Forked from mattjj/spmd_pipeline_example.py
Last active
November 25, 2021 22:26
This file contains hidden or bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
import itertools as it | |
import jax | |
import jax.numpy as jnp | |
jax.config.update('jax_enable_x64', True) | |
jax.config.update('jax_platform_name', 'cpu') | |
L = num_stages = 5 | |
N = batch_size = 6 | |
M = num_microbatches = 2 | |
B = microbatch_size = 3 | |
assert N == M * B | |
F = num_feat = 3 | |
params = jax.random.normal(jax.random.PRNGKey(0), (L, F, F)) | |
inputs = jnp.arange(N * F).reshape(N, F) | |
def fn(params, inputs): | |
assert params.ndim == 2 and inputs.ndim == 1 | |
return jnp.tanh(jnp.dot(params, inputs)) | |
state = inputs | |
for i in range(L): | |
state = jax.vmap(fn, (None, 0))(params[i], state) | |
outputs = state | |
print(outputs) | |
def spmd_pipeline(fn, params, inputs): | |
inputs = jnp.pad(inputs, [[0, L-1], [0, 0], [0, 0]]) | |
outputs = jnp.zeros((M+L-1, B, F)) | |
state = jnp.zeros([L, B, F]) | |
for i in range(M + L - 1): | |
state = shift_and_insert(state, inputs[i]) | |
state = jax.vmap(jax.vmap(fn, (None, 0)))(params, state) | |
outputs = outputs.at[i].set(state[-1]) # last layer output | |
return outputs[L-1:] | |
def shift_and_insert(arr, x): | |
padding = [[1, 0]] + [[0, 0]] * (arr.ndim - 1) | |
arr = jnp.pad(arr, padding)[:-1] | |
iota = jax.lax.broadcasted_iota('int32', arr.shape, 0) | |
return jnp.where(iota == 0, x, arr) | |
outputs2 = spmd_pipeline(fn, params, inputs.reshape(M, B, F)).reshape(N, F) | |
print(outputs2) |
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment