[Feat] Support VSA with any resolution. (#650)

This commit is contained in:
Zhang Peiyuan
2025-07-28 20:14:40 -07:00
committed by GitHub
parent 2fa8d4ae6d
commit cbc3a6bb9d
25 changed files with 972 additions and 1954 deletions
+1 -1
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@@ -326,7 +326,7 @@ jobs:
volume_size: 100
disk_size: 100
image: "ghcr.io/${{ github.repository }}/fastvideo-dev:py3.12-latest"
test_command: "uv pip install -e .[test] && python csrc/attn/tests/test_block_sparse.py"
test_command: "uv pip install -e .[test] && python csrc/attn/tests/test_vsa.py"
timeout_minutes: 30
secrets:
RUNPOD_API_KEY: ${{ secrets.RUNPOD_API_KEY }}
+15 -14
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@@ -2,12 +2,7 @@
# Attention Kernel Used in FastVideo
## Sliding Tile Attention (STA)
We only support H100 for STA.
```bash
git submodule update --init --recursive
python setup_sta.py install
```
## Video Sparse Attention (VSA)
We support H100 (via TK) and RTX 4090 (via triton) for VSA.
@@ -16,6 +11,7 @@ git submodule update --init --recursive
python setup_vsa.py install
```
If you encounter error during installation, try below:
Install C++20 for ThunderKittens:
```bash
@@ -35,9 +31,17 @@ export LD_LIBRARY_PATH=${CUDA_HOME}/lib64:$LD_LIBRARY_PATH
```
## Sliding Tile Attention (STA)
We only support H100 for STA.
```bash
git submodule update --init --recursive
python setup_sta.py install
```
## Usage
### STA
### Usage
End-2-end inference with FastVideo:
```bash
bash scripts/inference/v1_inference_wan_STA.sh
@@ -57,22 +61,19 @@ out = sliding_tile_attention(q, k, v, window_size, text_length)
out = sliding_tile_attention(q, k, v, window_size, 0, False)
```
### VSA
We do not officially supoort end-2-end inference with VSA in FastVideo yet. Stay tuned.
## Test
### Test
```bash
python tests/test_sta.py # test STA
python tests/test_block_sparse.py # test VSA
```
## Benchmark
### Benchmark
```bash
python benchmarks/bench_sta.py
```
## How Does STA Work?
### How Does STA Work?
We give a demo for 2D STA with window size (6,6) operating on a (10, 10) image.
+15 -17
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@@ -1,9 +1,9 @@
import torch
import argparse
from flash_attn.utils.benchmark import benchmark_forward
from triton.testing import do_bench
from vsa import block_sparse_fwd, block_sparse_bwd
from vsa import BLOCK_M, BLOCK_N
import triton
import numpy as np
import random
@@ -23,7 +23,7 @@ def parse_arguments():
parser = argparse.ArgumentParser(description='Benchmark Block Sparse Attention')
parser.add_argument('--batch_size', type=int, default=1, help='Batch size')
parser.add_argument('--num_heads', type=int, default=12, help='Number of heads')
parser.add_argument('--head_dim', type=int, default=64, help='Head dimension')
parser.add_argument('--head_dim', type=int, default=128, help='Head dimension')
parser.add_argument('--topk', type=int, default=None, help='Number of kv blocks each q block attends to')
parser.add_argument('--seq_lengths', type=int, nargs='+', default=[49152], help='Sequence lengths to benchmark')
return parser.parse_args()
@@ -134,15 +134,14 @@ def benchmark_block_sparse_attention(q, k, v, q2k_block_sparse_index, q2k_block_
torch.cuda.synchronize()
# Benchmark forward
_, fwd_time = benchmark_forward(
block_sparse_fwd,
q, k, v, q2k_block_sparse_index, q2k_block_sparse_num,
repeats=20,
verbose=False,
desc='Block Sparse Forward'
fwd_time = do_bench(
lambda: block_sparse_fwd(q, k, v, q2k_block_sparse_index, q2k_block_sparse_num),
warmup=5,
rep=20,
quantiles=None
)
sparse_tflops = flops / fwd_time.mean * 1e-12
sparse_tflops = flops / fwd_time * 1e-12 * 1e3
print(f"Block Sparse Forward - TFLOPS: {sparse_tflops:.2f}")
# Backward pass
@@ -154,16 +153,15 @@ def benchmark_block_sparse_attention(q, k, v, q2k_block_sparse_index, q2k_block_
torch.cuda.synchronize()
# Benchmark backward
_, bwd_time = benchmark_forward(
block_sparse_bwd,
q, k, v, o, l_vec, grad_output, k2q_block_sparse_index, k2q_block_sparse_num,
repeats=20,
verbose=False,
desc='Block Sparse Backward'
bwd_time = do_bench(
lambda: block_sparse_bwd(q, k, v, o, l_vec, grad_output, k2q_block_sparse_index, k2q_block_sparse_num),
warmup=5,
rep=20,
quantiles=None
)
bwd_flops = 2.5 * flops # Approximation
sparse_bwd_tflops = bwd_flops / bwd_time.mean * 1e-12
sparse_bwd_tflops = bwd_flops / bwd_time * 1e-12 * 1e3
print(f"Block Sparse Backward - TFLOPS: {sparse_bwd_tflops:.2f}")
return sparse_tflops, sparse_bwd_tflops
-289
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@@ -1,289 +0,0 @@
import torch
import argparse
from flash_attn.utils.benchmark import benchmark_forward
from flash_attn import flash_attn_func
from vsa import block_sparse_attn
from vsa import BLOCK_M, BLOCK_N
import numpy as np
import random
import gc
def set_seed(seed: int = 42):
# Python random module
random.seed(seed)
# NumPy
np.random.seed(seed)
# PyTorch
torch.manual_seed(seed)
torch.cuda.manual_seed(seed)
torch.cuda.manual_seed_all(seed) # if using multi-GPU
@torch.no_grad
def precision_metric(quant_o, fa2_o):
x, xx = quant_o.float(), fa2_o.float()
sim = torch.nn.functional.cosine_similarity(x.reshape(1, -1), xx.reshape(1, -1)).item()
l1 = ((x - xx).abs().sum() / xx.abs().sum() ).item()
rmse = torch.sqrt(torch.mean((x -xx) ** 2)).item()
return sim, l1, rmse
def create_input_tensors(batch, head, seq_len, headdim):
"""Create random input tensors for attention."""
q = torch.randn(batch, head, seq_len, headdim, dtype=torch.bfloat16, device="cuda")
k = torch.randn(batch, head, seq_len, headdim, dtype=torch.bfloat16, device="cuda")
v = torch.randn(batch, head, seq_len, headdim, dtype=torch.bfloat16, device="cuda")
return q, k, v
def generate_block_sparse_pattern(bs, h, num_q_blocks, num_kv_blocks, k, device="cuda"):
"""
Generate a block sparse pattern where each q block attends to exactly k kv blocks.
Args:
bs: batch size
h: number of heads
num_q_blocks: number of query blocks
num_kv_blocks: number of key-value blocks
k: number of kv blocks each q block attends to
device: device to create tensors on
Returns:
q2k_block_sparse_index: [bs, h, num_q_blocks, k]
Contains the indices of kv blocks that each q block attends to.
q2k_block_sparse_num: [bs, h, num_q_blocks]
Contains the number of kv blocks that each q block attends to (all equal to k).
k2q_block_sparse_index: [bs, h, num_kv_blocks, num_q_blocks]
Contains the indices of q blocks that attend to each kv block.
k2q_block_sparse_num: [bs, h, num_kv_blocks]
Contains the number of q blocks that attend to each kv block.
block_sparse_mask: [bs, h, num_q_blocks, num_kv_blocks]
Binary mask where 1 indicates attention connection.
"""
# Ensure k is not larger than num_kv_blocks
k = min(k, num_kv_blocks)
# Create random scores for sampling
scores = torch.rand(bs, h, num_q_blocks, num_kv_blocks, device=device)
# Get top-k indices for each q block
_, q2k_block_sparse_index = torch.topk(scores, k, dim=-1)
q2k_block_sparse_index = q2k_block_sparse_index.to(torch.int32)
# sort q2k_block_sparse_index
q2k_block_sparse_index, _ = torch.sort(q2k_block_sparse_index, dim=-1)
# All q blocks attend to exactly k kv blocks
q2k_block_sparse_num = torch.full((bs, h, num_q_blocks), k, dtype=torch.int32, device=device)
# Create the corresponding mask
block_sparse_mask = torch.zeros(bs, h, num_q_blocks, num_kv_blocks, dtype=torch.bool, device=device)
# Fill in the mask based on the indices
for b in range(bs):
for head in range(h):
for q_idx in range(num_q_blocks):
kv_indices = q2k_block_sparse_index[b, head, q_idx]
block_sparse_mask[b, head, q_idx, kv_indices] = True
# Create the reverse mapping (k2q)
# First, initialize lists to collect q indices for each kv block
k2q_indices_list = [[[] for _ in range(num_kv_blocks)] for _ in range(bs * h)]
# Populate the lists based on q2k mapping
for b in range(bs):
for head in range(h):
flat_idx = b * h + head
for q_idx in range(num_q_blocks):
kv_indices = q2k_block_sparse_index[b, head, q_idx].tolist()
for kv_idx in kv_indices:
k2q_indices_list[flat_idx][kv_idx].append(q_idx)
# Find the maximum number of q blocks that attend to any kv block
max_q_per_kv = 0
for flat_idx in range(bs * h):
for kv_idx in range(num_kv_blocks):
max_q_per_kv = max(max_q_per_kv, len(k2q_indices_list[flat_idx][kv_idx]))
# Create tensors for k2q mapping
k2q_block_sparse_index = torch.full((bs, h, num_kv_blocks, max_q_per_kv), -1,
dtype=torch.int32, device=device)
k2q_block_sparse_num = torch.zeros((bs, h, num_kv_blocks),
dtype=torch.int32, device=device)
# Fill the tensors
for b in range(bs):
for head in range(h):
flat_idx = b * h + head
for kv_idx in range(num_kv_blocks):
q_indices = k2q_indices_list[flat_idx][kv_idx]
num_q = len(q_indices)
k2q_block_sparse_num[b, head, kv_idx] = num_q
if num_q > 0:
k2q_block_sparse_index[b, head, kv_idx, :num_q] = torch.tensor(
q_indices, dtype=torch.int32, device=device)
return q2k_block_sparse_index, q2k_block_sparse_num, k2q_block_sparse_index, k2q_block_sparse_num, block_sparse_mask
def main(args):
set_seed(42)
# Extract parameters
batch = args.batch_size
head = args.num_heads
headdim = args.head_dim
num_iterations = args.num_iterations
print(f"Block Sparse Attention Benchmark")
print(f"batch: {batch}, head: {head}, headdim: {headdim}, iterations: {num_iterations}")
# Test with different sequence lengths
for seq_len in args.seq_lengths:
# Skip very long sequences if they might cause OOM
# if seq_len > 16384 and batch > 1:
# continue
print("="*100)
print(f"\nSequence length: {seq_len}")
# Collect metrics across iterations
forward_metrics = {'sim': [], 'l1': [], 'rmse': []}
grad_q_metrics = {'sim': [], 'l1': [], 'rmse': []}
grad_k_metrics = {'sim': [], 'l1': [], 'rmse': []}
grad_v_metrics = {'sim': [], 'l1': [], 'rmse': []}
for iter_idx in range(num_iterations):
if num_iterations > 1:
print(f"\nIteration {iter_idx+1}/{num_iterations}")
# Create input tensors
q, k, v = create_input_tensors(batch, head, seq_len, headdim)
# Setup block sparse parameters
num_q_blocks = seq_len // BLOCK_M
num_kv_blocks = seq_len // BLOCK_N
# Determine k value (number of kv blocks per q block)
topk = args.topk
if topk is None:
topk = num_kv_blocks // 10 # Default to ~90% sparsity if k is not specified
topk = max(1, topk)
if iter_idx == 0: # Only print this once
print(f"Using topk={topk} kv blocks per q block (out of {num_kv_blocks} total kv blocks)")
# Generate block sparse pattern
q2k_block_sparse_index, q2k_block_sparse_num, k2q_block_sparse_index, k2q_block_sparse_num, block_sparse_mask = generate_block_sparse_pattern(
batch, head, num_q_blocks, num_kv_blocks, topk, device="cuda")
# expand block_sparse_mask to full mask
block_mask_expanded = block_sparse_mask.unsqueeze(-1).unsqueeze(-2) # [b, h, num_q_blocks, num_kv_blocks, 1, 1]
block_mask_expanded = block_mask_expanded.expand(-1, -1, -1, -1, BLOCK_M, BLOCK_N) # [b, h, num_q_blocks, num_kv_blocks, BLOCK_M, BLOCK_N]
full_mask = block_mask_expanded.permute(0, 1, 2, 4, 3, 5).reshape(batch, head, seq_len, seq_len)
q.requires_grad = True
k.requires_grad = True
v.requires_grad = True
# testing forward
o = block_sparse_attn(q, k, v, q2k_block_sparse_index, q2k_block_sparse_num, k2q_block_sparse_index, k2q_block_sparse_num)
del q2k_block_sparse_index, q2k_block_sparse_num, k2q_block_sparse_index, k2q_block_sparse_num, block_sparse_mask, block_mask_expanded
grad_o = torch.randn_like(o)
o.backward(grad_o)
# clear memory
q_sdpa = q.detach().clone()
k_sdpa = k.detach().clone()
v_sdpa = v.detach().clone()
q_sdpa.requires_grad = True
k_sdpa.requires_grad = True
v_sdpa.requires_grad = True
q.data = torch.empty(0, device=q.device)
k.data = torch.empty(0, device=k.device)
v.data = torch.empty(0, device=v.device)
torch.cuda.empty_cache()
o_sdpa = torch.nn.functional.scaled_dot_product_attention(q_sdpa, k_sdpa, v_sdpa, attn_mask=full_mask)
sim, l1, rmse = precision_metric(o, o_sdpa)
assert sim > 0.9999, f"SSIM too low: {sim}"
assert l1 < 8e-5, f"l1 too large: {l1}"
assert rmse < 2e-5, f"RMSE too large: {rmse}"
forward_metrics['sim'].append(sim)
forward_metrics['l1'].append(l1)
forward_metrics['rmse'].append(rmse)
print(f"block_sparse_fwd vs torch.nn.functional.scaled_dot_product_attention:\nsim: {sim}, l1: {l1}, rmse: {rmse}")
# test backward
o_sdpa.backward(grad_o)
sim, l1, rmse = precision_metric(q.grad, q_sdpa.grad)
# Error bounds collected on H100
assert sim > 0.9999, f"SSIM too low: {sim}"
assert l1 < 4e-3, f"l1 too large: {l1}"
assert rmse < 3e-4, f"RMSE too large: {rmse}"
grad_q_metrics['sim'].append(sim)
grad_q_metrics['l1'].append(l1)
grad_q_metrics['rmse'].append(rmse)
print(f"block_sparse_bwd vs torch.nn.functional.scaled_dot_product_attention grad_q:\nsim: {sim}, l1: {l1}, rmse: {rmse}")
sim, l1, rmse = precision_metric(k.grad, k_sdpa.grad)
assert sim > 0.9999, f"SSIM too low: {sim}"
assert l1 < 4e-3, f"l1 too large: {l1}"
assert rmse < 2e-4, f"RMSE too large: {rmse}"
grad_k_metrics['sim'].append(sim)
grad_k_metrics['l1'].append(l1)
grad_k_metrics['rmse'].append(rmse)
print(f"block_sparse_bwd vs torch.nn.functional.scaled_dot_product_attention grad_k:\nsim: {sim}, l1: {l1}, rmse: {rmse}")
sim, l1, rmse = precision_metric(v.grad, v_sdpa.grad)
assert sim > 0.9999, f"SSIM too low: {sim}"
assert l1 < 1e-4, f"l1 too large: {l1}"
assert rmse < 2e-5, f"RMSE too large: {rmse}"
grad_v_metrics['sim'].append(sim)
grad_v_metrics['l1'].append(l1)
grad_v_metrics['rmse'].append(rmse)
print(f"block_sparse_bwd vs torch.nn.functional.scaled_dot_product_attention grad_v:\nsim: {sim}, l1: {l1}, rmse: {rmse}")
del o, o_sdpa, grad_o, q_sdpa, k_sdpa, v_sdpa
gc.collect()
torch.cuda.empty_cache()
# Print summary statistics if multiple iterations were run
if num_iterations > 1:
print("\n" + "="*50)
print(f"Summary Statistics (over {num_iterations} iterations):")
print("\nForward metrics:")
print(f"Similarity: mean={np.mean(forward_metrics['sim']):.6f}, std={np.std(forward_metrics['sim']):.6f}, min={np.min(forward_metrics['sim']):.6f}")
print(f"L1 error: mean={np.mean(forward_metrics['l1']):.6f}, std={np.std(forward_metrics['l1']):.6f}, max={np.max(forward_metrics['l1']):.6f}")
print(f"RMSE: mean={np.mean(forward_metrics['rmse']):.6f}, std={np.std(forward_metrics['rmse']):.6f}, max={np.max(forward_metrics['rmse']):.6f}")
print("\nGradient Q metrics:")
print(f"Similarity: mean={np.mean(grad_q_metrics['sim']):.6f}, std={np.std(grad_q_metrics['sim']):.6f}, min={np.min(grad_q_metrics['sim']):.6f}")
print(f"L1 error: mean={np.mean(grad_q_metrics['l1']):.6f}, std={np.std(grad_q_metrics['l1']):.6f}, max={np.max(grad_q_metrics['l1']):.6f}")
print(f"RMSE: mean={np.mean(grad_q_metrics['rmse']):.6f}, std={np.std(grad_q_metrics['rmse']):.6f}, max={np.max(grad_q_metrics['rmse']):.6f}")
print("\nGradient K metrics:")
print(f"Similarity: mean={np.mean(grad_k_metrics['sim']):.6f}, std={np.std(grad_k_metrics['sim']):.6f}, min={np.min(grad_k_metrics['sim']):.6f}")
print(f"L1 error: mean={np.mean(grad_k_metrics['l1']):.6f}, std={np.std(grad_k_metrics['l1']):.6f}, max={np.max(grad_k_metrics['l1']):.6f}")
print(f"RMSE: mean={np.mean(grad_k_metrics['rmse']):.6f}, std={np.std(grad_k_metrics['rmse']):.6f}, max={np.max(grad_k_metrics['rmse']):.6f}")
print("\nGradient V metrics:")
print(f"Similarity: mean={np.mean(grad_v_metrics['sim']):.6f}, std={np.std(grad_v_metrics['sim']):.6f}, min={np.min(grad_v_metrics['sim']):.6f}")
print(f"L1 error: mean={np.mean(grad_v_metrics['l1']):.6f}, std={np.std(grad_v_metrics['l1']):.6f}, max={np.max(grad_v_metrics['l1']):.6f}")
print(f"RMSE: mean={np.mean(grad_v_metrics['rmse']):.6f}, std={np.std(grad_v_metrics['rmse']):.6f}, max={np.max(grad_v_metrics['rmse']):.6f}")
if __name__ == "__main__":
parser = argparse.ArgumentParser(description='Benchmark Block Sparse Attention')
parser.add_argument('--batch_size', type=int, default=4, help='Batch size')
parser.add_argument('--num_heads', type=int, default=6, help='Number of heads')
parser.add_argument('--head_dim', type=int, default=128, help='Head dimension')
parser.add_argument('--topk', type=int, default=64, help='Number of kv blocks each q block attends to')
parser.add_argument('--seq_lengths', type=int, nargs='+', default=[29120], help='Sequence lengths to benchmark')
parser.add_argument('--num_iterations', type=int, default=50, help='Number of test iterations to run')
args = parser.parse_args()
main(args)
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@@ -1,289 +0,0 @@
import torch
import argparse
from flash_attn.utils.benchmark import benchmark_forward
from flash_attn import flash_attn_func
from vsa import triton_attention_sparse
from vsa import BLOCK_M, BLOCK_N
import numpy as np
import random
import gc
def set_seed(seed: int = 42):
# Python random module
random.seed(seed)
# NumPy
np.random.seed(seed)
# PyTorch
torch.manual_seed(seed)
torch.cuda.manual_seed(seed)
torch.cuda.manual_seed_all(seed) # if using multi-GPU
@torch.no_grad
def precision_metric(quant_o, fa2_o):
x, xx = quant_o.float(), fa2_o.float()
sim = torch.nn.functional.cosine_similarity(x.reshape(1, -1), xx.reshape(1, -1)).item()
l1 = ((x - xx).abs().sum() / xx.abs().sum() ).item()
rmse = torch.sqrt(torch.mean((x -xx) ** 2)).item()
return sim, l1, rmse
def create_input_tensors(batch, head, seq_len, headdim):
"""Create random input tensors for attention."""
q = torch.randn(batch, head, seq_len, headdim, dtype=torch.bfloat16, device="cuda")
k = torch.randn(batch, head, seq_len, headdim, dtype=torch.bfloat16, device="cuda")
v = torch.randn(batch, head, seq_len, headdim, dtype=torch.bfloat16, device="cuda")
return q, k, v
def generate_block_sparse_pattern(bs, h, num_q_blocks, num_kv_blocks, k, device="cuda"):
"""
Generate a block sparse pattern where each q block attends to exactly k kv blocks.
