https://github.com/pytorch/pytorch/issues/148222
Goal:
At the moment autograd saved tensors hooks are run in eager after compiled forward.
They are executed at the same time for all saved tensors.
Hooks can be used to reduce amout of memory used for saved tensors, doing quantization or offloading to cpu.
This is suboptimal for optimization of peak memory.
Better solution will be to put the hooks in the graph, as close as possible to the last usage of the tensor.
To get user specified autograd saved tensors hooks in the graph.
Logic:
UX:
If user specifies with torch.autograd.graph.saved_tensors_hooks(pack_gm, unpack_gm).
Where pack_gm and unpack_gm are torch.fx.GraphModule.
Then AotAutograd will retrace those graph modules, doing decompositions and functionalization in aot_autograd, inlining the result graphs in forward epilogue and backward prologue.
User may want to use control logic in the hooks, for example applying quantization only for specific dtypes and sizes.
This is also possible, user can put it into torch.fx.wrap function and use symbolic trace to make a GraphModule.
In that case AotAutograd cahing will work only in case when user explicitly set to the torch.fx.wrap call_function node "user_cache_hash" metadata.
If this metadata set - then aot_autograd cache can use saved cache artifact.
If metadata is not set - then cache is bypassed.
Dynamo:
Dynamo traces pack and unpack hooks and installs them as subgraph and explicitly adds to the output_graph. (As those subgraphs are not used and will not be copied in the result by default).
The complexity here is that at this moment we do not have example of inputs for the hooks.
We trace pack_hook with some Tensor from the inputs.
The result subgraphs are added to the hashing of AotAutograd Cache.
In AotAutograd we retrace the graph with the true saved tensors coming from partitioner.
Backwards Compatibility:
As current hooks are executed in eager mode and not all of them will be traceable - we only try to put in the graph hooks, explicitly marked by user with annotation (@_inlineable_saved_tensors_hooks).
For other hooks or if compiled autograd is enabled - keep the same logic.
Recompilations:
Hooks are guarded with lambda guard matching function id to cause recompilation if user reruns compiled function.
Aot_autograd:
After partitioner prepared forward and backward module - we trace prepared at Dynamo graphs for pack and unpack hooks and inline them in epilogue of forward and prologue of backward. Forward outputs and backward inputs are changed, transparently for user.
We do not try to put it close the last usage etc., relying on inductor to do this optimization.
```
INFO: TRACED GRAPH
===== Forward graph pre saved_tensors_hooks inlining 3 =====
/data/users/ivankobzarev/a/pytorch/torch/fx/_lazy_graph_module.py class GraphModule(torch.nn.Module):
def forward(self, primals_1: "Sym(s0)", primals_2: "Sym(s1)", primals_3: "f32[s0, s1][s1, 1]cuda:0"):
# File: /data/users/ivankobzarev/a/pytorch/test/functorch/test_aotdispatch.py:6660 in simple_fn, code: x = x + 1
add: "f32[s0, s1][s1, 1]cuda:0" = torch.ops.aten.add.Tensor(primals_3, 1); primals_3 = None
# File: /data/users/ivankobzarev/a/pytorch/test/functorch/test_aotdispatch.py:6661 in simple_fn, code: x = SAF.apply(x)
view: "f32[s0, s1][s1, 1]cuda:0" = torch.ops.aten.view.default(add, [primals_1, primals_2])
return (view, add, primals_1, primals_2)
INFO: TRACED GRAPH
===== Backward graph pre saved_tensors_hooks inlining 3 =====
/data/users/ivankobzarev/a/pytorch/torch/fx/_lazy_graph_module.py class GraphModule(torch.nn.Module):
def forward(self, primals_1: "Sym(s0)", primals_2: "Sym(s1)", primals_3: "f32[s0, s1][s1, 1]cuda:0"):
# File: /data/users/ivankobzarev/a/pytorch/test/functorch/test_aotdispatch.py:6660 in simple_fn, code: x = x + 1
add: "f32[s0, s1][s1, 1]cuda:0" = torch.ops.aten.add.Tensor(primals_3, 1); primals_3 = None
# File: /data/users/ivankobzarev/a/pytorch/test/functorch/test_aotdispatch.py:6661 in simple_fn, code: x = SAF.apply(x)
view: "f32[s0, s1][s1, 1]cuda:0" = torch.ops.aten.view.default(add, [primals_1, primals_2])
