Files
StarPilot/tinygrad_repo/examples/gradaccum_mnist.py
T
firestar5683 22a8575199 Vendor dependencies and resources for standalone builds
Keep official openpilot ancestry and dependency licenses. Store resources directly in Git, remove LFS setup requirements, and leave the downloadable big model outside the source tree.
2026-10-03 21:01:18 +00:00

108 lines
3.9 KiB
Python

import itertools
from typing import Callable
from tinygrad import nn, Tensor, dtypes, Device, TinyJit, Context
from tinygrad.helpers import getenv, trange, partition
class Model:
def __init__(self):
self.layers: list[Callable[[Tensor], Tensor]] = [
nn.Conv2d(1, 32, 5), Tensor.relu,
nn.Conv2d(32, 32, 5), Tensor.relu,
nn.BatchNorm(32), Tensor.max_pool2d,
nn.Conv2d(32, 64, 3), Tensor.relu,
nn.Conv2d(64, 64, 3), Tensor.relu,
nn.BatchNorm(64), Tensor.max_pool2d,
lambda x: x.flatten(1), nn.Linear(576, 10)]
def __call__(self, x:Tensor) -> Tensor: return x.sequential(self.layers)
# TODO: refactor this into optim/onnx
def functional_adam(g:Tensor, m:Tensor, v:Tensor, b1_t:Tensor, b2_t:Tensor, lr=0.001, b1=0.9, b2=0.999, eps=1e-6) -> Tensor:
b1_t *= b1
b2_t *= b2
m.assign(b1 * m + (1.0 - b1) * g)
v.assign(b2 * v + (1.0 - b2) * (g * g))
m_hat = m / (1.0 - b1_t)
v_hat = v / (1.0 - b2_t)
return lr * (m_hat / (v_hat.sqrt() + eps))
if __name__ == "__main__":
BS = getenv("BS", 512)
ACC_STEPS = getenv("ACC_STEPS", 8)
X_train, Y_train, X_test, Y_test = nn.datasets.mnist()
model = Model()
params = nn.state.get_parameters(model)
# init params
for x in params:
x.replace(x.contiguous())
Tensor.realize(*params)
# split params (with grads) and buffers (without)
params, buffers = partition(params, lambda x: x.is_param)
print(f"params: {len(params)} buffers: {len(buffers)}")
# optim params
pos_params = list(itertools.accumulate(params, lambda x,y: x+y.numel(), initial=0))
adam_m = Tensor.zeros(pos_params[-1], device="CPU").contiguous()
adam_v = Tensor.zeros(pos_params[-1], device="CPU").contiguous()
adam_b1_t = Tensor.ones((1,), dtype=dtypes.float32, device="CPU").contiguous()
adam_b2_t = Tensor.ones((1,), dtype=dtypes.float32, device="CPU").contiguous()
adam_params = [adam_m, adam_v, adam_b1_t, adam_b2_t]
# create loss and grads. init all state so the JIT works on microbatch
for x in params: x.assign(x.detach())
loss = Tensor.zeros(tuple()).contiguous()
grads = Tensor.zeros(pos_params[-1]).contiguous()
Tensor.realize(*params, *buffers, *adam_params, loss, grads)
@TinyJit
@Context(TRAINING=1)
def microbatch():
samples = Tensor.randint(BS // ACC_STEPS, high=X_train.shape[0])
for t in params: t.grad = None
# divide by ACC_STEPS at the loss
uloss = (model(X_train[samples]).sparse_categorical_crossentropy(Y_train[samples]) / ACC_STEPS).backward()
ugrads = Tensor.cat(*[t.grad.contiguous().flatten() for t in params], dim=0)
for t in params: t.grad = None
# concat the grads and assign them
loss.assign(loss + uloss)
grads.assign(grads + ugrads)
Tensor.realize(*params, *buffers, loss, grads)
@TinyJit
def optimizer():
# run optimizer (on CPU, where adam params live)
delta = functional_adam(grads.to("CPU"), adam_m, adam_v, adam_b1_t, adam_b2_t)
# update the params, copying back the delta one at a time to avoid OOM
# NOTE: the scheduler is ordering things poorly, all the copies are happening before the adds
for j,tt in enumerate(params):
tt.assign(tt.detach() - delta[pos_params[j]:pos_params[j+1]].reshape(tt.shape).to(Device.DEFAULT))
# realize everything, zero out loss and grads
loss.assign(Tensor.zeros_like(loss))
grads.assign(Tensor.zeros_like(grads))
Tensor.realize(*params, *adam_params, loss, grads)
@TinyJit
def get_test_acc() -> Tensor: return (model(X_test).argmax(axis=1) == Y_test).mean()*100
test_acc = float('nan')
for i in (t:=trange(getenv("STEPS", 70))):
# microbatch sets the gradients
for _ in range(ACC_STEPS): microbatch()
# get the loss before the optimizer clears it
# this is already realized so this isn't a schedule
loss_item = loss.item()
# run the optimizer
optimizer()
# eval
if i%10 == 9: test_acc = get_test_acc().item()
t.set_description(f"loss: {loss_item:6.2f} test_accuracy: {test_acc:5.2f}%")