Args:
bs: batch size
h: number of heads
num_q_blocks: number of query blocks
num_kv_blocks: number of key-value blocks
k: number of kv blocks each q block attends to
device: device to create tensors on
Returns:
q2k_block_sparse_index: [bs, h, num_q_blocks, k]
Contains the indices of kv blocks that each q block attends to.
q2k_block_sparse_num: [bs, h, num_q_blocks]
Contains the number of kv blocks that each q block attends to (all equal to k).
k2q_block_sparse_index: [bs, h, num_kv_blocks, num_q_blocks]
Contains the indices of q blocks that attend to each kv block.
k2q_block_sparse_num: [bs, h, num_kv_blocks]
Contains the number of q blocks that attend to each kv block.
block_sparse_mask: [bs, h, num_q_blocks, num_kv_blocks]
Binary mask where 1 indicates attention connection.
"""
# Ensure k is not larger than num_kv_blocks
k = min(k, num_kv_blocks)
# Create random scores for sampling
scores = torch.rand(bs, h, num_q_blocks, num_kv_blocks, device=device)
# Get top-k indices for each q block
_, q2k_block_sparse_index = torch.topk(scores, k, dim=-1)
q2k_block_sparse_index = q2k_block_sparse_index.to(torch.int32)
# sort q2k_block_sparse_index
q2k_block_sparse_index, _ = torch.sort(q2k_block_sparse_index, dim=-1)
# All q blocks attend to exactly k kv blocks
q2k_block_sparse_num = torch.full((bs, h, num_q_blocks), k, dtype=torch.int32, device=device)
# Create the corresponding mask
block_sparse_mask = torch.zeros(bs, h, num_q_blocks, num_kv_blocks, dtype=torch.bool, device=device)
# Fill in the mask based on the indices
for b in range(bs):
for head in range(h):
for q_idx in range(num_q_blocks):
kv_indices = q2k_block_sparse_index[b, head, q_idx]
block_sparse_mask[b, head, q_idx, kv_indices] = True
# Create the reverse mapping (k2q)
# First, initialize lists to collect q indices for each kv block
k2q_indices_list = [[[] for _ in range(num_kv_blocks)] for _ in range(bs * h)]
# Populate the lists based on q2k mapping
for b in range(bs):
for head in range(h):
flat_idx = b * h + head
for q_idx in range(num_q_blocks):
kv_indices = q2k_block_sparse_index[b, head, q_idx].tolist()
for kv_idx in kv_indices:
k2q_indices_list[flat_idx][kv_idx].append(q_idx)
# Find the maximum number of q blocks that attend to any kv block
max_q_per_kv = 0
for flat_idx in range(bs * h):
for kv_idx in range(num_kv_blocks):
max_q_per_kv = max(max_q_per_kv, len(k2q_indices_list[flat_idx][kv_idx]))
# Create tensors for k2q mapping
k2q_block_sparse_index = torch.full((bs, h, num_kv_blocks, max_q_per_kv), -1,
dtype=torch.int32, device=device)
k2q_block_sparse_num = torch.zeros((bs, h, num_kv_blocks),
dtype=torch.int32, device=device)
# Fill the tensors
for b in range(bs):
for head in range(h):
flat_idx = b * h + head
for kv_idx in range(num_kv_blocks):
q_indices = k2q_indices_list[flat_idx][kv_idx]
num_q = len(q_indices)
k2q_block_sparse_num[b, head, kv_idx] = num_q
if num_q > 0:
k2q_block_sparse_index[b, head, kv_idx, :num_q] = torch.tensor(
q_indices, dtype=torch.int32, device=device)
return q2k_block_sparse_index, q2k_block_sparse_num, k2q_block_sparse_index, k2q_block_sparse_num, block_sparse_mask
def main(args):
set_seed(42)
# Extract parameters
batch = args.batch_size
head = args.num_heads
headdim = args.head_dim
num_iterations = args.num_iterations
print(f"Block Sparse Attention Benchmark")
print(f"batch: {batch}, head: {head}, headdim: {headdim}, iterations: {num_iterations}")
# Test with different sequence lengths
for seq_len in args.seq_lengths:
# Skip very long sequences if they might cause OOM
# if seq_len > 16384 and batch > 1:
# continue
print("="*100)
print(f"\nSequence length: {seq_len}")
# Collect metrics across iterations
forward_metrics = {'sim': [], 'l1': [], 'rmse': []}
grad_q_metrics = {'sim': [], 'l1': [], 'rmse': []}
grad_k_metrics = {'sim': [], 'l1': [], 'rmse': []}
grad_v_metrics = {'sim': [], 'l1': [], 'rmse': []}
for iter_idx in range(num_iterations):
if num_iterations > 1:
print(f"\nIteration {iter_idx+1}/{num_iterations}")
# Create input tensors
q, k, v = create_input_tensors(batch, head, seq_len, headdim)
# Setup block sparse parameters
num_q_blocks = seq_len // BLOCK_M
num_kv_blocks = seq_len // BLOCK_N
# Determine k value (number of kv blocks per q block)
topk = args.topk
if topk is None:
topk = num_kv_blocks // 10 # Default to ~90% sparsity if k is not specified
topk = max(1, topk)
if iter_idx == 0: # Only print this once
print(f"Using topk={topk} kv blocks per q block (out of {num_kv_blocks} total kv blocks)")
# Generate block sparse pattern
q2k_block_sparse_index, q2k_block_sparse_num, k2q_block_sparse_index, k2q_block_sparse_num, block_sparse_mask = generate_block_sparse_pattern(
batch, head, num_q_blocks, num_kv_blocks, topk, device="cuda")
# expand block_sparse_mask to full mask
block_mask_expanded = block_sparse_mask.unsqueeze(-1).unsqueeze(-2) # [b, h, num_q_blocks, num_kv_blocks, 1, 1]
block_mask_expanded = block_mask_expanded.expand(-1, -1, -1, -1, BLOCK_M, BLOCK_N) # [b, h, num_q_blocks, num_kv_blocks, BLOCK_M, BLOCK_N]
full_mask = block_mask_expanded.permute(0, 1, 2, 4, 3, 5).reshape(batch, head, seq_len, seq_len)
q.requires_grad = True
k.requires_grad = True
v.requires_grad = True
# testing forward
o = triton_attention_sparse(q, k, v, q2k_block_sparse_index, q2k_block_sparse_num, k2q_block_sparse_index, k2q_block_sparse_num)
del q2k_block_sparse_index, q2k_block_sparse_num, k2q_block_sparse_index, k2q_block_sparse_num, block_sparse_mask, block_mask_expanded
grad_o = torch.randn_like(o)
o.backward(grad_o)
# clear memory
q_sdpa = q.detach().clone()
k_sdpa = k.detach().clone()
v_sdpa = v.detach().clone()
q_sdpa.requires_grad = True
k_sdpa.requires_grad = True
v_sdpa.requires_grad = True
q.data = torch.empty(0, device=q.device)
k.data = torch.empty(0, device=k.device)
v.data = torch.empty(0, device=v.device)
torch.cuda.empty_cache()
o_sdpa = torch.nn.functional.scaled_dot_product_attention(q_sdpa, k_sdpa, v_sdpa, attn_mask=full_mask)
sim, l1, rmse = precision_metric(o, o_sdpa)
assert sim > 0.9999, f"SSIM too low: {sim}"
assert l1 < 8e-5, f"l1 too large: {l1}"
assert rmse < 5e-5, f"RMSE too large: {rmse}"
forward_metrics['sim'].append(sim)
forward_metrics['l1'].append(l1)
forward_metrics['rmse'].append(rmse)
print(f"block_sparse_attention_fwd vs torch.nn.functional.scaled_dot_product_attention:\nsim: {sim}, l1: {l1}, rmse: {rmse}")
# test backward
o_sdpa.backward(grad_o)
sim, l1, rmse = precision_metric(q.grad, q_sdpa.grad)
# Error bounds collected on H100
assert sim > 0.9999, f"SSIM too low: {sim}"
assert l1 < 4e-3, f"l1 too large: {l1}"
assert rmse < 5e-4, f"RMSE too large: {rmse}"
grad_q_metrics['sim'].append(sim)
grad_q_metrics['l1'].append(l1)
grad_q_metrics['rmse'].append(rmse)
print(f"block_sparse_attention_bwd vs torch.nn.functional.scaled_dot_product_attention grad_q:\nsim: {sim}, l1: {l1}, rmse: {rmse}")
sim, l1, rmse = precision_metric(k.grad, k_sdpa.grad)
assert sim > 0.9999, f"SSIM too low: {sim}"
assert l1 < 4e-3, f"l1 too large: {l1}"
assert rmse < 5e-4, f"RMSE too large: {rmse}"
grad_k_metrics['sim'].append(sim)
grad_k_metrics['l1'].append(l1)
grad_k_metrics['rmse'].append(rmse)
print(f"block_sparse_attention_bwd vs torch.nn.functional.scaled_dot_product_attention grad_k:\nsim: {sim}, l1: {l1}, rmse: {rmse}")
sim, l1, rmse = precision_metric(v.grad, v_sdpa.grad)
assert sim > 0.9999, f"SSIM too low: {sim}"
assert l1 < 4e-3, f"l1 too large: {l1}"
assert rmse < 5e-4, f"RMSE too large: {rmse}"
grad_v_metrics['sim'].append(sim)
grad_v_metrics['l1'].append(l1)
grad_v_metrics['rmse'].append(rmse)
print(f"block_sparse_attention_bwd vs torch.nn.functional.scaled_dot_product_attention grad_v:\nsim: {sim}, l1: {l1}, rmse: {rmse}")
del o, o_sdpa, grad_o, q_sdpa, k_sdpa, v_sdpa
gc.collect()
torch.cuda.empty_cache()
# Print summary statistics if multiple iterations were run
if num_iterations > 1:
print("\n" + "="*50)
print(f"Summary Statistics (over {num_iterations} iterations):")
print("\nForward metrics:")
print(f"Similarity: mean={np.mean(forward_metrics['sim']):.6f}, std={np.std(forward_metrics['sim']):.6f}, min={np.min(forward_metrics['sim']):.6f}")
print(f"L1 error: mean={np.mean(forward_metrics['l1']):.6f}, std={np.std(forward_metrics['l1']):.6f}, max={np.max(forward_metrics['l1']):.6f}")
print(f"RMSE: mean={np.mean(forward_metrics['rmse']):.6f}, std={np.std(forward_metrics['rmse']):.6f}, max={np.max(forward_metrics['rmse']):.6f}")
print("\nGradient Q metrics:")
print(f"Similarity: mean={np.mean(grad_q_metrics['sim']):.6f}, std={np.std(grad_q_metrics['sim']):.6f}, min={np.min(grad_q_metrics['sim']):.6f}")
print(f"L1 error: mean={np.mean(grad_q_metrics['l1']):.6f}, std={np.std(grad_q_metrics['l1']):.6f}, max={np.max(grad_q_metrics['l1']):.6f}")
print(f"RMSE: mean={np.mean(grad_q_metrics['rmse']):.6f}, std={np.std(grad_q_metrics['rmse']):.6f}, max={np.max(grad_q_metrics['rmse']):.6f}")
print("\nGradient K metrics:")
print(f"Similarity: mean={np.mean(grad_k_metrics['sim']):.6f}, std={np.std(grad_k_metrics['sim']):.6f}, min={np.min(grad_k_metrics['sim']):.6f}")
print(f"L1 error: mean={np.mean(grad_k_metrics['l1']):.6f}, std={np.std(grad_k_metrics['l1']):.6f}, max={np.max(grad_k_metrics['l1']):.6f}")
print(f"RMSE: mean={np.mean(grad_k_metrics['rmse']):.6f}, std={np.std(grad_k_metrics['rmse']):.6f}, max={np.max(grad_k_metrics['rmse']):.6f}")
print("\nGradient V metrics:")
print(f"Similarity: mean={np.mean(grad_v_metrics['sim']):.6f}, std={np.std(grad_v_metrics['sim']):.6f}, min={np.min(grad_v_metrics['sim']):.6f}")
print(f"L1 error: mean={np.mean(grad_v_metrics['l1']):.6f}, std={np.std(grad_v_metrics['l1']):.6f}, max={np.max(grad_v_metrics['l1']):.6f}")
print(f"RMSE: mean={np.mean(grad_v_metrics['rmse']):.6f}, std={np.std(grad_v_metrics['rmse']):.6f}, max={np.max(grad_v_metrics['rmse']):.6f}")
if __name__ == "__main__":
parser = argparse.ArgumentParser(description='Benchmark Block Sparse Attention')
parser.add_argument('--batch_size', type=int, default=4, help='Batch size')
parser.add_argument('--num_heads', type=int, default=6, help='Number of heads')
parser.add_argument('--head_dim', type=int, default=128, help='Head dimension')
parser.add_argument('--topk', type=int, default=4, help='Number of kv blocks each q block attends to')
parser.add_argument('--seq_lengths', type=int, nargs='+', default=[4096], help='Sequence lengths to benchmark')
parser.add_argument('--num_iterations', type=int, default=10, help='Number of test iterations to run')
args = parser.parse_args()
main(args)
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import torch
from flash_attn_interface import flash_attn_func
from st_attn import mha_forward, mha_backward
import random
from tqdm import tqdm
import matplotlib.pyplot as plt
import numpy as np
def pytorch_test(Q, K, V, dO):
q_ = Q.to(torch.float64).requires_grad_()
k_ = K.to(torch.float64).requires_grad_()
v_ = V.to(torch.float64).requires_grad_()
dO_ = dO.to(torch.float64)
# manual pytorch implementation of scaled dot product attention
QK = torch.matmul(q_, k_.transpose(-2, -1))
QK /= (q_.size(-1) ** 0.5)
# Causal mask removed since causal is always false
QK = torch.nn.functional.softmax(QK, dim=-1)
output = torch.matmul(QK, v_)
output.backward(dO_)
q_grad = q_.grad
k_grad = k_.grad
v_grad = v_.grad
return output, q_grad, k_grad, v_grad
def fa2_test(Q, K, V, dO):
Q.requires_grad = True
K.requires_grad = True
V.requires_grad = True
output = torch.nn.functional.scaled_dot_product_attention(Q, K, V, is_causal=False)
output.backward(dO)
return output, Q.grad, K.grad, V.grad
def mha_kernel_test(Q, K, V, dO, mode):
Q.requires_grad = True
K.requires_grad = True
V.requires_grad = True
o, l_vec = mha_forward(Q, K, V)
if mode == 'forward_only':
return o, None, None, None
else: # 'forward_backward'
qg, kg, vg = mha_backward(Q, K, V, o, l_vec, dO)
return o, qg, kg, vg
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, mean, std, num_iterations=100, error_mode='all', test_mode='forward_backward'):
results = {
'MHA vs PT': {'sum_diff': 0, 'sum_abs': 0, 'max_diff': 0},
'FA2 vs PT': {'sum_diff': 0, 'sum_abs': 0, 'max_diff': 0},
}
for _ in range(num_iterations):
torch.manual_seed(0)
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')
dO = generate_tensor((b, h, n, d), mean, std, torch.bfloat16, 'cuda')
pt_o, pt_qg, pt_kg, pt_vg = pytorch_test(Q, K, V, dO)
fa2_o, fa2_qg, fa2_kg, fa2_vg = fa2_test(Q, K, V, dO)
if test_mode == 'forward_only':
mha_o, _, _, _ = mha_kernel_test(Q, K, V, dO, 'forward_only')
tensors_mha_pt = [(pt_o, mha_o)]
tensors_fa2_pt = [(pt_o, fa2_o)]
else: # 'forward_backward'
mha_o, mha_qg, mha_kg, mha_vg = mha_kernel_test(Q, K, V, dO, 'forward_backward')
if error_mode == 'output':
tensors_mha_pt = [(pt_o, mha_o)]
tensors_fa2_pt = [(pt_o, fa2_o)]
elif error_mode == 'backward':
tensors_mha_pt = [(pt_qg, mha_qg),
(pt_kg, mha_kg),
(pt_vg, mha_vg)]
tensors_fa2_pt = [(pt_qg, fa2_qg),
(pt_kg, fa2_kg),
(pt_vg, fa2_vg)]
else: # 'all'
tensors_mha_pt = [(pt_o, mha_o),
(pt_qg, mha_qg),
(pt_kg, mha_kg),
(pt_vg, mha_vg)]
tensors_fa2_pt = [(pt_o, fa2_o),
(pt_qg, fa2_qg),
(pt_kg, fa2_kg),
(pt_vg, fa2_vg)]
for pt, mha in tensors_mha_pt:
diff = pt - mha
abs_diff = torch.abs(diff)
results['MHA vs PT']['sum_diff'] += torch.sum(abs_diff).item()
results['MHA vs PT']['sum_abs'] += torch.sum(torch.abs(pt)).item()
results['MHA vs PT']['max_diff'] = max(results['MHA vs PT']['max_diff'], torch.max(abs_diff).item())
for pt, fa2 in tensors_fa2_pt:
diff = pt - fa2
abs_diff = torch.abs(diff)
results['FA2 vs PT']['sum_diff'] += torch.sum(abs_diff).item()
results['FA2 vs PT']['sum_abs'] += torch.sum(torch.abs(pt)).item()
results['FA2 vs PT']['max_diff'] = max(results['FA2 vs PT']['max_diff'], torch.max(abs_diff).item())
torch.cuda.empty_cache()
# Calculate total elements based on test mode and error mode
if test_mode == 'forward_only':
total_elements = b * h * n * d * num_iterations
else: # 'forward_backward'
total_elements = b * h * n * d * num_iterations * (1 if error_mode == 'output' else 3 if error_mode == 'backward' else 4)
for name, data in results.items():
avg_diff = data['sum_diff'] / total_elements
max_diff = data['max_diff']
results[name] = {'avg_diff': avg_diff, 'max_diff': max_diff}
return results
def generate_error_tables(b, h, d, mean, std, error_mode='all', test_mode='forward_backward'):
seq_lengths = [768 * (2**i) for i in range(1)]
print(f"\n{'='*80}")
print(f"MHA ERROR COMPARISON TABLE (b={b}, h={h}, d={d}, mean={mean}, std={std})")
print(f"Mode: {error_mode}, Test: {test_mode}")
print(f"{'='*80}")
# Print header
print(f"{'Seq Length':<12} | {'MHA vs PT Avg':<15} | {'MHA vs PT Max':<15} | {'FA2 vs PT Avg':<15} | {'FA2 vs PT Max':<15}")
print(f"{'-'*12} | {'-'*15} | {'-'*15} | {'-'*15} | {'-'*15}")
for n in seq_lengths:
results = check_correctness(b, h, n, d, mean, std, error_mode=error_mode, test_mode=test_mode)
mha_pt_avg = results['MHA vs PT']['avg_diff']
mha_pt_max = results['MHA vs PT']['max_diff']
fa2_pt_avg = results['FA2 vs PT']['avg_diff']
fa2_pt_max = results['FA2 vs PT']['max_diff']
# Print row
print(f"{n:<12} | {mha_pt_avg:<15.6e} | {mha_pt_max:<15.6e} | {fa2_pt_avg:<15.6e} | {fa2_pt_max:<15.6e}")
print(f"{'='*80}\n")
# fix random seed
torch.manual_seed(0)
# Example usage
b, h, d = 2, 2, 64
mean = 1e-1
std = 10
# Test forward only
generate_error_tables(b, h, d, mean, std, error_mode='output', test_mode='forward_only')
# Test forward and backward
generate_error_tables(b, h, d, mean, std, error_mode='all', test_mode='forward_backward')
print("MHA attention error comparison completed.")
