Summary:
```
Use intrusive_ptr in Storage; replace unique_ptr<Storage> with Storage
This patch does two major changes:
- It replaces the use of Retainable in Storage with a new implementation
based on intrusive_ptr. This will be necessary because Caffe2 will
be using this class to implement intrusive_ptrs, and we need to
line these up for the merge. One good thing about the new implementation is
that the default copy/move constructors/assignment operators and destructor
work automatically, instead of needing to be hardcoded into Storage/Tensor.
- It replaces all places where we returned std::unique_ptr<Storage> with
Storage, collapsing an unnecessary double indirection that is no longer
necessary now that we have correctly working copy/move constructors.
I didn't initially want to do step (2), but it was very important to
eliminate all bare uses of new Storage and new StorageImpl, and this making
the API change was the most straightforward way to do this.
HOW TO FIX YOUR CODE IN THE NEW API
- You no longer need to dereference the result of tensor.storage() to pass
it to set. So, instead of:
x.set_(*y.storage());
just write:
x.set_(y.storage());
- If you were accessing methods on StorageImpl via the pImpl() method, you
must use the dot operator to run pImpl(). Even better; just drop pImpl,
we now have method forwarding. So, instead of:
storage->pImpl()->data();
just do:
storage->data();
// storage.pImpl()->data() works too but is not as recommended
- storage->getDevice() is no more; instead use storage->device().index()
MISC CODE UPDATES
- retain, release, weak_retain, weak_release and weak_lock are now
reimplemented using the "blessed API", and renamed to make it
clearer that their use is discouraged.
- nvcc OS X and general OS X portability improvements to intrusive_ptr
- A new comment in intrusive_ptr describing how stack allocated
intrusive_ptr_targets work differently than heap allocated ones
from c10::make_intrusive
CAVEAT EMPTOR
- THStorage_weakRetain used to work on strong pointers, but it NO LONGER
works with intrusive_ptr. You must reclaim the strong pointer into a
real strong pointer, construct a weak pointer from it, and then release
the strong and weak pointers. See StorageSharing.cpp for an example.
```
Pull Request resolved: https://github.com/pytorch/pytorch/pull/10488
Reviewed By: gchanan
Differential Revision: D9306134
Pulled By: ezyang
fbshipit-source-id: 02d58ef62dab8e4da6131e1a24834a65c21048e2
Summary:
This PR provides 4 fixes / features:
1. torch::nn::Cloneable inherits virtually from torch::nn::Module. We want to pass around a module with new functions, and the best way to do this is to do a diamond inheritance pattern, i.e.
```c++
struct MySuperModuleImpl : virtual public torch::nn::Module {
virtual void myFunction() = 0;
}
struct MySuperModule : public torch::nn::Cloneable<MySuperModule>, MySuperModuleImple {};
struct MyModule : public MySuperModule<MyModule> {
void myFunction() override;
};
```
This way, we can simply pass around MySuperModuleImpl around instead of torch::nn::Module.
2. Optimizer options are public now, since there's no way to decay the LR or modify it during training otherwise
3. Serialization functions creates autograd history and calls copy_! Bad!
4. Optimizers did not create buffers after add_parameters was called.
Pull Request resolved: https://github.com/pytorch/pytorch/pull/9837
Reviewed By: goldsborough
Differential Revision: D9199746
Pulled By: ebetica
fbshipit-source-id: 76d6b22e589a42637b7cc0b5bcd3c6b6662fb299
Summary:
The basic game plan is to stop accessing the type_ field directly,
and instead using the stored backend_, scalar_type_ and
is_variable_ to look up the appropriate Type from Context.
Storage of backend_ and scalar_type_ are new.
At some future point in time, I'd like to look at this code
carefully to see if I can get everything in this codepath inlining.
I didn't do it in this patch because there are circular include
problems making things difficult.
Some other details:
- Added Device::backend() which does what it says on the tin
- SparseTensorImpl is temporarily hard-coded to root in at::Context
for the appropriate context. If/when we put this in shared code,
we'll have to break this dep too, but for now it should be OK.
