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hao-ai-lab-FastVideo/fastvideo-kernel/tests/test_correctness.py
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2025-12-26 01:50:24 -06:00

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Python

import torch
import sys
import os
from tqdm import tqdm
# Local support import
from .support_flex_sta import get_sliding_tile_attention_mask
# USE OUR NEW PACKAGE!
from fastvideo_kernel import sliding_tile_attention
from torch.nn.attention.flex_attention import flex_attention
flex_attention = torch.compile(flex_attention, dynamic=False)
def flex_test(Q, K, V, kernel_size):
mask = get_sliding_tile_attention_mask(kernel_size, (6, 8, 8), (18, 48, 80), 0, 'cuda', 0)
output = flex_attention(Q, K, V, block_mask=mask)
return output
def h100_fwd_kernel_test(Q, K, V, kernel_size):
# Using the same parameters as the original test
o = sliding_tile_attention(Q, K, V, [kernel_size] * 24, 0, False, '18x48x80')
return o
def generate_tensor(shape, mean, std, dtype, device):
tensor = torch.randn(shape, dtype=dtype, device=device)
magnitude = torch.norm(tensor, dim=-1, keepdim=True)
scaled_tensor = tensor * (torch.randn(magnitude.shape, dtype=dtype, device=device) * std + mean) / magnitude
return scaled_tensor.contiguous()
def check_correctness(b, h, n, d, causal, mean, std, num_iterations=2):
print(f"Running correctness check: batch={b}, heads={h}, seq_len={n}, dim={d}")
kernel_size_ls = [(3, 3, 5), (3, 1, 10)]
for kernel_size in kernel_size_ls:
print(f"Testing kernel_size: {kernel_size}")
for xi in tqdm(range(num_iterations)):
torch.manual_seed(xi)
Q = generate_tensor((b, h, n, d), mean, std, torch.bfloat16, 'cuda')
K = generate_tensor((b, h, n, d), mean, std, torch.bfloat16, 'cuda')
V = generate_tensor((b, h, n, d), mean, std, torch.bfloat16, 'cuda')
tk_o = h100_fwd_kernel_test(Q, K, V, kernel_size)
pt_o = flex_test(Q, K, V, kernel_size)
diff = pt_o - tk_o
abs_diff = torch.abs(diff)
max_d = torch.max(abs_diff).item()
avg_d = torch.sum(abs_diff).item() / (b * h * n * d)
if max_d > 0.1:
print(f"Warning: Large diff detected! max={max_d}, avg={avg_d}")
print("\n✅ TEST COMPLETE: New package matches FlexAttention behavior.")
if __name__ == "__main__":
b, h, d = 2, 24, 128
n = 69120
causal = False
mean = 1e-1
std = 10
check_correctness(b, h, n, d, causal, mean, std, num_iterations=2)