lightning/pytorch_lightning/profiler/__init__.py

207 lines
9.2 KiB
Python

"""
Profiling your training run can help you understand if there are any bottlenecks in your code.
Built-in checks
---------------
PyTorch Lightning supports profiling standard actions in the training loop out of the box, including:
- on_epoch_start
- on_epoch_end
- on_batch_start
- tbptt_split_batch
- model_forward
- model_backward
- on_after_backward
- optimizer_step
- on_batch_end
- training_step_end
- on_training_end
Enable simple profiling
-----------------------
If you only wish to profile the standard actions, you can set `profiler="simple"`
when constructing your `Trainer` object.
.. code-block:: python
trainer = Trainer(..., profiler="simple")
The profiler's results will be printed at the completion of a training `fit()`.
.. code-block:: python
Profiler Report
Action | Mean duration (s) | Total time (s)
-----------------------------------------------------------------
on_epoch_start | 5.993e-06 | 5.993e-06
get_train_batch | 0.0087412 | 16.398
on_batch_start | 5.0865e-06 | 0.0095372
model_forward | 0.0017818 | 3.3408
model_backward | 0.0018283 | 3.4282
on_after_backward | 4.2862e-06 | 0.0080366
optimizer_step | 0.0011072 | 2.0759
on_batch_end | 4.5202e-06 | 0.0084753
on_epoch_end | 3.919e-06 | 3.919e-06
on_train_end | 5.449e-06 | 5.449e-06
Advanced Profiling
------------------
If you want more information on the functions called during each event, you can use the `AdvancedProfiler`.
This option uses Python's cProfiler_ to provide a report of time spent on *each* function called within your code.
.. _cProfiler: https://docs.python.org/3/library/profile.html#module-cProfile
.. code-block:: python
trainer = Trainer(..., profiler="advanced")
or
profiler = AdvancedProfiler()
trainer = Trainer(..., profiler=profiler)
The profiler's results will be printed at the completion of a training `fit()`. This profiler
report can be quite long, so you can also specify an `output_filename` to save the report instead
of logging it to the output in your terminal. The output below shows the profiling for the action
`get_train_batch`.
.. code-block:: python
Profiler Report
Profile stats for: get_train_batch
4869394 function calls (4863767 primitive calls) in 18.893 seconds
Ordered by: cumulative time
List reduced from 76 to 10 due to restriction <10>
ncalls tottime percall cumtime percall filename:lineno(function)
3752/1876 0.011 0.000 18.887 0.010 {built-in method builtins.next}
1876 0.008 0.000 18.877 0.010 dataloader.py:344(__next__)
1876 0.074 0.000 18.869 0.010 dataloader.py:383(_next_data)
1875 0.012 0.000 18.721 0.010 fetch.py:42(fetch)
1875 0.084 0.000 18.290 0.010 fetch.py:44(<listcomp>)
60000 1.759 0.000 18.206 0.000 mnist.py:80(__getitem__)
60000 0.267 0.000 13.022 0.000 transforms.py:68(__call__)
60000 0.182 0.000 7.020 0.000 transforms.py:93(__call__)
60000 1.651 0.000 6.839 0.000 functional.py:42(to_tensor)
60000 0.260 0.000 5.734 0.000 transforms.py:167(__call__)
You can also reference this profiler in your LightningModule to profile specific actions of interest.
If you don't want to always have the profiler turned on, you can optionally pass a `PassThroughProfiler`
which will allow you to skip profiling without having to make any code changes. Each profiler has a
method `profile()` which returns a context handler. Simply pass in the name of your action that you want
to track and the profiler will record performance for code executed within this context.
.. code-block:: python
from pytorch_lightning.profiler import Profiler, PassThroughProfiler
class MyModel(LightningModule):
def __init__(self, profiler=None):
self.profiler = profiler or PassThroughProfiler()
def custom_processing_step(self, data):
with profiler.profile('my_custom_action'):
# custom processing step
return data
profiler = Profiler()
model = MyModel(profiler)
trainer = Trainer(profiler=profiler, max_epochs=1)
PyTorch Profiling
-----------------
Autograd includes a profiler that lets you inspect the cost of different operators
inside your model - both on the CPU and GPU.
