Summary:
Pull Request resolved: https://github.com/pytorch/pytorch/pull/73166
This PR refactors, cleans up, and optimizes the implementation of `TORCH_DISTRIBUTED_DEBUG`. It also introduces three new user APIs: `get_debug_level()`, `set_debug_level()`, and `set_debug_level_from_env()` to retrieve and modify the debug level after a process has started.
ghstack-source-id: 149778566
Test Plan: Run the existing unit tests.
Reviewed By: rohan-varma
Differential Revision: D34371226
fbshipit-source-id: e18443b411adcbaf39b2ec999178c198052fcd5b
(cherry picked from commit 26d6bb1584b83a0490d8b766482656a5887fa21d)
Summary:
This PR fixes https://github.com/pytorch/pytorch/issues/64785 by introducing a `torch.LinAlgError` for reporting errors caused by bad values in linear algebra routines which should allow users to easily catch errors caused by numerical errors.
Pull Request resolved: https://github.com/pytorch/pytorch/pull/68571
Reviewed By: malfet
Differential Revision: D33254087
Pulled By: albanD
fbshipit-source-id: 94b59000fdb6a9765e397158e526d1f815f18f0f
Summary:
I've noticed that the `HANDLE_TH_ERRORS` macros are actually very expensive in terms of compile time. Moving the bulk of the catch statements out of line using a lippincott function significantly improves compile times and object file binary sizes. For just the generated autograd bindings, this halves serial build time from 8 minutes to 4 and binary size is more than halved for most files with the biggest difference being `python_variable_methods.cpp` which went from 126 MB to 43 MB.
Pull Request resolved: https://github.com/pytorch/pytorch/pull/69974
Reviewed By: mruberry
Differential Revision: D33160899
Pulled By: albanD
fbshipit-source-id: fc35fa86f69ffe5a0752557be30b438c8564e998
Summary:
This renames `WindowsTorchApiMacro.h` to `Export.h` to mirror the c10 header `c10/macros/Export.h` and also updates it to use `C10_EXPORT`/`C10_IMPORT`. This also removes the `THP_API` macro from `THP_export.h` which appears to serve the same purpose.
cc pietern mrshenli pritamdamania87 zhaojuanmao satgera rohan-varma gqchen aazzolini osalpekar jiayisuse SciPioneer H-Huang
Pull Request resolved: https://github.com/pytorch/pytorch/pull/68095
Reviewed By: jbschlosser
Differential Revision: D32810881
Pulled By: albanD
fbshipit-source-id: d6949ccd0d80d6c3e5ec1264207611fcfe2503e3
Summary:
Pull Request resolved: https://github.com/pytorch/pytorch/pull/68226
**Note that this PR is unusually big due to the urgency of the changes. Please reach out to me in case you wish to have a "pair" review.**
This PR introduces a major refactoring of the socket implementation of the C10d library. A big portion of the logic is now contained in the `Socket` class and a follow-up PR will further consolidate the remaining parts. As of today the changes in this PR offer:
- significantly better error handling and much more verbose logging (see the example output below)
- explicit support for IPv6 and dual-stack sockets
- correct handling of signal interrupts
- better Windows support
A follow-up PR will consolidate `send`/`recv` logic into `Socket` and fully migrate to non-blocking sockets.
## Example Output
```
[I logging.h:21] The client socket will attempt to connect to an IPv6 address on (127.0.0.1, 29501).
[I logging.h:21] The client socket is attempting to connect to [localhost]:29501.
[W logging.h:28] The server socket on [localhost]:29501 is not yet listening (Error: 111 - Connection refused), retrying...
[I logging.h:21] The server socket will attempt to listen on an IPv6 address.
[I logging.h:21] The server socket is attempting to listen on [::]:29501.
[I logging.h:21] The server socket has started to listen on [::]:29501.
[I logging.h:21] The client socket will attempt to connect to an IPv6 address on (127.0.0.1, 29501).
[I logging.h:21] The client socket is attempting to connect to [localhost]:29501.
[I logging.h:21] The client socket has connected to [localhost]:29501 on [localhost]:42650.
[I logging.h:21] The server socket on [::]:29501 has accepted a connection from [localhost]:42650.
[I logging.h:21] The client socket has connected to [localhost]:29501 on [localhost]:42722.
