Summary:
Pull Request resolved: https://github.com/pytorch/pytorch/pull/63496
This PR adds a (private) enable_python_mode context manager.
(see torch/utils/_python_dispatch.py).
enable_python_mode accepts the type of a __torch_dispatch__ object
as its argument. Whenever an operator gets called inside of the
context manager, it dispatches to the __torch_dispatch__ of
the passed-in type.
Example usage:
```
with enable_python_mode(LoggingTensor):
z = torch.empty([])
assert isinstance(z, LoggingTensor)
```
There are quite a few changes that were made to support this.
First, we added TorchDispatchTypeObject, a C++ struct that represents the
type of a `__torch_dispatch__` object (e.g. LoggingTensor).
It holds both the PyObject* representing the class and a PyInterpreter*
so we know which Python interpreter it came from.
Next, we updated the concrete_dispatch_fn in python_variable.cpp to accept
a `const std::shared_ptr<TorchDispatchTypeObject>&` argument. When this
is null, dispatching happens as usual. When it is non-null, we prepend
the TorchDispatchTypeObject's PyObject* to the overloaded args list so that
it is considered first for dispatch.
To get that to work, we changed how `handle_torch_dispatch_no_python_arg_parser`
works. The "overloaded args list" previously only consisted of Tensor PyObjects,
but now it can have types in addition to Tensors!
- We renamed `append_overloaded_arg` to `append_overloaded_arg`
- We added a new `append_overloaded_type` that appends a type to
overloaded_args
- We added special handling in `handle_torch_dispatch_no_python_arg_parser`
and `append_overloaded_arg` to handle types in addition to Tensors.
Then, there is PythonMode and PythonModeTLS.
- We reuse the DispatchKey::Python dispatch key as a mode key
- We use PythonMode::enter and PythonMode::exit to enable/disable
DispatchKey::Python and set the PythonModeTLS.
- PythonModeTLS stores a TorchDispatchTypeObject as metadata.
- PythonMode is in libtorch_python, and PythonModeTLS is in ATen.
This split is due to the libtorch_python library boundary (because we need
to save TLS in ATen/ThreadLocalState)
- We modify the PythonFallbackKernel to look up
the relevant TorchDispatchTypeObject (if Python Mode is active) and
dispatch using it.
There are two more miscellaneous changes:
- internal_new_from_data (torch/csrc/utils/tensor_new.cpp) gets an
exclude guard. enable_python_mode currently does not handle
torch.tensor and the exclude guard is to prevent a bug.
Future:
- This PR does not allow for the nesting of Python modes. In the future we
should be able to enable this with a more sane no_dispatch API and by changing
the TLS to a stack. For now I did not need this for CompositeImplicitAutograd testing.
Test Plan: - new tests
Reviewed By: malfet, albanD
Differential Revision: D30543236
Pulled By: zou3519
fbshipit-source-id: ef5444d96a5a957d1657b7e37dce80f9a497d452
Summary:
This PR implements the necessary hooks/stubs/enums/etc for complete ONNX Runtime (ORT) Eager Mode integration. The actual extension will live out of tree at https://github.com/pytorch/ort.
We have been [working on this at Microsoft](https://github.com/microsoft/onnxruntime-pytorch/tree/eager-ort/torch_onnxruntime) for the last few months, and are finally ready to contribute the PyTorch core changes upstream (nothing major or exciting, just the usual boilerplate for adding new backends).
The ORT backend will allow us to ferry [almost] all torch ops into granular ONNX kernels that ORT will eagerly execute against any devices it supports (therefore, we only need a single ORT backend from a PyTorch perspective).
Pull Request resolved: https://github.com/pytorch/pytorch/pull/58248
Reviewed By: astaff
Differential Revision: D30344992
Pulled By: albanD
fbshipit-source-id: 69082b32121246340d686e16653626114b7714b2
Summary:
Pull Request resolved: https://github.com/pytorch/pytorch/pull/62417
This diff adds an option to make enableProfiler enable callbacks only
for certain RecordScopes.
Why?
