Earlier, with inline flag we were lifting id-guarded tensors to the inputs to the Fx graph. But this offers no benefit. Main idea behind lifting parameters as inputs was to reuse the compilation units across many instances of the nn-module. However, if we are guarding on the `id`, we are explicitly specializing the compiled artifact to the parameter.
This PR installs the parameters back into the graph. The benefit is removal of all pre-graph bytecode to extract the id-guarded tensors from locals/globals. This increases speedup from 1.67x to 1.75x for an internal model that has large number of optimizer parameters.
Pull Request resolved: https://github.com/pytorch/pytorch/pull/147824
Approved by: https://github.com/jansel
Co-authored-by: Jason Ansel <jansel@meta.com>
## Context
> **Note:** `mark_traceable` got renamed to `nonstrict_trace` after
> offline discussion. The reasons are (1) it aligns with `torch.export`'s
> `nonstrict` notion, and (2) it's more definitive in behavior suggestion.
1. [Overall Design](https://docs.google.com/document/d/1O-dR2ZQaJQVt_v67AVcDCw2yJLtqgkZFwoXK0buEWRg/edit?tab=t.0)
2. [Dynamo graph representation with `torch._higher_order_ops.flat_apply`](https://docs.google.com/document/d/1YHl5nPTJvYeCPE5TO9uA18DPWNgUYGE4gCn6bFvXcBM/edit?tab=t.0#heading=h.xtw3hhbro4gn)
## Summary
This patch adds a `torch._dynamo.nonstrict_trace` decorator, which
currently is an enhanced version of `torch._dynamo.allow_in_graph` (see
docstring for their differences). Specifically, this patch focuses on
the UI and functionality prototyping/plumbing.
The main enhancement is supporting more input types, and the
implementation challenge lies in reconstructing the input objects from
Dynamo `VariableTracker` (while accounting for buffered side-effects and
guards). This patch takes a middle-ground (simple implementation with a
bit of user labor), by
1. asking the user to provide pytree registration for non-proxy-able
input types,
2. letting Dynamo trace through `pytree_flatten` (which accounts for
buffered side-effects and guards automatically),
3. and passing in the TreeSpec as a graph attribute constant into
`torch._higher_order_ops.flat_apply` (which unflattens the inputs and
invokes the underlying function).
## Next Steps
In subsequent patches, we will try to support the following:
- annotating on class method
- reads to global tensors
- inputs that contains `pytree.register_constant`-ed instances.
- function as input
- more output types (e.g., any pytree-registered type)
- `torch.nn.Module` as inputs
Pull Request resolved: https://github.com/pytorch/pytorch/pull/146367
Approved by: https://github.com/zou3519
ghstack dependencies: #146714
This is for "for some large number Z, make sure the error messages are readable English." - beginning to audit all `unimplemented` sites and making sure that all messages are at least English-readable. Hints may not necessarily be provided.
Pull Request resolved: https://github.com/pytorch/pytorch/pull/147385
Approved by: https://github.com/jansel
I cannot repro this. But this line shows up in internal logs, and I want
to know what the exception is and the context inside it. All of the
exceptions_allowed_to_be_fallback are dataclasses, so they should print
nicely.
