Fixed type hints for CosineAnnealingWarmRestarts:
- `T_mult` is not `Optional[int]` but just `int`
- `eta_min` is not `Optional[float]` but just `float`
- removed `step` method specific annotation as it is compatible with the base class
e132f09e88/torch/optim/lr_scheduler.py (L1365-L1375)
Otherwise, computation like this `self.T_i * self.T_mult` in `self.step` is not possible:
```
error: Unsupported operand types for * ("int" and "None")
```
Pull Request resolved: https://github.com/pytorch/pytorch/pull/102067
Approved by: https://github.com/janeyx99
Changes:
- #95200
1. Recognize `.py.in` and `.pyi.in` files as Python in VS Code for a better development experience.
2. Fix deep setting merge in `tools/vscode_settings.py`.
- #95267
3. Use `Namedtuple` rather than `namedtuple + __annotations__` for `torch.nn.utils.rnn.PackedSequence_`:
`namedtuple + __annotations__`:
```python
PackedSequence_ = namedtuple('PackedSequence_',
['data', 'batch_sizes', 'sorted_indices', 'unsorted_indices'])
# type annotation for PackedSequence_ to make it compatible with TorchScript
PackedSequence_.__annotations__ = {'data': torch.Tensor, 'batch_sizes': torch.Tensor,
'sorted_indices': Optional[torch.Tensor],
'unsorted_indices': Optional[torch.Tensor]}
```
`Namedtuple`: Python 3.6+
```python
class PackedSequence_(NamedTuple):
data: torch.Tensor
batch_sizes: torch.Tensor
sorted_indices: Optional[torch.Tensor]
unsorted_indices: Optional[torch.Tensor]
```
- => this PR: #95268
4. Sort import statements and remove unnecessary imports in `.pyi`, `.pyi.in` files.
5. Format `.pyi`, `.pyi.in` files and remove unnecessary ellipsis `...` in type stubs.
Pull Request resolved: https://github.com/pytorch/pytorch/pull/95268
Approved by: https://github.com/huydhn
Hi, we noticed in our team that by using CyclicLR, there is a problem with memory clearance on GPU (probably it will be the case without the GPU as well, but that was our use case) After initializing CyclicLR, GPU memory is not cleared even after the model, optimizer and scheduler are out of scope (e.g. reference count is zero). This is because `__init__` method inside `CyclicLR` creates reference to its own methods and it will not get removed until `gc.collect()` is called manually. This is a problem if people want to test multiple models in one run of a script, after testing the first model, second one will fail on `CUDA out of memory error` because the first one is not cleared from the memory.
I propose a simple fix by using `weakref`, similarly as in `_LRScheduler` base class, but if you have any comments I am happy to change it.
Here is the code to reproduce the bug:
```
import torch
import weakref
from transformers import DetrForObjectDetection
class X:
def __init__(self, optimizer):
self.optimizer = optimizer
# Will cause cyclic reference.
self.func = self.dummy
# Will work as expected, memory cleared after instance count is zero.
# self.func = weakref.WeakMethod(self.dummy)
def dummy(self, x):
return 1.
def test():
model = DetrForObjectDetection.from_pretrained('facebook/detr-resnet-50')
model.to('cuda')
optimizer = torch.optim.Adam(model.parameters())
x = X(optimizer)
test()
print(f'{torch.cuda.memory_reserved()}, {torch.cuda.memory_allocated()}') # Should print (<some memory>, 0), but with cyclic reference, it will print (<some memory>, <some memory>).
```
Pull Request resolved: https://github.com/pytorch/pytorch/pull/85462
Approved by: https://github.com/albanD
Summary:
- ~optimizer isn't required for `SequentialLR` since it's already present in the schedulers. Trying to match the signature of it with `ChainedScheduler`.~
- ~`verbose` isn't really used anywhere so removed it.~
updated missing docs and added a small check
Pull Request resolved: https://github.com/pytorch/pytorch/pull/69817
Reviewed By: ngimel
Differential Revision: D33069589
Pulled By: albanD
fbshipit-source-id: f015105a35a2ca39fe94c70acdfd55cdf5601419
Summary:
Partially resolves https://github.com/pytorch/vision/issues/4281
In this PR we are proposing a new scheduler --SequentialLR-- which enables list of different schedulers called in different periods of the training process.