[I logging.h:21] The server socket on [::]:29501 has accepted a connection from [localhost]:42722.
[I logging.h:21] The client socket will attempt to connect to an IPv6 address on (127.0.0.1, 29501).
[I logging.h:21] The client socket is attempting to connect to [localhost]:29501.
[I logging.h:21] The client socket has connected to [localhost]:29501 on [localhost]:42724.
[I logging.h:21] The server socket on [::]:29501 has accepted a connection from [localhost]:42724.
[I logging.h:21] The client socket will attempt to connect to an IPv6 address on (127.0.0.1, 29501).
[I logging.h:21] The client socket is attempting to connect to [localhost]:29501.
[I logging.h:21] The client socket has connected to [localhost]:29501 on [localhost]:42726.
[I logging.h:21] The server socket on [::]:29501 has accepted a connection from [localhost]:42726.
```
ghstack-source-id: 143501987
Test Plan: Run existing unit and integration tests on devserver, Fedora, Ubuntu, macOS Big Sur, Windows 10.
Reviewed By: Babar, wilson100hong, mrshenli
Differential Revision: D32372333
fbshipit-source-id: 2204ffa28ed0d3683a9cb3ebe1ea8d92a831325a
Summary:
Fixes https://github.com/pytorch/pytorch/issues/50209
This adds a new warning handler that stores all warnings in a shared
queue, which can be "replayed" at a later time and, crucially, on
another thread. Then, I use this inside the autograd engine to ensure
that warnings are processed by the handler registered on the main
thread.
For testing, I also add an operator that always warns in the backward
pass and test that the warning is a normal Python warning.
cc ezyang albanD zou3519 gqchen pearu nikitaved soulitzer Lezcano Varal7
Pull Request resolved: https://github.com/pytorch/pytorch/pull/66235
Reviewed By: ejguan
Differential Revision: D31505413
Pulled By: albanD
fbshipit-source-id: 1a7f60b038f55c20591c0748b9e86735b3fec2f9
Summary:
Pull Request resolved: https://github.com/pytorch/pytorch/pull/65376
Let's suppose there's a bug in PyTorch and python_error gets thrown
and never gets caught. Typically, you'll get a very useless error
message like this:
```
terminate called after throwing an instance of 'python_error'
what():
Aborted (core dumped)
```
Now, you'll get:
```
what(): unknown Python error (for more information, try rerunning with TORCH_SHOW_CPP_STACKTRACES=1)
```
and with TORCH_SHOW_CPP_STACKTRACES=1 you'll get:
```
what(): error message from Python object
```
If we're OK with making Python exceptions go even slower, we could
eagerly populate unconditionally. I'm also not so happy we don't get
a Python backtrace or the Python error name, that's worth improving
(this is a minimal diff to get the discussion going.)
Signed-off-by: Edward Z. Yang <ezyang@fb.com>
Test Plan: Imported from OSS
Reviewed By: albanD
Differential Revision: D31067632
Pulled By: ezyang
fbshipit-source-id: 9cfda47cafb349ee3d6853cdfb0f319073b87bff
Summary:
As GoogleTest `TEST` macro is non-compliant with it as well as `DEFINE_DISPATCH`
All changes but the ones to `.clang-tidy` are generated using following script:
```
for i in `find . -type f -iname "*.c*" -or -iname "*.h"|xargs grep cppcoreguidelines-avoid-non-const-global-variables|cut -f1 -d:|sort|uniq`; do sed -i "/\/\/ NOLINTNEXTLINE(cppcoreguidelines-avoid-non-const-global-variables)/d" $i; done
```
Pull Request resolved: https://github.com/pytorch/pytorch/pull/62008
Reviewed By: driazati, r-barnes
Differential Revision: D29838584
Pulled By: malfet
fbshipit-source-id: 1b2f8602c945bd4ce50a9bfdd204755556e31d13
Summary:
This is an automatic change generated by the following script:
```
#!/usr/bin/env python3
from subprocess import check_output, check_call
import os
def get_compiled_files_list():
import json
with open("build/compile_commands.json") as f:
data = json.load(f)
files = [os.path.relpath(node['file']) for node in data]
for idx, fname in enumerate(files):
if fname.startswith('build/') and fname.endswith('.DEFAULT.cpp'):
files[idx] = fname[len('build/'):-len('.DEFAULT.cpp')]