Test Plan:
- code reading
Pull Request resolved: https://github.com/pytorch/pytorch/pull/146357
Approved by: https://github.com/williamwen42
Fixes#143406
After this PR the error for missing Triton is:
```py
Traceback (most recent call last):
File "/home/jansel/pytorch/repro.py", line 51, in <module>
fp32_compiled = optimized_model(low_input)
^^^^^^^^^^^^^^^^^^^^^^^^^^
File "/home/jansel/pytorch/torch/nn/modules/module.py", line 1739, in _wrapped_call_impl
return self._call_impl(*args, **kwargs)
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
File "/home/jansel/pytorch/torch/nn/modules/module.py", line 1750, in _call_impl
return forward_call(*args, **kwargs)
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
File "/home/jansel/pytorch/torch/_dynamo/eval_frame.py", line 580, in _fn
raise e.remove_dynamo_frames() from None # see TORCHDYNAMO_VERBOSE=1
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
File "/home/jansel/pytorch/torch/_inductor/scheduler.py", line 3624, in create_backend
raise TritonMissing(inspect.currentframe())
torch._dynamo.exc.TritonMissing: Cannot find a working triton installation. Either the package is not installed or it is too old. More information on installing Triton can be found at: https://github.com/triton-lang/triton
Set TORCH_LOGS="+dynamo" and TORCHDYNAMO_VERBOSE=1 for more information
You can suppress this exception and fall back to eager by setting:
import torch._dynamo
torch._dynamo.config.suppress_errors = True
```
Setting `TORCHDYNAMO_VERBOSE=1` yields something like the old error:
```py
Traceback (most recent call last):
File "/home/jansel/pytorch/repro.py", line 51, in <module>
fp32_compiled = optimized_model(low_input)
^^^^^^^^^^^^^^^^^^^^^^^^^^
File "/home/jansel/pytorch/torch/nn/modules/module.py", line 1739, in _wrapped_call_impl
return self._call_impl(*args, **kwargs)
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
File "/home/jansel/pytorch/torch/nn/modules/module.py", line 1750, in _call_impl
return forward_call(*args, **kwargs)
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
File "/home/jansel/pytorch/torch/_dynamo/eval_frame.py", line 580, in _fn
raise e.remove_dynamo_frames() from None # see TORCHDYNAMO_VERBOSE=1
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
File "/home/jansel/pytorch/torch/_dynamo/eval_frame.py", line 576, in _fn
return fn(*args, **kwargs)
^^^^^^^^^^^^^^^^^^^
File "/home/jansel/pytorch/torch/nn/modules/module.py", line 1739, in _wrapped_call_impl
return self._call_impl(*args, **kwargs)
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
File "/home/jansel/pytorch/torch/nn/modules/module.py", line 1750, in _call_impl
return forward_call(*args, **kwargs)
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
File "/home/jansel/pytorch/torch/_dynamo/convert_frame.py", line 1383, in __call__
return self._torchdynamo_orig_callable(
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
File "/home/jansel/pytorch/torch/_dynamo/convert_frame.py", line 1167, in __call__
result = self._inner_convert(
^^^^^^^^^^^^^^^^^^^^
File "/home/jansel/pytorch/torch/_dynamo/convert_frame.py", line 548, in __call__
return _compile(
^^^^^^^^^
File "/home/jansel/pytorch/torch/_dynamo/convert_frame.py", line 988, in _compile
guarded_code = compile_inner(code, one_graph, hooks, transform)
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
File "/home/jansel/pytorch/torch/_dynamo/convert_frame.py", line 716, in compile_inner
return _compile_inner(code, one_graph, hooks, transform)
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
File "/home/jansel/pytorch/torch/_utils_internal.py", line 95, in wrapper_function
return function(*args, **kwargs)
^^^^^^^^^^^^^^^^^^^^^^^^^
File "/home/jansel/pytorch/torch/_dynamo/convert_frame.py", line 751, in _compile_inner
out_code = transform_code_object(code, transform)
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
File "/home/jansel/pytorch/torch/_dynamo/bytecode_transformation.py", line 1361, in transform_code_object
transformations(instructions, code_options)
File "/home/jansel/pytorch/torch/_dynamo/convert_frame.py", line 232, in _fn
return fn(*args, **kwargs)
^^^^^^^^^^^^^^^^^^^
File "/home/jansel/pytorch/torch/_dynamo/convert_frame.py", line 663, in transform
tracer.run()
File "/home/jansel/pytorch/torch/_dynamo/symbolic_convert.py", line 2870, in run
super().run()
File "/home/jansel/pytorch/torch/_dynamo/symbolic_convert.py", line 1053, in run
while self.step():
^^^^^^^^^^^
File "/home/jansel/pytorch/torch/_dynamo/symbolic_convert.py", line 963, in step
self.dispatch_table[inst.opcode](self, inst)
File "/home/jansel/pytorch/torch/_dynamo/symbolic_convert.py", line 3050, in RETURN_VALUE
self._return(inst)
File "/home/jansel/pytorch/torch/_dynamo/symbolic_convert.py", line 3035, in _return
self.output.compile_subgraph(
File "/home/jansel/pytorch/torch/_dynamo/output_graph.py", line 1102, in compile_subgraph
self.compile_and_call_fx_graph(
File "/home/jansel/pytorch/torch/_dynamo/output_graph.py", line 1383, in compile_and_call_fx_graph