Profiling has some overhead when we repeatedly execute callbacks for
alls copes. On mobile side when we often have small quantized models
this overhead can be large. We observed that by only profiling top level
op and skipping profiling of other atend ops called within we can limit
this overhead. For example, instead of profling at::conv2d -> at::convolution ->
at::convolution_ and further more if ops like transpose etc. are called,
skipping profiling of those. Of course this limits the visibility, but
at the least this way we get a choice.
Test Plan: Imported from OSS
Reviewed By: ilia-cher
Differential Revision: D29993659
fbshipit-source-id: 852d3ae7822f0d94dc6e507bd4019b60d488ef69
Summary:
Pull Request resolved: https://github.com/pytorch/pytorch/pull/61792
KinetoEvent
This PR adds module hierarchy information to events.
What is module hierarchy information attached to events?
During profiling a TorchScript module, when events are added, we ask JIT
what is the module hierarchy associated with the node being
executed. At the time of execution of that node, there might be multiple
frames in the stack of interpreter. For each frame, we find
corresponding node and the corresponding module hierarchy is queried.
Module hierarchy corresponding to the node is associated with node's
InlinedCallStack. InlinedCallStack of node tracks the path via which the
node is inlined. Thus during the inlining process we annotate
module information corresponding to the CallMethod nodes being inlined.
With this PR, chrome trace will contain additional metadata:
"Module Hierarchy". This can look like this:
TOP(ResNet)::forward.SELF(ResNet)::_forward_impl.layer1(Sequential)::forward.0(BasicBlock)::forward.conv1(Conv2d)::forward.SELF(Conv2d)::_conv_forward
It contains module instance, type name and the method name in the
callstack.
Test Plan:
test_profiler
Imported from OSS
Reviewed By: raziel, ilia-cher
Differential Revision: D29745442
fbshipit-source-id: dc8dfaf7c5b8ab256ff0b2ef1e5ec265ca366528
Summary:
When using saved tensors hooks (especially default hooks),
if the user defines a `pack_hook` that modifies its input,
it can cause some surprising behavior.
The goal of this PR is to prevent future user headache by catching
inplace modifications of the input of `pack_hook` and raising an error if
applicable.
Pull Request resolved: https://github.com/pytorch/pytorch/pull/62717
Reviewed By: albanD
Differential Revision: D30255243
Pulled By: Varal7
fbshipit-source-id: 8d73f1e1b50b697a59a2849b5e21cf0aa7493b76
Summary:
Pull Request resolved: https://github.com/pytorch/pytorch/pull/61931
This PR consolidates the profiling code around a new C++ implementation
(profiler_kineto.h/cpp) and uses it unconditionally from
torch.autograd.profiler/torch.profiler:
1. Always use profiler_kineto.h/cpp as the C++ implementation
2. Simplify profiler.py to remove unneeded parts depending on legacy
impl
3. Move some of the legacy logic into profiler_legacy.py (to be fully
deleted later)
Test Plan:
USE_KINETO=1 USE_CUDA=1 USE_MKLDNN=1 BLAS=MKL BUILD_BINARY=1 python setup.py develop install --cmake
python test/test_profiler.py -v
USE_KINETO=0 USE_CUDA=1 USE_MKLDNN=1 BLAS=MKL BUILD_BINARY=1 python setup.py develop install --cmake
python test/test_profiler.py -v
Imported from OSS
Reviewed By: gdankel
Differential Revision: D29801599
fbshipit-source-id: 9794d29f2af38dddbcd90dbce4481fc8575fa29e
Summary:
Pull Request resolved: https://github.com/pytorch/pytorch/pull/62563
Expose a pair of functions to Python users: torch.autograd.graph.set_saved_tensors_default_hooks(pack, unpack) and torch.autograd.graph.reset_saved_tensors_default_hooks().
These functions control the hooks applied to saved tensors: all tensors saved in that context will be packed using the pack function, then unpacked accordingly when needed.
Currently, this works by simply calling register_hooks (cf #60975) directly at the end of the constructor of a SavedVariable. This could be optimized further by not performing the copy before registering default hooks, but this would require a small refactor. Edit: the refactor is done in #61927.