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import torch
from tqdm import tqdm
import matplotlib.pyplot as plt
import numpy as np
from vsa import triton_attention
def pytorch_test(Q, K, V, dO):
q_ = Q.to(torch.float64).requires_grad_()
k_ = K.to(torch.float64).requires_grad_()
v_ = V.to(torch.float64).requires_grad_()
q_.grad = None
k_.grad = None
v_.grad = None
dO_ = dO.to(torch.float64)
# manual pytorch implementation of scaled dot product attention
QK = torch.matmul(q_, k_.transpose(-2, -1))
QK /= (q_.size(-1) ** 0.5)
# Causal mask removed since causal is always false
QK = torch.nn.functional.softmax(QK, dim=-1)
output = torch.matmul(QK, v_)
output.backward(dO_)
q_grad = q_.grad
k_grad = k_.grad
v_grad = v_.grad
return output, q_grad, k_grad, v_grad
def fa2_test(Q, K, V, dO):
Q.requires_grad = True
K.requires_grad = True
V.requires_grad = True
Q.grad = None
K.grad = None
V.grad = None
output = torch.nn.functional.scaled_dot_product_attention(Q, K, V, is_causal=False)
output.backward(dO)
return output, Q.grad, K.grad, V.grad
def triton_test(Q, K, V, dO):
Q.requires_grad = True
K.requires_grad = True
V.requires_grad = True
Q.grad = None
K.grad = None
V.grad = None
output = triton_attention(Q, K, V)
output.backward(dO)
q_grad = Q.grad
k_grad = K.grad
v_grad = V.grad
return output.to(Q.dtype) if output is not None else None, q_grad, k_grad, v_grad
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, mean, std, num_iterations=100, error_mode='all', test_mode='forward_backward'):
results = {
'FA2 vs PT': {'sum_diff': 0.0, 'sum_abs': 0.0, 'max_diff': 0.0},
'Triton vs PT': {'sum_diff': 0.0, 'sum_abs': 0.0, 'max_diff': 0.0},
}
for _ in range(num_iterations):
torch.manual_seed(0)
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')
dO = generate_tensor((b, h, n, d), mean, std, torch.bfloat16, 'cuda')
pt_o, pt_qg, pt_kg, pt_vg = pytorch_test(Q, K, V, dO)
fa2_o, fa2_qg, fa2_kg, fa2_vg = fa2_test(Q, K, V, dO)
triton_o, triton_qg, triton_kg, triton_vg = triton_test(Q, K, V, dO)
if test_mode == 'forward_only':
tensors_fa2_pt = [(pt_o, fa2_o)]
tensors_triton_pt = [(pt_o, triton_o)]
else: # 'forward_backward'
if error_mode == 'output':
tensors_fa2_pt = [(pt_o, fa2_o)]
tensors_triton_pt = [(pt_o, triton_o)]
elif error_mode == 'backward':
tensors_fa2_pt = [(pt_qg, fa2_qg),
(pt_kg, fa2_kg),
(pt_vg, fa2_vg)]
tensors_triton_pt = [(pt_qg, triton_qg),
(pt_kg, triton_kg),
(pt_vg, triton_vg)]
else: # 'all'
tensors_fa2_pt = [(pt_o, fa2_o),
(pt_qg, fa2_qg),
(pt_kg, fa2_kg),
(pt_vg, fa2_vg)]
tensors_triton_pt = [(pt_o, triton_o),
(pt_qg, triton_qg),
(pt_kg, triton_kg),
(pt_vg, triton_vg)]
for pt, fa2 in tensors_fa2_pt:
diff = pt - fa2
abs_diff = torch.abs(diff)
results['FA2 vs PT']['sum_diff'] += torch.sum(abs_diff).item()
results['FA2 vs PT']['sum_abs'] += torch.sum(torch.abs(pt)).item()
results['FA2 vs PT']['max_diff'] = max(results['FA2 vs PT']['max_diff'], torch.max(abs_diff).item())
for pt, triton in tensors_triton_pt:
diff = pt - triton
abs_diff = torch.abs(diff)
results['Triton vs PT']['sum_diff'] += torch.sum(abs_diff).item()
results['Triton vs PT']['sum_abs'] += torch.sum(torch.abs(pt)).item()
results['Triton vs PT']['max_diff'] = max(results['Triton vs PT']['max_diff'], torch.max(abs_diff).item())
torch.cuda.empty_cache()
# Calculate total elements based on test mode and error mode
if test_mode == 'forward_only':
total_elements = b * h * n * d * num_iterations
else: # 'forward_backward'
total_elements = b * h * n * d * num_iterations * (1 if error_mode == 'output' else 3 if error_mode == 'backward' else 4)
for name, data in results.items():
avg_diff = data['sum_diff'] / total_elements
max_diff = data['max_diff']
results[name] = {'avg_diff': avg_diff, 'max_diff': max_diff}
return results
def generate_error_tables(b, h, d, mean, std, error_mode='all', test_mode='forward_backward'):
seq_lengths = [768 * (2**i) for i in range(1)]
print(f"\n{'='*100}")
print(f"ATTENTION ERROR COMPARISON TABLE (b={b}, h={h}, d={d}, mean={mean}, std={std})")
print(f"Mode: {error_mode}, Test: {test_mode}")
print(f"{'='*100}")
# Print header
print(f"{'Seq Length':<12} | {'FA2 vs PT Avg':<15} | {'FA2 vs PT Max':<15} | {'Triton vs PT Avg':<15} | {'Triton vs PT Max':<15}")
print(f"{'-'*12} | {'-'*15} | {'-'*15} | {'-'*15} | {'-'*15}")
for n in seq_lengths:
results = check_correctness(b, h, n, d, mean, std, error_mode=error_mode, test_mode=test_mode)
fa2_pt_avg = results['FA2 vs PT']['avg_diff']
fa2_pt_max = results['FA2 vs PT']['max_diff']
triton_pt_avg = results['Triton vs PT']['avg_diff']
triton_pt_max = results['Triton vs PT']['max_diff']
# Print row with both comparisons
print(f"{n:<12} | {fa2_pt_avg:<15.6e} | {fa2_pt_max:<15.6e} | {triton_pt_avg:<15.6e} | {triton_pt_max:<15.6e}")
print(f"{'='*100}\n")
# fix random seed
torch.manual_seed(0)
mean = 1e-1
std = 10
configs = [
(4, 1, 128), # Larger batch, single head, larger dim
(2, 8, 64), # Medium batch, many heads, medium dim
]
for b, h, d in configs:
print(f"\nConfiguration: batch={b}, heads={h}, dim={d}")
generate_error_tables(b, h, d, mean, std, error_mode='backward', test_mode='forward_backward')
print("Attention error comparison completed.")
+159
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@@ -0,0 +1,159 @@
import torch
import sys
import os
import numpy as np
from tqdm import tqdm
# Add the parent directory to the path to import block_sparse_attn
sys.path.append(os.path.dirname(os.path.dirname(os.path.abspath(__file__))))
from tests.utils import generate_block_sparse_mask_for_function, create_full_mask_from_block_mask
from vsa import block_sparse_attn
BLOCK_M = 64
BLOCK_N = 64
def pytorch_test(Q, K, V, block_sparse_mask, dO):
q_ = Q.clone().requires_grad_()
k_ = K.clone().requires_grad_()
v_ = V.clone().requires_grad_()
QK = torch.matmul(q_, k_.transpose(-2, -1))
QK /= (q_.size(-1) ** 0.5)
QK = QK.masked_fill(~block_sparse_mask.unsqueeze(0), float('-inf'))
QK = torch.nn.functional.softmax(QK, dim=-1)
output = torch.matmul(QK, v_)
dO_ = dO
output.backward(dO_)
return (
output.to(torch.bfloat16),
q_.grad.to(torch.bfloat16),
k_.grad.to(torch.bfloat16),
v_.grad.to(torch.bfloat16),
)
def block_sparse_kernel_test(Q, K, V, block_sparse_mask, variable_block_sizes, non_pad_index, dO):
Q = Q.clone().requires_grad_()
K = K.clone().requires_grad_()
V = V.clone().requires_grad_()
q_padded = vsa_pad(Q, non_pad_index, variable_block_sizes.shape[0], BLOCK_M)
k_padded = vsa_pad(K, non_pad_index, variable_block_sizes.shape[0], BLOCK_M)
v_padded = vsa_pad(V, non_pad_index, variable_block_sizes.shape[0], BLOCK_M)
output, _= block_sparse_attn(q_padded, k_padded, v_padded, block_sparse_mask, variable_block_sizes)
output = output[:, :, non_pad_index, :]
output.backward(dO)
return output, Q.grad, K.grad, V.grad
def get_non_pad_index(
vid_len: torch.LongTensor,
n_win: int,
win_size: int,
):
device = vid_len.device
starts_pad = torch.arange(n_win, device=device) * win_size
index_pad = starts_pad[:, None] + torch.arange(win_size, device=device)[None, :]
index_mask = torch.arange(win_size, device=device)[None, :] < vid_len[:, None]
return index_pad[index_mask]
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 generate_variable_block_sizes(num_blocks, min_size=32, max_size=64, device="cuda"):
return torch.randint(min_size, max_size + 1, (num_blocks,), device=device, dtype=torch.int32)
def vsa_pad(x, non_pad_index, num_blocks, block_size):
padded_x = torch.zeros((1, x.shape[1], num_blocks * BLOCK_M, x.shape[3]), device=x.device, dtype=x.dtype)
padded_x[:, :, non_pad_index, :] = x
return padded_x
def check_correctness(h, d, num_blocks, k, mean, std, num_iterations=20, error_mode='all'):
results = {
'gO': {'sum_diff': 0.0, 'sum_abs': 0.0, 'max_diff': 0.0},
'gQ': {'sum_diff': 0.0, 'sum_abs': 0.0, 'max_diff': 0.0},
'gK': {'sum_diff': 0.0, 'sum_abs': 0.0, 'max_diff': 0.0},
'gV': {'sum_diff': 0.0, 'sum_abs': 0.0, 'max_diff': 0.0},
}
device = "cuda" if torch.cuda.is_available() else "cpu"
variable_block_sizes = generate_variable_block_sizes(num_blocks, device=device)
S = int(variable_block_sizes.sum().item())
padded_S = num_blocks * BLOCK_M
non_pad_index = get_non_pad_index(variable_block_sizes, num_blocks, BLOCK_M)
block_mask = generate_block_sparse_mask_for_function(h, num_blocks, k, device)
full_mask = create_full_mask_from_block_mask(block_mask, variable_block_sizes, device)
for _ in range(num_iterations):
Q = generate_tensor((1, h, S, d), mean, std, torch.bfloat16, device)
K = generate_tensor((1, h, S, d), mean, std, torch.bfloat16, device)
V = generate_tensor((1, h, S, d), mean, std, torch.bfloat16, device)
dO = generate_tensor((1, h, S, d), mean, std, torch.bfloat16, device)
# dO_padded = torch.zeros_like(dO_padded)
# dO_padded[:, :, non_pad_index, :] = dO
pt_o, pt_qg, pt_kg, pt_vg = pytorch_test(Q, K, V, full_mask, dO)
bs_o, bs_qg, bs_kg, bs_vg = block_sparse_kernel_test(Q, K, V, block_mask.unsqueeze(0), variable_block_sizes,non_pad_index, dO)
for name, (pt, bs) in zip(['gQ', 'gK', 'gV', 'gO'], [(pt_qg, bs_qg), (pt_kg, bs_kg), (pt_vg, bs_vg), (pt_o, bs_o)]):
if bs is not None:
diff = pt - bs
abs_diff = torch.abs(diff)
results[name]['sum_diff'] += torch.sum(abs_diff).item()
results[name]['sum_abs'] += torch.sum(torch.abs(pt)).item()
results[name]['max_diff'] = max(results[name]['max_diff'], torch.max(abs_diff).item())
if torch.cuda.is_available():
torch.cuda.empty_cache()
total_elements = h * S * d * num_iterations
for name, data in results.items():
avg_diff = data['sum_diff'] / total_elements
max_diff = data['max_diff']
results[name] = {'avg_diff': avg_diff, 'max_diff': max_diff}
return results
def generate_error_graphs(h, d, mean, std, error_mode='all'):
test_configs = [
{"num_blocks": 16, "k": 2, "description": "Small sequence"},
{"num_blocks": 32, "k": 4, "description": "Medium sequence"},
{"num_blocks": 53, "k": 6, "description": "Large sequence"},
]
print(f"\nError Analysis for h={h}, d={d}, mean={mean}, std={std}, mode={error_mode}")
print("=" * 150)
print(f"{'Config':<20} {'Blocks':<8} {'K':<4} "
f"{'gQ Avg':<12} {'gQ Max':<12} "
f"{'gK Avg':<12} {'gK Max':<12} "
f"{'gV Avg':<12} {'gV Max':<12} "
f"{'gO Avg':<12} {'gO Max':<12}")
print("-" * 150)
for config in test_configs:
num_blocks = config["num_blocks"]
k = config["k"]
description = config["description"]
results = check_correctness(h, d, num_blocks, k, mean, std, error_mode=error_mode)
print(f"{description:<20} {num_blocks:<8} {k:<4} "
f"{results['gQ']['avg_diff']:<12.6e} {results['gQ']['max_diff']:<12.6e} "
f"{results['gK']['avg_diff']:<12.6e} {results['gK']['max_diff']:<12.6e} "
f"{results['gV']['avg_diff']:<12.6e} {results['gV']['max_diff']:<12.6e} "
f"{results['gO']['avg_diff']:<12.6e} {results['gO']['max_diff']:<12.6e}")
print("-" * 150)
if __name__ == "__main__":
h, d = 16, 128
mean = 0.0
std = 1
print("Block Sparse Attention with Variable Block Sizes Analysis")
print("=" * 60)
for mode in ['backward']:
generate_error_graphs(h, d, mean, std, error_mode=mode)
print("\nAnalysis completed for all modes.")
+54
View File
@@ -0,0 +1,54 @@
import torch
def generate_block_sparse_mask_for_function(h, num_blocks, k, device="cuda"):
"""
Generate block sparse mask of shape [h, num_blocks, num_blocks].
Args:
h: number of heads
num_blocks: number of blocks
k: number of kv blocks each q block attends to
device: device to create tensors on
Returns:
block_sparse_mask: [h, num_blocks, num_blocks] bool tensor
"""
k = min(k, num_blocks)
scores = torch.rand(h, num_blocks, num_blocks, device=device)
_, indices = torch.topk(scores, k, dim=-1)
block_sparse_mask = torch.zeros(h, num_blocks, num_blocks, dtype=torch.bool, device=device)
block_sparse_mask = block_sparse_mask.scatter_(2, indices, 1).bool()
return block_sparse_mask
def create_full_mask_from_block_mask(block_sparse_mask, variable_block_sizes, device="cuda"):
"""
Convert block-level sparse mask to full attention mask.
