vllm/tests/kernels/test_layernorm.py
2023-09-05 16:57:38 -07:00

59 lines
1.7 KiB
Python

import pytest
import torch
import torch.nn as nn
from vllm import layernorm_ops
DTYPES = [torch.half, torch.bfloat16, torch.float]
HIDDEN_SIZES = [67, 768, 2048, 5120, 8192] # Arbitrary values for testing
NUM_TOKENS = [7, 83, 4096] # Arbitrary values for testing
SEEDS = [0]
class RefRMSNorm(nn.Module):
def __init__(self, hidden_size, eps=1e-6):
super().__init__()
weight = torch.empty(hidden_size)
weight.normal_(mean=1.0, std=0.1)
self.weight = nn.Parameter(weight)
self.variance_epsilon = eps
def forward(self, hidden_states):
input_dtype = hidden_states.dtype
hidden_states = hidden_states.to(torch.float32)
variance = hidden_states.pow(2).mean(-1, keepdim=True)
hidden_states = hidden_states * torch.rsqrt(variance +
self.variance_epsilon)
return self.weight * hidden_states.to(input_dtype)
@pytest.mark.parametrize("num_tokens", NUM_TOKENS)
@pytest.mark.parametrize("hidden_size", HIDDEN_SIZES)
@pytest.mark.parametrize("dtype", DTYPES)
@pytest.mark.parametrize("seed", SEEDS)
@torch.inference_mode()
def test_rms_norm(
num_tokens: int,
hidden_size: int,
dtype: torch.dtype,
seed: int,
) -> None:
torch.random.manual_seed(seed)
torch.cuda.manual_seed(seed)
scale = float(hidden_size**-0.5)
x = torch.empty(num_tokens, hidden_size, dtype=dtype, device="cuda")
x.uniform_(-scale, scale)
ref = RefRMSNorm(hidden_size).to(dtype).cuda()
out = torch.empty_like(x)
layernorm_ops.rms_norm(
out,
x,
ref.weight.data,
ref.variance_epsilon,
)
ref_out = ref(x)
assert torch.allclose(out, ref_out, atol=1e-2, rtol=1e-5)