- There's a stupid problem with globalContext() deadlocking if
you didn't actually initialize it before loading libtorch.so
(which is bringing along the variable hooks). I fixed this by
reordering the static initializers. Fixes#9784
Signed-off-by: Edward Z. Yang <ezyang@fb.com>
Pull Request resolved: https://github.com/pytorch/pytorch/pull/10210
Differential Revision: D9150697
Pulled By: ezyang
fbshipit-source-id: 89e2006c88688bcfab0dcee82dc369127c198c35
Summary:
Pull Request resolved: https://github.com/pytorch/pytorch/pull/10130
Update some include paths to make them internally consistent
Reviewed By: ezyang
Differential Revision: D9119906
fbshipit-source-id: b44e5cab8e8e795ee18afe9ffc6caf1f2b413467
Summary:
…e_/is_variable_
The basic game plan is to stop accessing the type_ field directly,
and instead using the stored backend_, scalar_type_ and
is_variable_ to look up the appropriate Type from Context.
Storage of backend_ and scalar_type_ are new.
At some future point in time, I'd like to look at this code
carefully to see if I can get everything in this codepath inlining.
I didn't do it in this patch because there are circular include
problems making things difficult.
Some other details:
- Added Device::backend() which does what it says on the tin
- SparseTensorImpl is temporarily hard-coded to root in at::Context
for the appropriate context. If/when we put this in shared code,
we'll have to break this dep too, but for now it should be OK.
- There's a stupid problem with globalContext() deadlocking if
you didn't actually initialize it before loading libtorch.so
(which is bringing along the variable hooks). I didn't fix
it in this PR; it's tracked in #9784
Signed-off-by: Edward Z. Yang <ezyang@fb.com>
Pull Request resolved: https://github.com/pytorch/pytorch/pull/9787
Reviewed By: cpuhrsch
Differential Revision: D8980971
Pulled By: ezyang
fbshipit-source-id: 2b4d867abfdc3999a836a220c638c109053145a8
Summary:
More clang tidy cleanups in `torch/csrc`. This time:
1. `hicpp-use-equals-default` recommends `= default` instead of `{}` for constructors/destructors. This is better practice because it expresses the intent better (https://stackoverflow.com/questions/6502828/what-does-default-mean-after-a-class-function-declaration)
2. `readability-inconsistent-declaration-parameter-name` enforces that parameter names in the declaration match parameter names in the definition. This is just generally useful and can prevent confusion and bugs.
Also updated my script a little bit.
apaszke ezyang
Pull Request resolved: https://github.com/pytorch/pytorch/pull/9737
Differential Revision: D9069069
Pulled By: goldsborough
fbshipit-source-id: f7b3f3a4eb4c9fadc30425a153566d3b613a41ae
Summary:
I split it into two parts, _local_scalar and _local_scalar_dense (unchecked)
so I could reuse the sparse logic in both paths.
_local_scalar became a method on Tensor to work around a circular
include problem.
This is resurrected copy of #9652
Pull Request resolved: https://github.com/pytorch/pytorch/pull/9762
Differential Revision: D8972348
Pulled By: ezyang
fbshipit-source-id: 2232dbfc8e1286b8a4a1c67d285c13a7771aad4c
Summary:
I got some tensor->variable conversion exceptions from `torch/csrc/autograd/variable.h`, which used the `TORCH_ASSERTM` macros instead of `AT_CHECK`, so they didn't have backtraces. This was such a substantial loss for debugability that I decided to update the whole codebase to use the backtrace-enabled ATen macros instead of `TORCH_ASSERT` and `JIT_ASSERT`, the latter having been an alias of the former.
ezyang apaszke zdevito
Pull Request resolved: https://github.com/pytorch/pytorch/pull/9575
Differential Revision: D8924566
Pulled By: goldsborough
fbshipit-source-id: 7a4013b13eec9dbf024cef94cf49fca72f61d441
Summary:
This can hardly be called an improvement (we now print
CPUFloatType instead of CPUFloatTensor) but it was the
simplest way I could think of devirtualizing this function in
the short term. Probably need some sort of native function
that gives string information about a tensor.