return files
def run_clang_tidy(fname):
check_call(["python3", "tools/clang_tidy.py", "-c", "build", "-x", fname,"-s"])
changes = check_output(["git", "ls-files", "-m"])
if len(changes) == 0:
return
check_call(["git", "commit","--all", "-m", f"NOLINT stubs for {fname}"])
def main():
git_files = check_output(["git", "ls-files"]).decode("ascii").split("\n")
compiled_files = get_compiled_files_list()
for idx, fname in enumerate(git_files):
if fname not in compiled_files:
continue
if fname.startswith("caffe2/contrib/aten/"):
continue
print(f"[{idx}/{len(git_files)}] Processing {fname}")
run_clang_tidy(fname)
if __name__ == "__main__":
main()
```
Pull Request resolved: https://github.com/pytorch/pytorch/pull/56892
Reviewed By: H-Huang
Differential Revision: D27991944
Pulled By: malfet
fbshipit-source-id: 5415e1eb2c1b34319a4f03024bfaa087007d7179
Summary:
Pull Request resolved: https://github.com/pytorch/pytorch/pull/53377
My underlying goal is I want to make the test suite ignore
NotImplementedError without failing when bringing up a backend (meta)
that doesn't have very many functions implemented.
Signed-off-by: Edward Z. Yang <ezyang@fb.com>
Test Plan: Imported from OSS
Reviewed By: mrshenli
Differential Revision: D26850766
Pulled By: ezyang
fbshipit-source-id: ffbdecd22b06b5ac23e1997723a6e2a71dfcd14a
Summary:
Today in PyTorch, warnings triggered in C++ are printed to Python users like this:
`../aten/src/ATen/native/BinaryOps.cpp:81: UserWarning: Integer division of tensors using div or / is deprecated, and in a future release div will perform true division as in Python 3. Use true_divide or floor_divide (// in Python) instead.`
This may be unhelpful to Python users, who have complained it's difficult to relate these messages back to their programs. After this PR, warnings that go through the PyWarningHandler and allow it to add context print like this:
```
test/test_torch.py:16463: UserWarning: Integer division of tensors using div or / is deprecated, and in a future release div will perform true division as in Python 3. Use true_divide or floor_divide (// in Python) instead. (Triggered internally at ../aten/src/ATen/native/BinaryOps.cpp:81.)
cpu_result = getattr(cpu_tensor, op_str)(*cpu_args)
```
This relates the warning back to the user's program. The information about the cpp file and line number is preserved in the body of the warning message.
Some warnings, like those generated in the JIT, already account for a user's Python context, and so they specify that they should be printed verbatim and are unaffected by this change. Warnings originating in Python and warnings that go through c10's warning handler, which prints to cerr, are also unaffected.
A test is added to test_torch.py for this behavior. The test relies on uint8 indexing being deprecated and its warning originating from its current header file, which is an unfortunate dependency. We could implement a `torch.warn` function, instead.
Pull Request resolved: https://github.com/pytorch/pytorch/pull/36052
Differential Revision: D20887740
Pulled By: mruberry
fbshipit-source-id: d3515c6658a387acb7fccaf83f23dbb452f02847
Summary:
Fixes https://github.com/pytorch/pytorch/issues/33899
In the issue, we have
```
TypeError("expected %s (got %s)", dispatch_key, toString(other.key_set()).c_str());
```
which results in `dispatch_key` being interpreted as a c-string by `sprintf`. Adding `__attrbute__((format))` to the `TypeError` constructor allows gcc or clang to detect this at compile time. Then `-Werror=format` makes it a hard error at compile time.
Pull Request resolved: https://github.com/pytorch/pytorch/pull/34019
Differential Revision: D20194842
Pulled By: ezyang
fbshipit-source-id: fa4448916c309d91e3d949fa65bb3aa7cca5c6a8
Summary:
This PR adds the following items:
- **1st item**: `ArrayRef<TensorIndex>` and `std::initializer_list<TensorIndex>` overloads for `Tensor::index` and `Tensor::index_put_`, to be used specifically for multi-dim indexing purpose.