compiled_fn = self.call_user_compiler(gm)
^^^^^^^^^^^^^^^^^^^^^^^^^^^
File "/home/jansel/pytorch/torch/_dynamo/output_graph.py", line 1433, in call_user_compiler
return self._call_user_compiler(gm)
^^^^^^^^^^^^^^^^^^^^^^^^^^^^
File "/home/jansel/pytorch/torch/_dynamo/output_graph.py", line 1463, in _call_user_compiler
compiled_fn = compiler_fn(gm, self.example_inputs())
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
File "/home/jansel/pytorch/torch/_dynamo/repro/after_dynamo.py", line 130, in __call__
compiled_gm = compiler_fn(gm, example_inputs)
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
File "/home/jansel/pytorch/torch/__init__.py", line 2314, in __call__
return compile_fx(model_, inputs_, config_patches=self.config)
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
File "/home/jansel/pytorch/torch/_inductor/compile_fx.py", line 1880, in compile_fx
return aot_autograd(
^^^^^^^^^^^^^
File "/home/jansel/pytorch/torch/_dynamo/backends/common.py", line 83, in __call__
cg = aot_module_simplified(gm, example_inputs, **self.kwargs)
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
File "/home/jansel/pytorch/torch/_functorch/aot_autograd.py", line 1145, in aot_module_simplified
compiled_fn = AOTAutogradCache.load(
^^^^^^^^^^^^^^^^^^^^^^
File "/home/jansel/pytorch/torch/_functorch/_aot_autograd/autograd_cache.py", line 754, in load
compiled_fn = dispatch_and_compile()
^^^^^^^^^^^^^^^^^^^^^^
File "/home/jansel/pytorch/torch/_functorch/aot_autograd.py", line 1131, in dispatch_and_compile
compiled_fn, _ = create_aot_dispatcher_function(
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
File "/home/jansel/pytorch/torch/_functorch/aot_autograd.py", line 580, in create_aot_dispatcher_function
return _create_aot_dispatcher_function(
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
File "/home/jansel/pytorch/torch/_functorch/aot_autograd.py", line 830, in _create_aot_dispatcher_function
compiled_fn, fw_metadata = compiler_fn(
^^^^^^^^^^^^
File "/home/jansel/pytorch/torch/_functorch/_aot_autograd/jit_compile_runtime_wrappers.py", line 676, in aot_dispatch_autograd
compiled_fw_func = aot_config.fw_compiler(fw_module, adjusted_flat_args)
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
File "/home/jansel/pytorch/torch/_functorch/aot_autograd.py", line 489, in __call__
return self.compiler_fn(gm, example_inputs)
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
File "/home/jansel/pytorch/torch/_inductor/compile_fx.py", line 1758, in fw_compiler_base
return inner_compile(
^^^^^^^^^^^^^^
File "/home/jansel/pytorch/torch/_inductor/compile_fx.py", line 572, in compile_fx_inner
return wrap_compiler_debug(_compile_fx_inner, compiler_name="inductor")(
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
File "/home/jansel/pytorch/torch/_dynamo/repro/after_aot.py", line 102, in debug_wrapper
inner_compiled_fn = compiler_fn(gm, example_inputs)
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
File "/home/jansel/pytorch/torch/_inductor/compile_fx.py", line 686, in _compile_fx_inner
mb_compiled_graph = fx_codegen_and_compile(
^^^^^^^^^^^^^^^^^^^^^^^
File "/home/jansel/pytorch/torch/_inductor/compile_fx.py", line 1129, in fx_codegen_and_compile
return scheme.codegen_and_compile(gm, example_inputs, inputs_to_check, graph_kwargs)
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
File "/home/jansel/pytorch/torch/_inductor/compile_fx.py", line 1044, in codegen_and_compile
compiled_fn = graph.compile_to_module().call
^^^^^^^^^^^^^^^^^^^^^^^^^
File "/home/jansel/pytorch/torch/_inductor/graph.py", line 1975, in compile_to_module
return self._compile_to_module()
^^^^^^^^^^^^^^^^^^^^^^^^^
File "/home/jansel/pytorch/torch/_inductor/graph.py", line 1981, in _compile_to_module
self.codegen_with_cpp_wrapper() if self.cpp_wrapper else self.codegen()
^^^^^^^^^^^^^^
File "/home/jansel/pytorch/torch/_inductor/graph.py", line 1916, in codegen
self.scheduler.codegen()
File "/home/jansel/pytorch/torch/_inductor/scheduler.py", line 3667, in codegen
return self._codegen()
^^^^^^^^^^^^^^^
File "/home/jansel/pytorch/torch/_inductor/scheduler.py", line 3761, in _codegen
if device is not None and self.get_backend(device).ready_to_flush():
^^^^^^^^^^^^^^^^^^^^^^^^
File "/home/jansel/pytorch/torch/_inductor/scheduler.py", line 3631, in get_backend
self.backends[device] = self.create_backend(device)
^^^^^^^^^^^^^^^^^^^^^^^^^^^
File "/home/jansel/pytorch/torch/_inductor/scheduler.py", line 3624, in create_backend
raise TritonMissing(inspect.currentframe())
torch._dynamo.exc.TritonMissing: Cannot find a working triton installation. Either the package is not installed or it is too old. More information on installing Triton can be found at: https://github.com/triton-lang/triton
You can suppress this exception and fall back to eager by setting:
import torch._dynamo
torch._dynamo.config.suppress_errors = True
```
This PR also strips dynamo stack frames from other types of backend compile errors.
