Re: [PyCUDA] mpi4py and GPUArray in Python 3
by Freddie Witherden
On 07/06/18 21:53, Yiyin Zhou wrote:
> I ran into issues when running the following gist written by Lev.
> https://gist.github.com/lebedov/8514d3456a94a6c73e6d#file-mpi4py_pycuda_d...
> Basically the code works fine under Python 2.7 but I got the following
> error in Python 3.6 (both with openmpi 3.0.0 and mpi4py 3.0.0).
>
> Traceback (most recent call last):
> File "mpi4py_pycuda_demo.py", line 64, in <module>
> comm.Recv([bufint(x_gpu), dtype_to_mpi(x_gpu.dtype)], source=0)
> File "mpi4py/MPI/Comm.pyx", line 283, in mpi4py.MPI.Comm.Recv
> File "mpi4py/MPI/msgbuffer.pxi", line 402, in mpi4py.MPI.message_p2p_recv
> File "mpi4py/MPI/msgbuffer.pxi", line 388, in
> mpi4py.MPI._p_msg_p2p.for_recv
> File "mpi4py/MPI/msgbuffer.pxi", line 155, in mpi4py.MPI.message_simple
> File "mpi4py/MPI/msgbuffer.pxi", line 94, in mpi4py.MPI.message_basic
> File "mpi4py/MPI/asbuffer.pxi", line 308, in mpi4py.MPI.getbuffer
> File "mpi4py/MPI/asbuffer.pxi", line 135, in mpi4py.MPI.PyMPI_GetBuffer
> BufferError: memoryview: underlying buffer is not writable
>
> I am using 2017.1.1, so presumably the as_buffer method should already
> return a writable buffer from a fix two years ago. Any suggestion is
> appreciated!
The fix was incomplete. If I recall there are two places where it need
be applied, and it somehow only ended up being fixed in one of them.
As a workaround:
from ctypes import c_int, c_ssize_t, c_void_p, pythonapi, py_object
_make_pybuf = pythonapi.PyMemoryView_FromMemory
_make_pybuf.argtypes = [c_void_p, c_ssize_t, c_int]
_make_pybuf.restype = py_object
buf = _make_pybuf(my_alloc, nbytes, 0x200)
Regards, Freddie.
>
> Thanks,
> Yiyin
>
>
>
>
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> PyCUDA mailing list
> PyCUDA(a)tiker.net
> https://lists.tiker.net/listinfo/pycuda
>
11 months, 3 weeks
Re: [PyCUDA] mpi4py and GPUArray in Python 3
by Yiyin Zhou
It seems that I was looking at a wrong line and referred to the as_buffer
method for the pointer_holder_base class that was fixed.
The same fix is needed for the device_allocation class as well, I believe:
https://github.com/inducer/pycuda/blob/master/src/cpp/cuda.hpp#L1559
Yiyin
On Thu, Jun 7, 2018 at 4:53 PM, Yiyin Zhou <heerozhou(a)gmail.com> wrote:
> Hi,
>
> I ran into issues when running the following gist written by Lev.
> https://gist.github.com/lebedov/8514d3456a94a6c73e6d#
> file-mpi4py_pycuda_demo-py
> Basically the code works fine under Python 2.7 but I got the following
> error in Python 3.6 (both with openmpi 3.0.0 and mpi4py 3.0.0).
>
> Traceback (most recent call last):
> File "mpi4py_pycuda_demo.py", line 64, in <module>
> comm.Recv([bufint(x_gpu), dtype_to_mpi(x_gpu.dtype)], source=0)
> File "mpi4py/MPI/Comm.pyx", line 283, in mpi4py.MPI.Comm.Recv
> File "mpi4py/MPI/msgbuffer.pxi", line 402, in mpi4py.MPI.message_p2p_recv
> File "mpi4py/MPI/msgbuffer.pxi", line 388, in
> mpi4py.MPI._p_msg_p2p.for_recv
> File "mpi4py/MPI/msgbuffer.pxi", line 155, in mpi4py.MPI.message_simple
> File "mpi4py/MPI/msgbuffer.pxi", line 94, in mpi4py.MPI.message_basic
> File "mpi4py/MPI/asbuffer.pxi", line 308, in mpi4py.MPI.getbuffer
> File "mpi4py/MPI/asbuffer.pxi", line 135, in mpi4py.MPI.PyMPI_GetBuffer
> BufferError: memoryview: underlying buffer is not writable
>
> I am using 2017.1.1, so presumably the as_buffer method should already
> return a writable buffer from a fix two years ago. Any suggestion is
> appreciated!
>
> Thanks,
> Yiyin
>
>
>
11 months, 3 weeks
mpi4py and GPUArray in Python 3
by Yiyin Zhou
Hi,
I ran into issues when running the following gist written by Lev.
https://gist.github.com/lebedov/8514d3456a94a6c73e6d#file-mpi4py_pycuda_d...
Basically the code works fine under Python 2.7 but I got the following
error in Python 3.6 (both with openmpi 3.0.0 and mpi4py 3.0.0).
Traceback (most recent call last):
File "mpi4py_pycuda_demo.py", line 64, in <module>
comm.Recv([bufint(x_gpu), dtype_to_mpi(x_gpu.dtype)], source=0)
File "mpi4py/MPI/Comm.pyx", line 283, in mpi4py.MPI.Comm.Recv
File "mpi4py/MPI/msgbuffer.pxi", line 402, in mpi4py.MPI.message_p2p_recv
File "mpi4py/MPI/msgbuffer.pxi", line 388, in
mpi4py.MPI._p_msg_p2p.for_recv
File "mpi4py/MPI/msgbuffer.pxi", line 155, in mpi4py.MPI.message_simple
File "mpi4py/MPI/msgbuffer.pxi", line 94, in mpi4py.MPI.message_basic
File "mpi4py/MPI/asbuffer.pxi", line 308, in mpi4py.MPI.getbuffer
File "mpi4py/MPI/asbuffer.pxi", line 135, in mpi4py.MPI.PyMPI_GetBuffer
BufferError: memoryview: underlying buffer is not writable
I am using 2017.1.1, so presumably the as_buffer method should already
return a writable buffer from a fix two years ago. Any suggestion is
appreciated!
Thanks,
Yiyin
11 months, 3 weeks