Design rationale:
* C++ `Tensor::index` and `Tensor::index_put_` are both existing tensor APIs, and they currently (before this PR) only accept a list of tensors (i.e. `ArrayRef<Tensor>`) as indices. If we change their signatures to also accept non-tensors as indices (i.e. `ArrayRef<TensorIndex>`, and `TensorIndex` is convertible from `Tensor` / `Slice` / `None` / `Ellipsis`), it would slow down the original code path (since now it has to go through more steps), which is undesirable.
To get around this problem, the proposed solution is to keep the original `ArrayRef<Tensor>` overload, and add `ArrayRef<TensorIndex>` and `std::initializer_list<TensorIndex>` overloads to `Tensor::index` and `Tensor::index_put_`. This way, the original code path won’t be affected, and the tensor multi-dim indexing API is only used when the user explicitly pass an `ArrayRef<TensorIndex>` or a braced-init-list of `TensorIndex`-convertible types to `Tensor::index` and `Tensor::index_put_` .
Note that the above proposed solution would still affect perf for the user’s original `Tensor::index` or `Tensor::index_put_` call sites that use a braced-init-list of tensors as input, e.g. `tensor.index({...})` or `tensor.index_put_({...}, value)`, since now such function calls would take the multi-dim indexing path instead of the original advanced indexing path. However, there are only two instances of this in our codebase (one in ATen cpp test, one in a C++ API nn init function), and they can be easily changed to explicitly use `ArrayRef<Tensor>` as input (I changed them in this PR). For external user’s code, since this is part of the C++ frontend which is still considered experimental, we will only talk about this change in the release note, and ask users to switch to using `ArrayRef<Tensor>` explicitly if they want to keep using the original advanced indexing code path.
- **2nd item**: Mechanisms for parsing `ArrayRef<TensorIndex>` indices and performing indexing operations (mirroring the functions in `torch/csrc/autograd/python_variable_indexing.cpp`).
- **3rd item**: Simple tests to demonstrate that the `Tensor::index()` and `Tensor::index_put_()` APIs work. I will add more tests after the first few PRs are reviewed.
- **4th item**: Merge Python/C++ indexing code paths, for code simplicity. I tested locally and found that there is no perf regression resulting from the merge. I will get more concrete numbers for common use cases when we settle on the overall design.
This PR supersedes https://github.com/pytorch/pytorch/pull/30425.
Pull Request resolved: https://github.com/pytorch/pytorch/pull/32841
Differential Revision: D19919692
Pulled By: yf225
fbshipit-source-id: 7467e64f97fc0e407624809dd183c95ea16b1482
Summary:
Closes https://github.com/pytorch/pytorch/issues/30027
The idea here is that you can bind a function with `pybind11` in a single line and without modifying the function:
```cpp
m.def("foo", foo, py::call_guard<torch::PyWarningHandler>());
```
Where warnings are handled by the [`call_guard`](https://pybind11.readthedocs.io/en/stable/advanced/functions.html#call-guard) and exceptions are handled by the `pybind11` exception translator. To do this, I have added support for handling C++ exceptions in `torch::PyWarningHandler`'s destructor without setting the python error state before hand.
Pull Request resolved: https://github.com/pytorch/pytorch/pull/30588
Differential Revision: D19905626
Pulled By: albanD
fbshipit-source-id: 90c0a5e298b123cc0c8ab9c52c91be4e96ea47c6
Summary:
The Python C API documentation states "Access to the [PyObject]
members must be done by using the macros Py_REFCNT and Py_TYPE."
Pull Request resolved: https://github.com/pytorch/pytorch/pull/31388
Differential Revision: D19161790
Pulled By: colesbury
fbshipit-source-id: ac9a3738c913ad290a6d3460d0d657ec5c13b711
Summary:
Given that pybind11 implements these gil functions, I don't think it makes sense for Pytorch to have its own bespoke versions.
Fixes https://github.com/pytorch/pytorch/issues/29065
Pull Request resolved: https://github.com/pytorch/pytorch/pull/29095
Differential Revision: D18301806
Pulled By: ezyang
fbshipit-source-id: 03da6a26c41ee65aaadf7b67b9f0b14d2def2a5a
Summary:
Pull Request resolved: https://github.com/pytorch/pytorch/pull/29143
THP_CORE macro is a very old macro that appeared to have served
two purposes:
1. The torch-python equivalent of CAFFE2_BUILD_MAIN_LIB, to toggle
symbol visibility headers
2. Some sort of ad hoc way of hiding certain definitions from headers
so external clients can't get at them.