A current limitation is that if users create tensors in this context, they will not be able to register additional hooks on the saved tensor.
For instance, to perform something like #28997, one could define a pack function that saves to disk whenever the tensor size is too big and returns a filename, then unpack simply reads the content of the file and outputs a tensor, e.g.:
```
def pack(x):
name = os.path.join(tmp_dir, str(uuid.uuid4()))
torch.save(x, name)
return name
def unpack(name):
return torch.load(name)
```
Relanding previous PR: https://github.com/pytorch/pytorch/pull/61834
Original PR led to timeout error in: https://www.internalfb.com/mast/job/yuguo-release_canary_offline_training-inlinecvrp_a-canary_offline_train_28a7ecfc
Now passing: https://www.internalfb.com/mast/job/quach-release_canary_offline_training-inlinecvrp_a-canary_offline_train_9bb57e98
The difference with the new version is we don't need to acquire the GIL when calling `PyDefaultSavedVariableHooks::get_hooks`.
Test Plan: Imported from OSS
Reviewed By: iramazanli
Differential Revision: D30045405
Pulled By: Varal7
fbshipit-source-id: 7f6c07af3a56fe8835d5edcc815c15ea4fb4e332
Summary:
Pull Request resolved: https://github.com/pytorch/pytorch/pull/61834
Expose a pair of functions to Python users: torch.autograd.graph.set_saved_tensors_default_hooks(pack, unpack) and torch.autograd.graph.reset_saved_tensors_default_hooks().
These functions control the hooks applied to saved tensors: all tensors saved in that context will be packed using the pack function, then unpacked accordingly when needed.
Currently, this works by simply calling register_hooks (cf #60975) directly at the end of the constructor of a SavedVariable. This could be optimized further by not performing the copy before registering default hooks, but this would require a small refactor. Edit: the refactor is done in #61927.
A current limitation is that if users create tensors in this context, they will not be able to register additional hooks on the saved tensor.
For instance, to perform something like #28997, one could define a pack function that saves to disk whenever the tensor size is too big and returns a filename, then unpack simply reads the content of the file and outputs a tensor, e.g.:
```
def pack(x):
name = os.path.join(tmp_dir, str(uuid.uuid4()))
torch.save(x, name)
return name
def unpack(name):
return torch.load(name)
```
Test Plan: Imported from OSS
Reviewed By: zou3519
Differential Revision: D29792193
Pulled By: Varal7
fbshipit-source-id: 33e931230ef59faa3ec8b5d11ef7c05539bce77c
Summary:
Pull Request resolved: https://github.com/pytorch/pytorch/pull/59760
See https://github.com/pytorch/pytorch/issues/59049
There are some moving parts to this PR, I'll structure this explanation so the straightforward parts go first, and then the less straightforward parts.
**The actual dispatch to Python.** The core logic of dispatch to Python lives in `concrete_dispatch_fn` in `torch/csrc/autograd/python_variable.cpp`. It takes the input IValue stack, scans all the arguments for Tensor arguments, and defers most of the heavy lifting to `handle_torch_function_no_python_arg_parser` which actually does all of the logic for calling out to torch dispatch (in particular, this function handles multiple dispatch situations for you). Because we have a different function name than regular `__torch_function__` handling, `handle_torch_function_no_python_arg_parser` is generalized to accept a magic method name to look for when testing if Tensors have custom handling or not. Unlike `__torch_function__`, by default there is no `__torch_dispatch__` on Tensor classes.
**Maintaining the Python dispatch key.** In order to get to the dispatch to Python logic, we must tag Tensors with the `__torch_dispatch__` magic method with the newly added Python dispatch key (separated from PythonFuncTorch to allow for a transitional period while they migrate to this mechanism). We expose a new private property `_is_python_dispatch` that assists in debugging if a Tensor is participating in Python dispatch or not. We apply the Python dispatch key the first time a PyObject for a Tensor is constructed (THPVariable_NewWithVar), testing if `__torch_dispatch__` exists with then newly added `check_has_torch_dispatch`.
