Summary:
Pull Request resolved: https://github.com/pytorch/pytorch/pull/42249
Main change is to bring Caffe2's superior error messages for cuda initialization into c10 and use them in all code paths.
Basic logic:
| Case | Call to device_count() | init_cuda, e.g. allocating tensor |
| -- | -- | -- |
| all good | non-zero | just works |
| no gpus | 0, no warning | throw exception with good message |
| driver issues | 0, produce warning | throw exception with good message |
| out of memory with ASAN | 0, produce warning| throw exception with ASAN message |
Previously, the error thrown from init_cuda was very generic and the ASAN warning (if any) was buried in the logs.
Other clean up changes:
* cache device_count() always in a static variable
* move all asan macros in c10
Test Plan:
Hard to unittest because of build modes. Verified manually that the behavior from the table above holds by running the following script in different modes (ASAN/no-ASAN, CUDA_VISIBLE_DEVICES=):
```
print('before import')
import torch
print('after import')
print('devices: ', torch.cuda.device_count())
x = torch.tensor([1,2,3])
print('tensor creation')
x = x.cuda()
print('moved to cuda')
```
Reviewed By: ngimel
Differential Revision: D22824329
fbshipit-source-id: 5314007313a3897fc955b02f8b21b661ae35fdf5
Summary:
* Make c10::cuda functions regular non-inlined functions
* Add driver_version() and device_synchronize() functions
With this change I don't see anymore direct calls to CUDA API when look at Modules.cpp.obj
FYI malfet
Pull Request resolved: https://github.com/pytorch/pytorch/pull/42251
Reviewed By: malfet
Differential Revision: D22826505
Pulled By: ziab
fbshipit-source-id: 8dc2f3e209d3710e2ce78411982a10e8c727573c
Summary: Pull Request resolved: https://github.com/pytorch/pytorch/pull/41405
Test Plan:
**Imported from GitHub: all checks have passed**
{F244195355}
**The Intern Builds & Tests have 127 success, 5 no signals, and 1 failure. Double check the failed test log file, the failure is result differences:**
- AssertionError: 0.435608434677124 != 0.4356083869934082
- AssertionError: 0.4393022060394287 != 0.4393021583557129
- AssertionError: 0.44707541465759276 != 0.44707536697387695
These are all very small numerical errors (within 0.0000001).
Reviewed By: malfet
Differential Revision: D22531486
Pulled By: threekindoms
fbshipit-source-id: 21543ec76bb9b502885b5146c8ba5ede719be9ff
Summary:
Add `torch._C._cuda_getArchFlags()` that returns list of architecture `torch_cuda` were compiled with
Add `torch.cuda.get_arch_list()` and `torch.cuda.get_gencode_flags()` methods that returns architecture list and gencode flags PyTorch were compiled with
Print warning if some of GPUs is not compatible with any of the CUBINs
Pull Request resolved: https://github.com/pytorch/pytorch/pull/41173
Differential Revision: D22459998
Pulled By: malfet
fbshipit-source-id: 65d40ae29e54a0ba0f3f2da11b821fdb4d452d95
Summary:
Following up on this: https://github.com/pytorch/pytorch/pull/35851 cross dtype storage copy is not being used internally, so I have not included cross dtype copy for complex.
Pull Request resolved: https://github.com/pytorch/pytorch/pull/35771
Differential Revision: D21319650
Pulled By: anjali411
fbshipit-source-id: 07c72996ee598eba0cf401ad61534494d6f5b5b3
Summary:
# Goals
Do the following things during a distributed backward pass.
1. Accumulate the gradient of a variable to RPC context once the gradient is ready instead of at the very end of the backward pass.
2. Run post/pre hooks installed in`AccumulateGrad` nodes once the gradient is ready for the variable. Currently, the hooks in `AccumulateGrad` are not executed just because the function `AccumulateGrad` itself is not even evaluated by the local engine.