Pull Request resolved: https://github.com/pytorch/pytorch/pull/143552
Approved by: https://github.com/yanboliang
This PR implements the deduplication pass (blocked by config currently) for dynamo where identical regions from https://github.com/pytorch/pytorch/pull/141381 are replaced with a common subgraph.
The two phases of deduplication are explained below.
**Subgraph creation**:
Subgraph creation works by taking one representative region from each region group and creating a subgraph from it, which will then be used to replace all regions in the group. This is implemented by first copying all nodes of the region to the new subgraph and then finding all inputs which are not within the region and creating placeholders for them. For the outputs, all regions in a region group need to be scanned to ensure the largest set of outputs is found, and then an output node is created which returns a tuple of all outputs.
**Graph replacement**:
To replace each region with the extracted subgraph, the node index in the region and argument index within the node's flattened args and kwargs are recorded once during subgraph creation. This allows us to determine which (external to the region) nodes and in which order these nodes are passed as inputs. For the outputs, getitem nodes are created for each output, and all nodes in the region with external outputs are replaced by the proper getitem node. Finally, all original nodes are erased (there should be no uses of these left in the graph).
Pull Request resolved: https://github.com/pytorch/pytorch/pull/141383
Approved by: https://github.com/zou3519
ghstack dependencies: #141381, #141382
This PR implements graph region tracking for later extraction into common subgraphs. The algorithm is as follows:
`GraphRegionTracker` tracks each node added to the output graph and generates a key based on the source location, instruction pointer, input shapes, and global state at the time the node is inserted into the graph. Nodes with the same key are grouped together in a list of identical nodes.
Once graph capture is complete, these nodes are organized into region groups. A region group looks like this:
[[IdenticalNode1], [IdenticalNode2], [IdenticalNode3]] and each sublist is called a region. For each region group (starting at the topologically latest region group), the inner regions are gradually expanded one node at time from args and kwargs of the node in each region provided that for all regions in the group, the nodes being added are also identical (ie have the same key computed above). The `get_identical_regions` function is the main entry point which will be used by the graph replacement algorithm in #141383
Edge cases to add more testing for in future PRs (in progress):
* ~~multiple nodes on the same line~~ (implemented)
* ~~dynamic shapes checking (need to verify symbolic inputs are the same across subgraphs)~~ (implemented)
* ensure we don't expand regions where it will create a cycle during subgraph replacement
* ensure outputs are always tensors (or tuples of tensors iirc)
* ~~out of order kwargs, unevenly nested kwargs~~ (implemented)
* input aliasing - TBD, we may add support for this in `invoke_subgraph` or reuse the aliasing analysis here to not form regions with these properties
* ~~all global state~~ (implemented)
Other followups:
* consolidate global state checking across all caching infra
Pull Request resolved: https://github.com/pytorch/pytorch/pull/141381
Approved by: https://github.com/zou3519
This patch
1. removes `AutoDerefLocalSource` in favor of `LocalSource`, thereby
removing its special handling in guards.
2. introduces a `LocalCellSource` for cells from the root frame, with
only `reconstruct` implemented, to programmatically enforce that thse
cells should never be used by other components like guards.
