* [fx] add some comment and docstrings.
* [fx] add dataflow analysis for an autograd graph.
* add intepretation for graph analysis.
* [fx] before doing save_tensor_hooks.
* [fx] provide an accurate estimation of memory except for GPT-2.
* [fx] provide an accurate estimation of memory except for GPT-2.
* [fx] provide an accurate estimation of memory except for GPT-2.
* [fx] a very accurate version on GPT-2.
* [fx] refactor code.
* [fx] remove redundant inplace=True.
* [fx] refactor code.
* [fx] refactor code.
* [fx] refactor code.
* [fx] dive into backward memory.
* [fx] fix variable names in ckpt_solvers and unskip tests.
* [fx] commit my changes.
* [fx] restore skips.
* [fx] restore skips.
* [fx] chaange stage into phase.
* [fx] chaange stage into phase.
* [fx] chaange stage into phase.
* [fx] compute memory stat and flop count for MetaInfoProp.
* [fx] modify node attribute.
* [fx] modify ckpt_chen.
* [fx] fix compatibility.
* [fx] fix import error.
* [fx] skip test for MetaInfoProp.
* [fx] skip test for MetaInfoProp.
* [fx] skip test for MetaInfoProp.
* [fx] skip test for MetaInfoProp.
* [fx] skip if torch 1.11.0.
* [fx] recover MetaInfoProp support for PyTorch 1.11.
* [fx] provide a stable but not accurate enough version of profiler.
* [fx] provide a stable but not accurate enough version of profiler.
* [fx] fix compatibility in tests.
* [fx] fix compatibility in tests.
* [fx] fix compatibility in tests.
* [fx] fix compatibility in tests.
* [fx] fix compatibility in tests.
* [fx] fix compatibility in tests.
* [fx] fix compatibility in tests.
* [fx] fix compatibility in tests.
* [fx] fix compatibility in tests.
* [fx] fix compatibility in tests.
* [fx] fix import error.