ScatterGather exceptions triggered by `distributions.Categorical.log_prob`
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Description
When training my model which samples from Categorical distribution I every now and then get this stack trace
/cvlabdata2/home/tyszkiew/PhD/points/algorithm.py in point_distribution(logits)
23 spatial_dist = Categorical(logits=logits)
24 candidate_marks = spatial_dist.sample()
---> 25 spatial_logp = spatial_dist.log_prob(candidate_marks)
26
27 survival_logits = torch.gather(
/usr/local/lib/python3.6/dist-packages/torch/distributions/categorical.py in log_prob(self, value)
114 value, log_pmf = torch.broadcast_tensors(value, self.logits)
115 value = value[..., :1]
--> 116 return log_pmf.gather(-1, value).squeeze(-1)
117
118 def entropy(self):
RuntimeError: cuda runtime error (710) : device-side assert triggered at /pytorch/aten/src/THC/generic/THCTensorScatterGather.cu:75
This problem seems to be ameliorated by decreasing the magnitude of logits, but is otherwise elusive. I was thinking that normalization fails due to numerical precision and samples go outside of the allowed range but it seems to be handled.
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Research direction
Start with the stack trace in algorithm.py, especially point_distribution, and inspect the referenced torch/distributions/categorical.py log_prob path. Reproduce the intermittent CUDA device-side assertion with the reported Categorical logits and compare behavior as their magnitude changes; done means identifying the failure cause and covering the corrected behavior with a regression test.
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Assessment
- Tech stack
- python, pytorch
- Domain
- machine-learning
- Issue type
- Bug
- Difficulty
- 4/5
- Estimated time
- 3-5 days
- Activity status
- Stale
- Clarity
- Mostly clear
- Newbie friendliness
- 25/100