**Shallow copy and detach.** For the simple examples tested in this PR, most creations of Tensor route through the dispatcher. The exception to this is `shallow_copy_and_detach`, which bypasses the dispatcher and is used when saving tensors for backwards. When a Tensor is Python dispatch, we override the behavior of `shallow_copy_and_detach` to instead directly call into `__torch_dispatch__` to perform a `detach` operation (in the same way it would be invoked if you called `detach` directly). Because this Python call is triggered directly from c10::TensorImpl, it must be indirected through `PyInterpreter::detach`, which is the general mechanism for dynamic dispatching to the Python interpreter associated with a TensorImpl.
**torchdeploy compatibility.** The dispatch to Python logic cannot be directly registered to the dispatcher as it is compiled in the Python library, which will get loaded multiple times per torchdeploy interpreter. Thus, we must employ a two phase process. First, we register a fallback inside a non-Python library (aten/src/ATen/core/PythonFallbackKernel.cpp). Its job is to determine the appropriate PyInterpreter to handle the Python dispatch by going through all of the arguments and finding the first argument that has a PyObject/PyInterpreter. With this PyInterpreter, it makes another dynamic dispatch via "dispatch" which will go to the correct torchdeploy interpreter to handle dispatching to actual Python.
**Testing.** We provide a simple example of a LoggingTensor for testing, which can be used to generate TorchScript-like traces to observe what operations are being called when a Tensor is invoked. Although a LoggingTensor would be better implemented via an is-a relationship rather than a has-a relationship (as is done in the test), we've done it this way to show that arbitrarily complex compositions of tensors inside a tensor work properly.
**Known limitations.**
* We haven't adjusted any operator code, so some patterns may not work (as they lose the Python subclass in an unrecoverable way)
* `__torch_function__` must be explicitly disabled with `_disabled_torch_function_impl` otherwise things don't work quite correctly (in particular, what is being disabled is default subclass preservation behavior.)
* We don't ever populate kwargs, even when an argument is kwarg-only
Signed-off-by: Edward Z. Yang <ezyang@fb.com>
Differential Revision:
D29017912
D29017912
Test Plan: Imported from OSS
Reviewed By: bdhirsh
Pulled By: ezyang
fbshipit-source-id: a67714d9e541d09203a8cfc85345b8967db86238
Summary:
Pull Request resolved: https://github.com/pytorch/pytorch/pull/59027
Add underscores to some of the internal names
Test Plan:
python test/test_profiler.py -v
Imported from OSS
Reviewed By: mrshenli
Differential Revision: D28724294
fbshipit-source-id: 1f6252e4befdf1928ac103d0042cbbf40616f74a
Summary:
Pull Request resolved: https://github.com/pytorch/pytorch/pull/57386
Here is the PR for what's discussed in the RFC https://github.com/pytorch/pytorch/issues/55374 to enable the autocast for CPU device. Currently, this PR only enable BF16 as the lower precision datatype.
Changes:
1. Enable new API `torch.cpu.amp.autocast` for autocast on CPU device: include the python API, C++ API, new Dispatchkey etc.
2. Consolidate the implementation for each cast policy sharing between CPU and GPU devices.
3. Add the operation lists to corresponding cast policy for cpu autocast.
Test Plan: Imported from OSS
Reviewed By: soulitzer
Differential Revision: D28572219
Pulled By: ezyang
fbshipit-source-id: db3db509973b16a5728ee510b5e1ee716b03a152
Summary:
Fixes https://github.com/pytorch/pytorch/issues/56608
- Adds binding to the `c10::InferenceMode` RAII class in `torch._C._autograd.InferenceMode` through pybind. Also binds the `torch.is_inference_mode` function.
- Adds context manager `torch.inference_mode` to manage an instance of `c10::InferenceMode` (global). Implemented in `torch.autograd.grad_mode.py` to reuse the `_DecoratorContextManager` class.
