Fix shared_ptr refcycle in graph executor#10222
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zou3519 wants to merge 1 commit intopytorch:masterfrom
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Fix shared_ptr refcycle in graph executor#10222zou3519 wants to merge 1 commit intopytorch:masterfrom
zou3519 wants to merge 1 commit intopytorch:masterfrom
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Fixes pytorch#10032 When capturing an output, GraphExecutorAutogradFunction creates SavedVariable with is_output=False and owns it: https://github.com/pytorch/pytorch/blob/master/torch/csrc/jit/graph_executor.cpp#L87 Constructing SavedVariable with is_output=False makes it own a copy of the shared_ptr<GraphExecutorAutogradFunction>, which causes a reference cycle: https://github.com/pytorch/pytorch/blob/6456b944fd3dfe1b7db830b27afd44b15ba5a6e9/torch/csrc/autograd/saved_variable.cpp#L27 The solution in this PR is to construct the SavedVariable with is_output=True if the captured value is an output. Test Plan Turn on cuda memory checking for JitTestCase. If the test's name includes "cuda" or "gpu" in it, the cuda memory checking test happens.
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Summary: Fixes pytorch#10032 When capturing an output, GraphExecutorAutogradFunction creates SavedVariable with is_output=False and owns it: https://github.com/pytorch/pytorch/blob/master/torch/csrc/jit/graph_executor.cpp#L87 Constructing SavedVariable with is_output=False makes it own a copy of the shared_ptr<GraphExecutorAutogradFunction>, which causes a reference cycle: https://github.com/pytorch/pytorch/blob/6456b944fd3dfe1b7db830b27afd44b15ba5a6e9/torch/csrc/autograd/saved_variable.cpp#L27 The solution in this PR is to construct the SavedVariable with is_output=True if the captured value is an output. Test Plan Turn on cuda memory checking for JitTestCase. If the test's name includes "cuda" or "gpu" in it, the cuda memory checking test happens. cc zdevito Pull Request resolved: pytorch#10222 Reviewed By: ezyang Differential Revision: D9162995 Pulled By: zou3519 fbshipit-source-id: aeace85a09160c7a7e79cf35f6ac61eac87cbf66
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Fixes #10032
When capturing an output, GraphExecutorAutogradFunction creates
SavedVariable with is_output=False and owns it:
https://github.com/pytorch/pytorch/blob/master/torch/csrc/jit/graph_executor.cpp#L87
Constructing SavedVariable with is_output=False makes it own a copy of
the shared_ptr, which causes a reference
cycle:
pytorch/torch/csrc/autograd/saved_variable.cpp
Line 27 in 6456b94
The solution in this PR is to construct the SavedVariable with
is_output=True if the captured value is an output.
Test Plan
Turn on cuda memory checking for JitTestCase. If the test's name
includes "cuda" or "gpu" in it, the cuda memory checking test happens.
cc @zdevito