Signed-off-by: Edward Z. Yang <ezyang@fb.com>
Approved in #9710
Pull Request resolved: https://github.com/pytorch/pytorch/pull/9758
Differential Revision: D8966935
Pulled By: ezyang
fbshipit-source-id: a4641affe0a6153f90cdd9f4f2a1100e46d1a2db
Summary:
As in the title. Lets us simplify a lot of code.
Depends on #9363, so please review only the last commit.
zdevito
Pull Request resolved: https://github.com/pytorch/pytorch/pull/9414
Reviewed By: zdevito
Differential Revision: D8836496
Pulled By: apaszke
fbshipit-source-id: 9b3c3d1f001a9dc522f8478abc005b6b86cfa3e3
Summary:
Prior to this diff, there have been two ways of compiling the bulk of the torch codebase. There was no interaction between them - you had to pick one or the other.
1) with setup.py. This method
- used the setuptools C extension functionality
- worked on all platforms
- did not build test_jit/test_api binaries
- did not include the C++ api
- always included python functionality
- produced _C.so
2) with cpp_build. This method
- used CMake
- did not support Windows or ROCM
- was capable of building the test binaries
- included the C++ api
- did not build the python functionality
- produced libtorch.so
This diff combines the two.
1) cpp_build/CMakeLists.txt has become torch/CMakeLists.txt. This build
- is CMake-based
- works on all platforms
- builds the test binaries
- includes the C++ api
- does not include the python functionality
- produces libtorch.so
2) the setup.py build
- compiles the python functionality
- calls into the CMake build to build libtorch.so
- produces _C.so, which has a dependency on libtorch.so
In terms of code changes, this mostly means extending the cmake build to support the full variety of environments and platforms. There are also a small number of changes related to the fact that there are now two shared objects - in particular, windows requires annotating some symbols with dllimport/dllexport, and doesn't allow exposing thread_local globals directly.
Pull Request resolved: https://github.com/pytorch/pytorch/pull/8792
Reviewed By: ezyang
Differential Revision: D8764181
Pulled By: anderspapitto
fbshipit-source-id: abec43834f739049da25f4583a0794b38eb0a94f
Summary:
Add `WeakTensor` - a `Tensor` counterpart which doesn't keep the data (or any other expensive resources) alive. They can be `.lock()`ed and return `at::optional<Tensor>` if they're still alive.
Pull Request resolved: https://github.com/pytorch/pytorch/pull/9363
Reviewed By: ezyang
Differential Revision: D8815434
Pulled By: apaszke
fbshipit-source-id: 1b3e96503c1285d78ef124c585e65c7630f3253e
Summary:
I'm cramming through clang tidy emitted warnings. This PR addresses the `hi-cpp-override` check which warns that `virtual` + `override` is redundant, since `override` already signifies that a function is overriding and thus virtual.
Where there was `virtual` + `override` I removed the `virtual`, where there was `virtual` and no `override` I removed `virtual` and added `override`.