3. Make it extensible to support post hooks installed by DDP's reducer.
# Introduce GradCapturePreHook
## Why do we need this?
### Root issue:
* dist engine uses the autograd.grad-like API on the vanilla engine and then in the Future callback populates the context with the gradients. This is a bad emulation of the .backward() call on the vanilla engine.
### Practical issue:
* The leaf’s hook are not called (because associated with the AccumulateGrad that is not call in the autograd.grad-like API). Modules like DDP rely on these hooks.
* The Future is marked as completed before the context is actually populated with the grads leading to unexpected behavior on the user side.
* The Future callback is only called at the complete end of the backward and so too late for DDP if they want to overlap compute/transfert.
### Proposed solution:
* Provide hooks in the autograd.grad-like API that will allow the distributed engine to populate the context and call the hooks to better emulate the .backward call.
## Who can install a grad capture pre-hook?
This will be an internal hook at C++ level and it won’t be exposed to PyThon code. Only call-sites directly interacting with the local engine can install such hooks.
## Signature
The returned `grad` will be captured.
```
virtual const torch::Tensor& grad operator()(const torch::Tensor& grads) = 0;
```
## Where are hooks installed?
Grad capture pre-hooks are install in GraphTask::ExecInfo::Capture. ExecInfo is per node. Every backward run will have its own GraphTask instance.
## When/How will hooks be called?
When the local engine captures the grads for a node, all grad capture pre hooks are called one by one in the order they are added. The output grads of the hooks will replace the original grads.
The output of the last hook will be used for grad capturing.
Pull Request resolved: https://github.com/pytorch/pytorch/pull/34501
Test Plan:
All existing tests should pass.
```
python setup.py develop
python test/distributed/rpc/test_dist_autograd_spawn.py DistAutogradTestWithSpawn.test_post_hooks
```
Differential Revision: D20953673
Pulled By: hczhu
fbshipit-source-id: 543b3844823330ea9f9856bab7c5cb2679290a53
Summary:
Older versions of MIOpen (<=2.2) don't have the `miopenGetVersion` api, but MIOpen is always a part of the ROCm builds, so do NOT set `lib` to None for ROCm builds. `__cudnn_version` will be `None` for older versions of MIOpen.
Setting `lib` to `None` ends up printing the following erroneous warning when running unit tests:
```
/root/.local/lib/python3.6/site-packages/torch/backends/cudnn/__init__.py:120: UserWarning: cuDNN/MIOpen library not found. Check your LD_LIBRARY_PATH
}.get(sys.platform, 'LD_LIBRARY_PATH')))
```
Eg.: https://ci.pytorch.org/jenkins/job/pytorch-builds/job/py3.6-clang7-rocmdeb-ubuntu16.04-test2/18387/consoleFull
Pull Request resolved: https://github.com/pytorch/pytorch/pull/33837
Differential Revision: D20369285
Pulled By: xw285cornell
fbshipit-source-id: e82e6f8f5bccb486213cf868f40aece41ce11f98
Summary:
Because `torch_python` is supposed to be thin wrapper around `torch`
In this PR, all invocation of functions from nccl library are moved from python_nccl.cpp (which is part of torch_python) to nccl.cpp (which is part of torch_cuda)
Pull Request resolved: https://github.com/pytorch/pytorch/pull/36193
Test Plan: CI
Differential Revision: D20930047
Pulled By: malfet
fbshipit-source-id: 7f278610077df6ac5dc3471c1a1b5d51e653ef9c
Summary:
This PR aims to improve the interoperability with [CuPy](https://github.com/cupy/cupy/pulls).
Instead of having two separate and conflicting memory pools. With this PR, CuPy can directly alloc memory from the PyTorch allocator by means of this proposal https://github.com/cupy/cupy/pull/3126
We would like to gather feedback to know if this approach makes sense for PyTorch, or other alternative designs.
