EXECUTION cuda runtime_error ai_generated true

RuntimeError: cuDNN error: CUDNN_STATUS_EXECUTION_FAILED on RNN backward

ID: cuda/cudnn-rnn-backward-error

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82%Fix Rate
85%Confidence
3Evidence
2023-01-01First Seen

Version Compatibility

VersionStatusIntroducedDeprecatedNotes
12 active — — —

Root Cause

cuDNN RNN backward pass fails. Often caused by non-contiguous tensors or workspace memory exhaustion.

generic

Workarounds

  1. 90% success Ensure input tensors are contiguous before passing to RNN 
    input = input.contiguous(); h0 = h0.contiguous()
  2. 85% success Reduce batch size to give cuDNN more workspace memory
  3. 82% success Set torch.backends.cudnn.enabled=True but benchmark=False for deterministic mode 
    torch.backends.cudnn.benchmark = False  # avoids workspace size instability

Dead Ends

Common approaches that don't work:

  1. Disable cuDNN for all operations globally 80% fail

    Disabling cuDNN causes 5-10x slowdown on convolutions and other operations unrelated to the RNN issue

  2. Replace LSTM/GRU with manual implementation 85% fail

    Manual RNN implementations are much slower and lose cuDNN-optimized fused kernels