It did (2) in a very confusing manner, because we set THP_CORE in both
torch and torch-python (it shouldn't do anything in torch). In this
PR I just get rid of use case (2) entirely (so everything shows up in
headers all the time), and then redo (1) using a new THP_BUILD_MAIN_LIB
macro. This cleans up some of the macro definitions and makes my life
easier for working on #27215.
Signed-off-by: Edward Z. Yang <ezyang@fb.com>
Test Plan: Imported from OSS
Differential Revision: D18309594
Pulled By: ezyang
fbshipit-source-id: adcb6d7cb387cd818480137e2b94e5e761dbfefc
Summary:
Pull Request resolved: https://github.com/pytorch/pytorch/pull/29041
1) Enhanced autograd unit tests to test the
torch.distributed.autograd.backward() API more thoroughly on Python UDFs.
2) Enhanced `python_error` to override `what` such that it returns an
appropriate error string if we call `what()` on this error. This ensures we can
propagate exceptions over the wire during RPCs (since we get the error string
by calling what() on the exception)
ghstack-source-id: 93098679
ghstack-source-id: 93098679
Test Plan: waitforbuildbot
Reviewed By: mrshenli
Differential Revision: D18273041
fbshipit-source-id: 85d3932fed6337668a812367fdfce233c1b3ff8e
Summary:
Pull Request resolved: https://github.com/pytorch/pytorch/pull/28824
1) Enhanced autograd unit tests to test the
torch.distributed.autograd.backward() API more thoroughly on Python UDFs.
2) Enhanced `python_error` to override `what` such that it returns an
appropriate error string if we call `what()` on this error. This ensures we can
propagate exceptions over the wire during RPCs (since we get the error string
by calling what() on the exception)
ghstack-source-id: 92972494
Test Plan: waitforbuildbot
Differential Revision: D18195584
fbshipit-source-id: b795daf644ba1816fdec484545192ab55a2f71e7
Summary:
This PR adds the final set of clang-tidy checks we should add for our codebase: a last set of performance-related checks. Most fixes here are around changing `auto` to `const auto&` in a few places where unnecessary copies were made, and adding `reserve()` calls before loops doing repeated `push_back()`. Also a few cases of calling `std::string::find` with a single-character string literal instead of a single char, which uses a less efficient string search algorithm meant for searching larger substrings.
ezyang apaszke
Pull Request resolved: https://github.com/pytorch/pytorch/pull/15198
Differential Revision: D13468797
Pulled By: goldsborough
fbshipit-source-id: 2bed1ea1c7c162b7f3e0e1026f17125e88c4d5b2
Summary:
This PR fixes around 250 places in the codebase where we were making unnecessary copies of objects (some large, some small).
ezyang
Pull Request resolved: https://github.com/pytorch/pytorch/pull/15026
Differential Revision: D13458784
Pulled By: goldsborough
fbshipit-source-id: be5148b2ce09493588d70952e6f6d6ff5ec5199b
Summary:
This PR enables C++ frontend modules to be bound into Python and added as submodules of Python modules. For this, I added lots of pybind11 bindings for the `torch::nn::Module` class, and modified the `torch.nn.Module` class in Python to have a new Metaclass that makes `isinstance(m, torch.nn.Module)` return true when `m` is a C++ frontend module. The methods and fields of C++ modules are bound in such a way that they work seamlessly as submodules of Python modules for most operations (one exception I know of: calling `.to()` ends up calling `.apply()` on each submodule with a Python lambda, which cannot be used in C++ -- this may require small changes on Python side).
I've added quite a bunch of tests to verify the bindings and equality with Python. I think I should also try out adding a C++ module as part of some large PyTorch module, like a WLM or something, and see if everything works smoothly.
The next step for inter-op across our system is ScriptModule <-> C++ Frontend Module inter-op. I think this will then also allow using C++ frontend modules from TorchScript.
apaszke zdevito
CC dzhulgakov
Pull Request resolved: https://github.com/pytorch/pytorch/pull/13481
Differential Revision: D12981996
Pulled By: goldsborough
fbshipit-source-id: 147370d3596ebb0e94c82cec92993a148fee50a7
Summary:
Anywhere we used #include "foo.h", we now say #include <foo.h>
Paths are adjusted to be rooted out of aten/src, torch/lib, or
the root level directory.