ezyang apaszke
Pull Request resolved: https://github.com/pytorch/pytorch/pull/9335
Differential Revision: D8807082
Pulled By: goldsborough
fbshipit-source-id: e0a261053f6540a22cc56ec160a24aa285af6319
* Created TensorOptions
Storing the type in TensorOptions to solve the Variable problem
Created convenience creation functions for TensorOptions and added tests
Converted zeros to TensorOptions
Converted rand to TensorOptions
Fix codegen for TensorOptions and multiple arguments
Put TensorOptions convenience functions into torch namespace too
All factory functions except *_like support TensorOptions
Integrated with recent JIT changes
Support *_like functions
Fix in place modification
Some cleanups and fixes
Support sparse_coo_tensor
Fix bug in Type.cpp
Fix .empty calls in C++ API
Fix bug in Type.cpp
Trying to fix device placement
Make AutoGPU CPU compatible
Remove some auto_gpu.h uses
Fixing some headers
Fix some remaining CUDA/AutoGPU issues
Fix some AutoGPU uses
Fixes to dispatch_tensor_conversion
Reset version of new variables to zero
Implemented parsing device strings
Random fixes to tests
Self review cleanups
flake8
Undo changes to variable.{h,cpp} because they fail on gcc7.2
Add [cuda] tag to tensor_options_cuda.cpp
Move AutoGPU::set_index_from into .cpp file because Windows is stupid and sucks
Fix linker error in AutoGPU.cpp
Fix bad merge conflict in native_functions.yaml
Fixed caffe2/contrib/aten
Fix new window functions added to TensorFactories.cpp
* Removed torch::TensorOptions
Added code to generate wrapper functions for factory methods
Add implicit constructor from Backend to TensorOptions
Remove Var() from C++ API and use torch:: functions
Use torch:: functions more subtly in C++ API
Make AutoGPU::set_device more exception safe
Check status directly in DynamicCUDAHooksInterface
Rename AutoGPU to DeviceGuard
Removed set_requires_grad from python_variables.h and warn appropriately in Variable::set_requires_grad
remove python_default_init: self.type()
Add back original factory functions, but with deprecation warnings
Disable DeviceGuard for a couple functions in ATen
Remove print statement
Fix DeviceGuard construction from undefined tensor
Fixing CUDA device compiler issues
Moved as many methods as possible into header files
Dont generate python functions for deprecated factories
Remove merge conflict artefact
Fix tensor_options_cuda.cpp
Fix set_requires_grad not being checked
Fix tensor_new.h
TEMPORARILY put some methods in .cpp files to see if it solves issues on windows and mac
Fix bug in DeviceGuard.h
Missing includes
TEMPORARILY moving a few more methods into .cpp to see if it fixes windows
Fixing linker errors
* Fix up SummaryOps to use new factories
Undo device agnostic behavior of DeviceGuard
Use -1 instead of optional for default device index
Also move DeviceGuard methods into header
Fixes around device index after optional -> int32_t switch
Fix use of DeviceGuard in new_with_tensor_copy
Fix tensor_options.cpp
* Fix Type::copy(
* Remove test_non_float_params from ONNX tests
* Set requires_grad=False in ONNX tests that use ints
* Put layout/dtype/device on Tensor
* Post merge fixes
* Change behavior of DeviceGuard to match AutoGPU
* Fix C++ API integration tests
* Fix flip functions
* Add backward() to Tensor and Variable
* Add at:: in front of Tensor
* Trying to not move optional to appease windows?
* Move implementation into cpp file
* Undo some formatting changes
* Add efficient isVariable test to ATen.
This is done as a field on Type so that we can define a
non-virtual, inlinable function. The added ASSERTs probalby
affect runtime performance, we may need to toggle them off
on non-DEBUG builds.
Fixes#4814.
Signed-off-by: Edward Z. Yang <ezyang@fb.com>
* Rebase and brush up
* is_variable -> is_variable_or_undefined
* PyObject* <--> at::Tensor no longer unwraps variables, instead we expect end uses to always work with variable types, and we will only unwrap the variables when we optimize.
* Add torch::CPU, torch::CUDA and torch::getType
* at::CPU -> torch::CPU in extensions
This PR adds the possibility to build the C++ parts of autograd and jit, with no dependency on Python.
The goal is to allow taking a PyTorch IR representation (a tree s-expr) and running it with provided inputs.
Prerequisite: build PyTorch so that codegen runs once.
Instructions:
cd tools/cpp_build
bash build_all.sh
This will build libtorchjit and torchjit_test in tools/cpp_build/build/torchjit-build. The latter basically runs the code in test_jit.cpp for now.