Pull Request resolved: https://github.com/pytorch/pytorch/pull/141629
Approved by: https://github.com/jansel
ghstack dependencies: #141628
Prior to this patch, we are using `ConstantVariable.create` to create VT
for frozenset objects, and intended yet failed to predicate that on all
itmes being literals (see https://github.com/pytorch/pytorch/pull/140984#discussion_r1847393736).
The code was from https://github.com/pytorch/torchdynamo/commit/7c03434 and
the original goal was to help DBR quantization, but as the new test in
this patch shows, it could lead to silent incorrectness.
Upon a closer look, this exposes some subtleties in how Dynamo handles
`ConstantVariable` and `LOAD_CONST`, so this patch both fixes the
aforementioned issue and documents, enforces, and makes explicit the
invariants around `ConstantVariable` and `LOAD_CONST` -- only immutable
objects are supported.
Specifically, this patch:
1. refine the checks for wrapping a `frozenset` object, document why we
can't just wrap its items directly due to lack of `Sourcec` for set
items, and use a safe workaround (`SourcelessBuilder`) to ensure
soundness while keeping the DBR quantization support.
2. Adds more types to `common_constant_types`, thereby making
`ConstantVariable.is_base_literal` more lenient, and strictly checks
this property in the constructor of `ConstantVariable`.
3. Change relevant uses of `create_instruction("LOAD_CONST", ...)` to
`create_load_const` which checks `is_safe_constant`, and makes
developer overrides explicit by using `create_load_const_unchecked`
when needed.
4. In a few places, use more specific `VariableTracker`, e.g.,
`TypingVariable` rather than `ConstantVariable`, and
`FrozensetVariable` rather than `SetVariable`.
(2) and (3) are mainly to future-proof Dynamo against bugs like (1).
Pull Request resolved: https://github.com/pytorch/pytorch/pull/141504
Approved by: https://github.com/jansel
Fixes a bunch of benchmarks that failed with cudagraph errors including `tlp python benchmarks/dynamo/timm_models.py --device cuda --inductor --accuracy --amp --training --only resmlp_12_224` when `specialize_float=False`
Also brings down number of overall failures (with keep-going) from 108 => 62. I'd estimate >80% of those 62 are wobbly expect tests.
Pull Request resolved: https://github.com/pytorch/pytorch/pull/140346
Approved by: https://github.com/ezyang
ghstack dependencies: #140983, #141003
* Automatically applies ruff rule 401. Turns loops into equivalent list comprehensions which are faster and do not leak the scope of the loop variables.
* list comprehensions not only often have better typing, but are 50+% faster than for loops on overhead. They also preserve length information etc and are better for the interpreter to optimize.
* Manually went back and made mypy happy after the change.
* Also fixed style lints in files covered by flake8 but not by pyfmt
Pull Request resolved: https://github.com/pytorch/pytorch/pull/140980
Approved by: https://github.com/justinchuby, https://github.com/malfet
Here's the overview:
There's a new contextmanager singleton called MetricsContext. Entering the MetricsContext is how we demarcate the boundary on which we'll create a single CompilationMetrics object, and therefore, a single dynamo_compile log entry. While we're inside the MetricsContext, we can update/set many different metrics. Most importantly: `dynamo_timed` can also update the in-progress MetricsContext. In the proposal here, we tell `dynamo_timed` that we want it to do so by providing the name of the MetricsContext field to increment. There can be many `dynamo_timed` calls in different parts of the code updating different fields. Then when the MetricsContext exits, that's when the logging of everything gathered finally happens. One potential footgun is trying to use `dynamo_timed` when we haven't entered the MetricsContext, but we assert on that problem. Another problem is that we re-enter the context recursively, but we watch for that and do the logging only when the outermost exits.
Some specifics:
* Introduce MetricsContext - a context manager that on exit, records the CompilationMetrics (which also logs to dynamo_compile).
* Completely remove the concept of frame_phase_timing. Instead, update the MetricsContext during compilation, either directly or via dynamo_timed.
* Remove some globals we previously used to accumulate counters to later populate a CompilationMetrics. We use CompilationMetrics set/update/increment APIs instead.
* `record_compilation_metrics` is now called on exit from MetricsContext.
* Populate legacy CompilationMetrics fields right before logging, inside `record_compilation_metrics`.
* Remove the one-off `add_remote_cache_time_saved` helper; capture that timing directly into the MetricsContext.