- Adds some tests based on those linked in the issue + several more for just the context manager
Issues/todos (not necessarily for this PR):
- Improve short inference mode description
- Small example
- Improved testing since there is no direct way of checking TLS/dispatch keys
-
Pull Request resolved: https://github.com/pytorch/pytorch/pull/58045
Reviewed By: agolynski
Differential Revision: D28390595
Pulled By: soulitzer
fbshipit-source-id: ae98fa036c6a2cf7f56e0fd4c352ff804904752c
Summary:
Pull Request resolved: https://github.com/pytorch/pytorch/pull/58133
Adding CUDA event fallback for cases when CUPTI tracing is not
available, this corresponds to the legacy profiler GPU profiling
Test Plan: python test/test_profiler.py -v
Reviewed By: gdankel
Differential Revision: D28379596
Pulled By: ilia-cher
fbshipit-source-id: 2db3b2cd8c1c3e6e596784ab00a226c69db2ef27
Summary:
Pull Request resolved: https://github.com/pytorch/pytorch/pull/57253
This PR:
1. Adds is_async getter/setter to RecordFunction
2. Adds is_async field to LegacyEvent and KinetoEvent, read from RecordFunction
3. Modifies python profiler code to check is_async via this flag (and keeps the old thread check as well)
4. Sets profiling of c10d collectives as async in ProcessGroup.cpp
5. Modifies tests to ensure is_async is set
This also fixes flaky tests such as #50840 and #56690 which have been flaky due to the profiling part (https://github.com/pytorch/pytorch/pull/56963 tried to do so as well but this is a better approach).
ghstack-source-id: 128021158
Test Plan: CI
Reviewed By: walterddr, ilia-cher
Differential Revision: D28086719
fbshipit-source-id: 4473db4aed939a71fbe9db5d6655f3008347cb29
Summary:
Pull Request resolved: https://github.com/pytorch/pytorch/pull/53424
Fixes https://github.com/pytorch/pytorch/issues/24807 and supersedes the stale https://github.com/pytorch/pytorch/issues/25093 (Cc Microsheep). If you now run the reproduction
```python
import torch
if __name__ == "__main__":
t = torch.tensor([1, 2, 3], dtype=torch.float64)
```
with `pylint==2.6.0`, you get the following output
```
test_pylint.py:1:0: C0114: Missing module docstring (missing-module-docstring)
test_pylint.py:4:8: E1101: Module 'torch' has no 'tensor' member; maybe 'Tensor'? (no-
member)
test_pylint.py:4:38: E1101: Module 'torch' has no 'float64' member (no-member)
```
Now `pylint` doesn't recognize `torch.tensor` at all, but it is promoted in the stub. Given that it also doesn't recognize `torch.float64`, I think fixing this is out of scope of this PR.
---
## TL;DR
This BC-breaking only for users that rely on unintended behavior. Since `torch/__init__.py` loaded `torch/tensor.py` it was populated in `sys.modules`. `torch/__init__.py` then overwrote `torch.tensor` with the actual function. With this `import torch.tensor as tensor` does not fail, but returns the function rather than the module. Users that rely on this import need to change it to `from torch import tensor`.
Reviewed By: zou3519
Differential Revision: D26223815
Pulled By: bdhirsh
fbshipit-source-id: 125b9ff3d276e84a645cd7521e8d6160b1ca1c21
Summary:
Pull Request resolved: https://github.com/pytorch/pytorch/pull/53143
Meta is now an honest to goodness device type, like cpu, so you can use
device='meta' to trigger allocation of meta tensors. This way better
than empty_meta since we now have working API for most factory functions
(they don't necessarily work yet, though, because need to register Meta
versions of those functions.)
Some subtleties:
- I decided to drop the concept of CPU versus CUDA meta tensors; meta
tensors are device agnostic. It's hard to say exactly what the
correct level of abstraction here is, but in this particular case
implementation considerations trump semantic considerations: it
is way easier to have just a meta device, than to have a meta device
AND a cpu device AND a cuda device. This may limit the applicability
of meta tensors for tracing models that do explicit cpu()/cuda()
conversions (unless, perhaps, we make those operations no-ops on meta
tensors).