Pull Request resolved: https://github.com/pytorch/pytorch/pull/33860
Differential Revision: D20212788
Pulled By: ngimel
fbshipit-source-id: bc1e08a66da1992d26021147bf645dc65239581c
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:
Fixes https://github.com/pytorch/pytorch/issues/23401
We cannot rely on `multiprocessing.util.register_after_fork` since it is only
called for processes created by the `multiprocessing` module and not `os.fork()`.
Moving to `pthread_atfork` does always get called. However, I don't think it's safe to call python functions inside of the `atfork` handler so the python code has to be a bit more careful when checking `_initialized`.
Pull Request resolved: https://github.com/pytorch/pytorch/pull/29101
Differential Revision: D18355451
Pulled By: ezyang
fbshipit-source-id: 4d4253a3669796212c099dad4e5bdfdb0df40469
Summary:
Fixes https://github.com/pytorch/pytorch/issues/6962
The PR implements the handle pool mechanism for cublas as suggested by mcarilli in https://github.com/pytorch/pytorch/issues/6962#issuecomment-530563872.
~~I didn't add any unit test here yet because as mcarilli mentioned:~~
> ~~On my local machine, out of curiosity I also rewrote that test to use gemms instead of convolutions. The race condition seemed rarer, but the test did show that cublas use is not thread safe. I can share the script if you want.~~
~~Please share your script with me mcarilli. And if the race condition is rare, would it still be possible for the CI to detect it?~~
cc: colesbury
Pull Request resolved: https://github.com/pytorch/pytorch/pull/29233
Differential Revision: D18372007
Pulled By: ezyang
fbshipit-source-id: 3492bf13410598e8452e89cf4e3e63e8df9c8c3d
Summary:
Adds comprehensive memory instrumentation to the CUDA caching memory allocator.
# Counters
Added comprehensive instrumentation for the following stats:
- Allocation requests (`allocation`)
- Allocated memory (`allocated_bytes`)
- Reserved segments from cudaMalloc (`segment`)
- Reserved memory (`reserved_bytes`)
- Active memory blocks (`active`)
- Active memory (`active_bytes`)
- Inactive, non-releasable blocks (`inactive_split`)
- Inactive, non-releasable memory (`inactive_split_bytes`)
- Number of failed cudaMalloc calls that result in a cache flush and retry (`cuda_malloc_retries`)
- Number of OOMs (`num_ooms`)
Except for the last two, these stats are segmented between all memory, large blocks, and small blocks. Along with the current value of each stat, historical counts of allocs/frees as well as peak usage are tracked by the allocator.
# Snapshots
Added the capability to get a "memory snapshot" – that is, to generate a complete dump of the allocator block/segment state.
# Implementation: major changes
- Added `torch.cuda.memory_stats()` (and associated C++ changes) which returns all instrumented stats as a dictionary.
- Added `torch.cuda.snapshot()` (and associated C++ changes) which returns a complete dump of the allocator block/segment state as a list of segments.
- Added memory summary generator in `torch.cuda.memory_summary()` for ease of client access to the instrumentation stats. Potentially useful to dump when catching OOMs. Sample output here: https://pastebin.com/uKZjtupq
# Implementation: minor changes
- Add error-checking helper functions for Python dicts and lists in `torch/csrc/utils/`.
- Existing memory management functions in `torch.cuda` moved from `__init__.py` to `memory.py` and star-imported to the main CUDA module.
- Add various helper functions to `torch.cuda` to return individual items from `torch.cuda.memory_stats()`.
- `torch.cuda.reset_max_memory_cached()` and `torch.cuda.reset_max_memory_allocated()` are deprecated in favor of `reset_peak_stats`. It's a bit difficult to think of a case where only one of those stats should be reset, and IMO this makes the peak stats collectively more consistent.
- `torch.cuda.memory_cached()` and `torch.cuda.max_memory_cached()` are deprecated in favor of `*memory_reserved()`.