And specifically, several changes to dynamo_timed:
* "Modernize" the parameters and update all callsites accordingly.
* Move the backwards logging of the CompilationMetrics to the backwards compile location.
* Add a parameter for which CompilationMetrics field to update
Pull Request resolved: https://github.com/pytorch/pytorch/pull/139849
Approved by: https://github.com/ezyang
This patch fixes 2 things which are exposed if we have `NewCellVariable`
rather than `ClosureVariable` to model python cells:
1. `codegen_save_tempvars` must run first, to establish `source` for
objects, otherwise they can't reconstruct.
2. `prune_dead_object_new` must account for `OutputGraph.backward_state`
as well, since it also contains variables that must live.
Pull Request resolved: https://github.com/pytorch/pytorch/pull/140201
Approved by: https://github.com/jansel
ghstack dependencies: #140035, #140036, #140149, #140150, #140151
The `cell_or_freevar` was added in #106403 to help us ensure
Dynamo-export only allows graph input that depends on the frame input
(rather than a captured cell, for instance).
However, when taken literally, the `cell_or_freevar` condition is
actually not accurate, because for frame inputs that are also cells
(i.e., captured by some inner function), we actually set the
`cell_or_freevar` flag to false. This makes sense, because otherwise the
existing implementation would prevent Dynamo-export to add any of these
inputs to the graph.
To help with reasoning, this patch refines the `cell_or_freevar` flag to
what we really want to check -- `is_input`, and updates the relevant use
sites.
Pull Request resolved: https://github.com/pytorch/pytorch/pull/140151
Approved by: https://github.com/jansel
ghstack dependencies: #140035, #140036, #140149, #140150
Here's the overview:
There's a new contextmanager singleton called MetricsContext. Entering the MetricsContext is how we demarcate the boundary on which we'll create a single CompilationMetrics object, and therefore, a single dynamo_compile log entry. While we're inside the MetricsContext, we can update/set many different metrics. Most importantly: `dynamo_timed` can also update the in-progress MetricsContext. In the proposal here, we tell `dynamo_timed` that we want it to do so by providing the name of the MetricsContext field to increment. There can be many `dynamo_timed` calls in different parts of the code updating different fields. Then when the MetricsContext exits, that's when the logging of everything gathered finally happens. One potential footgun is trying to use `dynamo_timed` when we haven't entered the MetricsContext, but we assert on that problem. Another problem is that we re-enter the context recursively, but we watch for that and do the logging only when the outermost exits.
Some specifics:
* Introduce MetricsContext - a context manager that on exit, records the CompilationMetrics (which also logs to dynamo_compile).
* Completely remove the concept of frame_phase_timing. Instead, update the MetricsContext during compilation, either directly or via dynamo_timed.
* Remove some globals we previously used to accumulate counters to later populate a CompilationMetrics. We use CompilationMetrics set/update/increment APIs instead.
* `record_compilation_metrics` is now called on exit from MetricsContext.
* Populate legacy CompilationMetrics fields right before logging, inside `record_compilation_metrics`.
* Remove the one-off `add_remote_cache_time_saved` helper; capture that timing directly into the MetricsContext.
And specifically, several changes to dynamo_timed:
* "Modernize" the parameters and update all callsites accordingly.
* Move the backwards logging of the CompilationMetrics to the backwards compile location.
* Add a parameter for which CompilationMetrics field to update
Pull Request resolved: https://github.com/pytorch/pytorch/pull/139849
Approved by: https://github.com/ezyang
ghstack dependencies: #140094
There are 4 parts (they are hard to further break into smaller ones cause they're highly coupled) in this PR:
1. **Whenever we call create_graph_input, we try to bind the symbols in the graph input.**
We've enforced the invariant that all create_graph_inputs calls must provide an example value, we could intercept at the create_graph_input calls (This PR only handles free symbols in tensors).
2. **We cache the bound_symbols** to avoid lift the same symbol repeated.
3. For lifted symbols, we re-used **lifted_freevars** i.e. the mapping between symbol proxy in parent graph to the lifted phs in current subgraph, which we handle lifted tensors. In this way, all hops that supports lifted tensors should be able to handle lifted_symints automatically (at least in dynamo part).
