def _test_wait_stream(self, source, target, cuda_sleep=None):
with use_stream(target):
if is_cuda(target):
cuda_sleep(0.5)
x = torch.ones(100, 100, device=get_device(target))
wait_stream(source, target)
with use_stream(source):
assert x.sum().item() == 10000
def _test_copy_wait(prev_stream, next_stream, cuda_sleep=None):
device = get_device(prev_stream)
with use_stream(prev_stream):
if is_cuda(prev_stream):
cuda_sleep(0.5)
x = torch.ones(100, device=device, requires_grad=True)
(y,) = Copy.apply(prev_stream, next_stream, x)
(y,) = Wait.apply(prev_stream, next_stream, x)
with use_stream(next_stream):
assert torch.allclose(y.sum(), torch.tensor(100.0, device=device))
y.norm().backward()
with use_stream(prev_stream):
assert torch.allclose(x.grad.sum(), torch.tensor(10.0, device=device))
def test_record_stream_cuda(self, cuda_sleep):
# This test detects unexpected block reallocation. For reliable test,
# the stream to allocate tensors is isolated. The allocator will not
# reuse free blocks which were allocated from another stream.
stream_alloc = new_stream(torch.device("cuda"))
with torch.cuda.stream(stream_alloc):
x = torch.rand(1, device=torch.device("cuda"))
stream = new_stream(torch.device("cuda"))
record_stream(x, stream)
with use_stream(stream):
cuda_sleep(0.5)
# 'x' is deleted at Python's perspective. But the block of 'x' is still
# required for 'stream'. 'y' shouldn't be allocated to the block.
data_ptr = x.data_ptr()
del x
stream_alloc.synchronize()
with torch.cuda.stream(stream_alloc):
y = torch.rand(1, device=torch.device("cuda"))
assert y.data_ptr() != data_ptr
# Pause Python until 'stream' finishes tasks queued. Now the block of
# 'x' is free to be reallocated.
wait_stream(CPUStream, stream)
with torch.cuda.stream(stream_alloc):
z = torch.rand(1, device=torch.device("cuda"))
assert z.data_ptr() == data_ptr
def test_record_stream_shifted_view(self, cuda_sleep):
# Issue: https://github.com/pytorch/pytorch/issues/27366
stream_alloc = new_stream(torch.device("cuda"))
with torch.cuda.stream(stream_alloc):
x = torch.rand(2, device=torch.device("cuda"))
y = x[1:]
assert y.data_ptr() > x.data_ptr()
stream = new_stream(torch.device("cuda"))
with use_stream(stream):
cuda_sleep(0.5)
record_stream(y, stream)
data_ptr = x.data_ptr()
del x, y
stream_alloc.synchronize()
with torch.cuda.stream(stream_alloc):
z = torch.rand(2, device=torch.device("cuda"))
assert z.data_ptr() != data_ptr
def test_use_stream_cuda(self):
stream = new_stream(torch.device("cuda"))
with use_stream(stream):
assert current_stream(torch.device("cuda")) == stream
def test_use_stream_cpu(self):
with use_stream(CPUStream):
pass