- Style (add access modifiers in the allocator class, random nit fixes, etc.)
# Testing
- Added consistency check for stats in `test_cuda.py`. This verifies that the data from `memory_stats()` is faithful to the data from `snapshot()`.
- Ran on various basic workflows (toy example, CIFAR)
# Performance
Running the following speed benchmark: https://pastebin.com/UNndQg50
- Before this PR: 45.98 microseconds per tensor creation
- After this PR: 46.65 microseconds per tensor creation
Pull Request resolved: https://github.com/pytorch/pytorch/pull/27361
Differential Revision: D17758747
Pulled By: jma127
fbshipit-source-id: 5a84e82d696c40c505646b9a1b4e0c3bba38aeb6
Summary:
Follow-up to gh-25483, more of the same fixes for warnings like:
```
../torch/csrc/autograd/python_variable.cpp:503:31: warning: cast between incompatible function types from ‘PyObject* (*)(THPVariable*)’ {aka ‘_object* (*)(THPVariable*)’} to ‘getter’ {aka ‘_object* (*)(_object*, void*)’} [-Wcast-function-type]
503 | {"_backward_hooks", (getter)THPVariable_get_backwards_hooks, (setter)THPVariable_set_backwards_hooks, nullptr, nullptr},
| ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
```
This takes the build log output for a full rebuild with GCC 9.1 from ~10,000 to ~7,000 lines.
`clang-tidy` is going to complain, no way around that - see discussion at the end of gh-25483.
Pull Request resolved: https://github.com/pytorch/pytorch/pull/26104
Differential Revision: D17396831
Pulled By: ezyang
fbshipit-source-id: d71696bfe4dbe25519e4bcb7753151c118bd39f7
Summary:
This is achieved by using `cuDevicePrimaryCtxGetState` as a way to check whether a primary context exists on a device. It is not too slow, from this benchmark of a single call to it on CUDA 10.1, Titan Xp, driver 415.27:
```
---------------------------------------------------------------------
Benchmark Time CPU Iterations
---------------------------------------------------------------------
BM_cuDevicePrimaryCtxGetState 301 ns 301 ns 2319746
```
Commits:
1. Add `CUDAHooks::getDeviceWithPrimaryContext` which returns a device index with primary context (if exists).
Link `c10/cuda` against `libcuda` for device API calls.
2. Use `getDeviceWithPrimaryContext` to check primary context in `pin_memory`.
Fix `OptionalDeviceGuard` doc.
3. Refactor `test_cuda_primary_ctx.py` to support multiple tests.
Add test for this in that file.
Fixes https://github.com/pytorch/pytorch/issues/21081.
Pull Request resolved: https://github.com/pytorch/pytorch/pull/22229
Differential Revision: D16170194
Pulled By: zou3519
fbshipit-source-id: 485a45f211b7844c9e69c63f3b3b75194a796c5d
Summary:
As part of the Variable/Tensor merge work: https://github.com/pytorch/pytorch/issues/13638, we make the following changes in this PR:
1. Remove the `Variable::Impl` class and the `DifferentiableViewImpl` class
2. Change all `Variable.data()` call sites to either use `Variable` directly, or use `Variable.tensor_data()`
3. Remove `Variable.data()` API
3. Add `Variable.variable_data()` that matches `tensor.data` in Python API, which creates a new `Variable` that shares the same storage and tensor metadata with the original `Variable`, but with a completely new autograd history.
After this PR, Variable doesn't wrap a Tensor internally anymore, and both Variable and Tensor use the same TensorImpl class as its `impl_`. The only difference is that Variable always has AutogradMeta in its TensorImpl, but Tensor doesn't.