4. For **unbacked symbols** created during tracing, we need to also bound these symbols to its proxy. This is to support the tests cases where we want to lift unbacked symbols as input. We need the proxy of the unbacked symbol in parent graph in order to properly create the args to the hop.
5. We change all the tests after free symbols are lifted in subgraphs. And also supports the lifted symbols in existing higher order ops.
**The interaction of nested tracers:**
The previous design for lifting tensor closures is that: suppose we're in nested tracers, whenever we see a new proxy that's not created by create tracer, we recursively look for the proxy in parent tracer until we find the tracer that creates this proxy (either a placeholder or some intermediate results). More detail is in Note [Nested SubgraphTracer and free_variable handling].
Given the above design, the plan for lifting the free symbols is: whenever we lift a free tensor to be the inputs of current subgraph, we'll look at the symbols in it and bind the symbols at the same time.
For example, suppose we have the following function:
```python
def f(x: [s1, s2]):
def true_f():
def true_f_inner():
return x.sin()
```
what will happen in time order:
1. we create a subtracer 1 and start to speculate the outer cond's true_f
2. we create a another subtracer 2 and start to speculate the inner cond's true_f_inner.
3. dynamo realize the tensor input x by calling wrap_tensor in top-level to create graph input x (tracer 0), we bind the symbol s1, s2 after ph for x is created. So the graph now looks like:
```python
def gm(s1, s2, x):
```
4. when seeing TensorVariable.call_method of x, tracer2 wants to create a call_function(sin, proxy_of_x), but it finds that proxy_of_x is not created by current tracer. So it recursively look up its parent tracer1 and find parent tracer1 also doesn't track this proxy_of_x then it finds the root tracer0, who is the creator of it and tracks it as a ph. Then tracer 1 create_graph_input to lift the closure to its input ph1 and add (proxy_of_x: ph1) k-v in **lifted_freevars** of tracer 1.
Now the graph looks like:
```python
def gm(s1, s2, x):
def true_gm(x):
```
5. Since there are free symbols inside this new tensor input, tracer 1 also binds the symbols (maybe_bind_symbol), which calls create_graph_input for s1 and s2. Now the graph looks like
```python
def gm(s1, s2, x):
def true_gm(s1, s2, x):
```
6. then it goes back to tracer 2, and call create_graph_input for x and get ph2, tracer 2's **lifted_freevars** records (ph1, ph2). and tracer 2 also binds the symbols in this new tensor input. Now the graph looks like:
```python
def gm(s1, s2, x):
def true_gm(s1, s2, x):
def true_gm_inner(s1, s2, x):
```
7. Finally the sin call_function node is created by tracer 2.
**This PR also handles the following cases:**
- What if we lift two tensors share the same symbol? e.g. x1 [s1, s2], x2 [s2, s3]? Each subtracer maintains bound_symbols as a cache that maps a symbol.expr to its proxy in current tracer. So when we see x1, we'll track s1 and s2 as inputs and bound s1 to ph1, s2 to ph2. So when we try to bind symbols of x2, s2 will already be tracked so no graph input is created.
- what if a subgraph close over a symint? e.g.
```python
def f(x):
def true_f():
c = x.size(0)
def true_fn_inner():
return c
```
When we speculate true_fn_inner, we find proxy_of_c is not tracked by tracer 2, so it recursively looks up its parent. At this point, x and its symbols have been lifted as input of true_f (as a result of lifting x during tracing true_f in tracer 1. Specifically the graph looks like:
```python
def gm(s1, s2, x):
def true_gm(s1, s2, x):
def true_gm_inner():
```
So tracer 2 is able to find that s1 have been tracked as ph in tracer 1 so it returns back to gm and call create_graph_input on s1. The graph now looks like:
```python
def gm(s1, s2, x):
def true_gm(s1, s2, x):
def true_gm_inner(s1):
return s1
```
- What if subgraph close over an unbacked symint? e.g.
```python
def f(x):
def true_f():
c = x.item()
def true_f_inner():
return c
```
When x.item() is called, proxy_of_c and its symnode variable is created for tracer 1, and we also call track_unbacked_symbols to record this relationship. So when tracer 2 finds proxy_of_c is not created by current tracer, it recursivelly looks up its parent tracer and finds that that expression u0 has been tracked as a result of track_unbacked_symbol in tracer 1. So it will stop the recursion and create_graph_input u0 in tracer 2. Graph looks like:
```python
def f(x):
def true_f(s1, s2, x):
c = x.item()
def true_gm_inner(u0):
return u0
cond(pred, true_gm_inner, false_gm_inner, (c,))
```
- what if subgraph close over a tensor with unbacked symint shape?