The main motivation of this scheduler is recently gained popularity of warming up phase in the training time. It has been shown that having a small steps in initial stages of training can help convergence procedure get faster.
With the help of SequentialLR we mainly enable to call a small constant (or linearly increasing) learning rate followed by actual target learning rate scheduler.
```PyThon
scheduler1 = ConstantLR(optimizer, factor=0.1, total_iters=2)
scheduler2 = ExponentialLR(optimizer, gamma=0.9)
scheduler = SequentialLR(optimizer, schedulers=[scheduler1, scheduler2], milestones=[5])
for epoch in range(100):
train(...)
validate(...)
scheduler.step()
```
which this code snippet will call `ConstantLR` in the first 5 epochs and will follow up with `ExponentialLR` in the following epochs.
This scheduler could be used to provide call of any group of schedulers next to each other. The main consideration we should make is every time we switch to a new scheduler we assume that new scheduler starts from the beginning- zeroth epoch.
We also add Chained Scheduler to `optim.rst` and `lr_scheduler.pyi` files here.
Pull Request resolved: https://github.com/pytorch/pytorch/pull/64037
Reviewed By: albanD
Differential Revision: D30841099
Pulled By: iramazanli
fbshipit-source-id: 94f7d352066ee108eef8cda5f0dcb07f4d371751
Summary:
Partially unblocks https://github.com/pytorch/vision/issues/4281
Previously we have added WarmUp Schedulers to PyTorch Core in the PR : https://github.com/pytorch/pytorch/pull/60836 which had two mode of execution - linear and constant depending on warming up function.
In this PR we are changing this interface to more direct form, as separating linear and constant modes to separate Schedulers. In particular
```Python
scheduler1 = WarmUpLR(optimizer, warmup_factor=0.1, warmup_iters=5, warmup_method="constant")
scheduler2 = WarmUpLR(optimizer, warmup_factor=0.1, warmup_iters=5, warmup_method="linear")
```
will look like
```Python
scheduler1 = ConstantLR(optimizer, warmup_factor=0.1, warmup_iters=5)
scheduler2 = LinearLR(optimizer, warmup_factor=0.1, warmup_iters=5)
```
correspondingly.
Pull Request resolved: https://github.com/pytorch/pytorch/pull/64395
Reviewed By: datumbox
Differential Revision: D30753688
Pulled By: iramazanli
fbshipit-source-id: e47f86d12033f80982ddf1faf5b46873adb4f324
Summary:
Warm up of learning rate scheduling has initially been discussed by Priya et. al. in the paper: https://arxiv.org/pdf/1706.02677.pdf .
In the section 2.2 of the paper they discussed and proposed idea of warming up learning schedulers in order to prevent big variance / noise in the learning rate. Then idea has been further discussed in the following papers:
* Akilesh Gotmare et al. https://arxiv.org/abs/1810.13243
* Bernstein et al http://proceedings.mlr.press/v80/bernstein18a/bernstein18a.pdf
* Liyuan Liu et al: https://arxiv.org/pdf/1908.03265.pdf
There are two type of popularly used learning rate warm up ideas
* Constant warmup (start with very small constant learning rate)
* Linear Warmup ( start with small learning rate and gradually increase)
In this PR we are adding warm up as learning rate scheduler. Note that learning rates are chainable, which means that we can merge warmup scheduler with any other learning rate scheduler to make more sophisticated learning rate scheduler.
## Linear Warmup
Linear Warmup is multiplying learning rate with pre-defined constant - warmup_factor in the first epoch (epoch 0). Then targeting to increase this multiplication constant to one in warmup_iters many epochs. Hence we can derive the formula at i-th step to have multiplication constant equal to:
warmup_factor + (1-warmup_factor) * i / warmup_iters
Moreover, the fraction of this quantity at point i to point i-1 will give us
1 + (1.0 - warmup_factor) / [warmup_iters*warmup_factor+(i-1)*(1-warmup_factor)]
which is used in get_lr() method in our implementation. Below we provide an example how to use linear warmup scheduler and to give an example to show how does it works.