Args:
block_sparse_mask: [h, num_blocks, num_blocks] bool tensor
variable_block_sizes: [num_blocks] tensor
device: device to create tensors on
Returns:
full_mask: [h, S, S] bool tensor where S = total sequence length
"""
h, num_blocks, _ = block_sparse_mask.shape
total_seq_len = variable_block_sizes.sum().item()
cumsum = torch.cat([torch.tensor([0], device=device), variable_block_sizes.cumsum(dim=0)[:-1]])
full_mask = torch.zeros(h, total_seq_len, total_seq_len, dtype=torch.bool, device=device)
for head in range(h):
for q_block in range(num_blocks):
q_start = cumsum[q_block]
q_end = q_start + variable_block_sizes[q_block]
for kv_block in range(num_blocks):
if block_sparse_mask[head, q_block, kv_block]:
kv_start = cumsum[kv_block]
kv_end = kv_start + variable_block_sizes[kv_block]
full_mask[head, q_start:q_end, kv_start:kv_end] = True
return full_mask
+2 -2
View File
@@ -9,10 +9,10 @@
#ifdef TK_COMPILE_BLOCK_SPARSE
extern std::vector<torch::Tensor> block_sparse_attention_forward(
torch::Tensor q, torch::Tensor k, torch::Tensor v, torch::Tensor q2k_block_sparse_index, torch::Tensor q2k_block_sparse_num
torch::Tensor q, torch::Tensor k, torch::Tensor v, torch::Tensor q2k_block_sparse_index, torch::Tensor q2k_block_sparse_num, torch::Tensor block_size
);
extern std::vector<torch::Tensor> block_sparse_attention_backward(
torch::Tensor q, torch::Tensor k, torch::Tensor v, torch::Tensor o, torch::Tensor l_vec, torch::Tensor og, torch::Tensor k2q_block_sparse_index, torch::Tensor k2q_block_sparse_num
torch::Tensor q, torch::Tensor k, torch::Tensor v, torch::Tensor o, torch::Tensor l_vec, torch::Tensor og, torch::Tensor k2q_block_sparse_index, torch::Tensor k2q_block_sparse_num, torch::Tensor block_size
);
#endif
+19 -218
View File
@@ -1,12 +1,17 @@
import torch
from typing import Tuple
from vsa.vsa import block_sparse_attn
block_sparse_attn=None
try:
from vsa_cuda import block_sparse_fwd, block_sparse_bwd
from vsa.block_sparse_wrapper import block_sparse_attn_SM90
block_sparse_attn = block_sparse_attn_SM90
except ImportError:
from vsa.block_sparse_wrapper import block_sparse_attn_triton
block_sparse_fwd = None
block_sparse_bwd = None
from vsa.block_sparse_attn_triton import attention as triton_attention, attention_sparse as triton_attention_sparse
block_sparse_attn = block_sparse_attn_triton
BLOCK_M = 64
BLOCK_N = 64
@@ -22,7 +27,7 @@ def torch_attention(q, k, v) -> Tuple[torch.Tensor, torch.Tensor]:
return output, QK
def video_sparse_attn(q, k, v, topk, block_size, compress_attn_weight=None):
def video_sparse_attn(q, k, v, variable_block_sizes, topk, block_size, compress_attn_weight=None):
"""
q: [batch_size, num_heads, seq_len, head_dim]
k: [batch_size, num_heads, seq_len, head_dim]
@@ -32,7 +37,7 @@ def video_sparse_attn(q, k, v, topk, block_size, compress_attn_weight=None):
video_shape: tuple of (T, H, W)
compress_attn_weight: [batch_size, num_heads, seq_len, head_dim]
select_attn_weight: [batch_size, num_heads, seq_len, head_dim]
NOTE: We assume q, k, v is zero padded!!
V1 of sparse attention. Include compress attn and sparse attn branch, use average pooling to compress.
Assume q, k, v is flattened in this way: [batch_size, num_heads, T//block_size[0], H//block_size[1], W//block_size[2], block_size[0], block_size[1], block_size[2]]
"""
@@ -41,16 +46,16 @@ def video_sparse_attn(q, k, v, topk, block_size, compress_attn_weight=None):
block_size = (block_size, block_size, block_size)
block_elements = block_size[0] * block_size[1] * block_size[2]
assert block_elements % 64 == 0 and block_elements >= 64
assert block_elements == 64
assert q.shape[2] % block_elements == 0
batch_size, num_heads, seq_len, head_dim = q.shape
# compress attn
q_compress = q.view(batch_size, num_heads, seq_len // block_elements,
block_elements, head_dim).mean(dim=3)
k_compress = k.view(batch_size, num_heads, seq_len // block_elements,
block_elements, head_dim).mean(dim=3)
v_compress = v.view(batch_size, num_heads, seq_len // block_elements,
block_elements, head_dim).mean(dim=3)
q_compress = (q.view(batch_size, num_heads, seq_len // block_elements,
block_elements, head_dim).float().sum(dim=3) / variable_block_sizes.view(1, 1, -1, 1)).to(q.dtype)
k_compress = (k.view(batch_size, num_heads, seq_len // block_elements,
block_elements, head_dim).float().sum(dim=3) / variable_block_sizes.view(1, 1, -1, 1)).to(k.dtype)
v_compress = (v.view(batch_size, num_heads, seq_len // block_elements,
block_elements, head_dim).float().sum(dim=3) / variable_block_sizes.view(1, 1, -1, 1)).to(v.dtype)
output_compress, block_attn_score = torch_attention(q_compress, k_compress,
v_compress)
@@ -62,13 +67,9 @@ def video_sparse_attn(q, k, v, topk, block_size, compress_attn_weight=None):
1).view(batch_size, num_heads,
seq_len, head_dim)
q2k_block_sparse_index, q2k_block_sparse_num, k2q_block_sparse_index, k2q_block_sparse_num = generate_topk_block_sparse_pattern(
block_attn_score, topk)
output_select = block_sparse_attn(q, k, v, q2k_block_sparse_index,
q2k_block_sparse_num,
k2q_block_sparse_index,
k2q_block_sparse_num)
topK_indices = torch.topk(block_attn_score, topk, dim=-1).indices
block_mask = torch.zeros_like(block_attn_score, dtype=torch.bool).scatter_(-1, topK_indices, True)
output_select, _ = block_sparse_attn(q, k, v, block_mask, variable_block_sizes)
if compress_attn_weight is not None:
final_output = output_compress * compress_attn_weight + output_select
@@ -76,203 +77,3 @@ def video_sparse_attn(q, k, v, topk, block_size, compress_attn_weight=None):
final_output = output_compress + output_select
return final_output
def generate_topk_block_sparse_pattern(block_attn_score: torch.Tensor,
topk: int):
"""
Generate a block sparse pattern where each q block attends to exactly topk kv blocks,
based on the provided attention scores.
Args:
block_attn_score: [bs, h, num_q_blocks, num_kv_blocks]
Attention scores between query and key blocks
topk: int
Number of kv blocks each q block attends to
Returns:
q2k_block_sparse_index: [bs, h, num_q_blocks, topk]
Contains the indices of kv blocks that each q block attends to.
q2k_block_sparse_num: [bs, h, num_q_blocks]
Contains the number of kv blocks that each q block attends to (all equal to topk).
k2q_block_sparse_index: [bs, h, num_kv_blocks, max_q_per_kv]
Contains the indices of q blocks that attend to each kv block.
k2q_block_sparse_num: [bs, h, num_kv_blocks]
Contains the number of q blocks that attend to each kv block.
"""
device = block_attn_score.device
# Extract dimensions from block_attn_score
bs, h, num_q_blocks, num_kv_blocks = block_attn_score.shape
sorted_result = torch.sort(block_attn_score, dim=-1, descending=True)
sorted_indice = sorted_result.indices
q2k_block_sparse_index, _ = torch.sort(sorted_indice[:, :, :, :topk],
dim=-1)
q2k_block_sparse_index = q2k_block_sparse_index.to(dtype=torch.int32)
q2k_block_sparse_num = torch.full((bs, h, num_q_blocks),
topk,
device=device,
dtype=torch.int32)
block_map = topk_index_to_map(q2k_block_sparse_index,
num_kv_blocks,
transpose_map=True)
k2q_block_sparse_index, k2q_block_sparse_num = map_to_index(
block_map.transpose(2, 3))
return q2k_block_sparse_index, q2k_block_sparse_num, k2q_block_sparse_index, k2q_block_sparse_num
## pytorch sdpa version of block sparse ##
import triton
import triton.language as tl
@triton.jit
def topk_index_to_map_kernel(
map_ptr,
index_ptr,
map_bs_stride,
map_h_stride,
map_q_stride,
map_kv_stride,
index_bs_stride,
index_h_stride,
index_q_stride,
index_kv_stride,
topk: tl.constexpr,
):
b, h, q = tl.program_id(0), tl.program_id(1), tl.program_id(2)
index_ptr_base = index_ptr + b * index_bs_stride + h * index_h_stride + q * index_q_stride
map_ptr_base = map_ptr + b * map_bs_stride + h * map_h_stride + q * map_q_stride
for i in tl.static_range(topk):
index = tl.load(index_ptr_base + i * index_kv_stride)
tl.store(map_ptr_base + index * map_kv_stride, 1.0)
@triton.jit
def map_to_index_kernel(
map_ptr,
index_ptr,
index_num_ptr,
map_bs_stride,
map_h_stride,
map_q_stride,
map_kv_stride,
index_bs_stride,
index_h_stride,
index_q_stride,
index_kv_stride,
index_num_bs_stride,
index_num_h_stride,
index_num_q_stride,
num_kv_blocks: tl.constexpr,
):
b, h, q = tl.program_id(0), tl.program_id(1), tl.program_id(2)
index_ptr_base = index_ptr + b * index_bs_stride + h * index_h_stride + q * index_q_stride
map_ptr_base = map_ptr + b * map_bs_stride + h * map_h_stride + q * map_q_stride
num = 0
for i in tl.static_range(num_kv_blocks):
map_entry = tl.load(map_ptr_base + i * map_kv_stride)
if map_entry:
tl.store(index_ptr_base + num * index_kv_stride, i)
num += 1
tl.store(
index_num_ptr + b * index_num_bs_stride + h * index_num_h_stride +
q * index_num_q_stride, num)
def topk_index_to_map(index: torch.Tensor,
num_kv_blocks: int,
transpose_map: bool = False):
"""
Convert topk indices to a map.
Args:
index: [bs, h, num_q_blocks, topk]
The topk indices tensor.
num_kv_blocks: int
The number of key-value blocks in the block_map returned
transpose_map: bool
If True, the block_map will be transposed on the final two dimensions.
Returns:
block_map: [bs, h, num_q_blocks, num_kv_blocks]
A binary map where 1 indicates that the q block attends to the kv block.
"""
bs, h, num_q_blocks, topk = index.shape
if transpose_map is False:
block_map = torch.zeros((bs, h, num_q_blocks, num_kv_blocks),
dtype=torch.bool,
device=index.device)
else:
block_map = torch.zeros((bs, h, num_kv_blocks, num_q_blocks),
dtype=torch.bool,
device=index.device)
block_map = block_map.transpose(2, 3)
grid = (bs, h, num_q_blocks)
topk_index_to_map_kernel[grid](
block_map,
index,
block_map.stride(0),
block_map.stride(1),
block_map.stride(2),
block_map.stride(3),
index.stride(0),
index.stride(1),
index.stride(2),
index.stride(3),
topk=topk,
)
return block_map
def map_to_index(block_map: torch.Tensor):
"""
Convert a block map to indices and counts.
Args:
block_map: [bs, h, num_q_blocks, num_kv_blocks]
The block map tensor.
Returns:
index: [bs, h, num_q_blocks, num_kv_blocks]
The indices of the blocks.
index_num: [bs, h, num_q_blocks]
The number of blocks for each q block.
"""
bs, h, num_q_blocks, num_kv_blocks = block_map.shape
index = torch.full((block_map.shape),
-1,
dtype=torch.int32,
device=block_map.device)
index_num = torch.empty((bs, h, num_q_blocks),
dtype=torch.int32,
device=block_map.device)
grid = (bs, h, num_q_blocks)
map_to_index_kernel[grid](
block_map,
index,
index_num,
block_map.stride(0),
block_map.stride(1),
block_map.stride(2),
block_map.stride(3),
index.stride(0),
index.stride(1),
index.stride(2),
index.stride(3),
index_num.stride(0),
index_num.stride(1),
index_num.stride(2),
num_kv_blocks=num_kv_blocks,
)
return index, index_num
+83 -341
View File
@@ -18,43 +18,6 @@ import math # small utility needed by the sparse wrapper
# ──────────────────────────── SPARSE ADDITION END ─────────────────────────────
@triton.jit
def _attn_fwd_inner(acc, l_i, m_i, q, #
K_block_ptr, V_block_ptr, #
start_m, qk_scale, #
BLOCK_M: tl.constexpr, HEAD_DIM: tl.constexpr, BLOCK_N: tl.constexpr, #
STAGE: tl.constexpr, offs_m: tl.constexpr, offs_n: tl.constexpr, #
N_CTX: tl.constexpr, fp8_v: tl.constexpr):
# loop over k, v and update accumulator
for start_n in range(0, N_CTX, BLOCK_N):
# -- compute qk ----
k = tl.load(K_block_ptr)
qk = tl.dot(q, k)
m_ij = tl.maximum(m_i, tl.max(qk, 1) * qk_scale)
qk = qk * qk_scale - m_ij[:, None]
p = tl.math.exp2(qk)
l_ij = tl.sum(p, 1)
# -- update m_i and l_i
alpha = tl.math.exp2(m_i - m_ij)
l_i = l_i * alpha + l_ij
# -- update output accumulator --
acc = acc * alpha[:, None]
# update acc
v = tl.load(V_block_ptr)
if fp8_v:
p = p.to(tl.float8e5)
else:
p = p.to(tl.bfloat16)
acc = tl.dot(p, v, acc)
# update m_i and l_i
m_i = m_ij
V_block_ptr = tl.advance(V_block_ptr, (BLOCK_N, 0))
K_block_ptr = tl.advance(K_block_ptr, (0, BLOCK_N))
return acc, l_i, m_i
# We don't run auto-tuning every time to keep the tutorial fast. Keeping
# the code below and commenting out the equivalent parameters is convenient for
# re-tuning.
@@ -71,6 +34,7 @@ configs = [
@triton.jit
def _attn_fwd_sparse(Q, K, V, sm_scale, #
q2k_index, q2k_num, max_kv_blks, #
variable_block_sizes,
M, Out, #
stride_qz, stride_qh, stride_qm, stride_qk,
stride_kz, stride_kh, stride_kn, stride_kk,
@@ -136,12 +100,15 @@ def _attn_fwd_sparse(Q, K, V, sm_scale, #
# ----- sparse loop over valid K/V tiles -----
for i in range(0, kv_blocks):
kv_idx = tl.load(kv_ptr + i).to(tl.int32)
block_size = tl.load(variable_block_sizes + kv_idx)
K_ptr = tl.advance(K_base, (0, kv_idx * BLOCK_N))
V_ptr = tl.advance(V_base, (kv_idx * BLOCK_N, 0))
k = tl.load(K_ptr)
qk = tl.dot(q, k)
# mask out invalid columns
mask = tl.arange(0, BLOCK_N) < block_size
qk = tl.where(mask[None, :], qk, -float("inf"))
m_ij = tl.maximum(m_i, tl.max(qk, 1) * qk_scale)
p = tl.math.exp2(qk * qk_scale - m_ij[:, None])
@@ -163,84 +130,6 @@ def _attn_fwd_sparse(Q, K, V, sm_scale, #
# ──────────────────────────── SPARSE ADDITION END ─────────────────────────────
@triton.autotune(configs, key=["N_CTX", "HEAD_DIM"])
@triton.jit
def _attn_fwd(Q, K, V, sm_scale, M, Out, #
stride_qz, stride_qh, stride_qm, stride_qk, #
stride_kz, stride_kh, stride_kn, stride_kk, #
stride_vz, stride_vh, stride_vk, stride_vn, #
stride_oz, stride_oh, stride_om, stride_on, #
Z, H, N_CTX, #
HEAD_DIM: tl.constexpr, #
BLOCK_M: tl.constexpr, #
BLOCK_N: tl.constexpr, #
STAGE: tl.constexpr #
):
tl.static_assert(BLOCK_N <= HEAD_DIM)
start_m = tl.program_id(0)
off_hz = tl.program_id(1)
off_z = off_hz // H
off_h = off_hz % H
qvk_offset = off_z.to(tl.int64) * stride_qz + off_h.to(tl.int64) * stride_qh
# block pointers
Q_block_ptr = tl.make_block_ptr(
base=Q + qvk_offset,
shape=(N_CTX, HEAD_DIM),
strides=(stride_qm, stride_qk),
offsets=(start_m * BLOCK_M, 0),
block_shape=(BLOCK_M, HEAD_DIM),
order=(1, 0),
)
v_order: tl.constexpr = (0, 1) if V.dtype.element_ty == tl.float8e5 else (1, 0)
V_block_ptr = tl.make_block_ptr(
base=V + qvk_offset,
shape=(N_CTX, HEAD_DIM),
strides=(stride_vk, stride_vn),
offsets=(0, 0),
block_shape=(BLOCK_N, HEAD_DIM),
order=v_order,
)
K_block_ptr = tl.make_block_ptr(
base=K + qvk_offset,
shape=(HEAD_DIM, N_CTX),
strides=(stride_kk, stride_kn),
offsets=(0, 0),
block_shape=(HEAD_DIM, BLOCK_N),
order=(0, 1),
)
O_block_ptr = tl.make_block_ptr(
base=Out + qvk_offset,
shape=(N_CTX, HEAD_DIM),
strides=(stride_om, stride_on),
offsets=(start_m * BLOCK_M, 0),
block_shape=(BLOCK_M, HEAD_DIM),
order=(1, 0),
)
# initialize offsets
offs_m = start_m * BLOCK_M + tl.arange(0, BLOCK_M)
offs_n = tl.arange(0, BLOCK_N)
# initialize pointer to m and l
m_i = tl.zeros([BLOCK_M], dtype=tl.float32) - float("inf")
l_i = tl.zeros([BLOCK_M], dtype=tl.float32) + 1.0
acc = tl.zeros([BLOCK_M, HEAD_DIM], dtype=tl.float32)
# load scales
qk_scale = sm_scale
qk_scale *= 1.44269504 # 1/log(2)
# load q: it will stay in SRAM throughout
q = tl.load(Q_block_ptr)
acc, l_i, m_i = _attn_fwd_inner(acc, l_i, m_i, q, K_block_ptr, V_block_ptr, #
start_m, qk_scale, #
BLOCK_M, HEAD_DIM, BLOCK_N, #
3, offs_m, offs_n, N_CTX, V.dtype.element_ty == tl.float8e5 #
)
# epilogue
m_i += tl.math.log2(l_i)
acc = acc / l_i[:, None]
m_ptrs = M + off_hz * N_CTX + offs_m
tl.store(m_ptrs, m_i)
tl.store(O_block_ptr, acc.to(Out.type.element_ty))
@triton.jit
@@ -267,6 +156,7 @@ def _attn_bwd_dkdv(dk, dv, #
DO, #
M, D, #
k2q_index, k2q_num, max_q_blks,
variable_block_sizes,
# shared by Q/K/V/DO.
stride_tok, stride_d, #
H, N_CTX, BLOCK_M1: tl.constexpr, #
@@ -291,6 +181,8 @@ def _attn_bwd_dkdv(dk, dv, #
q_blocks = tl.load(k2q_num + meta_base) # int32
q_ptr = k2q_index + meta_base * max_q_blks # ptr to list
block_size = tl.load(variable_block_sizes + kv_blk)
for blk_idx in range(q_blocks*2):
@@ -301,6 +193,9 @@ def _attn_bwd_dkdv(dk, dv, #
m = tl.load(M + offs_m)
qkT = tl.dot(k, qT)
pT = tl.math.exp2(qkT - m[None, :])
mask = tl.arange(0, BLOCK_N1) < block_size
pT = tl.where(mask[:, None], pT, 0.0)
do = tl.load(do_ptrs + block_sparse_offset * stride_tok)
# Compute dV.
ppT = pT
@@ -324,6 +219,7 @@ def _attn_bwd_dq(dq, q, K, V, #
do, m, D,
# shared by Q/K/V/DO.
q2k_index, q2k_num, max_kv_blks,
variable_block_sizes,
stride_tok, stride_d, #
H, N_CTX, #
BLOCK_M2: tl.constexpr, #
@@ -355,10 +251,13 @@ def _attn_bwd_dq(dq, q, K, V, #
for blk_idx in range(kv_blocks*2):
block_sparse_offset = (tl.load(kv_ptr + blk_idx//2).to(tl.int32)*2 + blk_idx%2) *step_n * stride_tok
block_size = tl.load(variable_block_sizes + blk_idx//2) - (blk_idx%2) * step_n
kT = tl.load(kT_ptrs + block_sparse_offset)
vT = tl.load(vT_ptrs + block_sparse_offset)
qk = tl.dot(q, kT)
p = tl.math.exp2(qk - m)
mask = tl.arange(0, BLOCK_N2) < block_size.to(tl.int32)
p = tl.where(mask[None, :], p , 0.0)
# Compute dP and dS.
dp = tl.dot(do, vT).to(tl.float32)
ds = p * (dp - Di[:, None])
@@ -378,6 +277,7 @@ def _attn_bwd(Q, K, V, sm_scale, #
M, D,
q2k_index, q2k_num, max_kv_blks,
k2q_index, k2q_num, max_q_blks,
variable_block_sizes,
# shared by Q/K/V/DO.
stride_z, stride_h, stride_tok, stride_d, #
H, N_CTX, #
@@ -428,6 +328,7 @@ def _attn_bwd(Q, K, V, sm_scale, #
DO, #
M, D, #
k2q_index, k2q_num, max_q_blks,
variable_block_sizes,
stride_tok, stride_d, #
H, N_CTX, #
BLOCK_M1, BLOCK_N1, HEAD_DIM, #
@@ -459,6 +360,7 @@ def _attn_bwd(Q, K, V, sm_scale, #
dq = _attn_bwd_dq(dq, q, K, V, #
do, m, D, #
q2k_index, q2k_num, max_kv_blks,
variable_block_sizes,
stride_tok, stride_d, #
H, N_CTX, #
BLOCK_M2, BLOCK_N2, HEAD_DIM, #
@@ -471,237 +373,77 @@ def _attn_bwd(Q, K, V, sm_scale, #
class _attention(torch.autograd.Function):
@staticmethod
def forward(ctx, q, k, v):
# shape constraints
sm_scale = 1.0 / (q.shape[-1] ** 0.5)
HEAD_DIM_Q, HEAD_DIM_K = q.shape[-1], k.shape[-1]