While writing the PR, it turned out that a few of Python.h includes were redundant. They were removed here (PyTorch tests still pass on my machine, we'll see CI).
* Introduce Python-free builds of autograd and jit
* Remove NO_PYTHON ifdef in functions/special
* Improve Function interface
* Undo tracer changes
* Fix bug in VariableType.set_history
* Rename function_counter and sequence_number to sequence_nr
* Clarify Function documentation
* Replace swap_next_edges with next_edges() getter
* Bring back set_gradient_edge
* Simplify special.cpp
* add_gradient_edge -> create_gradient_edge
* Add mutable getters for pre/post hooks
* Use make_variable with Edge
* Remove remove_gradient_edge in favor of detach_
* Fix documentation and remove create_gradient_edge friend method
* Canonicalize some includes
* Improve Variable interface
* Address comments from @apaszke and @colesbury
* string ::operator= is not noexcept
* Remove ir.h from tracer_state.h to improve build times
* Make Variable a struct and pack SavedVariable fields
* Implement as_variable_ref
* grad_fn_ptr() -> grad_fn_unsafe()
* Reduce hackiness of set_type hack
* Include variable.h and edge.h in tracer_state.h because it uses them
* class Variable -> struct Variable because Windows cant even
* Make Variable::output_nr uint32_t instead of int
* Add comment about tracing state
* Replaced more static_cast<Variable&> and improve docs
* Remove SavedVariable destructor and construct members in init list
* Clarify docs for Variable
* Variable::set_version -> set_version_counter
Don't check the ScalarType and Backend of arguments in VariableType.
Instead, only check that arguments are Variables of any type. The
precise type checks are handled by the base type.
Many of our functions take heterogeneous types. There isn't enough
information in Declarations.yaml to ensure the precise types of
arguments in VariableType, which makes it difficult to add new methods.
This is #4943 with a fix to the memset call
Don't check the ScalarType and Backend of arguments in VariableType.
Instead, only check that arguments are Variables of any type. The
precise type checks are handled by the base type.
Many of our functions take heterogeneous types. There isn't enough
information in Declarations.yaml to ensure the precise types of
arguments in VariableType, which makes it difficult to add new methods.
* Enable scalars if compiled with WITH_SCALAR environment variable.
We are pretty close to enabling scalars (0-dimensional arrays); this allows turning them on
for development purposes and to be able to write code that works both with and without scalars enabled.
WITH_SCALARS is currently broken with distributions, but should work for test_torch, test_autograd, test_nn.
* Fix unsqueeze.
* Fix wrap dim, wrapping with Scalar.
* Convolution derivatives in ATen
This PR introduces ATen implementation of convolution, which dispatches to
THNN/CuDNN/nnpack based on input parameters. The general strategy is to compose
this function out of the various forward-backward pairs of specific
implementations, rather than write a monolithic function with backwards (which
is what we did before because the boilerplate of doing it otherwise would have
been very high.) The new API provides the following functions:
- _convolution, which is a fully generic, native convolution implementation
that dispatches to various other convolution implementations depending on
input characteristics. This is prefixed with an underscore because it
explicitly takes benchmark, deterministic and cudnn_enabled which are
implementation details for CuDNN. The intent is to eventually provide a
convolution that reads these parameters out of the context using #4104.
- _convolution_nogroup is a convolution implementation for non-CuDNN
algorithms which don't support group convolution natively.
- _convolution_double_backward is the generic double-backwards implementation
for convolution.
In more detail:
- Most functionality from torch/csrc/autograd/functions/convolution.cpp has been
moved into aten/src/ATen/native/Convolution.cpp
- We continue to make use of ConvParams, but we now construct the parameters
upon entry to a function from the function signature (which does not use
ConvParams; having convolution take ConvParams directly would require teaching
the code generator how to accept these as parameters, complicating ATen's API
model) and destruct them when making subprocedure calls.