return (view, add, primals_1, primals_2)
INFO: TRACED GRAPH
===== saved_tensors_pack_hook add 3 =====
/data/users/ivankobzarev/a/pytorch/torch/fx/_lazy_graph_module.py class pack_float8(torch.nn.Module):
def forward(self, x_1: "f32[s0, s1][s1, 1]cuda:0"):
# No stacktrace found for following nodes
_to_copy: "f8e4m3fn[s0, s1][s1, 1]cuda:0" = torch.ops.aten._to_copy.default(x_1, dtype = torch.float8_e4m3fn); x_1 = None
return (torch.float32, _to_copy)
INFO: TRACED GRAPH
===== saved_tensors_unpack_hook add 3 =====
<eval_with_key>.22 from /data/users/ivankobzarev/a/pytorch/torch/fx/experimental/proxy_tensor.py:1225 in wrapped class pack_float8(torch.nn.Module):
def forward(self, x_1: "f32[s0, s1][s1, 1]cuda:0"):
# No stacktrace found for following nodes
_to_copy: "f8e4m3fn[s0, s1][s1, 1]cuda:0" = torch.ops.aten._to_copy.default(x_1, dtype = torch.float8_e4m3fn); x_1 = None
return (torch.float32, _to_copy)
INFO: TRACED GRAPH
===== Forward graph 3 =====
/data/users/ivankobzarev/a/pytorch/torch/fx/_lazy_graph_module.py class GraphModule(torch.nn.Module):
def forward(self, primals_1: "Sym(s0)", primals_2: "Sym(s1)", primals_3: "f32[s0, s1][s1, 1]cuda:0"):
# File: /data/users/ivankobzarev/a/pytorch/test/functorch/test_aotdispatch.py:6660 in simple_fn, code: x = x + 1
add: "f32[s0, s1][s1, 1]cuda:0" = torch.ops.aten.add.Tensor(primals_3, 1); primals_3 = None
# No stacktrace found for following nodes
_to_copy: "f8e4m3fn[s0, s1][s1, 1]cuda:0" = torch.ops.aten._to_copy.default(add, dtype = torch.float8_e4m3fn)
# File: /data/users/ivankobzarev/a/pytorch/test/functorch/test_aotdispatch.py:6661 in simple_fn, code: x = SAF.apply(x)
view: "f32[s0, s1][s1, 1]cuda:0" = torch.ops.aten.view.default(add, [primals_1, primals_2]); add = None
return (view, _to_copy, primals_1, primals_2)
INFO: TRACED GRAPH
===== Backward graph 3 =====
<eval_with_key>.21 class GraphModule(torch.nn.Module):
def forward(self, primals_1: "Sym(s0)", primals_2: "Sym(s1)", add_packed_2: "f8e4m3fn[s0, s1][s1, 1]cuda:0", tangents_1: "f32[s0, s1][s1, 1]cuda:0"):
# No stacktrace found for following nodes
_to_copy: "f32[s0, s1][s1, 1]cuda:0" = torch.ops.aten._to_copy.default(add_packed_2, dtype = torch.float32); add_packed_2 = None
# File: /data/users/ivankobzarev/a/pytorch/test/functorch/test_aotdispatch.py:6661 in simple_fn, code: x = SAF.apply(x)
add_7: "f32[s0, s1][s1, 1]cuda:0" = torch.ops.aten.add.Tensor(tangents_1, _to_copy); tangents_1 = _to_copy = None
return (None, None, add_7)
```
Differential Revision: [D72187044](https://our.internmc.facebook.com/intern/diff/D72187044)
Pull Request resolved: https://github.com/pytorch/pytorch/pull/150032
Approved by: https://github.com/bdhirsh
Summary: I forgot to remove this unused field in D73809989.
Test Plan: `buck test 'fbcode//mode/opt' fbcode//caffe2/test:fbonly -- --exact 'caffe2/test:fbonly - test_compilation_metrics_logger_in_sync (caffe2.test.fb.test_fb.TestFBOnly)'`
Pull Request resolved: https://github.com/pytorch/pytorch/pull/153413
Approved by: https://github.com/c00w
Summary: I'm just trying to fix the test again. It's out of date because it's disabled and some dynamo_timed-related fields are gone now.
Test Plan: `python test/dynamo/test_utils.py -k dynamo_timed`
Pull Request resolved: https://github.com/pytorch/pytorch/pull/152387
Approved by: https://github.com/anijain2305
We correctly handed different python version in the explicit ir_nodes test, but
didn't handle it in the dynamo_timed test. Just explicitly deleting the fields
there so the dynamo_timed test passes on all python versions.
(I noticed it breaking on 3.13).
Pull Request resolved: https://github.com/pytorch/pytorch/pull/148987
Approved by: https://github.com/jansel
This gives us a decent proxy for how big of a graph we functionally had to parse.
Note that this is a cummulative counter. If people feel strongly, I can either write into the dynamo_timed datasets with metrics contexts, or clear the counters / write a counter per frame id as well.