# when v is in float8_e5m2 it is transposed.
HEAD_DIM_V = v.shape[-1]
assert HEAD_DIM_Q == HEAD_DIM_K and HEAD_DIM_K == HEAD_DIM_V
assert HEAD_DIM_K in {16, 32, 64, 128, 256}
o = torch.empty_like(q)
stage = 1
extra_kern_args = {}
grid = lambda args: (triton.cdiv(q.shape[2], args["BLOCK_M"]), q.shape[0] * q.shape[1], 1)
M = torch.empty((q.shape[0], q.shape[1], q.shape[2]), device=q.device, dtype=torch.float32)
_attn_fwd[grid](
q, k, v, sm_scale, M, o, #
q.stride(0), q.stride(1), q.stride(2), q.stride(3), #
k.stride(0), k.stride(1), k.stride(2), k.stride(3), #
v.stride(0), v.stride(1), v.stride(2), v.stride(3), #
o.stride(0), o.stride(1), o.stride(2), o.stride(3), #
q.shape[0], q.shape[1], #
N_CTX=q.shape[2], #
HEAD_DIM=HEAD_DIM_K, #
STAGE=stage, #
**extra_kern_args)
ctx.save_for_backward(q, k, v, o, M)
ctx.grid = grid
ctx.sm_scale = sm_scale
ctx.HEAD_DIM = HEAD_DIM_K
return o
@staticmethod
def backward(ctx, do):
q, k, v, o, M = ctx.saved_tensors
assert do.is_contiguous()
assert q.stride() == k.stride() == v.stride() == o.stride() == do.stride()
dq = torch.empty_like(q)
dk = torch.empty_like(k)
dv = torch.empty_like(v)
BATCH, N_HEAD, N_CTX = q.shape[:3]
PRE_BLOCK = 128
BLOCK_M1, BLOCK_N1, BLOCK_M2, BLOCK_N2 = 32, 64, 64, 32
RCP_LN2 = 1.4426950408889634 # = 1.0 / ln(2)
arg_k = k
arg_k = arg_k * (ctx.sm_scale * RCP_LN2)
PRE_BLOCK = 128
assert N_CTX % PRE_BLOCK == 0
pre_grid = (N_CTX // PRE_BLOCK, BATCH * N_HEAD)
delta = torch.empty_like(M)
_attn_bwd_preprocess[pre_grid](
o, do, #
delta, #
BATCH, N_HEAD, N_CTX, #
BLOCK_M=PRE_BLOCK, HEAD_DIM=ctx.HEAD_DIM #
)
grid = (N_CTX // BLOCK_N1, 1, BATCH * N_HEAD)
_attn_bwd[grid](
q, arg_k, v, ctx.sm_scale, do, dq, dk, dv, #
M, delta, #
q.stride(0), q.stride(1), q.stride(2), q.stride(3), #
N_HEAD, N_CTX, #
BLOCK_M1=BLOCK_M1, BLOCK_N1=BLOCK_N1, #
BLOCK_M2=BLOCK_M2, BLOCK_N2=BLOCK_N2, #
HEAD_DIM=ctx.HEAD_DIM #
)
return dq, dk, dv, None, None
attention = _attention.apply
# ──────────────────────────── SPARSE ADDITION BEGIN ───────────────────────────
class _attention_sparse(torch.autograd.Function):
"""
Thin autograd wrapper that uses the sparse forward kernel above and the
standard dense backward kernels defined earlier (no extra memory use).
"""
def triton_block_sparse_attn_forward(q, k, v, q2k_index, q2k_num, variable_block_sizes):
B, H, T, D = q.shape
sm_scale = 1.0 / math.sqrt(D)
max_kv_blks = q2k_index.shape[-1]
assert T % 64 == 0, f"T must be a multiple of 64, but got {T}"
assert T // 64 == q2k_num.shape[-1], f"shape mismatch, T // 64 = {T // 64}, q2k_num.shape[-2] = {q2k_num.shape[-2]}"
o = torch.empty_like(q)
M = torch.empty((B, H, T), dtype=torch.float32, device=q.device)
@staticmethod
def forward(ctx, q, k, v, q2k_index, q2k_num, k2q_index, k2q_num):
B, H, T, D = q.shape
sm_scale = 1.0 / math.sqrt(D)
max_kv_blks = q2k_index.shape[-1]
assert T % 64 == 0, f"T must be a multiple of 64, but got {T}"
assert T // 64 == q2k_num.shape[-1], f"shape mismatch, T // 64 = {T // 64}, q2k_num.shape[-2] = {q2k_num.shape[-2]}"
o = torch.empty_like(q)
M = torch.empty((B, H, T), dtype=torch.float32, device=q.device)
grid = lambda _: (triton.cdiv(T, 64), B * H, 1)
_attn_fwd_sparse[grid](
q, k, v, sm_scale,
q2k_index, q2k_num, max_kv_blks,
variable_block_sizes,
M, o,
q.stride(0), q.stride(1), q.stride(2), q.stride(3),
k.stride(0), k.stride(1), k.stride(2), k.stride(3),
v.stride(0), v.stride(1), v.stride(2), v.stride(3),
o.stride(0), o.stride(1), o.stride(2), o.stride(3),
B, H, T,
HEAD_DIM=D, STAGE=3
)
grid = lambda _: (triton.cdiv(T, 64), B * H, 1)
_attn_fwd_sparse[grid](
q, k, v, sm_scale,
q2k_index, q2k_num, max_kv_blks,
M, o,
q.stride(0), q.stride(1), q.stride(2), q.stride(3),
k.stride(0), k.stride(1), k.stride(2), k.stride(3),
v.stride(0), v.stride(1), v.stride(2), v.stride(3),
o.stride(0), o.stride(1), o.stride(2), o.stride(3),
B, H, T,
HEAD_DIM=D, STAGE=3
)
return o, M
ctx.save_for_backward(q, k, v, o, M, q2k_index, q2k_num, k2q_index, k2q_num)
ctx.grid = None
ctx.sm_scale = sm_scale
ctx.HEAD_DIM = D
return o
def triton_block_sparse_attn_backward(do, q, k, v, o, M, q2k_index, q2k_num, k2q_index, k2q_num, variable_block_sizes):
assert do.is_contiguous()
assert q.stride() == k.stride() == v.stride() == o.stride() == do.stride()
B, H, T, D = q.shape
sm_scale = 1.0 / math.sqrt(D)
dq = torch.empty_like(q)
dk = torch.empty_like(k)
dv = torch.empty_like(v)
BATCH, N_HEAD, N_CTX = q.shape[:3]
BLOCK_M1, BLOCK_N1, BLOCK_M2, BLOCK_N2 = 32, 64, 64, 32
RCP_LN2 = 1.4426950408889634 # = 1.0 / ln(2)
arg_k = k
arg_k = arg_k * (sm_scale * RCP_LN2)
PRE_BLOCK = 64
assert N_CTX % PRE_BLOCK == 0
pre_grid = (N_CTX // PRE_BLOCK, BATCH * N_HEAD)
delta = torch.empty_like(M)
_attn_bwd_preprocess[pre_grid](
o, do, #
delta, #
BATCH, N_HEAD, N_CTX, #
BLOCK_M=PRE_BLOCK, HEAD_DIM=D #
)
max_q_blks = k2q_index.shape[-1]
max_kv_blks = q2k_index.shape[-1]
grid = (N_CTX // BLOCK_N1, 1, BATCH * N_HEAD)
_attn_bwd[grid](
q, arg_k, v, sm_scale, do, dq, dk, dv, #
M, delta, #
q2k_index, q2k_num, max_kv_blks,
k2q_index, k2q_num, max_q_blks,
variable_block_sizes,
q.stride(0), q.stride(1), q.stride(2), q.stride(3), #
N_HEAD, N_CTX, #
BLOCK_M1=BLOCK_M1, BLOCK_N1=BLOCK_N1, #
BLOCK_M2=BLOCK_M2, BLOCK_N2=BLOCK_N2, #
HEAD_DIM=D #
)
@staticmethod
def backward(ctx, do):
q, k, v, o, M, q2k_index, q2k_num, k2q_index, k2q_num = ctx.saved_tensors
assert do.is_contiguous()
assert q.stride() == k.stride() == v.stride() == o.stride() == do.stride()
dq = torch.empty_like(q)
dk = torch.empty_like(k)
dv = torch.empty_like(v)
BATCH, N_HEAD, N_CTX = q.shape[:3]
PRE_BLOCK = 128
BLOCK_M1, BLOCK_N1, BLOCK_M2, BLOCK_N2 = 32, 64, 64, 32
RCP_LN2 = 1.4426950408889634 # = 1.0 / ln(2)
arg_k = k
arg_k = arg_k * (ctx.sm_scale * RCP_LN2)
PRE_BLOCK = 128
assert N_CTX % PRE_BLOCK == 0
pre_grid = (N_CTX // PRE_BLOCK, BATCH * N_HEAD)
delta = torch.empty_like(M)
_attn_bwd_preprocess[pre_grid](
o, do, #
delta, #
BATCH, N_HEAD, N_CTX, #
BLOCK_M=PRE_BLOCK, HEAD_DIM=ctx.HEAD_DIM #
)
max_q_blks = k2q_index.shape[-1]
max_kv_blks = q2k_index.shape[-1]
grid = (N_CTX // BLOCK_N1, 1, BATCH * N_HEAD)
_attn_bwd[grid](
q, arg_k, v, ctx.sm_scale, do, dq, dk, dv, #
M, delta, #
q2k_index, q2k_num, max_kv_blks,
k2q_index, k2q_num, max_q_blks,
q.stride(0), q.stride(1), q.stride(2), q.stride(3), #
N_HEAD, N_CTX, #
BLOCK_M1=BLOCK_M1, BLOCK_N1=BLOCK_N1, #
BLOCK_M2=BLOCK_M2, BLOCK_N2=BLOCK_N2, #
HEAD_DIM=ctx.HEAD_DIM #
)
return dq, dk, dv, None, None, None, None
attention_sparse = _attention_sparse.apply
# ──────────────────────────── SPARSE ADDITION END ─────────────────────────────
return dq, dk, dv
try:
from flash_attn.flash_attn_interface import \
flash_attn_qkvpacked_func as flash_attn_func
HAS_FLASH = True
except BaseException:
HAS_FLASH = False
TORCH_HAS_FP8 = hasattr(torch, 'float8_e5m2')
BATCH, N_HEADS, HEAD_DIM = 4, 32, 128
# vary seq length for fixed head and batch=4
configs = []
for mode in ["fwd", "bwd"]:
configs.append(
triton.testing.Benchmark(
x_names=["N_CTX"],
x_vals=[2**i for i in range(10, 15)],
line_arg="provider",
line_vals=["triton-fp16"] + (["triton-fp8"] if TORCH_HAS_FP8 else []) +
(["flash"] if HAS_FLASH else []),
line_names=["Triton [FP16]"] + (["Triton [FP8]"] if TORCH_HAS_FP8 else []) +
(["Flash-2"] if HAS_FLASH else []),
styles=[("red", "-"), ("blue", "-"), ("green", "-")],
ylabel="ms",
plot_name=f"fused-attention-batch{BATCH}-head{N_HEADS}-d{HEAD_DIM}-{mode}",
args={
"H": N_HEADS,
"BATCH": BATCH,
"HEAD_DIM": HEAD_DIM,
"mode": mode,
},
))
@triton.testing.perf_report(configs)
def bench_flash_attention(BATCH, H, N_CTX, HEAD_DIM, mode, provider, device="cuda"):
assert mode in ["fwd", "bwd"]
warmup = 25
rep = 100
dtype = torch.bfloat16
if "triton" in provider:
q = torch.randn((BATCH, H, N_CTX, HEAD_DIM), dtype=dtype, device=device, requires_grad=True)
k = torch.randn((BATCH, H, N_CTX, HEAD_DIM), dtype=dtype, device=device, requires_grad=True)
v = torch.randn((BATCH, H, N_CTX, HEAD_DIM), dtype=dtype, device=device, requires_grad=True)
if mode == "fwd" and "fp8" in provider:
q = q.to(torch.float8_e5m2)
k = k.to(torch.float8_e5m2)
v = v.permute(0, 1, 3, 2).contiguous()
v = v.permute(0, 1, 3, 2)
v = v.to(torch.float8_e5m2)
fn = lambda: attention(q, k, v)
if mode == "bwd":
o = fn()
do = torch.randn_like(o)
fn = lambda: o.backward(do, retain_graph=True)
ms = triton.testing.do_bench(fn, warmup=warmup, rep=rep)
if provider == "flash":
qkv = torch.randn((BATCH, N_CTX, 3, H, HEAD_DIM), dtype=dtype, device=device, requires_grad=True)
fn = lambda: flash_attn_func(qkv, causal=False)
if mode == "bwd":
o = fn()
do = torch.randn_like(o)
fn = lambda: o.backward(do, retain_graph=True)
ms = triton.testing.do_bench(fn, warmup=warmup, rep=rep)
flops_per_matmul = 2.0 * BATCH * H * N_CTX * N_CTX * HEAD_DIM
total_flops = 2 * flops_per_matmul
if mode == "bwd":
total_flops *= 2.5 # 2.0(bwd) + 0.5(recompute)
return total_flops / ms * 1e-9
if __name__ == "__main__":
# only works on post-Ampere GPUs right now
bench_flash_attention.run(save_path=".", print_data=True)
+66 -240
View File
@@ -46,225 +46,9 @@ template<int D> struct fwd_globals {
int32_t *__restrict__ q2k_block_sparse_index;
int32_t *__restrict__ q2k_block_sparse_num;
int32_t *__restrict__ block_size;
};
template<int D>
__global__ __launch_bounds__(128, 3) // encourage compiler to reduce register usage so that an SM can hold 3 CTAs. Performance will drop from 391T to 353T if not specified explicitly.