- I introduce a new idiom, input_r, which represents a const Tensor& reference,
which will subsequently be assigned to a local Tensor input. This is helpful
because a lot of the existing algorithms relied on being able to assign to
locals, which is not permitted with a const reference.
- The native argument parser now supports std::array<bool,2> inputs (NB: there
MUST NOT be a space; this is the same hack as is applied to derivatives.yaml)
- Native parser now supports Tensor? arguments, which indicates a nullable
tensor. Previously this function was only used by NN methods.
- Documentation updates on THNN library
- I added an extra fgradInput argument to VolumetricConvolutionMM_updateOutput
and VolumetricConvolutionMM_accGradParameters so that its buffer list lines up
with the backward argument list. This makes it possible to write derivative
for conv3d which previously was not supported (commented out in
derivatives.yaml)
- Extra double_backward declarations for all convolution backwards functions was
added.
- You can now use the syntax Tensor? in native_functions.yaml to indicate that a
tensor argument is nullable. There are adjustments to propagate this to the
Python argument parser.
- NNPACK was ported to ATen, and ATen now builds and links against ATen if
possible. New AT_NNPACK_ENABLED macro. The nnpack functions are
nnpack_spatial_convolution.
- Some modest CuDNN convolution refactoring to remove _forward from names.
- There's a new cudnn_convolution_backward function to deal with the fact that
CuDNN convolution double backward requires you to have computed all gradients
in one go.
- Variable set_flags now checks if the tensor is undefined, fixing a silent memory
corruption.
- checkSameType updated to not raise an exception if called with Variable arguments
- "no ATen declaration found for" error message is improved to say what available declarations are
- make_variable now accepts undefined tensors, and returns an undefined tensor in this case.
This removes volatile from Variable. The functionality is mostly
replaced by a global (thread-local) flag, which is controlled by
torch.set_grad_enabled() and the context manager torch.no_grad().
In C++, the flag is exposed through GradMode::is_enabled() and GradMode::set_enabled()
Fixes#3627
* Implement Variable.cuda using ATen
This adds an optional async flag to Tensor::copy_, which attempts to do
a non-blocking copy if the one of the tensors is in pinned memory and
the other is a CUDA tensor.
* Perform cross-device copy in CopyBackwards
Also call torch.cuda._lazy_init() from Variable.cuda()
* Implement Variable.type via ATen
* Changes from review:
- remove copy_out
- remove unnecessary include
- fix default device for .cuda()
* Combine if statements in dispatch_type
Add (fully opt-in) functionality to support setting pretty names for
nodes in the graph. In particular
- Variable now has a `name` parameter in the constructor
- export now has `input_names` and `export_names` parameters
Nodes that are not named via this mechanism continue to be named
internally with unique integers.
Names have a few rules.
- They must all be unique in the graph.
- They may not be integers (because of potential conflicts with
internally generated names).
Previously, an in-place operation on a view that caused the view to be
volatile would not propagate up to the base. This often happens in
backward passes involving CopySlices which would increase memory usage
by making grad non-volatile.
Previously, we checked that Variables were at least one dimensional in
the Python binding (wrap_outputs.h) and in the backwards functions. This
was necessary because some Tensor functions returned Scalar types, which
must be zero dimensional. This moves the wrapping logic into
VariableType.
Allow in-place operations on views
Adds VariableViewImpl, a subclass of VariableImpl which has a pointer to
the base Variable on which it is a view. In-place operations on views
change the grad_fn of the base.
Note that in-place operations only work on views that are the first output of the function that created them. All C++/ATen implemented functions have this behavior, but it's possible to write Python-implemented autograd functions that do not. In-place operations on these view will raise an exception.
Fixes#3313
In many "non-Python" headers, we include Python.h because we need
to declare a pointer to PyObject, and solely because of that. It
would be a lot better if we had a simpler version of Python.h that
just declared PyObject available for pointers, without anything
else. This is what torch/csrc/utils/python_stub.h does.
The good thing about not including Python.h is that it is easy to
be warning-less; no more ugly insertions of Python.h on headers
where it has no good reason to be.