```python
import torch
from torch.nn import Parameter
from torch.optim import SGD
from torch.optim.lr_scheduler import WarmUpLR
model = [Parameter(torch.randn(2, 2, requires_grad=True))]
optimizer = SGD(model, 0.1)
scheduler = WarmUpLR(optimizer, warmup_factor=0.1, warmup_iters=10, warmup_method="linear")
for epoch in range(15):
print(epoch, scheduler.get_last_lr()[0])
optimizer.step()
scheduler.step()
```
```
0 0.010000000000000002
1 0.019000000000000003
2 0.028000000000000008
3 0.03700000000000001
4 0.04600000000000001
5 0.055000000000000014
6 0.06400000000000002
7 0.07300000000000002
8 0.08200000000000003
9 0.09100000000000004
10 0.10000000000000005
11 0.10000000000000005
12 0.10000000000000005
13 0.10000000000000005
14 0.10000000000000005
```
## Constant Warmup
Constant warmup has straightforward idea, to multiply learning rate by warmup_factor until we reach to epoch warmup_factor, then do nothing for following epochs
```python
import torch
from torch.nn import Parameter
from torch.optim import SGD
from torch.optim.lr_scheduler import WarmUpLR
model = [Parameter(torch.randn(2, 2, requires_grad=True))]
optimizer = SGD(model, 0.1)
scheduler = WarmUpLR(optimizer, warmup_factor=0.1, warmup_iters=5, warmup_method="constant")
for epoch in range(10):
print(epoch, scheduler.get_last_lr()[0])
optimizer.step()
scheduler.step()
```
```
0 0.010000000000000002
1 0.010000000000000002
2 0.010000000000000002
3 0.010000000000000002
4 0.010000000000000002
5 0.10000000000000002
6 0.10000000000000002
7 0.10000000000000002
8 0.10000000000000002
9 0.10000000000000002
```
Pull Request resolved: https://github.com/pytorch/pytorch/pull/60836
Reviewed By: saketh-are
Differential Revision: D29537615
Pulled By: iramazanli
fbshipit-source-id: d910946027acc52663b301f9c56ade686e62cb69
Summary:
## problem
```python
class LambdaLR(_LRScheduler):
"""Sets the learning rate of each parameter group to the initial lr
times a given function. When last_epoch=-1, sets initial lr as lr.
Args:
optimizer (Optimizer): Wrapped optimizer.
lr_lambda (function or list): A function which computes a multiplicative
factor given an integer parameter epoch, or a list of such
functions, one for each group in optimizer.param_groups.
last_epoch (int): The index of last epoch. Default: -1.
Example:
>>> # Assuming optimizer has two groups.
>>> lambda1 = lambda epoch: epoch // 30
>>> lambda2 = lambda epoch: 0.95 ** epoch
>>> scheduler = LambdaLR(optimizer, lr_lambda=[lambda1, lambda2])
>>> for epoch in range(100):
>>> train(...)
>>> validate(...)
>>> scheduler.step()
"""
```
`LambdaLR` takes a lambda that returns a float and takes a int, or a list of such lambdas.
## related issue
Resolve https://github.com/pytorch/pytorch/issues/32645
Pull Request resolved: https://github.com/pytorch/pytorch/pull/33271
Differential Revision: D19878665
Pulled By: vincentqb
fbshipit-source-id: 50b16caea13de5a3cbd187e688369f33500499d0
Summary:
Some interfaces of schedulers defined in lr_scheduler.py are missing in lr_scheduler.pyi.
Pull Request resolved: https://github.com/pytorch/pytorch/pull/23934
Differential Revision: D16726622
Pulled By: ezyang
fbshipit-source-id: 45fd2d28fbb658c71f6fcd33b8997d6ee8e2b17d
Summary:
Added stubs for:
* The `device` module
* The `cuda` module
* Parts of the `optim` module
* Began adding stubs for the `autograd` module. I'll annotate more later but `no_grad` and friends are probably the most used exports from it so it seemed like a good place to start.
This would close#16996, although comments on that issue reference other missing stubs so maybe it's worth keeping open as an umbrella issue.
The big remaining missing package is `nn`.
Also added a `py.typed` file so mypy will pick up on the type stubs. That closes#17639.
Pull Request resolved: https://github.com/pytorch/pytorch/pull/18511
Differential Revision: D14715053
Pulled By: ezyang
fbshipit-source-id: 9e4882ac997063650e6ce47604b3eaf1232c61c9