- I noticed that the DeviceType uppercase strings are kind of weird.
Are they really supposed to be all caps? That's weird.
- I moved the Meta dispatch key to live with the rest of the "device"
dispatch keys.
- I intentionally did NOT add a Backend for Meta. For now, I'm going to
hope meta tensors never exercise any of the Backend conversion code;
even if it does, better to fix the code to just stop converting to and
from Backend.
Signed-off-by: Edward Z. Yang <ezyang@fb.com>
Test Plan: Imported from OSS
Reviewed By: samestep
Differential Revision: D26763552
Pulled By: ezyang
fbshipit-source-id: 14633b6ca738e60b921db66a763155d01795480d
Summary:
Apple recently announced ML Compute, a new framework available in macOS Big Sur, which enables users to accelerate the training of neural networks on Mac hardware. This PR is the first on a series of PRs that will enable the integration with ML Compute. Most of the integration code will live on a separate subrepo named `mlc`.
The integration with `mlc` (ML Compute) will be very similar to that of xla. We rely on registering our ops through:
TORCH_LIBRARY_IMPL(aten, PrivateUse1, m) {
m.impl_UNBOXED(<op_schema_name>, &customized_op_kernel)
...
}
Pull Request resolved: https://github.com/pytorch/pytorch/pull/50634
Reviewed By: malfet
Differential Revision: D26614213
Pulled By: smessmer
fbshipit-source-id: 3b492b346c61cc3950ac880ac01a82fbdddbc07b
Summary:
Add the FLOPS metric computation to the experimental Kineto profiler.
This includes saving necessary extra arguments and compute flops in the C++ code,
and extract the FLOPS value from the Python frontend.
Pull Request resolved: https://github.com/pytorch/pytorch/pull/51503
Test Plan:
Build PyTorch with USE_KINETO option, then run the unit test:
```python
python test/test_profiler.py -k test_flops
```
Reviewed By: ilia-cher
Differential Revision: D26202711
Pulled By: xuzhao9
fbshipit-source-id: 7dab7c513f454355a220b72859edb3ccbddcb3ff
Summary:
Pull Request resolved: https://github.com/pytorch/pytorch/pull/48963
This PR makes the binding code treat `Parameter` the same way as `Tensor`, unlike all other `Tensor` subclasses. This does change the semantics of `THPVariable_CheckExact`, but it isn't used much and it seemed to make sense for the half dozen or so places that it is used.
Test Plan: Existing unit tests. Benchmarks are in #48966
Reviewed By: ezyang
Differential Revision: D25590733
Pulled By: robieta
fbshipit-source-id: 060ecaded27b26e4b756898eabb9a94966fc9840
Summary:
Pull Request resolved: https://github.com/pytorch/pytorch/pull/49408
Nearly every non-test callsite doesn't need to capture any variables anyway, and this saves 48 bytes per callback.
ghstack-source-id: 118665808
Test Plan:
Wait for GitHub CI since we had C++14-specific issues with
this one in previous PR https://github.com/pytorch/pytorch/pull/48629
Reviewed By: malfet
Differential Revision: D25563207
fbshipit-source-id: 6a2831205917d465f8248ca37429ba2428d5626d
Summary:
Pull Request resolved: https://github.com/pytorch/pytorch/pull/48629
Nearly every non-test callsite doesn't need to capture any variables anyway, and this saves 48 bytes per callback.
ghstack-source-id: 118568240
Test Plan: CI
Reviewed By: dhruvbird
Differential Revision: D25135415
fbshipit-source-id: 5e92dc79da6473ed15d1e381a21ed315879168f3
Summary:
Pull Request resolved: https://github.com/pytorch/pytorch/pull/48620
In preparation for storing bare function pointer (8 bytes)
instead of std::function (32 bytes).
ghstack-source-id: 118568242
Test Plan: CI
Reviewed By: ezyang
Differential Revision: D25132183
fbshipit-source-id: 3790cfb5d98479a46cf665b14eb0041a872c13da
Summary:
Pull Request resolved: https://github.com/pytorch/pytorch/pull/46227
Follow up from https://github.com/pytorch/pytorch/issues/45419, in
this PR I've removed as many PyCFunction casts as I could from the codebase.