**Note that this PR is BC-breaking in the following use cases:**
**Use Case 1:**
Previously, `x.data = y` works even if `x` and `y` are of different TensorImpl type (e.g. `x` is a CPU dense tensor whose impl is of type TensorImpl, while `y` is a CPU sparse tensor whose impl is of type SparseTensorImpl). However, after this PR, `x.data = y` doesn't work anymore if `x` and `y` are of different TensorImpl type, because the underlying implementation `variable.set_data(tensor)` no longer works if `variable` and `tensor` have different TensorImpl type.
**Use Case 2:**
If a tensor `x`'s `grad` is sparse, accumulating dense gradients to `x` will change the tensor that `x.grad` is pointing to. This is better illustrated with the following example:
```python
params = torch.tensor([1.5, 1.5]).requires_grad_()
with torch.no_grad():
# Change gradient to a sparse tensor
params.grad = torch.sparse_coo_tensor(torch.tensor([[1, 1]]).long(), torch.tensor([1., 1.]))
grad_saved = params.grad
params.backward(torch.tensor([1.5, 1.5]))
assert id(grad_saved) == id(params.grad) # This will fail after this PR
```
The assertion in the last line will fail after this PR, because adding dense gradients to sparse gradients will change the `params.grad` tensor reference.
Pull Request resolved: https://github.com/pytorch/pytorch/pull/17072
Differential Revision: D14075257
Pulled By: yf225
fbshipit-source-id: 0e681df641270dea586042dd26db59f2e76b5957
Summary:
Pull Request resolved: https://github.com/pytorch/pytorch/pull/18445
ghimport-source-id: 30d018737bf6989bc68b7e3676f44e0ca6141fde
Stack from [ghstack](https://github.com/ezyang/ghstack):
* #18242 Test running a CUDA build on CPU machine.
* **#18445 Unify cudaGetDeviceCount implementations.**
I went about doing this by searching for calls to cudaGetDeviceCount,
and then methodically replacing them with references to c10::cuda::device_count()
or at::cuda::device_count().
There is a point to doing this: the various implementations wildly differed
in their handling of what to do when cudaGetDeviceCount returns an error.
The final standardized behavior is that **all errors are swallowed** and
we return device count of zero. This indirectly fixes running CUDA builds
on CPU, which was broken in #17847.
I added 'noexcept' to the 'deviceCount' virtual method on DeviceGuardImpl.
This is a BC-breaking change for anyone inheriting from DeviceGuardImpl
but all you need to do is put 'noexcept' on your method and it is backwards
compatible with older libtorch.
Signed-off-by: Edward Z. Yang <ezyang@fb.com>
Differential Revision: D14612189
fbshipit-source-id: 3c8d186e3dd623c0e27625212c7ce30f75d943cb
Summary:
This is to fix#16141 and similar issues.
The idea is to track a reference to every shared CUDA Storage and deallocate memory only after a consumer process deallocates received Storage.
ezyang Done with cleanup. Same (insignificantly better) performance as in file-per-share solution, but handles millions of shared tensors easily. Note [ ] documentation in progress.
Pull Request resolved: https://github.com/pytorch/pytorch/pull/16854
Differential Revision: D13994490
Pulled By: VitalyFedyunin
fbshipit-source-id: 565148ec3ac4fafb32d37fde0486b325bed6fbd1
Summary:
This is the first commit from a series of planned changes in order to add boolean tensors to PyTorch. The whole plan looks like this:
0. Storage Implementation (this change)
1. Tensor Creation.
2. Tensor Conversions.
3. Tensor Indexing.
4. Tensor Operations.
5. Back compatibility related changes.
This feature was requested by the community:
https://github.com/pytorch/pytorch/issues/4764https://github.com/pytorch/pytorch/issues/4219https://github.com/pytorch/pytorch/issues/4288
**Change**:
Added boolean type to the Storage class for CPU and CUDA backends.