Find the Pytorch Profiler doc at [PyTorch Profiler](https://pytorch-lightning.readthedocs.io/en/stable/profiler.html)
.. code-block:: python
trainer = Trainer(..., profiler="pytorch")
or
profiler = PyTorchProfiler(...)
trainer = Trainer(..., profiler=profiler)
This profiler works with PyTorch ``DistributedDataParallel``.
If ``output_filename`` is provided, each rank will save their profiled operation to their own file.
The profiler's results will be printed on the completion of a training `fit()`. This profiler
report can be quite long, so you can also specify an `output_filename` to save the report instead
of logging it to the output in your terminal.
This profiler will record only for `training_step_and_backward`, `evaluation_step` and `test_step` functions by default.
The output below shows the profiling for the action `training_step_and_backward`.
The user can provide ``PyTorchProfiler(profiled_functions=[...])`` to extend the scope of profiled functions.
.. note:: When using the PyTorch Profiler, wall clock time will not not be representative of the true wall clock time. This is due to forcing profiled operations to be measured synchronously, when many CUDA ops happen asynchronously. It is recommended to use this Profiler to find bottlenecks/breakdowns, however for end to end wall clock time use the `SimpleProfiler`. # noqa E501
.. code-block:: python
Profiler Report
Profile stats for: training_step_and_backward
--------------------- --------------- --------------- --------------- --------------- ---------------
Name Self CPU total % Self CPU total CPU total % CPU total CPU time avg
--------------------- --------------- --------------- --------------- --------------- ---------------
t 62.10% 1.044ms 62.77% 1.055ms 1.055ms
addmm 32.32% 543.135us 32.69% 549.362us 549.362us
mse_loss 1.35% 22.657us 3.58% 60.105us 60.105us
mean 0.22% 3.694us 2.05% 34.523us 34.523us
div_ 0.64% 10.756us 1.90% 32.001us 16.000us
ones_like 0.21% 3.461us 0.81% 13.669us 13.669us
sum_out 0.45% 7.638us 0.74% 12.432us 12.432us
transpose 0.23% 3.786us 0.68% 11.393us 11.393us
as_strided 0.60% 10.060us 0.60% 10.060us 3.353us
to 0.18% 3.059us 0.44% 7.464us 7.464us
empty_like 0.14% 2.387us 0.41% 6.859us 6.859us
empty_strided 0.38% 6.351us 0.38% 6.351us 3.175us
fill_ 0.28% 4.782us 0.33% 5.566us 2.783us
expand 0.20% 3.336us 0.28% 4.743us 4.743us
empty 0.27% 4.456us 0.27% 4.456us 2.228us
copy_ 0.15% 2.526us 0.15% 2.526us 2.526us
broadcast_tensors 0.15% 2.492us 0.15% 2.492us 2.492us
size 0.06% 0.967us 0.06% 0.967us 0.484us
is_complex 0.06% 0.961us 0.06% 0.961us 0.481us
stride 0.03% 0.517us 0.03% 0.517us 0.517us
--------------------- --------------- --------------- --------------- --------------- ---------------
Self CPU time total: 1.681ms
When running with `PyTorchProfiler(emit_nvtx=True)`. You should run as following::
nvprof --profile-from-start off -o trace_name.prof -- <regular command here>
To visualize the profiled operation, you can either:
* Use::
nvvp trace_name.prof
* Use::
python -c 'import torch; print(torch.autograd.profiler.load_nvprof("trace_name.prof"))'
"""
from pytorch_lightning.profiler.profilers import AdvancedProfiler, BaseProfiler, PassThroughProfiler, SimpleProfiler
from pytorch_lightning.profiler.pytorch import PyTorchProfiler
__all__ = [
'BaseProfiler',
'SimpleProfiler',
'AdvancedProfiler',
'PassThroughProfiler',
"PyTorchProfiler",
]