The only ones I didn't remove were the ones with `METH_VARARGS | METH_KEYWORDS`
which have 3 parameters instead of 2 and had to be casted. Example: `
{"copy_", (PyCFunction)(void(*)(void))THPStorage_(copy_), METH_VARARGS |
METH_KEYWORDS, nullptr},`
ghstack-source-id: 114632704
Test Plan: waitforbuildbot
Reviewed By: albanD
Differential Revision: D24269435
fbshipit-source-id: 025cfd43a9a2a3e59f6b2951c1a78749193d77cf
Summary:
Pull Request resolved: https://github.com/pytorch/pytorch/pull/44664
Closes https://github.com/pytorch/pytorch/issues/39971. This PR adds support for functions decorated with `rpc.functions.async_execution` to be profiled over RPC as builtins, jit functions, and blocking python UDFs currently can be. The reasoning for this is to provide complete feature support in terms of RPC profiling and the various types of functions users can run.
To enable this, the PR below this enables calling `disableProfiler()` safely from another thread. We use that functionality to defer disabling the profiler on the server until the future corresponding to the RPC request completes (rather than only the blocking `processRPC` call as was done previously). Since when the future completes we've kicked off the async function and the future corresponding to it has completed, we are able to capture any RPCs the function would have called and the actual work done on the other node.
For example, if the following async function is ran on a server over RPC:
```
def slow_add(x, y):
time.sleep(1)
return torch.add(x, y)
rpc.functions.async_execution
def slow_async_add(to, x, y):
return rpc.rpc_async(to, slow_add, args=(x, y))
```
we expect to see the original RPC profiled, the nested RPC profiled, and the actual torch.add() work. All of these events should be recorded with the correct node id. Here is an example profiling output:
```
------------------------------------------------------------------------------------------------------------------------- --------------- --------------- --------------- --------
------- --------------- --------------- ---------------
Name Self CPU total % Self CPU total CPU total % CPU total CPU time avg Number of Calls Node ID
------------------------------------------------------------------------------------------------------------------------- --------------- --------------- --------------- --------
------- --------------- --------------- --------------- rpc_async#slow_async_add(worker1 -> worker2) 0.00% 0.000us 0 1.012s
1.012s 1 1
aten::empty 7.02% 11.519us 7.02% 11.519us 11.519us 1 1
rpc_async#slow_async_add(worker1 -> worker2)#remote_op: rpc_async#slow_add(worker2 -> worker3) 0.00% 0.000us 0 1.006s
1.006s 1 2 rpc_async#slow_async_add(worker1 -> worker2)#remote_op: aten::empty 7.21% 11.843us 7.21% 11.843us
11.843us 1 2
rpc_async#slow_async_add(worker1 -> worker2)#remote_op: rpc_async#slow_add(worker2 -> worker3)#remote_op: aten::add 71.94% 118.107us 85.77% 140.802us 140.802us 1 3
rpc_async#slow_async_add(worker1 -> worker2)#remote_op: rpc_async#slow_add(worker2 -> worker3)#remote_op: aten::empty 13.82% 22.695us 13.82% 22.695us
22.695us 1 3 ------------------------------------------------------------------------------------------------------------------------- --------------- --------------- --------------- --------
------- --------------- --------------- ---------------
Self CPU time total: 164.164us
```
This PR also moves a bunch of the profiling logic to `rpc/utils.cpp` to declutter `request_callback` code.
ghstack-source-id: 112868470
Test Plan:
```
rvarm1@devbig978:fbcode (52dd34f6)$ buck test mode/no-gpu mode/dev-nosan //caffe2/test/distributed/rpc:process_group_agent -- test_rpc_profiling_async_function --print-passing-details --stress-runs 1
```
Reviewed By: mrshenli
Differential Revision: D23638387
fbshipit-source-id: eedb6d48173a4ecd41d70a9c64048920bd4807c4