**Tested via**:
1. unit tests
2. running this:
-> import torch
-> torch.BoolStorage
<class 'torch.BoolStorage'>
-> torch.cuda.BoolStorage
<class 'torch.cuda.BoolStorage'>
Pull Request resolved: https://github.com/pytorch/pytorch/pull/16810
Reviewed By: gchanan
Differential Revision: D14087246
Pulled By: izdeby
fbshipit-source-id: 042642ced1cb0fd1bb6bff05f9ca871a5c54ee5e
Summary:
When Variable and Tensor are merged, the dynamic type of the tensors passed to certain functions will become variables, and expecting `type()` on those variables to still return non-Variable types will cause type mismatch error.
One way to fix this problem is to use the thread-local guard `at::AutoNonVariableTypeMode` to force `type()` to return non-Variable type, but ideally we want to limit the use of `at::AutoNonVariableTypeMode` to be only in VariableType.cpp. Another way to fix the problem is to use `at::globalContext().getNonVariableType()` instead to get the non-Variable type of the tensor, which is what this PR is trying to achieve.
Pull Request resolved: https://github.com/pytorch/pytorch/pull/16325
Differential Revision: D14012022
Pulled By: yf225
fbshipit-source-id: 77ef1d2a02f78bff0063bdd72596e34046f1e00d
Summary:
Some renaming and renamespacing also took place. I was originally planning not to do anything, but it turns out that it was easier to make HIPify work by using a namespace CUDACachingAllocator:: rather than THCCachingAllocator_, since :: is a word boundary but _ is not.
Pull Request resolved: https://github.com/pytorch/pytorch/pull/16119
Reviewed By: smessmer
Differential Revision: D13718768
fbshipit-source-id: 884a481d99027fd3e34471c020f826aa12225656
Summary:
Pull Request resolved: https://github.com/pytorch/pytorch/pull/16117
This means I can move it to c10_cuda with minimal fuss.
Reviewed By: smessmer
Differential Revision: D13717836
fbshipit-source-id: a94c7dc649af64542480fc1c226b289588886c00
Summary:
Pull Request resolved: https://github.com/pytorch/pytorch/pull/16061
I discovered I needed to delete these names in preparation of moving
THCCachingAllocator to c10_cuda; might as well also fix all the other
sites too.
Reviewed By: dzhulgakov
Differential Revision: D13686869
fbshipit-source-id: e8cc55d39ac4bfd3e3a22c761f89a7a111ce5f5e
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/14246
This commit systematically eliminates THCStream entirely from THC, replacing it
with at::cuda::CUDAStream. In places where the previous pointer type showed up
in a public API signature, those functions are now only available to C++
clients. (It would not be too difficult to make a C-compatible version of
CUDAStream, as it's really just a simple struct, but we leave this for
future work.)
All functions in THC that referred to THCStream were expunged in favor of their
modern counterparts.
One annoyance was that I didn't feel like redoing how the torch.cuda.Stream
binding code worked, but I really wanted to get rid of the stored THCStream*
pointer. So I repurposed the bit-packing code I implemented for Stream hashing,
and used that to (reversibly) store streams in a uint64_t cdata field. A perhaps
more future proof solution would be to get rid of cdata entirely, and store the
device and stream ID directly.
Billing of changes:
- All CUDAStream_ pointer API functions are now hidden and anonymously
namespaced (instead of being in the impl namespace). All use sites
rewritten to use the modern C++ API. Since CUDAStreamInternals is no
longer part of the public API, the CUDAStreamInternals constructor and
internals() method have been removed, and replaced with anonymous
functions in the C++ file.
- device_index() returns DeviceIndex rather than int64_t now
- Stream and CUDAStream now have pack/unpack methods. (CUDAStream checks
that the unpacked bit-pattern is for a CUDA device.)
- THCStream.h header is removed entirely
- Most THCStream handling functions in THC API are removed
Reviewed By: gchanan
Differential Revision: D13121531
fbshipit-source-id: 48873262cc0a37c3eec75a7ba1c93c800da40222