void fwd_attend_ker_even(const __grid_constant__ fwd_globals<D> g) {
extern __shared__ int __shm[];
tma_swizzle_allocator al((int*)&__shm[0]);
using K = fwd_attend_ker_tile_dims<D>;
using q_tile = st_bf<64, K::tile_width>;
using k_tile = st_bf<128, K::tile_width>;
using v_tile = st_bf<128, K::tile_width>;
using k_tile_half = st_bf<64, K::tile_width>;
using v_tile_half = st_bf<64, K::tile_width>;
using l_col_vec = col_vec<st_fl<64, K::tile_width>>;
using o_tile = st_bf<64, K::tile_width>;
q_tile (&q_smem)[1] = al.allocate<q_tile, 1>();
k_tile_half (&k_smem_0)[1] = al.allocate<k_tile_half, 1 >();
k_tile_half (&k_smem_1)[1] = al.allocate<k_tile_half, 1 >();
k_tile (*k_smem) = reinterpret_cast<k_tile(*)>(k_smem_0);
v_tile_half (&v_smem_0)[1] = al.allocate<v_tile_half, 1 >();
v_tile_half (&v_smem_1)[1] = al.allocate<v_tile_half, 1 >();
v_tile (*v_smem) = reinterpret_cast<v_tile(*)>(v_smem_0);
l_col_vec (&l_smem)[1] = al.allocate<l_col_vec, 1>();
auto (*o_smem) = reinterpret_cast<o_tile(*)>(q_smem);
int kv_head_idx = blockIdx.y / g.hr;
int seq_idx = blockIdx.x;
int32_t* q2k_block_sparse_index_ptr = g.q2k_block_sparse_index + blockIdx.z * gridDim.y * gridDim.x * g.max_kv_blocks_per_q + blockIdx.y * gridDim.x * g.max_kv_blocks_per_q + blockIdx.x * g.max_kv_blocks_per_q;
int32_t* q2k_block_sparse_num_ptr = g.q2k_block_sparse_num + blockIdx.z * gridDim.y * gridDim.x + blockIdx.y * gridDim.x + blockIdx.x;
int32_t kv_blocks = q2k_block_sparse_num_ptr[0] / 2; // each iter load 2 kv blocks
__shared__ kittens::semaphore qsmem_semaphore, k_smem_arrived, v_smem_arrived;
if (threadIdx.x == 0) {
int32_t kv_block_index[2];
reinterpret_cast<float2*>(kv_block_index)[0] = reinterpret_cast<float2*>(q2k_block_sparse_index_ptr)[0];
init_semaphore(qsmem_semaphore, 0, 1);
init_semaphore(k_smem_arrived, 0, 1);
init_semaphore(v_smem_arrived, 0, 1);
// preload q block
coord<q_tile> q_tile_idx = {blockIdx.z, blockIdx.y, seq_idx, 0};
tma::expect_bytes(qsmem_semaphore, sizeof(q_smem));
tma::load_async(q_smem[0], g.q, q_tile_idx, qsmem_semaphore);
// preload the zeroth block of kv
tma::expect_bytes(k_smem_arrived, sizeof(k_tile));
coord<k_tile_half> k_tile_idx_0 = {blockIdx.z, kv_head_idx, kv_block_index[0], 0};
coord<k_tile_half> k_tile_idx_1 = {blockIdx.z, kv_head_idx, kv_block_index[1], 0};
tma::load_async(k_smem_0[0], g.k, k_tile_idx_0, k_smem_arrived);
tma::load_async(k_smem_1[0], g.k, k_tile_idx_1, k_smem_arrived);
tma::expect_bytes(v_smem_arrived, sizeof(v_tile));
coord<v_tile_half> v_tile_idx_0 = {blockIdx.z, kv_head_idx, kv_block_index[0], 0};
coord<v_tile_half> v_tile_idx_1 = {blockIdx.z, kv_head_idx, kv_block_index[1], 0};
tma::load_async(v_smem_0[0], g.v, v_tile_idx_0, v_smem_arrived);
tma::load_async(v_smem_1[0], g.v, v_tile_idx_1, v_smem_arrived);
}
__syncthreads();
rt_fl<16, 128> att_block;
rt_bf<16, 128> att_block_mma;
rt_fl<16, K::tile_width> o_reg;
col_vec<rt_fl<16, 128>> max_vec, norm_vec, max_vec_last_scaled, max_vec_scaled;
neg_infty(max_vec);
zero(norm_vec);
zero(o_reg);
// wait for q block
wait(qsmem_semaphore, 0);
for (int kv_idx = 0; kv_idx < kv_blocks - 1; kv_idx++) {
// preload kv index
int32_t kv_block_index[2];
reinterpret_cast<float2*>(kv_block_index)[0] = reinterpret_cast<float2*>(q2k_block_sparse_index_ptr)[kv_idx + 1];
// wait k
wait(k_smem_arrived, kv_idx % 2);
// compute QK^T
warpgroup::mm_ABt(att_block, q_smem[0], k_smem[0]);
copy(max_vec_last_scaled, max_vec);
if constexpr (D == 64) { mul(max_vec_last_scaled, max_vec_last_scaled, 1.44269504089f*0.125f); }
else { mul(max_vec_last_scaled, max_vec_last_scaled, 1.44269504089f*0.08838834764f); }
warpgroup::mma_async_wait();
// load K
if (threadIdx.x == 0) {
tma::expect_bytes(k_smem_arrived, sizeof(k_tile));
coord<k_tile_half> k_tile_idx_0 = {blockIdx.z, kv_head_idx, kv_block_index[0], 0};
coord<k_tile_half> k_tile_idx_1 = {blockIdx.z, kv_head_idx, kv_block_index[1], 0};
tma::load_async(k_smem_0[0], g.k, k_tile_idx_0, k_smem_arrived);
tma::load_async(k_smem_1[0], g.k, k_tile_idx_1, k_smem_arrived);
}
// exp
row_max(max_vec, att_block, max_vec);
if constexpr (D == 64) {
mul(att_block, att_block, 1.44269504089f*0.125f);
mul(max_vec_scaled, max_vec, 1.44269504089f*0.125f);
}
else {
mul(att_block, att_block, 1.44269504089f*0.08838834764f);
mul(max_vec_scaled, max_vec, 1.44269504089f*0.08838834764f);
}
sub_row(att_block, att_block, max_vec_scaled);
exp2(att_block, att_block);
sub(max_vec_last_scaled, max_vec_last_scaled, max_vec_scaled);
exp2(max_vec_last_scaled, max_vec_last_scaled);
mul(norm_vec, norm_vec, max_vec_last_scaled);
row_sum(norm_vec, att_block, norm_vec);
add(att_block, att_block, 0.f);
copy(att_block_mma, att_block);
mul_row(o_reg, o_reg, max_vec_last_scaled);
// wait v
wait(v_smem_arrived, kv_idx % 2);
// compute SV
warpgroup::mma_AB(o_reg, att_block_mma, v_smem[0]);
warpgroup::mma_async_wait();
// load V
if (threadIdx.x == 0) {
tma::expect_bytes(v_smem_arrived, sizeof(v_tile));
// coord<v_tile> v_tile_idx = {blockIdx.z, kv_head_idx, kv_idx + 1, 0};
// tma::load_async(v_smem[0], g.v, v_tile_idx, v_smem_arrived);
coord<v_tile_half> v_tile_idx_0 = {blockIdx.z, kv_head_idx, kv_block_index[0], 0};
coord<v_tile_half> v_tile_idx_1 = {blockIdx.z, kv_head_idx, kv_block_index[1], 0};
tma::load_async(v_smem_0[0], g.v, v_tile_idx_0, v_smem_arrived);
tma::load_async(v_smem_1[0], g.v, v_tile_idx_1, v_smem_arrived);
}
}
// last iter
{
int kv_idx = kv_blocks - 1;
// wait k
wait(k_smem_arrived, kv_idx % 2);
// compute QK^T
warpgroup::mm_ABt(att_block, q_smem[0], k_smem[0]);
copy(max_vec_last_scaled, max_vec);
if constexpr (D == 64) { mul(max_vec_last_scaled, max_vec_last_scaled, 1.44269504089f*0.125f); }
else { mul(max_vec_last_scaled, max_vec_last_scaled, 1.44269504089f*0.08838834764f); }
warpgroup::mma_async_wait();
// exp
row_max(max_vec, att_block, max_vec);
if constexpr (D == 64) {
mul(att_block, att_block, 1.44269504089f*0.125f);
mul(max_vec_scaled, max_vec, 1.44269504089f*0.125f);
}
else {
mul(att_block, att_block, 1.44269504089f*0.08838834764f);
mul(max_vec_scaled, max_vec, 1.44269504089f*0.08838834764f);
}
sub_row(att_block, att_block, max_vec_scaled);
exp2(att_block, att_block);
sub(max_vec_last_scaled, max_vec_last_scaled, max_vec_scaled);
exp2(max_vec_last_scaled, max_vec_last_scaled);
mul(norm_vec, norm_vec, max_vec_last_scaled);
row_sum(norm_vec, att_block, norm_vec);
add(att_block, att_block, 0.f);
copy(att_block_mma, att_block);
mul_row(o_reg, o_reg, max_vec_last_scaled);
// wait v
wait(v_smem_arrived, kv_idx % 2);
// compute SV
warpgroup::mma_AB(o_reg, att_block_mma, v_smem[0]);
warpgroup::mma_async_wait();
}
div_row(o_reg, o_reg, norm_vec);
warpgroup::store(o_smem[0], o_reg);
__syncthreads();
// TK store_async internally calls syncwarp so we need to route on warp level
if (threadIdx.x / 32 == 0) {
coord<o_tile> o_tile_idx = {blockIdx.z, blockIdx.y, seq_idx, 0};
tma::store_async(g.o, o_smem[0], o_tile_idx);
}
mul(max_vec_scaled, max_vec_scaled, 0.69314718056f);
log(norm_vec, norm_vec);
add(norm_vec, norm_vec, max_vec_scaled);
if constexpr (D == 64) { mul(norm_vec, norm_vec, -8.0f); }
else { mul(norm_vec, norm_vec, -11.313708499f); }
warpgroup::store(l_smem[0], norm_vec);
__syncthreads();
if (threadIdx.x / 32 == 0) {
coord<l_col_vec> tile_idx = {blockIdx.z, blockIdx.y, 0, seq_idx};
tma::store_async(g.l, l_smem[0], tile_idx);
}
tma::store_async_wait();
}
template<int D>
__global__ __launch_bounds__(128, 4)
@@ -357,6 +141,7 @@ void fwd_attend_ker(const __grid_constant__ fwd_globals<D> g) { // use block siz
}
// exp
right_fill(att_block, att_block, g.block_size[q2k_block_sparse_index_ptr[kv_idx]], base_types::constants<float>::neg_infty());
row_max(max_vec, att_block, max_vec);
if constexpr (D == 64) {
@@ -409,6 +194,8 @@ void fwd_attend_ker(const __grid_constant__ fwd_globals<D> g) { // use block siz
warpgroup::mma_async_wait();
// exp
right_fill(att_block, att_block, g.block_size[q2k_block_sparse_index_ptr[kv_idx]], base_types::constants<float>::neg_infty());
row_max(max_vec, att_block, max_vec);
if constexpr (D == 64) {
@@ -484,8 +271,9 @@ struct bwd_prep_globals {
d_gl d;
};
constexpr int PREP_NUM_WARPS = (1);
template<int D>
__global__ __launch_bounds__(4*kittens::WARP_THREADS, (D == 64) ? 2 : 1)
__global__ __launch_bounds__(PREP_NUM_WARPS*kittens::WARP_THREADS, (D == 64) ? 6 / PREP_NUM_WARPS : 3 / PREP_NUM_WARPS)
void bwd_attend_prep_ker(const __grid_constant__ bwd_prep_globals<D> g) {
extern __shared__ int __shm[];
tma_swizzle_allocator al((int*)&__shm[0]);
@@ -496,9 +284,9 @@ void bwd_attend_prep_ker(const __grid_constant__ bwd_prep_globals<D> g) {
using o_tile = st_bf<4*16, D>;
using d_tile = col_vec<st_fl<4*16, D>>;
og_tile (&og_smem)[4] = al.allocate<og_tile, 4>();
o_tile (&o_smem) [4] = al.allocate<o_tile , 4>();
d_tile (&d_smem) [4] = al.allocate<d_tile , 4>();
og_tile (&og_smem)[PREP_NUM_WARPS] = al.allocate<og_tile, PREP_NUM_WARPS>();
o_tile (&o_smem) [PREP_NUM_WARPS] = al.allocate<o_tile , PREP_NUM_WARPS>();
d_tile (&d_smem) [PREP_NUM_WARPS] = al.allocate<d_tile , PREP_NUM_WARPS>();
rt_fl<4*16, D> og_reg, o_reg;
col_vec<rt_fl<4*16, D>> d_reg;
@@ -507,13 +295,13 @@ void bwd_attend_prep_ker(const __grid_constant__ bwd_prep_globals<D> g) {
if (threadIdx.x == 0) {
init_semaphore(smem_semaphore, 0, 1);
tma::expect_bytes(smem_semaphore, sizeof(og_smem[0]) * 4 * 2);
tma::expect_bytes(smem_semaphore, sizeof(og_smem[0]) * PREP_NUM_WARPS * 2);
}
__syncthreads();
if (warpid == 0) {
for (int w = 0; w < 4; w++) {
coord<o_tile> tile_idx = {blockIdx.z, blockIdx.y, (blockIdx.x * 4) + w, 0};
for (int w = 0; w < PREP_NUM_WARPS; w++) {
coord<o_tile> tile_idx = {blockIdx.z, blockIdx.y, (blockIdx.x * PREP_NUM_WARPS) + w, 0};
tma::load_async(o_smem[w], g.o, tile_idx, smem_semaphore);
tma::load_async(og_smem[w], g.og, tile_idx, smem_semaphore);
}
@@ -528,8 +316,8 @@ void bwd_attend_prep_ker(const __grid_constant__ bwd_prep_globals<D> g) {
__syncthreads();
if (warpid == 0) {
for (int w = 0; w < 4; w++) {
coord<d_tile> tile_idx = {blockIdx.z, blockIdx.y, 0, (blockIdx.x * 4) + w};
for (int w = 0; w < PREP_NUM_WARPS; w++) {
coord<d_tile> tile_idx = {blockIdx.z, blockIdx.y, 0, (blockIdx.x * PREP_NUM_WARPS) + w};
tma::store_async(g.d, d_smem[w], tile_idx);
}
}
@@ -591,6 +379,7 @@ struct bwd_globals {
int32_t *__restrict__ k2q_block_sparse_index;
int32_t *__restrict__ k2q_block_sparse_num;
int32_t *__restrict__ block_size;
};
__device__ static inline void
@@ -713,7 +502,7 @@ void bwd_attend_ker(const __grid_constant__ bwd_globals<D> g) {
// wait for kv
wait(kv_b, 0);
int fill_start = g.block_size[blockIdx.x] - 16 * kittens::warpid();
for (int qo_idx = 0; qo_idx < qo_blocks - 1; qo_idx++) {
// preload q index
store_qg_block_index = load_q_block_index;
@@ -732,7 +521,8 @@ void bwd_attend_ker(const __grid_constant__ bwd_globals<D> g) {
if constexpr (D == 64) { mul(s_block_t, s_block_t, 1.44269504089f*0.125f); }
else { mul(s_block_t, s_block_t, 1.44269504089f*0.08838834764f); }
lower_fill(s_block_t, s_block_t, fill_start, base_types::constants<float>::neg_infty());
exp2(s_block_t, s_block_t); // P_i
copy(p_block_t, s_block_t);
copy(p_block_t_mma, s_block_t);
@@ -810,7 +600,7 @@ void bwd_attend_ker(const __grid_constant__ bwd_globals<D> g) {
if constexpr (D == 64) { mul(s_block_t, s_block_t, 1.44269504089f*0.125f); }
else { mul(s_block_t, s_block_t, 1.44269504089f*0.08838834764f); }
lower_fill(s_block_t, s_block_t, fill_start, base_types::constants<float>::neg_infty());
exp2(s_block_t, s_block_t); // P_i
copy(p_block_t, s_block_t);
copy(p_block_t_mma, s_block_t);
@@ -876,7 +666,14 @@ void bwd_attend_ker(const __grid_constant__ bwd_globals<D> g) {
#include <iostream>
std::vector<torch::Tensor>
block_sparse_attention_forward(torch::Tensor q, torch::Tensor k, torch::Tensor v, torch::Tensor q2k_block_sparse_index, torch::Tensor q2k_block_sparse_num)
block_sparse_attention_forward(
torch::Tensor q,
torch::Tensor k,
torch::Tensor v,
torch::Tensor q2k_block_sparse_index,
torch::Tensor q2k_block_sparse_num,
torch::Tensor block_size
)
{
CHECK_INPUT(q);
CHECK_INPUT(k);
@@ -888,6 +685,10 @@ block_sparse_attention_forward(torch::Tensor q, torch::Tensor k, torch::Tensor v
auto qo_heads = q.size(1);
auto kv_heads = k.size(1);
auto max_kv_blocks_per_q = q2k_block_sparse_index.size(3);
auto num_q_blocks = block_size.size(0);
TORCH_CHECK(batch==1, "Batch size dim will be removed in the future, please set batch to 1");
TORCH_CHECK(num_q_blocks * 64 == seq_len, "This kernel supports variable block size, but it assumes the input sequence is properly padded.");
TORCH_CHECK(num_q_blocks == q2k_block_sparse_index.size(2), "Number of Q blocks does not match between q2k_block_sparse_index and block_size");
// check to see that these dimensions match for all inputs
TORCH_CHECK(q.size(0) == batch, "Q batch dimension - idx 0 - must match for all inputs");
TORCH_CHECK(k.size(0) == batch, "K batch dimension - idx 0 - must match for all inputs");
@@ -967,7 +768,19 @@ block_sparse_attention_forward(torch::Tensor q, torch::Tensor k, torch::Tensor v
l_global lg_arg{d_l, static_cast<unsigned int>(batch), static_cast<unsigned int>(qo_heads), 1U, static_cast<unsigned int>(seq_len)};
o_global og_arg{d_o, static_cast<unsigned int>(batch), static_cast<unsigned int>(qo_heads), static_cast<unsigned int>(seq_len), 64U};
globals g{qg_arg, kg_arg, vg_arg, lg_arg, og_arg, static_cast<int>(seq_len), static_cast<int>(hr), static_cast<int>(max_kv_blocks_per_q), reinterpret_cast<int32_t*>(q2k_block_sparse_index.data_ptr()), reinterpret_cast<int32_t*>(q2k_block_sparse_num.data_ptr())};
globals g{
qg_arg,
kg_arg,
vg_arg,
lg_arg,
og_arg,
static_cast<int>(seq_len),
static_cast<int>(hr),
static_cast<int>(max_kv_blocks_per_q),
reinterpret_cast<int32_t*>(q2k_block_sparse_index.data_ptr()),
reinterpret_cast<int32_t*>(q2k_block_sparse_num.data_ptr()),
reinterpret_cast<int32_t*>(block_size.data_ptr())
};
constexpr int mem_size = 54000;
@@ -1006,7 +819,19 @@ block_sparse_attention_forward(torch::Tensor q, torch::Tensor k, torch::Tensor v
l_global lg_arg{d_l, static_cast<unsigned int>(batch), static_cast<unsigned int>(qo_heads), 1U, static_cast<unsigned int>(seq_len)};
o_global og_arg{d_o, static_cast<unsigned int>(batch), static_cast<unsigned int>(qo_heads), static_cast<unsigned int>(seq_len), 128U};
globals g{qg_arg, kg_arg, vg_arg, lg_arg, og_arg, static_cast<int>(seq_len), static_cast<int>(hr), static_cast<int>(max_kv_blocks_per_q), reinterpret_cast<int32_t*>(q2k_block_sparse_index.data_ptr()), reinterpret_cast<int32_t*>(q2k_block_sparse_num.data_ptr())};
globals g{
qg_arg,
kg_arg,
vg_arg,
lg_arg,
og_arg,
static_cast<int>(seq_len),
static_cast<int>(hr),
static_cast<int>(max_kv_blocks_per_q),
reinterpret_cast<int32_t*>(q2k_block_sparse_index.data_ptr()),
reinterpret_cast<int32_t*>(q2k_block_sparse_num.data_ptr()),
reinterpret_cast<int32_t*>(block_size.data_ptr())
};
constexpr int mem_size = 54000;
@@ -1036,7 +861,8 @@ block_sparse_attention_backward(torch::Tensor q,
torch::Tensor l_vec,
torch::Tensor og,
torch::Tensor k2q_block_sparse_index,
torch::Tensor k2q_block_sparse_num)
torch::Tensor k2q_block_sparse_num,
torch::Tensor block_size)
{
CHECK_INPUT(q);
CHECK_INPUT(k);
@@ -1049,7 +875,7 @@ block_sparse_attention_backward(torch::Tensor q,
auto seq_len = q.size(2);
auto head_dim = q.size(3);
auto max_q_blocks_per_kv = k2q_block_sparse_index.size(3);
