Re: [PyCUDA] Question about gpuarray
I just did this ... my solution was to malloc a large GPUarray, then construct pointers to within this region. GPUarrays made from these pointers pass in the master array as the base. I think what I was trying to do is better served by slice notation however. Previously I was not certain what a slice of a GPUarray actually was so I was handling things manually. --mrule. On Fri, Dec 4, 2009 at 2:43 PM, Andreas Klöckner li...@informa.tiker.netwrote: On Freitag 04 Dezember 2009, you wrote: Hi Andreas - As part of my work to get host cuda functions compilable through PyCUDA, I've needed to come up with a mechanism for creating GPUArrays from device pointers produced by host functions. I've been able to do that, but only by commenting out an assertion in gpuarray.py on line 89: if gpudata is None: ... else: self.gpudata = gpudata assert base is not None What is GPUArray.base for, and if we really need it, what data is expected there? I can't find GPUArray.base being used anywhere in the PyCUDA code base. Same as numpy.base--its sole purpose is to establish lifetime dependencies. Say you create an array A that's a view of another array B (a slice, say). Then you'd very much like B to not be destroyed before A. HTH, Andreas ___ PyCUDA mailing list PyCUDA@tiker.net http://tiker.net/mailman/listinfo/pycuda_tiker.net ___ PyCUDA mailing list PyCUDA@tiker.net http://tiker.net/mailman/listinfo/pycuda_tiker.net
Re: [PyCUDA] Question about gpuarray
On Freitag 04 Dezember 2009, Bryan Catanzaro wrote: Thanks for the explanation. In that case, do you have objections to removing the assertion that if a GPUArray is created and given a preexisting buffer, that the new array must be a view of another array? In my situation, I don't think this assertion is true: I would like to transfer ownership of a gpu buffer (created outside of PyCUDA by some host code) to a particular GPUArray. This means I instantiate a GPUArray with gpudata=the pointer created by the host code, but base should still be None, since this new GPUArray is not a view of any other array, and so this GPUArray should have sole ownership of the buffer being given at initialization. If I understand you correctly, then whatever you assign to .gpudata already establishes the lifetime dependency, right? In that case, yes, the assert should go away. Andreas PS: Please keep the PyCUDA list cc'ed, unless there's good reason not to. signature.asc Description: This is a digitally signed message part. ___ PyCUDA mailing list PyCUDA@tiker.net http://tiker.net/mailman/listinfo/pycuda_tiker.net
