torch.cuda.graphs.register_graph_replay_start_hook

torch.cuda.graphs.register_graph_replay_start_hook(fn)

Register a hook run with each CUDA graph at the start of every replay, just before it is launched. Returns a RemovableHandle; call .remove() to unregister.

Note

Replay is the hot path and this fires for EVERY graph on EVERY replay – keep it cheap. With nothing registered the cost is a single dict emptiness check.

Return type:

RemovableHandle