This makes PyTorch warning clean again.
Signed-off-by: Edward Z. Yang <ezyang@fb.com>
I've also made the version counter and the "live" reference count
atomics.
Note that it's not safe to set the version counter (operator=) from
multiple threads, because shared_ptr assignment isn't thread safe.
Currently, the only call sites to these functions are on newly created
variables before they can be accessed from other threads.
See #3111
This adds some generated autograd functions implemented in C++, which
are generated from derivatives.yaml. It also generates Python bindings
for the Variable methods. The generated files are:
Functions.cpp/h: subclasses of torch::autograd::Function
VariableType.cpp/h: The at::Type for autograd Variables
python_variable_methods.cpp: Python bindings to torch::autograd::Variable
python_variable_methods_dispatch.h: wrapper which releases GIL and sets the
CUDA device
python_functions.cpp/h: exposes generated autograd functions as Python
objects
The generated functions are mostly shadowed by the definitions in
variable.py. We'll remove the Python implementations in favor of the
generated C++ implementations in a subsequent commit.
Also squash a warning about an implicit conversion that will never
occur (because the type being converted to is a superclass).
Signed-off-by: Edward Z. Yang <ezyang@fb.com>
Variable is now a subclass of at::Tensor backed by a VariableImpl* pImpl. The implementation of the ATen functions is defined in the auto-generated VariableType.h/cpp file.
Currently, only functions which fall through to the base type, such as sizes() and isCuda() are implemented. Differentiable ops like add() and mul() will be added in a subsequent PR.
* Variables now hold a list of ValueTracingStates and can participate
in multiple traces.
* Refactored Traceable to maintain a list of traces, and only stop
tracing once it records all stages
Previously, our AST was a DAG, where shared Nodes indicated a computation
should be reused. This commit rewrites the IR into a new functional
representation which represents sharing explicitly using variable
bindings.
We offer a few justifications for this new style:
1. The new representation is not all that different from the
old one; it is about as easy to construct, and the lack of an
explicit graph doesn't negatively impact our ability to interpret
the graph, since we've chosen, as a matter of design, to NOT have
the IR participate in the actual execution of a graph.
2. The new let-binding representation has an implicit ordering,
which we can use to conveniently keep track of the original order
the trace showed up as. This automatically gives us a topsort,
and gives us an easier to read textual representation of our
IR:
%14 = Embedding %11, %0, -1, None, 2, False, False
%15 = Dropout %14, 0.2, True, False
%16 = Index %12, 0
%17 = Index %12, 1
%18 = Index %13, 0
%19 = Index %13, 1
%20 = Index %15, 0
%21 = Linear %20, %1, %3
%22 = Linear %16, %2, %4
3. It moves us closer to a Futhark style language
(http://futhark-lang.org/publications/pldi17.pdf).
Major aspects of the diff
- Node is replaced with Expr and Arg, a pair of mutually recursive
structures which represent our new language. In BNF, the language
looks like this:
a ::= c | %i
e ::= %i, ... = e
| PyOp e, ...
| Ret %i, ...
Technically, Ret is not actually a return (no control flow is involved),
it just tuples up a series of tensors (identified by variables).
One important invariant is that locals are always tensors; they
are never constants (this is asymmetric with Args.)
- Arguments support Python constants. This is an important piece because
many operators take extra Python literals like integers and tuples in
order to specify extra parameters about how an operator operates. Adding
this was essential to getting word_language_model to work.
- As both Expr and Arg have multiple variants, there is new infrastructure
for doing case on the variants using ExprVisitor and ArgVisitor. The
strategy here is adapted from WebAssembly's visitors, although we have
generalized to permit arbitrary argument forwarding, which is necessary
to support tail-recursive visitor calls. TCO is important because our
interpreter may recurse arbitrarily deep into a stack of nested lets.
If users wish, they can also manually case on the type tag.