I modified CMakeLists.txt by hand to remove TH and THC from
the include paths.
I used the following script to do the canonicalization:
```
import subprocess
import re
import os.path
files = subprocess.check_output(['git', 'ls-files']).decode('utf-8').rstrip().split('\n')
for fn in files:
if not any(fn.endswith(suff) for suff in ['.cu', '.cpp', '.in', '.h', '.hpp', '.cu', '.cuh', '.cc']):
continue
if not any(fn.startswith(pref) for pref in ["aten/", "torch/"]):
continue
with open(fn, 'r') as f:
c = f.read()
def fmt(p):
return "#include <{}>".format(p)
def repl(m):
p = m.group(1)
if p in ["dlfcn.h", "unistd.h", "nvrtc.h", "cuda.h", "cuda_runtime.h", "cstdint", "cudnn.h", "Python.h", "cusparse.h", "cuda_runtime_api.h", "cuda_fp16.h", "cublas_v2.h", "stdint.h", "curand_kernel.h"]:
return fmt(p)
if any(p.startswith(pref) for pref in ["torch/csrc", "c10/", "ATen/", "caffe2/", "TH/", "THC/", "Eigen/", "gtest/", "zdl/", "gloo/", "onnx/", "miopen/"]):
return fmt(p)
for root in ["aten/src", "torch/lib", ""]:
for bad_root in [os.path.dirname(fn), "aten/src/TH", "aten/src/THC", "torch/csrc"]:
new_p = os.path.relpath(os.path.join(bad_root, p), root)
if not new_p.startswith("../") and (os.path.exists(os.path.join(root, new_p)) or os.path.exists(os.path.join(root, new_p + ".in"))):
return fmt(new_p)
print("ERROR: ", fn, p)
return m.group(0)
new_c = re.sub(r'#include "([^"]+)"', repl, c)
if new_c != c:
print(fn)
with open(fn, 'w') as f:
f.write(new_c)
```
Signed-off-by: Edward Z. Yang <ezyang@fb.com>
Pull Request resolved: https://github.com/pytorch/pytorch/pull/14849
Reviewed By: dzhulgakov
Differential Revision: D13363445
Pulled By: ezyang
fbshipit-source-id: 52361f878a672785f9306c9e9ab2513128092b68
Summary:
Pull Request resolved: https://github.com/pytorch/pytorch/pull/12792
This is a follow up diff after D10238910.
Only non-codemod change is the removal of ATen/Error.h and ATen/core/Error.h. Other files are basically changing the inclusion path + clang format for inclusion order.
Reviewed By: bddppq
Differential Revision: D10437824
fbshipit-source-id: 7f885f80ab5827468d1351cfb2765d0e3f555a69
Summary:
There are still a few work to be done:
- Move logging and unify AT_WARN with LOG(ERROR).
- A few header files are still being plumbed through, need cleaning.
- caffe2::EnforceNotMet aliasing is not done yet.
- need to unify the macros. See c10/util/Exception.h
This is mainly a codemod and not causing functional changes. If you find your job failing and trace back to this diff, usually it can be fixed by the following approaches:
(1) add //caffe2/c10:c10 to your dependency (or transitive dependency).
(2) change objects such as at::Error, at::Optional to the c10 namespace.
(3) change functions to the c10 namespace. Especially, caffe2::MakeString is not overridden by the unified c10::str function. Nothing else changes.
Please kindly consider not reverting this diff - it involves multiple rounds of rebasing and the fix is usually simple. Contact jiayq@ or AI Platform Dev for details.
Pull Request resolved: https://github.com/pytorch/pytorch/pull/12354
Reviewed By: orionr
Differential Revision: D10238910
Pulled By: Yangqing
fbshipit-source-id: 7794d5bf2797ab0ca6ebaccaa2f7ebbd50ff8f32
Summary:
How did we get so many uses of `NULL` again?
ezyang
Pull Request resolved: https://github.com/pytorch/pytorch/pull/11047
Differential Revision: D9566799
Pulled By: goldsborough
fbshipit-source-id: 83469f352ac69aa65bdaf1a1a21f922d892e0db3
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
