]>> wrote:
Hi Ashwin,
I'll add two functions returning the bare CUDA and OpenCL handles.
Best regards,
Karli
On 10/19/2014 03:42 PM, Ashwin Srinath wrote:
Hi everyone
Just wondering what the consensus is. I'm happy to submit a PR if
someone can tell me what goes where!
Thanks
Ashwin
On 18 Oct 2014 01:46, "Karl Rupp" <[email protected]
<mailto:[email protected]>
<mailto:[email protected] <mailto:[email protected]>>__>
wrote:
Hi,
>> > Why would we want this? The packages themselves
(CUDA/ViennaCL) only
expose
memory using these specific types. What use is it
to wrap
these up in
a void * if you
just have to caste back down to use them. Isn't it
better to
maintain
type-specific, and
type safe, interfaces for this stuff?
The biggest problem I faced was that there was no
way to
access device
memory using petsc4py - since there is no
equivalent for
VecCUSPGetArray. So returning a raw pointer may not
be very
helpful
for C++/CUSP users (they already have a nice way to
access
device
memory) but it would definitely make things a lot
easier for
Python users.
To me it sounds like something that should be dealt
with in the
library
that does the python bindings, not in PETSc itself. (...)
Unfortunately, this is not so easy: If the Python wrapper
has to
take care of such a conversion, then it needs to use the
*exactly
same build environment* as PETSc. The reason is that the
CUSP and
ViennaCL types are C++ beasts, not having a defined ABI, so
one can
run into all sorts of hard-to-debug problems when finally
linking
libpetsc.so with the Python wrapper. If, however, PETSc
provides
these low-level memory buffers, the Python wrapper can
attach to a
well-defined ABI.
Best regards,
Karli