- Tracing is now turned on and off using _tracer_enter/_tracer_exit in
torch._C. _tracer_enter accepts a list of variables which are to be
treated as arguments; _tracer_exit accepts the list of traced variables
which should be returned when you reexecute the trace, and returns
the trace expression which can be reexecuted. GlobalTracingState
is a global variable which tracks whether or not we are tracing or not.
- You use run_forward to execute a trace on some set of parameters.
- When under tracing, variables keep track, via trace_local, what the
name of their variables in the IR are.
Here is a simple runner which leaks memory but can be used to JIT models:
import torch.autograd.function as F
import torch._C
def jit(model):
import types
real_forward = model.forward
def forward(self, *args):
def flatten(x):
return tuple(F._iter_variables(x))
if not hasattr(self, "saved_trace"):
torch._C._tracer_enter(tuple(self.parameters()) + flatten(args))
out = real_forward(*args)
self.saved_trace = torch._C._tracer_exit(flatten(out))
self.saved_outs = out
return out
else:
flat_out = Variable._execution_engine.run_forward(self.saved_trace, tuple(self.parameters()) + flatten(args))
return F._unflatten(flat_out, self.saved_outs)
Major problems:
- Sanity checking is spotty at best, especially when users pass in variables.
- The interpreter leaks tensor memory from the store. When we add back def-use
we should be able to deallocate tensors as soon as we know they are no longer
necessary.
- The interpreter needs to reach feature parity with the old execution engine.
From there, we need to see if backwards can be subsumed as well.
- I still have no confidence in having memory managed everything correctly.
This requires a close look.
- Rather than return an *open* expression as a trace, we should return a
*lambda* instead, which knows about how many formal parameters it
requires.
- The IR is not introspectable from Python at the moment, but this is simply a
matter of implementing all the binding code.
- The tracer is NOT reentrant (you can't trace while you're inside a trace.)
Furthermore, no sanity checking is done if you try to incorrectly reuse
things from one trace in another.
Signed-off-by: Edward Z. Yang <ezyang@fb.com>
Primary things I had to fix:
- Suppress _XOPEN_SOURCE warnings by ensuring that Python.h is included
first, because it always unconditionally defines this macro.
- Turn off strict aliasing, because Python 2 doesn't work with strict
aliasing.
- Workaround setuptools bug, where it's incorrectly passing
-Wstrict-prototypes to C++ compilers (where this doesn't make
any sense)
To compile csrc with -Werror, run `CFLAGS="-Werror" python setup.py build_ext`
Signed-off-by: Edward Z. Yang <ezyang@fb.com>
* Fix gc_refs assertion failure
Ensure that each THPVariable -> THPFunction reference contributes one
ref count to the THPFunction by creating a new shared_ptr for each ref.
Because multiple shared_ptrs can again manage a single THPFunction, it's
not safe to use std::weak_ptr where it may point to a PyFunction. It's
still safe to use weak_ptr for grad_accumulator since these are never
PyFunctions.
Fixes#1626
* Remove stale comment
* A pile of misc doc fixes.
Signed-off-by: Edward Z. Yang <ezyang@fb.com>
* Handle @apaszke review comments.
Signed-off-by: Edward Z. Yang <ezyang@fb.com>
* Initial csrc documentation.
Signed-off-by: Edward Z. Yang <ezyang@fb.com>
* Fix clang warnings
* Raise errors when unsupported ConvNd configurations are used
* Properly handle Variable indexing with LongTensors
* Support both tensors and variables in Variable.type_as
Because of this Variables can no longer appear in the graph.
Every usage of a leaf Variable will leave an AccumulateGrad
function that has no outputs, but modifies var.grad as a side
effect.
The core autograd Variable, Function, and Engine no longer depend on the
Python API. This let's us implement functions in C++. In the future, we
can also multithread engine and release the GIL for most of the
non-Python backwards.
Only references to their data and version counters are stored.
Also, it is now possible to have None arguments in save_for_backward
and return too many values from backward (as long as the excessive
results are None).