Pull Request resolved: https://github.com/pytorch/pytorch/pull/147149
Approved by: https://github.com/jansel
Summary: Gather the compilation time of individual triton kernels and log them to dynamo_compile:
* Time compilation in `_worker_compile_triton` and pass back to the main process and logged from `get_result()`.
* Added a way to track the "top N" (or N most-expensive compiles) in the metrics_context. I did this because I doubt we really care to capture potentially thousands of kernel compile times. That would be problematic for scuba logging anyway, so let's limit the number we track from the beginning. Arbitrarily chose 25 for now.
* Format the list of compile times as a json string before logging.
Test Plan:
`python benchmarks/dynamo/torchbench.py --performance --training --amp --backend inductor --device cuda --print-compilation-time --repeat 5 --cold-start-latency --only nanogpt`
Scuba: https://fburl.com/scuba/dynamo_compile/sandbox/nc4dzm3r
Pull Request resolved: https://github.com/pytorch/pytorch/pull/147022
Approved by: https://github.com/jamesjwu
This bit me while I was trying to debug some trace issues.
In general this config is already quite large when dumping, so adding
more fields doesn't make it significantly worse.
Also a number of the items we are type checking for (except the test
configs), don't even show up. Primarily this will help us when debugging
rocm, halide, and trace configs.
Pull Request resolved: https://github.com/pytorch/pytorch/pull/144700
Approved by: https://github.com/ezyang
We don't support assigning to objects or numeric constants at the top level in
config modules, no need to test for them.
(This specifically breaks later sorting refactoring, since it requires <
to be implemented).
Pull Request resolved: https://github.com/pytorch/pytorch/pull/143535
Approved by: https://github.com/ppanchalia
Summary:
Support garbage collection after pt2 compilation.
Add jk to control the global rollout / rollback of this functionality
Add env var to control individual job's rollout
Test Plan:
Test the model training job with / without this changes
Reviewers:
@yuxihu @ezyang , @Yuzhen11 ,
Subscribers:
Tasks:
Tags:
Fixes #ISSUE_NUMBER
Pull Request resolved: https://github.com/pytorch/pytorch/pull/143364
Approved by: https://github.com/ezyang
Summary: Fix outstanding TODOs related to logging of CompilationMetrics by moving the population of common fields to record_compilation_metrics() instead of populating those independently wherever we use a the metrics_context contextmanager:
* Keep track of start and end time in MetricsContext and pass those to record_compilation_metrics() and populate those fields in that function.
* Pass exception info to record_compilation_metrics() and populate those field in that function.
* Add a new contextmanager, chromium_event_timed, to create the start/end "dynamo" event. This is important because I want this contextmanager to complete _after_ building the CompilationMetrics.
* Populate the compile_id field centrally in record_compilation_metrics().
* Populate the structured_logging_overhead centrally in record_compilation_metrics().
* Add the CompilationMetrics to the current chromium event in record_compilation_metrics(), after all common fields have been added. In a future diff, I can also add _all_ compilation metrics to the chromium event.
Test plan: Unit tests. Also see internal testing:
* dynamo_compile: https://fburl.com/scuba/dynamo_compile/sandbox/jrascnf9
* pt2_compile_events: https://fburl.com/scuba/pt2_compile_events/l3jnla06
* tlparse: https://fburl.com/bq5a9nqs
Pull Request resolved: https://github.com/pytorch/pytorch/pull/141291
Approved by: https://github.com/jamesjwu
Summary:
Add the following inductor fx graph cache stats to dynamo compile
- inductor_fx_cache_hit_count
- inductor_fx_cache_miss_count
- inductor_fx_cache_backend_type
- inductor_fx_cache_hit_keys
- inductor_fx_cache_miss_keys
- remote_cache_version
Test Plan: Run local tests and staging logger: P1683061460
Differential Revision: D66232206
Pull Request resolved: https://github.com/pytorch/pytorch/pull/141190
Approved by: https://github.com/masnesral
Adding some dynamo timed for the purpose of better understanding AOTI compilation time.
Probably would require a few more passes. A lot of time is spent in Scheduler.__init__, and not enough annotations are there.
run_command_and_check takes a lot time as well. But there is probably not much we can do. Maybe we can add a config to tune C++ optimization level?
traces:
<img width="1205" alt="Screenshot 2024-11-08 at 4 41 10 PM" src="https://github.com/user-attachments/assets/61645264-b3af-4d4a-804d-700b0f831c7c">
Differential Revision: D65554141
Pull Request resolved: https://github.com/pytorch/pytorch/pull/140198
Approved by: https://github.com/desertfire
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
