Enable TPU support (#868)

* added tpu docs

* added tpu flags

* add tpu docs + init training call

* amp

* amp

* amp

* amp

* optimizer step

* added auto data transfer to TPU

* added auto data transfer to TPU

* added auto data transfer to TPU

* added auto data transfer to TPU

* added auto data transfer to TPU

* added auto data transfer to TPU

* added auto data transfer to TPU

* added auto data transfer to TPU

* added auto data transfer to TPU

* added auto data transfer to TPU

* added auto data transfer to TPU

* added auto data transfer to TPU

* added auto data transfer to TPU

* added auto data transfer to TPU

* added auto data transfer to TPU

* added auto data transfer to TPU

* added auto data transfer to TPU

* added auto data transfer to TPU

* added auto data transfer to TPU

* added auto data transfer to TPU

* added auto data transfer to TPU

* added auto data transfer to TPU

* added auto data transfer to TPU

* added auto data transfer to TPU

* fix test pkg create (#873)

* added auto data transfer to TPU

* added auto data transfer to TPU

* added auto data transfer to TPU

* added test return and print

* added test return and print

* added test return and print

* added test return and print

* added test return and print

* Update pytorch_lightning/trainer/trainer.py

Co-Authored-By: Luis Capelo <luiscape@gmail.com>

* Fix segmentation example (#876)

* removed torchvision model and added custom model

* minor fix

* Fixed relative imports issue

* Fix/typo (#880)

* Update greetings.yml

* Update greetings.yml

* Changelog (#869)

* Create CHANGELOG.md

* Update CHANGELOG.md

* Update CHANGELOG.md

* Update PULL_REQUEST_TEMPLATE.md

* Update PULL_REQUEST_TEMPLATE.md

* Add PR links to Version 0.6.0 in CHANGELOG.md

* Add PR links for Unreleased in CHANGELOG.md

* Update PULL_REQUEST_TEMPLATE.md

* Fixing Function Signatures (#871)