```python
def f(x):
def true_f():
c = x.item()
r = torch.randn((c,))
def true_f_inner():
return r + 1
```
This is the same as the case of closing over tensors with backed shapes. where we first lift r, then bind u0 in it, which recursively bind_symint of u0 in its parent and found u0 is tracked in parent tracer as a result of .item() call.
Pull Request resolved: https://github.com/pytorch/pytorch/pull/138363
Approved by: https://github.com/zou3519
This patch addresses the renaming part of #133027, specifically, it
renames the following and adds documentation for relevant classes.
1. `VariableTracker.mutable_local` to `mutation_type`
2. `MatableLocal `to `ValueMutationNew`
3. `MutableSideEffects `to `ValueMutationExisting`
4. `MutableLocalSource` to `SourceType`
5. `MutableLocalSource.Local` to `New`
Note that (2), (3) and (5) are mainly to bring consistency between them
and `AttributeMutationNew`, `AttributeMutationExisting`.
Pull Request resolved: https://github.com/pytorch/pytorch/pull/139339
Approved by: https://github.com/jansel, https://github.com/mlazos, https://github.com/anijain2305
This refactoring is for getting a deterministic ordering of binding tensors and sizes of tensors. When seeing a free tensor x with shape (s0,) in subgraph, the ordering of lifting changes from
```
lift_x_in_child, lift_s0_in_child, lift_s0_in_parent, lift_x_in_parent
```
to
```
lift_x_in_parent, lift_s0_in_parent, lift_x_in_child, lift_s0_in_child
```
This produces a determinstic ordering of handling the symints in lifted tensors.
This is also the current contract of dynamo top-level graph: we lift free_symbols in sizes after tensor x and insert the free symbols before the tensor x's proxy.
Pull Request resolved: https://github.com/pytorch/pytorch/pull/138559
Approved by: https://github.com/zou3519
ghstack dependencies: #138345, #138428, #138558, #138737
Code refactoring only. We move the wrap_to_fake_tensor_logic out of wrap_fx_proxy for placeholders to provide the invariant that **all graph inputs must set their example values when creating the inputs**. This invariant helps us to identify all the free symbols in the graph in top-level and sub-graphs.
Pull Request resolved: https://github.com/pytorch/pytorch/pull/138428
Approved by: https://github.com/ezyang, https://github.com/zou3519
ghstack dependencies: #138345
This addresses
https://github.com/pytorch/pytorch/pull/137677/files#r1799836499, which
had to set `allow_cache=False` for codegen on `DataPtrVariable.base`,
which is a `TensorVariable`, otherwise we observe failure of
`test_no_grad_copy` when testing with Dynamo.
I've seen `test_no_grad_copy` failing a few times, and every single time
it's related to cyclic reference, my best guess is the cyclic reference
holds some tensor object longer in memory than necessary, preventing the
optimization introduced in #11165.
This patch makes `OutputGraph.cleanup()` more aggressive by clearing out
all fields that might reference a `VariableTracker`. As a result, we can
remove the aforementioned `allow_cache=False`, which helps generate
better code (e.g., in the case of `test_no_grad_copy`, it skipped generating
a redundant graph whose only op is returning the input tensor; instead we just
generate a single `LOAD_FAST`).
Pull Request resolved: https://github.com/pytorch/pytorch/pull/139487
Approved by: https://github.com/jansel, https://github.com/aakhundov
This diff considerably changes the column format of PT2 Compile Events:
- Now, instead of logging one new column per every piece of metadata, we just log a single column, "metadata". This vastly decreases the number of columns we need to log, which should help with retention.
- Now, we only log to scuba for a set of dynamo_timed() events that we actually care about aggregating. To do so, we add a boolean to dynamo_timed() that decides whether or not to log a pt2_compile_event. We'll always log a chromium_event for every dynamo_timed(), but only log a subset of those to scuba.
Differential Revision: [D65225598](https://our.internmc.facebook.com/intern/diff/D65225598/)
Pull Request resolved: https://github.com/pytorch/pytorch/pull/139309
Approved by: https://github.com/oulgen
