Add grad checkpointing and PE in the transformer example (#387)

* Add grad checkpointing and PE in the transformer example

* Remove other frameworks from LM example

* Remove the other frameworks from MNIST example

* Improve the transformer LM example

* Fix black and change LR
This commit is contained in:
Angelos Katharopoulos
2024-02-01 13:04:03 -08:00
committed by GitHub
parent ec14583c2a
commit e9b32747b4
8 changed files with 36 additions and 946 deletions

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@@ -1,83 +0,0 @@
# Copyright © 2023 Apple Inc.
import functools
import time
import jax
import jax.numpy as jnp
import mnist
def init_model(key, num_layers, input_dim, hidden_dim, output_dim):
params = []
layer_sizes = [hidden_dim] * num_layers
for idim, odim in zip([input_dim] + layer_sizes, layer_sizes + [output_dim]):
key, wk = jax.random.split(key, 2)
W = 1e-2 * jax.random.normal(wk, (idim, odim))
b = jnp.zeros((odim,))
params.append((W, b))
return params
def feed_forward(params, X):
for W, b in params[:-1]:
X = jnp.maximum(X @ W + b, 0)
W, b = params[-1]
return X @ W + b
def loss_fn(params, X, y):
logits = feed_forward(params, X)
logits = jax.nn.log_softmax(logits, 1)
return -jnp.mean(logits[jnp.arange(y.size), y])
@jax.jit
def eval_fn(params, X, y):
logits = feed_forward(params, X)
return jnp.mean(jnp.argmax(logits, axis=1) == y)
def batch_iterate(key, batch_size, X, y):
perm = jax.random.permutation(key, y.size)
for s in range(0, y.size, batch_size):
ids = perm[s : s + batch_size]
yield X[ids], y[ids]
if __name__ == "__main__":
seed = 0
num_layers = 2
hidden_dim = 32
num_classes = 10
batch_size = 256
num_epochs = 10
learning_rate = 1e-1
dataset = "mnist"
# Load the data
train_images, train_labels, test_images, test_labels = getattr(mnist, dataset)()
# Load the model
key, subkey = jax.random.split(jax.random.PRNGKey(seed))
params = init_model(
subkey, num_layers, train_images.shape[-1], hidden_dim, num_classes
)
loss_and_grad_fn = jax.jit(jax.value_and_grad(loss_fn))
update_fn = jax.jit(
functools.partial(jax.tree_map, lambda p, g: p - learning_rate * g)
)
for e in range(num_epochs):
tic = time.perf_counter()
key, subkey = jax.random.split(key)
for X, y in batch_iterate(subkey, batch_size, train_images, train_labels):
loss, grads = loss_and_grad_fn(params, X, y)
params = update_fn(params, grads)
accuracy = eval_fn(params, test_images, test_labels)
toc = time.perf_counter()
print(
f"Epoch {e}: Test accuracy {accuracy.item():.3f},"
f" Time {toc - tic:.3f} (s)"
)

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# Copyright © 2023 Apple Inc.
import argparse
import time
import torch
import mnist
class MLP(torch.nn.Module):
def __init__(self, num_layers, input_dim, hidden_dim, output_dim):
super().__init__()
layer_sizes = [hidden_dim] * num_layers
self.layers = torch.nn.ModuleList(
[
torch.nn.Linear(idim, odim)
for idim, odim in zip(
[input_dim] + layer_sizes, layer_sizes + [output_dim]
)
]
)
def forward(self, x):
x = self.layers[0](x)
for l in self.layers[1:]:
x = l(x.relu())
return x
def loss_fn(model, X, y):
logits = model(X)
return torch.nn.functional.cross_entropy(logits, y)
@torch.no_grad()
def eval_fn(model, X, y):
logits = model(X)
return torch.mean((logits.argmax(-1) == y).float())
def batch_iterate(batch_size, X, y, device):
perm = torch.randperm(len(y), device=device)
for s in range(0, len(y), batch_size):
ids = perm[s : s + batch_size]
yield X[ids], y[ids]
if __name__ == "__main__":
parser = argparse.ArgumentParser("Train a simple MLP on MNIST with PyTorch.")
parser.add_argument("--gpu", action="store_true", help="Use the Metal back-end.")
parser.add_argument(
"--dataset",
type=str,
default="mnist",
choices=["mnist", "fashion_mnist"],
help="The dataset to use.",
)
args = parser.parse_args()
if not args.gpu:
torch.set_num_threads(1)
device = "cpu"
else:
device = "mps"
seed = 0
num_layers = 2
hidden_dim = 32
num_classes = 10
batch_size = 256
num_epochs = 10
learning_rate = 1e-1
# Load the data
def to_tensor(x):
if x.dtype != "uint32":
return torch.from_numpy(x).to(device)
else:
return torch.from_numpy(x.astype(int)).to(device)
train_images, train_labels, test_images, test_labels = map(
to_tensor, getattr(mnist, args.dataset)()
)
# Load the model
model = MLP(num_layers, train_images.shape[-1], hidden_dim, num_classes).to(device)
opt = torch.optim.SGD(model.parameters(), lr=learning_rate, momentum=0.0)
for e in range(num_epochs):
tic = time.perf_counter()
for X, y in batch_iterate(batch_size, train_images, train_labels, device):
opt.zero_grad()
loss_fn(model, X, y).backward()
opt.step()
accuracy = eval_fn(model, test_images, test_labels)
toc = time.perf_counter()
print(
f"Epoch {e}: Test accuracy {accuracy.item():.3f},"
f" Time {toc - tic:.3f} (s)"
)