TORCH_CHECK(k2q_block_sparse_index.size(2) == block_size.size(0), "k2q_block_sparse_index.size(2) must match block_size.size(0)");
// check to see that these dimensions match for all inputs
TORCH_CHECK(q.size(0) == batch, "Q batch dimension - idx 0 - must match for all inputs");
TORCH_CHECK(k.size(0) == batch, "K batch dimension - idx 0 - must match for all inputs");
@@ -1136,7 +962,7 @@ block_sparse_attention_backward(torch::Tensor q,
float* d_vg = reinterpret_cast<float*>(vg_ptr);
constexpr int mem_size = kittens::MAX_SHARED_MEMORY;
int threads = 4 * kittens::WARP_THREADS;
int threads = PREP_NUM_WARPS * kittens::WARP_THREADS;
//cudadevicesynchronize();
const c10::cuda::OptionalCUDAGuard device_guard(q.device());
@@ -1145,7 +971,7 @@ block_sparse_attention_backward(torch::Tensor q,
// cudaStreamSynchronize(stream);
// TORCH_CHECK(seq_len % (4*kittens::TILE_DIM*4) == 0, "sequence length must be divisible by 256");
dim3 grid_bwd(seq_len/(4*kittens::TILE_ROW_DIM<bf16>*4), qo_heads, batch);
dim3 grid_bwd(seq_len/(PREP_NUM_WARPS*kittens::TILE_ROW_DIM<bf16>*4), qo_heads, batch);
if (head_dim == 64) {
using og_tile = st_bf<4*16, 64>;
@@ -1220,8 +1046,8 @@ block_sparse_attention_backward(torch::Tensor q,
static_cast<int>(hr),
static_cast<int>(max_q_blocks_per_kv),
reinterpret_cast<int32_t*>(k2q_block_sparse_index.data_ptr()),
reinterpret_cast<int32_t*>(k2q_block_sparse_num.data_ptr())
};
reinterpret_cast<int32_t*>(k2q_block_sparse_num.data_ptr()),
reinterpret_cast<int32_t*>(block_size.data_ptr())};
dim3 grid_bwd_2(seq_len/64, qo_heads, batch);
threads = 128;
@@ -1324,8 +1150,8 @@ block_sparse_attention_backward(torch::Tensor q,
static_cast<int>(hr),
static_cast<int>(max_q_blocks_per_kv),
reinterpret_cast<int32_t*>(k2q_block_sparse_index.data_ptr()),
reinterpret_cast<int32_t*>(k2q_block_sparse_num.data_ptr())
};
reinterpret_cast<int32_t*>(k2q_block_sparse_num.data_ptr()),
reinterpret_cast<int32_t*>(block_size.data_ptr())};
dim3 grid_bwd_2(seq_len/64, qo_heads, batch);
threads = 128;
+182
View File
@@ -0,0 +1,182 @@
import torch
try:
from vsa_cuda import block_sparse_fwd, block_sparse_bwd
except ImportError:
block_sparse_fwd = None
block_sparse_bwd = None
from vsa.block_sparse_attn_triton import triton_block_sparse_attn_forward, triton_block_sparse_attn_backward
assert torch.__version__ >= "2.4.0", "VSA requires PyTorch 2.4.0 or higher"
from vsa.index import map_to_index
from typing import Tuple, Optional
@torch.library.custom_op("vsa::block_sparse_attn_SM90", mutates_args=(), device_types="cuda")
def block_sparse_attn_SM90(
q_padded: torch.Tensor,
k_padded: torch.Tensor,
v_padded: torch.Tensor,
block_map: torch.Tensor,
variable_block_sizes: torch.Tensor,
)-> Tuple[torch.Tensor, torch.Tensor]:
q_padded = q_padded.contiguous()
k_padded = k_padded.contiguous()
v_padded = v_padded.contiguous()
q2k_block_sparse_index, q2k_block_sparse_num = map_to_index(block_map)
variable_block_sizes = variable_block_sizes.int()
o_padded, lse_padded = block_sparse_fwd(q_padded, k_padded, v_padded, q2k_block_sparse_index, q2k_block_sparse_num, variable_block_sizes)
return o_padded, lse_padded
@torch.library.register_fake("vsa::block_sparse_attn_SM90")
def _block_sparse_attn_SM90_fake(
q_padded: torch.Tensor,
k_padded: torch.Tensor,
v_padded: torch.Tensor,
block_map: torch.Tensor,
variable_block_sizes: torch.Tensor,
) -> Tuple[torch.Tensor, torch.Tensor]:
q_padded, k_padded, v_padded = [x.contiguous() for x in (q_padded, k_padded, v_padded)]
B, H, S, D = q_padded.shape
o_padded = torch.empty_like(q_padded)
lse_padded = torch.empty((B, H, S, 1), device=q_padded.device, dtype=torch.float32)
return o_padded, lse_padded
@torch.library.custom_op("vsa::block_sparse_attn_backward_SM90", mutates_args=(), device_types="cuda")
def block_sparse_attn_backward_SM90(
grad_output_padded: torch.Tensor,
q_padded: torch.Tensor,
k_padded: torch.Tensor,
v_padded: torch.Tensor,
o_padded: torch.Tensor,
lse_padded: torch.Tensor,
block_map: torch.Tensor,
variable_block_sizes: torch.Tensor,
)-> Tuple[torch.Tensor, torch.Tensor, torch.Tensor]:
grad_output_padded = grad_output_padded.contiguous()
k2q_block_sparse_index, k2q_block_sparse_num = map_to_index(block_map.transpose(-1, -2))
grad_q_padded, grad_k_padded, grad_v_padded = block_sparse_bwd(
q_padded, k_padded, v_padded, o_padded, lse_padded, grad_output_padded, k2q_block_sparse_index, k2q_block_sparse_num, variable_block_sizes
)
grad_q_padded = grad_q_padded.to(grad_output_padded.dtype)
grad_k_padded = grad_k_padded.to(grad_output_padded.dtype)
grad_v_padded = grad_v_padded.to(grad_output_padded.dtype)
return grad_q_padded, grad_k_padded, grad_v_padded
@torch.library.register_fake("vsa::block_sparse_attn_backward_SM90")
def _block_sparse_attn_backward_SM90_fake(
grad_output_padded: torch.Tensor,
q_padded: torch.Tensor,
k_padded: torch.Tensor,
v_padded: torch.Tensor,
o_padded: torch.Tensor,
lse_padded: torch.Tensor,
block_map: torch.Tensor,
variable_block_sizes: torch.Tensor,
) -> Tuple[torch.Tensor, torch.Tensor, torch.Tensor, torch.Tensor]:
torch._check(grad_output_padded.dtype == torch.bfloat16)
torch._check(lse_padded.dtype == torch.float32)
grad_output_padded = grad_output_padded.contiguous()
dq = torch.empty_like(grad_output_padded)
dk = torch.empty_like(grad_output_padded)
dv = torch.empty_like(grad_output_padded)
return dq, dk, dv
def backward_SM90(ctx, grad_output1, grad_output2):
q_padded, k_padded, v_padded, o_padded, lse_padded, block_map, variable_block_sizes= ctx.saved_tensors
dq, dk, dv = block_sparse_attn_backward_SM90(grad_output1, q_padded, k_padded, v_padded, o_padded, lse_padded, block_map, variable_block_sizes)
return dq, dk, dv, None, None
def setup_context_SM90(ctx, inputs, output):
q_padded, k_padded, v_padded, block_map, variable_block_sizes = inputs
o_padded, lse_padded = output
ctx.save_for_backward(q_padded, k_padded, v_padded, o_padded, lse_padded, block_map, variable_block_sizes)
block_sparse_attn_SM90.register_autograd(backward_SM90, setup_context=setup_context_SM90)
@torch.library.custom_op("vsa::block_sparse_attn_triton", mutates_args=(), device_types="cuda")
def block_sparse_attn_triton(
q: torch.Tensor,
k: torch.Tensor,
v: torch.Tensor,
block_map: torch.Tensor,
variable_block_sizes: torch.Tensor,
) -> Tuple[torch.Tensor, torch.Tensor]:
q = q.contiguous()
k = k.contiguous()
v = v.contiguous()
block_map = block_map.int()
q2k_block_sparse_index, q2k_block_sparse_num = map_to_index(block_map)
o, M = triton_block_sparse_attn_forward(q, k, v, q2k_block_sparse_index, q2k_block_sparse_num, variable_block_sizes)
return o, M
@torch.library.register_fake("vsa::block_sparse_attn_triton")
def _block_sparse_attn_triton_fake(
q: torch.Tensor,
k: torch.Tensor,
v: torch.Tensor,
block_map: torch.Tensor,
variable_block_sizes: torch.Tensor,
) -> Tuple[torch.Tensor, torch.Tensor]:
q = q.contiguous()
k = k.contiguous()
v = v.contiguous()
o = torch.empty_like(q)
M = torch.empty((q.shape[0], q.shape[1], q.shape[2]), device=q.device, dtype=torch.float32)
return o, M
@torch.library.custom_op("vsa::block_sparse_attn_backward_triton", mutates_args=(), device_types="cuda")
def block_sparse_attn_backward_triton(
grad_output_padded: torch.Tensor,
q_padded: torch.Tensor,
k_padded: torch.Tensor,
v_padded: torch.Tensor,
o_padded: torch.Tensor,
M: torch.Tensor,
block_map: torch.Tensor,
variable_block_sizes: torch.Tensor,
) -> Tuple[torch.Tensor, torch.Tensor, torch.Tensor]:
grad_output_padded = grad_output_padded.contiguous()
q2k_block_sparse_index, q2k_block_sparse_num = map_to_index(block_map)
k2q_block_sparse_index, k2q_block_sparse_num = map_to_index(block_map.transpose(-1, -2))
dq, dk, dv = triton_block_sparse_attn_backward(grad_output_padded, q_padded, k_padded, v_padded, o_padded, M, q2k_block_sparse_index, q2k_block_sparse_num, k2q_block_sparse_index, k2q_block_sparse_num, variable_block_sizes)
return dq, dk, dv
@torch.library.register_fake("vsa::block_sparse_attn_backward_triton")
def _block_sparse_attn_backward_triton_fake(
grad_output_padded: torch.Tensor,
q_padded: torch.Tensor,
k_padded: torch.Tensor,
v_padded: torch.Tensor,
o_padded: torch.Tensor,
M: torch.Tensor,
block_map: torch.Tensor,
variable_block_sizes: torch.Tensor,
) -> Tuple[torch.Tensor, torch.Tensor, torch.Tensor]:
grad_output_padded = grad_output_padded.contiguous()
dq = torch.empty_like(grad_output_padded)
dk = torch.empty_like(grad_output_padded)
dv = torch.empty_like(grad_output_padded)
return dq, dk, dv
def backward_triton(ctx, grad_output1, grad_output2):
q_padded, k_padded, v_padded, o_padded, M, block_map, variable_block_sizes = ctx.saved_tensors
dq, dk, dv = block_sparse_attn_backward_triton(grad_output1, q_padded, k_padded, v_padded, o_padded, M, block_map, variable_block_sizes)
return dq, dk, dv, None, None
def setup_context_triton(ctx, inputs, output):
q_padded, k_padded, v_padded, block_map, variable_block_sizes = inputs
o_padded, M = output
ctx.save_for_backward(q_padded, k_padded, v_padded, o_padded, M, block_map, variable_block_sizes)
block_sparse_attn_triton.register_autograd(backward_triton, setup_context=setup_context_triton)
+152
View File
@@ -0,0 +1,152 @@
## pytorch sdpa version of block sparse ##
import triton
import triton.language as tl
import torch
@triton.jit
def topk_index_to_map_kernel(
map_ptr,
index_ptr,
map_bs_stride,
map_h_stride,
map_q_stride,
map_kv_stride,
index_bs_stride,
index_h_stride,
index_q_stride,
index_kv_stride,
topk,
):
b, h, q = tl.program_id(0), tl.program_id(1), tl.program_id(2)
index_ptr_base = index_ptr + b * index_bs_stride + h * index_h_stride + q * index_q_stride
map_ptr_base = map_ptr + b * map_bs_stride + h * map_h_stride + q * map_q_stride
for i in tl.static_range(topk):
index = tl.load(index_ptr_base + i * index_kv_stride)
tl.store(map_ptr_base + index * map_kv_stride, 1.0)
@triton.jit
def map_to_index_kernel(
map_ptr,
index_ptr,
index_num_ptr,
map_bs_stride,
map_h_stride,
map_q_stride,
map_kv_stride,
index_bs_stride,
index_h_stride,
index_q_stride,
index_kv_stride,
index_num_bs_stride,
index_num_h_stride,
index_num_q_stride,
num_kv_blocks,
):
b, h, q = tl.program_id(0), tl.program_id(1), tl.program_id(2)
index_ptr_base = index_ptr + b * index_bs_stride + h * index_h_stride + q * index_q_stride
map_ptr_base = map_ptr + b * map_bs_stride + h * map_h_stride + q * map_q_stride
num = 0
for i in tl.range(num_kv_blocks):
map_entry = tl.load(map_ptr_base + i * map_kv_stride)
if map_entry:
tl.store(index_ptr_base + num * index_kv_stride, i)
num += 1
tl.store(
index_num_ptr + b * index_num_bs_stride + h * index_num_h_stride +
q * index_num_q_stride, num)
def topk_index_to_map(index: torch.Tensor,
num_kv_blocks: int,
transpose_map: bool = False):
"""
Convert topk indices to a map.
Args:
index: [bs, h, num_q_blocks, topk]
The topk indices tensor.
num_kv_blocks: int
The number of key-value blocks in the block_map returned
transpose_map: bool
If True, the block_map will be transposed on the final two dimensions.
Returns:
block_map: [bs, h, num_q_blocks, num_kv_blocks]
A binary map where 1 indicates that the q block attends to the kv block.
"""
bs, h, num_q_blocks, topk = index.shape
if transpose_map is False:
block_map = torch.zeros((bs, h, num_q_blocks, num_kv_blocks),
dtype=torch.bool,
device=index.device)
else:
block_map = torch.zeros((bs, h, num_kv_blocks, num_q_blocks),
dtype=torch.bool,
device=index.device)
block_map = block_map.transpose(2, 3)
grid = (bs, h, num_q_blocks)
topk_index_to_map_kernel[grid](
block_map,
index,
block_map.stride(0),
block_map.stride(1),
block_map.stride(2),
block_map.stride(3),
index.stride(0),
index.stride(1),
index.stride(2),
index.stride(3),
topk=topk,
)
return block_map
def map_to_index(block_map: torch.Tensor):
"""
Convert a block map to indices and counts.
Args:
block_map: [bs, h, num_q_blocks, num_kv_blocks]
The block map tensor.
Returns:
index: [bs, h, num_q_blocks, num_kv_blocks]
The indices of the blocks.
index_num: [bs, h, num_q_blocks]
The number of blocks for each q block.
"""
bs, h, num_q_blocks, num_kv_blocks = block_map.shape
index = torch.full((block_map.shape),
-1,
dtype=torch.int32,
device=block_map.device)
index_num = torch.empty((bs, h, num_q_blocks),
dtype=torch.int32,
device=block_map.device)
grid = (bs, h, num_q_blocks)
map_to_index_kernel[grid](
block_map,
index,
index_num,
block_map.stride(0),
block_map.stride(1),
block_map.stride(2),
block_map.stride(3),
index.stride(0),
index.stride(1),
index.stride(2),
index.stride(3),
index_num.stride(0),
index_num.stride(1),
index_num.stride(2),
num_kv_blocks=num_kv_blocks,
)
return index, index_num
-47
View File
@@ -1,47 +0,0 @@
import torch
try:
from vsa_cuda import block_sparse_fwd, block_sparse_bwd
except ImportError:
block_sparse_fwd = None
block_sparse_bwd = None
from .block_sparse_attn_triton import attention_sparse as block_sparse_attn_triton
class BlockSparseAttentionFunction(torch.autograd.Function):
@staticmethod
def forward(ctx, q, k, v, q2k_block_sparse_index, q2k_block_sparse_num, k2q_block_sparse_index, k2q_block_sparse_num):
o, lse = block_sparse_fwd(q, k, v, q2k_block_sparse_index, q2k_block_sparse_num)
ctx.save_for_backward(q, k, v, o, lse, k2q_block_sparse_index, k2q_block_sparse_num)
return o
@staticmethod
def backward(ctx, grad_output):
q, k, v, o, lse, k2q_block_sparse_index, k2q_block_sparse_num = ctx.saved_tensors
grad_q, grad_k, grad_v = block_sparse_bwd(
q, k, v, o, lse, grad_output, k2q_block_sparse_index, k2q_block_sparse_num
)
return grad_q, grad_k, grad_v, None, None, None, None
@torch._dynamo.disable
def block_sparse_attn(q, k, v, q2k_block_sparse_index, q2k_block_sparse_num, k2q_block_sparse_index, k2q_block_sparse_num):
"""
Differentiable block sparse attention function.
Args:
q: Query tensor [batch_size, num_heads, seq_len_q, head_dim]
k: Key tensor [batch_size, num_heads, seq_len_kv, head_dim]
v: Value tensor [batch_size, num_heads, seq_len_kv, head_dim]
q2k_block_sparse_index: Indices for query-to-key sparse blocks
q2k_block_sparse_num: Number of sparse blocks for each query block
k2q_block_sparse_index: Indices for key-to-query sparse blocks (for backward pass)
k2q_block_sparse_num: Number of sparse blocks for each key block (for backward pass)
Returns:
output: Attention output tensor [batch_size, num_heads, seq_len_q, head_dim]
"""
if block_sparse_fwd is not None:
return BlockSparseAttentionFunction.apply(
q, k, v, q2k_block_sparse_index, q2k_block_sparse_num, k2q_block_sparse_index, k2q_block_sparse_num
)
else:
return block_sparse_attn_triton(q, k, v, q2k_block_sparse_index, q2k_block_sparse_num, k2q_block_sparse_index, k2q_block_sparse_num)
+1 -3
View File
@@ -28,9 +28,7 @@ def main():
sampling_param = SamplingParam.from_pretrained(model_name)
prompt = (
"A curious raccoon peers through a vibrant field of yellow sunflowers, its eyes "
"wide with interest. The playful yet serene atmosphere is complemented by soft "
"natural light filtering through the petals. Mid-shot, warm and cheerful tones."
"A neon-lit alley in futuristic Tokyo during a heavy rainstorm at night. The puddles reflect glowing signs in kanji, advertising ramen, karaoke, and VR arcades. A woman in a translucent raincoat walks briskly with an LED umbrella. Steam rises from a street food cart, and a cat darts across the screen. Raindrops are visible on the camera lens, creating a cinematic bokeh effect."