* added tpu docs

* added tpu flags

* add tpu docs + init training call

* amp

* amp

* amp

* amp

* optimizer step

* added auto data transfer to TPU

* added auto data transfer to TPU

* added auto data transfer to TPU

* added auto data transfer to TPU

* added auto data transfer to TPU

* added auto data transfer to TPU

* added auto data transfer to TPU

* added auto data transfer to TPU

* added auto data transfer to TPU

* added auto data transfer to TPU

* added auto data transfer to TPU

* added auto data transfer to TPU

* added auto data transfer to TPU

* added auto data transfer to TPU

* added auto data transfer to TPU

* added auto data transfer to TPU

* added auto data transfer to TPU

* added auto data transfer to TPU

* added auto data transfer to TPU

* added auto data transfer to TPU

* added auto data transfer to TPU

* added auto data transfer to TPU

* added auto data transfer to TPU

* added auto data transfer to TPU

* added auto data transfer to TPU

* added auto data transfer to TPU

* added auto data transfer to TPU

* added test return and print

* added test return and print

* added test return and print

* added test return and print

* added test return and print

* added test return and print

* added test return and print

* added test return and print

Co-authored-by: Jirka Borovec <Borda@users.noreply.github.com>
Co-authored-by: Luis Capelo <luiscape@gmail.com>
Co-authored-by: Akshay Kulkarni <akshayk.vnit@gmail.com>
Co-authored-by: Ethan Harris <ewah1g13@soton.ac.uk>
Co-authored-by: Shikhar Chauhan <xssChauhan@users.noreply.github.com>
This commit is contained in:
William Falcon
2020-02-17 16:01:20 -05:00
committed by GitHub
co-authored by Luis Capelo Jirka Borovec Akshay Kulkarni Ethan Harris Shikhar Chauhan
parent e38b18e9eb
commit d4a31f02e0
14 changed files with 489 additions and 48 deletions
+24 -6
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@@ -1,13 +1,18 @@
16-bit training
=================
Lightning offers 16-bit training for CPUs, GPUs and TPUs.
GPU 16-bit
-----------
Lightning uses NVIDIA apex to handle 16-bit precision training.
To use 16-bit precision, do two things:
1. Install Apex
2. Set the amp trainer flag.
2. Set the "precision" trainer flag.
Install apex
----------------------------------------------
^^^^^^^^^^^^
.. code-block:: bash
$ git clone https://github.com/NVIDIA/apex
@@ -31,12 +36,25 @@ Install apex
Enable 16-bit
--------------
^^^^^^^^^^^^^
.. code-block:: python
# turn on 16-bit
trainer = Trainer(amp_level='O1', precision=16)
If you need to configure the apex init for your particular use case or want to use a different way of doing
16-bit training, override :meth:`pytorch_lightning.core.LightningModule.configure_apex`.
TPU 16-bit
----------
16-bit on TPus is much simpler. To use 16-bit with TPUs set precision to 16 when using the tpu flag
.. code-block:: python
# DEFAULT
trainer = Trainer(amp_level='O1', use_amp=False)
trainer = Trainer(num_tpu_cores=8, precision=32)
# turn on 16-bit
trainer = Trainer(num_tpu_cores=8, precision=16)
If you need to configure the apex init for your particular use case or want to use a different way of doing
16-bit training, override :meth:`pytorch_lightning.core.LightningModule.configure_apex`.
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single_gpu
sequences
training_tricks
tpu
test_set
optimizers
profiler
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@@ -60,7 +60,7 @@ Then you could do rapid research by switching between these two and using the sa
else:
model = CoolerNotBERT()
trainer = Trainer(gpus=4, use_amp=True)
trainer = Trainer(gpus=4, precision=16)
trainer.fit(model)
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TPU support
===========
Lightning supports running on TPUs. At this moment, TPUs are only available
on Google Cloud (GCP). For more information on TPUs
`watch this video <https://www.youtube.com/watch?v=kPMpmcl_Pyw>`_.
Live demo
----------
Check out this `Google Colab <https://colab.research.google.com/drive/1-_LKx4HwAxl5M6xPJmqAAu444LTDQoa3>`_ to see how to train MNIST on TPUs.
TPU Terminology
---------------
A TPU is a Tensor processing unit. Each TPU has 8 cores where each
core is optimized for 128x128 matrix multiplies. In general, a single
TPU is about as fast as 5 V100 GPUs!
A TPU pod hosts many TPUs on it. Currently, TPU pod v2 has 2048 cores!