)
start_time = time.perf_counter()
video = generator.generate_video(prompt, output_path=OUTPUT_PATH, save_video=True, sampling_param=sampling_param)
+3 -6
View File
@@ -6,8 +6,7 @@ from dataclasses import dataclass, fields
from typing import TYPE_CHECKING, Any, Generic, Protocol, TypeVar
if TYPE_CHECKING:
from fastvideo.fastvideo_args import FastVideoArgs
from fastvideo.pipelines.pipeline_batch_info import ForwardBatch
pass
import torch
@@ -87,10 +86,8 @@ class AttentionMetadataBuilder(ABC, Generic[T]):
@abstractmethod
def build(
self,
current_timestep: int,
forward_batch: "ForwardBatch",
fastvideo_args: "FastVideoArgs",
) -> T:
**kwargs: dict[str, Any],
) -> AttentionMetadata:
"""Build attention metadata with on-device tensors."""
raise NotImplementedError
@@ -13,10 +13,8 @@ from fastvideo.attention.backends.abstract import (AttentionBackend,
AttentionMetadata,
AttentionMetadataBuilder)
from fastvideo.distributed import get_sp_group
from fastvideo.fastvideo_args import FastVideoArgs
from fastvideo.forward_context import ForwardContext, get_forward_context
from fastvideo.logger import init_logger
from fastvideo.pipelines.pipeline_batch_info import ForwardBatch
from fastvideo.utils import dict_to_3d_list
logger = init_logger(__name__)
@@ -76,13 +74,13 @@ class SlidingTileAttentionMetadataBuilder(AttentionMetadataBuilder):
def prepare(self):
pass
def build(
def build( # type: ignore
self,
STA_param: list[list[Any]],
current_timestep: int,
forward_batch: ForwardBatch,
fastvideo_args: FastVideoArgs,
**kwargs: dict[str, Any],
) -> SlidingTileAttentionMetadata:
param = forward_batch.STA_param
param = STA_param
if param is None:
return SlidingTileAttentionMetadata(
current_timestep=current_timestep, STA_param=[])
@@ -130,12 +128,6 @@ class SlidingTileAttentionImpl(AttentionImpl):
}
def tile(self, x: torch.Tensor) -> torch.Tensor:
x = rearrange(x,
"b (sp t h w) head d -> b (t sp h w) head d",
sp=self.sp_size,
t=self.dit_seq_shape_int[0] // self.sp_size,
h=self.dit_seq_shape_int[1],
w=self.dit_seq_shape_int[2])
return rearrange(
x,
"b (n_t ts_t n_h ts_h n_w ts_w) h d -> b (n_t n_h n_w ts_t ts_h ts_w) h d",
@@ -156,12 +148,7 @@ class SlidingTileAttentionImpl(AttentionImpl):
ts_t=self.STA_base_tile_size[0],
ts_h=self.STA_base_tile_size[1],
ts_w=self.STA_base_tile_size[2])
return rearrange(x,
"b (t sp h w) head d -> b (sp t h w) head d",
sp=self.sp_size,
t=self.dit_seq_shape_int[0] // self.sp_size,
h=self.dit_seq_shape_int[1],
w=self.dit_seq_shape_int[2])
return x
def preprocess_qkv(
self,
+156 -69
View File
@@ -1,25 +1,114 @@
# SPDX-License-Identifier: Apache-2.0
import functools
import math
from dataclasses import dataclass
import torch
from einops import rearrange
try:
from vsa import video_sparse_attn
except ImportError:
video_sparse_attn = None
from typing import Any
from fastvideo.attention.backends.abstract import (AttentionBackend,
AttentionImpl,
AttentionMetadata,
AttentionMetadataBuilder)
from fastvideo.distributed import get_sp_group
from fastvideo.fastvideo_args import FastVideoArgs
from fastvideo.logger import init_logger
from fastvideo.pipelines.pipeline_batch_info import ForwardBatch
logger = init_logger(__name__)
VSA_TILE_SIZE = (4, 4, 4)
@functools.lru_cache(maxsize=10)
def get_tile_partition_indices(
dit_seq_shape: tuple[int, int, int],
tile_size: tuple[int, int, int],
device: torch.device,
) -> torch.LongTensor:
T, H, W = dit_seq_shape
ts, hs, ws = tile_size
indices = torch.arange(T * H * W, device=device,
dtype=torch.long).reshape(T, H, W)
ls = []
for t in range(math.ceil(T / ts)):
for h in range(math.ceil(H / hs)):
for w in range(math.ceil(W / ws)):
ls.append(indices[t * ts:min(t * ts + ts, T),
h * hs:min(h * hs + hs, H),
w * ws:min(w * ws + ws, W)].flatten())
index = torch.cat(ls, dim=0)
return index
@functools.lru_cache(maxsize=10)
def get_reverse_tile_partition_indices(
dit_seq_shape: tuple[int, int, int],
tile_size: tuple[int, int, int],
device: torch.device,
) -> torch.LongTensor:
return torch.argsort(
get_tile_partition_indices(dit_seq_shape, tile_size, device))
@functools.lru_cache(maxsize=10)
def construct_variable_block_sizes(
dit_seq_shape: tuple[int, int, int],
num_tiles: tuple[int, int, int],
device: torch.device,
) -> torch.LongTensor:
"""
Compute the number of valid (non‑padded) tokens inside every
(ts_t × ts_h × ts_w) tile after padding ‑‑ flattened in the order
(t‑tile, h‑tile, w‑tile) that `rearrange` uses.
Returns
-------
torch.LongTensor # shape: [∏ full_window_size]
"""
# unpack
t, h, w = dit_seq_shape
ts_t, ts_h, ts_w = VSA_TILE_SIZE
n_t, n_h, n_w = num_tiles
def _sizes(dim_len: int, tile: int, n_tiles: int) -> torch.LongTensor:
"""Vector with the size of each tile along one dimension."""
sizes = torch.full((n_tiles, ), tile, dtype=torch.int, device=device)
# size of last (possibly partial) tile
remainder = dim_len - (n_tiles - 1) * tile
sizes[-1] = remainder if remainder > 0 else tile
return sizes
t_sizes = _sizes(t, ts_t, n_t) # [n_t]
h_sizes = _sizes(h, ts_h, n_h) # [n_h]
w_sizes = _sizes(w, ts_w, n_w) # [n_w]
# broadcast‑multiply to get voxels per tile, then flatten
block_sizes = (
t_sizes[:, None, None] # [n_t, 1, 1]
* h_sizes[None, :, None] # [1, n_h, 1]
* w_sizes[None, None, :] # [1, 1, n_w]
).reshape(-1) # [n_t * n_h * n_w]
return block_sizes
@functools.lru_cache(maxsize=10)
def get_non_pad_index(
variable_block_sizes: torch.LongTensor,
max_block_size: int,
):
n_win = variable_block_sizes.shape[0]
device = variable_block_sizes.device
starts_pad = torch.arange(n_win, device=device) * max_block_size
index_pad = starts_pad[:, None] + torch.arange(max_block_size,
device=device)[None, :]
index_mask = torch.arange(
max_block_size, device=device)[None, :] < variable_block_sizes[:, None]
return index_pad[index_mask]
class VideoSparseAttentionBackend(AttentionBackend):
@@ -52,6 +141,12 @@ class VideoSparseAttentionMetadata(AttentionMetadata):
current_timestep: int
dit_seq_shape: list[int]
VSA_sparsity: float
num_tiles: list[int]
total_seq_length: int
tile_partition_indices: torch.LongTensor
reverse_tile_partition_indices: torch.LongTensor
variable_block_sizes: torch.LongTensor
non_pad_index: torch.LongTensor
class VideoSparseAttentionMetadataBuilder(AttentionMetadataBuilder):
@@ -62,30 +157,44 @@ class VideoSparseAttentionMetadataBuilder(AttentionMetadataBuilder):
def prepare(self):
pass
def build(
def build( # type: ignore
self,
current_timestep: int,
forward_batch: ForwardBatch,
fastvideo_args: FastVideoArgs,
raw_latent_shape: tuple[int, int, int],
patch_size: tuple[int, int, int],
VSA_sparsity: float,
device: torch.device,
**kwargs: dict[str, Any],
) -> VideoSparseAttentionMetadata:
if forward_batch.latents is None:
raise ValueError("latents cannot be None")
patch_size = patch_size
dit_seq_shape = (raw_latent_shape[0] // patch_size[0],
raw_latent_shape[1] // patch_size[1],
raw_latent_shape[2] // patch_size[2])
raw_latent_shape = forward_batch.raw_latent_shape
if raw_latent_shape is None:
raise ValueError("raw_latent_shape cannot be None")
num_tiles = (math.ceil(dit_seq_shape[0] / VSA_TILE_SIZE[0]),
math.ceil(dit_seq_shape[1] / VSA_TILE_SIZE[1]),
math.ceil(dit_seq_shape[2] / VSA_TILE_SIZE[2]))
total_seq_length = math.prod(dit_seq_shape)
patch_size = fastvideo_args.pipeline_config.dit_config.patch_size
dit_seq_shape = [
raw_latent_shape[2] // patch_size[0],
raw_latent_shape[3] // patch_size[1],
raw_latent_shape[4] // patch_size[2]
]
VSA_sparsity = forward_batch.VSA_sparsity
tile_partition_indices = get_tile_partition_indices(
dit_seq_shape, VSA_TILE_SIZE, device)
reverse_tile_partition_indices = get_reverse_tile_partition_indices(
dit_seq_shape, VSA_TILE_SIZE, device)
variable_block_sizes = construct_variable_block_sizes(
dit_seq_shape, num_tiles, device)
non_pad_index = get_non_pad_index(variable_block_sizes,
math.prod(VSA_TILE_SIZE))
return VideoSparseAttentionMetadata(current_timestep=current_timestep,
dit_seq_shape=dit_seq_shape,
VSA_sparsity=VSA_sparsity)
return VideoSparseAttentionMetadata(
current_timestep=current_timestep,
dit_seq_shape=dit_seq_shape, # type: ignore
VSA_sparsity=VSA_sparsity, # type: ignore
num_tiles=num_tiles, # type: ignore
total_seq_length=total_seq_length, # type: ignore
tile_partition_indices=tile_partition_indices, # type: ignore
reverse_tile_partition_indices=reverse_tile_partition_indices,
variable_block_sizes=variable_block_sizes,
non_pad_index=non_pad_index)
class VideoSparseAttentionImpl(AttentionImpl):
@@ -103,66 +212,44 @@ class VideoSparseAttentionImpl(AttentionImpl):
self.prefix = prefix
sp_group = get_sp_group()
self.sp_size = sp_group.world_size
self.VSA_base_tile_size = [4, 4, 4]
self.dit_seq_shape: list[int]
self.full_window_size: list[int]
self.img_seq_length: int
def tile(self, x: torch.Tensor) -> torch.Tensor:
x = rearrange(x,
"b (sp t h w) head d -> b (t sp h w) head d",
sp=self.sp_size,
t=self.dit_seq_shape[0] // self.sp_size,
h=self.dit_seq_shape[1],
w=self.dit_seq_shape[2])
def tile(self, x: torch.Tensor, num_tiles: list[int],
tile_partition_indices: torch.LongTensor,
non_pad_index: torch.LongTensor) -> torch.Tensor:
t_padded_size = num_tiles[0] * VSA_TILE_SIZE[0]
h_padded_size = num_tiles[1] * VSA_TILE_SIZE[1]
w_padded_size = num_tiles[2] * VSA_TILE_SIZE[2]
return rearrange(
x,
"b (n_t ts_t n_h ts_h n_w ts_w) h d -> b (n_t n_h n_w ts_t ts_h ts_w) h d",
n_t=self.full_window_size[0],
n_h=self.full_window_size[1],
n_w=self.full_window_size[2],
ts_t=self.VSA_base_tile_size[0],
ts_h=self.VSA_base_tile_size[1],
ts_w=self.VSA_base_tile_size[2])
x_padded = torch.zeros(
(x.shape[0], t_padded_size * h_padded_size * w_padded_size,
x.shape[-2], x.shape[-1]),
device=x.device,
dtype=x.dtype)
x_padded[:, non_pad_index] = x[:, tile_partition_indices]
return x_padded
def untile(self, x: torch.Tensor) -> torch.Tensor:
x = rearrange(
x,
"b (n_t n_h n_w ts_t ts_h ts_w) h d -> b (n_t ts_t n_h ts_h n_w ts_w) h d",
n_t=self.full_window_size[0],
n_h=self.full_window_size[1],
n_w=self.full_window_size[2],
ts_t=self.VSA_base_tile_size[0],
ts_h=self.VSA_base_tile_size[1],
ts_w=self.VSA_base_tile_size[2])
return rearrange(x,
"b (t sp h w) head d -> b (sp t h w) head d",
sp=self.sp_size,
t=self.dit_seq_shape[0] // self.sp_size,
h=self.dit_seq_shape[1],
w=self.dit_seq_shape[2])
def untile(self, x: torch.Tensor,
reverse_tile_partition_indices: torch.LongTensor,
non_pad_index: torch.LongTensor) -> torch.Tensor:
x = x[:, non_pad_index][:, reverse_tile_partition_indices]
return x
def preprocess_qkv(
self,
qkv: torch.Tensor,
attn_metadata: VideoSparseAttentionMetadata,
) -> torch.Tensor:
self.dit_seq_shape = attn_metadata.dit_seq_shape
self.full_window_size = [
self.dit_seq_shape[0] // self.VSA_base_tile_size[0],
self.dit_seq_shape[1] // self.VSA_base_tile_size[1],
self.dit_seq_shape[2] // self.VSA_base_tile_size[2]
]
self.img_seq_length = math.prod(self.dit_seq_shape)
return self.tile(qkv)
return self.tile(qkv, attn_metadata.num_tiles,
attn_metadata.tile_partition_indices,
attn_metadata.non_pad_index)
def postprocess_output(
self,
output: torch.Tensor,
attn_metadata: VideoSparseAttentionMetadata,
) -> torch.Tensor:
return self.untile(output)
return self.untile(output, attn_metadata.reverse_tile_partition_indices,
attn_metadata.non_pad_index)
def forward( # type: ignore[override]
self,
@@ -181,17 +268,17 @@ class VideoSparseAttentionImpl(AttentionImpl):
cur_topk = math.ceil(
(1 - VSA_sparsity) *
(self.img_seq_length / math.prod(self.VSA_base_tile_size)))
(attn_metadata.total_seq_length / math.prod(VSA_TILE_SIZE)))
if video_sparse_attn is None:
raise NotImplementedError("video_sparse_attn is not installed")
hidden_states = video_sparse_attn(
query,
key,
value,
variable_block_sizes=attn_metadata.variable_block_sizes,
topk=cur_topk,
block_size=(4, 4, 4),
block_size=VSA_TILE_SIZE,
compress_attn_weight=gate_compress).transpose(1, 2)
return hidden_states
@@ -120,38 +120,43 @@ class DistributedAutograd:
) == 4, f"input must be 4D tensor, got {input_.dim()} and shape {input_.shape}"
if scatter_dim == 2 and gather_dim == 1:
bs, shard_seqlen, hc, hs = input_.shape
bs, shard_seqlen, hn, hd = input_.shape
seqlen = shard_seqlen * world_size
shard_hc = hc // world_size
shard_hn = hn // world_size
input_t = input_.reshape(bs, shard_seqlen, world_size, shard_hc,
hs).transpose(0, 2).contiguous()
output = torch.empty_like(input_t)
input_ = input_.transpose(
0, 2).contiguous() # hn, shard_seqlen, bs, hd
output = torch.empty_like(input_)
dist.all_to_all_single(output, input_t, group=group)
dist.all_to_all_single(output, input_,
group=group) # hn, shard_seqlen, bs, hd
output = output.reshape(seqlen, bs, shard_hc,
hs).transpose(0, 1).contiguous()
output = output.reshape(bs, seqlen, shard_hc, hs)
output = torch.cat(output.split(shard_hn),
dim=1) # sharded hn, seqlen, bs, hd
output = output.transpose(
0, 2).contiguous() # bs, seqlen, sharded_hn, hd
return output
elif scatter_dim == 1 and gather_dim == 2:
bs, seqlen, shard_hc, hs = input_.shape
hc = shard_hc * world_size
bs, seqlen, shard_hn, hd = input_.shape
hn = shard_hn * world_size
shard_seqlen = seqlen // world_size
input_t = input_.reshape(bs, world_size, shard_seqlen, shard_hc,
hs)
input_t = input_t.transpose(0, 3).transpose(0, 1).contiguous()
input_t = input_t.reshape(world_size, shard_hc, shard_seqlen,
bs, hs)
input_ = input_.transpose(
0, 2).contiguous() # shard_hn, seqlen, bs, hd
output = torch.empty_like(input_t)
dist.all_to_all_single(output, input_t, group=group)
input_ = input_.reshape(shard_hn, world_size, shard_seqlen, bs,
hd).transpose(0, 1).reshape(
shard_hn * world_size, shard_seqlen,
bs, hd).contiguous()
output = output.reshape(hc, shard_seqlen, bs, hs)
output = output.transpose(0, 2).contiguous()
output = output.reshape(bs, shard_seqlen, hc, hs)
output = torch.empty_like(input_)
dist.all_to_all_single(output, input_, group=group)
output = output.transpose(
0, 2).contiguous() # bs, seqlen, sharded_hn, hd
return output
else:
+23 -9
View File
@@ -228,10 +228,17 @@ class DenoisingStage(PipelineStage):
self.attn_metadata_builder = self.attn_metadata_builder_cls(
)
# TODO(will): clean this up
attn_metadata = self.attn_metadata_builder.build(
current_timestep=i,
forward_batch=batch,
fastvideo_args=fastvideo_args,
attn_metadata = self.attn_metadata_builder.build( # type: ignore
current_timestep=i, # type: ignore
raw_latent_shape=batch.
raw_latent_shape[2:5], # type: ignore
patch_size=fastvideo_args.
pipeline_config. # type: ignore
dit_config.patch_size, # type: ignore
STA_param=batch.STA_param, # type: ignore
VSA_sparsity=fastvideo_args.
VSA_sparsity, # type: ignore
device=get_local_torch_device(),
)
assert attn_metadata is not None, "attn_metadata cannot be None"
else:
@@ -719,11 +726,18 @@ class DmdDenoisingStage(DenoisingStage):
self.attn_metadata_builder = self.attn_metadata_builder_cls(
)
# TODO(will): clean this up
attn_metadata = self.attn_metadata_builder.build(
current_timestep=i,
forward_batch=batch,
fastvideo_args=fastvideo_args,
)
attn_metadata = self.attn_metadata_builder.build( # type: ignore
current_timestep=i, # type: ignore
raw_latent_shape=batch.
raw_latent_shape[2:5], # type: ignore
patch_size=fastvideo_args.
pipeline_config. # type: ignore
dit_config.patch_size, # type: ignore
STA_param=batch.STA_param, # type: ignore
VSA_sparsity=fastvideo_args.
VSA_sparsity, # type: ignore
device=get_local_torch_device(), # type: ignore
) # type: ignore
assert attn_metadata is not None, "attn_metadata cannot be None"
else:
attn_metadata = None
+7 -9
View File
@@ -21,7 +21,7 @@ from tqdm.auto import tqdm
import fastvideo.envs as envs
from fastvideo.attention.backends.video_sparse_attn import (
VideoSparseAttentionMetadata)
VideoSparseAttentionMetadataBuilder)
from fastvideo.configs.sample import SamplingParam
from fastvideo.dataset import build_parquet_map_style_dataloader
from fastvideo.dataset.dataloader.schema import pyarrow_schema_t2v
@@ -260,15 +260,13 @@ class TrainingPipeline(LoRAPipeline, ABC):
assert latents_shape is not None
assert training_batch.timesteps is not None
if vsa_available and envs.FASTVIDEO_ATTENTION_BACKEND == "VIDEO_SPARSE_ATTN":
dit_seq_shape = [
latents_shape[2] // patch_size[0],
latents_shape[3] // patch_size[1],
latents_shape[4] // patch_size[2]
]
training_batch.attn_metadata = VideoSparseAttentionMetadata(
training_batch.attn_metadata = VideoSparseAttentionMetadataBuilder( # type: ignore
).build( # type: ignore
raw_latent_shape=latents_shape[2:5],
current_timestep=training_batch.timesteps,
dit_seq_shape=dit_seq_shape,
VSA_sparsity=current_vsa_sparsity)
patch_size=patch_size,
VSA_sparsity=current_vsa_sparsity,
device=get_local_torch_device())
else:
training_batch.attn_metadata = None
+3 -3
View File
@@ -10,9 +10,9 @@ fastvideo generate \
--sp-size $num_gpus \
--tp-size 1 \
--num-gpus $num_gpus \
--height 448 \
--width 832 \
--num-frames 61 \
--height 480 \
--width 848 \
--num-frames 81 \
--num-inference-steps 3 \
--fps 16 \
--prompt-txt assets/prompt.txt \