You can request a full pod from Google cloud or a "slice" which gives you
some subset of those 2048 cores.
How to access TPUs
-------------------
To access TPUs there are two main ways.
1. Using google colab.
2. Using Google Cloud (GCP).
Colab TPUs
-----------
Colab is like a jupyter notebook with a free GPU or TPU
hosted on GCP.
To get a TPU on colab, follow these steps:
1. Go to https://colab.research.google.com/.
2. Click "new notebook" (bottom right of pop-up).
3. Click runtime > change runtime settings. Select Python 3,
and hardware accelerator "TPU". This will give you a TPU with 8 cores.
4. Next, insert this code into the first cell and execute. This
will install the xla library that interfaces between PyTorch and
the TPU.
.. code-block:: python
import collections
from datetime import datetime, timedelta
import os
import requests
import threading
_VersionConfig = collections.namedtuple('_VersionConfig', 'wheels,server')
VERSION = "xrt==1.15.0" #@param ["xrt==1.15.0", "torch_xla==nightly"]
CONFIG = {
'xrt==1.15.0': _VersionConfig('1.15', '1.15.0'),
'torch_xla==nightly': _VersionConfig('nightly', 'XRT-dev{}'.format(
(datetime.today() - timedelta(1)).strftime('%Y%m%d'))),
}[VERSION]
DIST_BUCKET = 'gs://tpu-pytorch/wheels'
TORCH_WHEEL = 'torch-{}-cp36-cp36m-linux_x86_64.whl'.format(CONFIG.wheels)
TORCH_XLA_WHEEL = 'torch_xla-{}-cp36-cp36m-linux_x86_64.whl'.format(CONFIG.wheels)
TORCHVISION_WHEEL = 'torchvision-{}-cp36-cp36m-linux_x86_64.whl'.format(CONFIG.wheels)
# Update TPU XRT version
def update_server_xrt():
print('Updating server-side XRT to {} ...'.format(CONFIG.server))
url = 'http://{TPU_ADDRESS}:8475/requestversion/{XRT_VERSION}'.format(
TPU_ADDRESS=os.environ['COLAB_TPU_ADDR'].split(':')[0],
XRT_VERSION=CONFIG.server,
)
print('Done updating server-side XRT: {}'.format(requests.post(url)))
update = threading.Thread(target=update_server_xrt)
update.start()
# Install Colab TPU compat PyTorch/TPU wheels and dependencies
!pip uninstall -y torch torchvision
!gsutil cp "$DIST_BUCKET/$TORCH_WHEEL" .
!gsutil cp "$DIST_BUCKET/$TORCH_XLA_WHEEL" .
!gsutil cp "$DIST_BUCKET/$TORCHVISION_WHEEL" .
!pip install "$TORCH_WHEEL"
!pip install "$TORCH_XLA_WHEEL"
!pip install "$TORCHVISION_WHEEL"
!sudo apt-get install libomp5
update.join()
5. Once the above is done, install PyTorch Lightning (v 0.6.1+).
.. code-block::
! pip install pytorch-lightning
6. Then set up your LightningModule as normal.
7. TPUs require a DistributedSampler. That means you should change your
train_dataloader (and val, train) code as follows.
.. code-block:: python
import torch_xla.core.xla_model as xm
@pl.data_loader
def train_dataloader(self):
dataset = MNIST(
os.getcwd(),
train=True,
download=True,
transform=transforms.ToTensor()
)
# required for TPU support
sampler = None
if use_tpu:
sampler = torch.utils.data.distributed.DistributedSampler(
dataset,
num_replicas=xm.xrt_world_size(),
rank=xm.get_ordinal(),
shuffle=True
)
loader = DataLoader(
dataset,
sampler=sampler,
batch_size=32
)
return loader
8. Configure the number of TPU cores in the trainer. You can only choose
1 or 8. To use a full TPU pod skip to the TPU pod section.
.. code-block:: python
import pytorch_lightning as pl
my_model = MyLightningModule()
trainer = pl.Trainer(num_tpu_cores=8)
trainer.fit(my_model)
That's it! Your model will train on all 8 TPU cores.
TPU Pod
--------
To train on more than 8 cores, your code actually doesn't change!
All you need to do is submit the following command:
.. code-block:: bash
$ python -m torch_xla.distributed.xla_dist
--tpu=$TPU_POD_NAME
--conda-env=torch-xla-nightly
-- python /usr/share/torch-xla-0.5/pytorch/xla/test/test_train_imagenet.py --fake_data
16 bit precision
-----------------
Lightning also supports training in 16-bit precision with TPUs.
By default, TPU training will use 32-bit precision. To enable 16-bit, also
set the 16-bit flag.
.. code-block:: python
import pytorch_lightning as pl
my_model = MyLightningModule()
trainer = pl.Trainer(num_tpu_cores=8, precision=16)
trainer.fit(my_model)
Under the hood the xla library will use the `bfloat16 type <https://en.wikipedia.org/wiki/Bfloat16_floating-point_format>`_.
About XLA
----------
XLA is the library that interfaces PyTorch with the TPUs.
For more information check out `XLA <https://github.com/pytorch/xla>`_.