failed on h100

Co-authored-by: Peiyuan Zhang <a1286225768@gmail.com>

.github/workflows/fastvideo-publish.yml

@@ -0,0 +1,70 @@
+name: Publish FastVideo to PyPI on Version Change
+
+on:
+  push:
+    branches:
+      - main
+    paths:
+      - 'pyproject.toml'  # Trigger when pyproject.toml changes
+
+jobs:
+  check-version-change:
+    runs-on: ubuntu-latest
+    outputs:
+      version-changed: ${{ steps.check-version.outputs.changed }}
+      new-version: ${{ steps.check-version.outputs.new-version }}
+    steps:
+      - name: Checkout code
+        uses: actions/checkout@v3
+        with:
+          fetch-depth: 2
+
+      - name: Check if version changed
+        id: check-version
+        run: |
+          # Get current commit's version
+          NEW_VERSION=$(grep -oP 'version\s*=\s*"\K[^"]+' pyproject.toml)
+          echo "New version: $NEW_VERSION"
+          
+          # Get previous version from git history
+          OLD_VERSION=$(git show HEAD~1:./pyproject.toml | grep -oP 'version\s*=\s*"\K[^"]+' || echo "0.0.0")
+          echo "Old version: $OLD_VERSION"
+          
+          if [ "$NEW_VERSION" != "$OLD_VERSION" ]; then
+            echo "Version changed from $OLD_VERSION to $NEW_VERSION"
+            echo "changed=true" >> $GITHUB_OUTPUT
+            echo "new-version=$NEW_VERSION" >> $GITHUB_OUTPUT
+          else
+            echo "Version did not change"
+            echo "changed=false" >> $GITHUB_OUTPUT
+          fi
+
+  build-publish-main:
+    needs: check-version-change
+    if: needs.check-version-change.outputs.version-changed == 'true'
+    runs-on: ubuntu-latest
+    permissions:
+      id-token: write  # Needed for OIDC Trusted Publishing
+
+    steps:
+      - name: Checkout code
+        uses: actions/checkout@v3
+
+      - name: Set up Python
+        uses: actions/setup-python@v4
+        with:
+          python-version: '3.10'
+
+      - name: Install build dependencies
+        run: |
+          python -m pip install --upgrade pip
+          pip install build twine wheel
+
+      - name: Build package
+        run: |
+          python -m build
+          
+      - name: Publish release distributions to PyPI
+        uses: pypa/gh-action-pypi-publish@release/v1
+        with:
+          packages-dir: dist/

.github/workflows/sta-publish.yml

@@ -0,0 +1,221 @@
+name: Publish Sliding Tile Attention Kernel to PyPI on Version Change
+
+on:
+  push:
+    branches:
+      - main
+    paths:
+      - "csrc/sliding_tile_attention/setup.py"
+
+jobs:
+  check-version-change:
+    runs-on: ubuntu-latest
+    outputs:
+      version-changed: ${{ steps.check-version.outputs.changed }}
+      new-version: ${{ steps.check-version.outputs.new-version }}
+    steps:
+      - name: Checkout code
+        uses: actions/checkout@v3
+        with:
+          fetch-depth: 2
+
+      - name: Check if version changed
+        id: check-version
+        run: |
+          cd csrc/sliding_tile_attention
+          # Get current commit's version
+          NEW_VERSION=$(grep -oP 'VERSION\s*=\s*"\K[^"]+' setup.py)
+          echo "New version: $NEW_VERSION"
+          
+          # Get previous version from git history
+          OLD_VERSION=$(git show HEAD~1:./setup.py | grep -oP 'VERSION\s*=\s*"\K[^"]+' || echo "0.0.0")
+          echo "Old version: $OLD_VERSION"
+          
+          if [ "$NEW_VERSION" != "$OLD_VERSION" ]; then
+            echo "Version changed from $OLD_VERSION to $NEW_VERSION"
+            echo "changed=true" >> $GITHUB_OUTPUT
+            echo "new-version=$NEW_VERSION" >> $GITHUB_OUTPUT
+          else
+            echo "Version did not change"
+            echo "changed=false" >> $GITHUB_OUTPUT
+          fi
+
+  build_wheels:
+    name: Build Wheel
+    needs: check-version-change
+    if: needs.check-version-change.outputs.version-changed == 'true'
+    runs-on: ${{ matrix.os }}
+
+    strategy:
+      fail-fast: false
+      matrix:
+          # Using ubuntu-20.04 instead of 22.04 for more compatibility (glibc). Ideally we'd use the
+          # manylinux docker image, but I haven't figured out how to install CUDA on manylinux.
+          os: [ubuntu-22.04]
+          python-version: ['3.10', '3.11', '3.12', '3.13']
+          torch-version: ['2.5.1', '2.6.0']
+          cuda-version: ['12.4.1', '12.5.1', '12.6.3']
+
+    steps:
+      - name: Checkout
+        uses: actions/checkout@v4
+
+      - name: Set up Python
+        uses: actions/setup-python@v5
+        with:
+          python-version: ${{ matrix.python-version }}
+
+      - name: Install CUDA ${{ matrix.cuda-version }}
+        uses: Jimver/cuda-toolkit@v0.2.21
+        id: cuda-toolkit
+        with:
+          cuda: ${{ matrix.cuda-version }}
+          linux-local-args: '["--toolkit"]'
+          method: 'network'
+
+      - name: Install dependencies (GCC, Clang, CUDA Paths, Git)
+        run: |
+          sudo apt update
+          sudo apt install -y git patchelf gcc-11 g++-11 clang-11
+          sudo update-alternatives --install /usr/bin/gcc gcc /usr/bin/gcc-11 100 --slave /usr/bin/g++ g++ /usr/bin/g++-11
+
+          # Allow Git to Access Safe Directory
+          git config --global --add safe.directory /__w/FastVideo/FastVideo
+
+          # Set CUDA environment variables
+          export CUDA_HOME=/usr/local/cuda-${{ matrix.cuda-version }}
+          export PATH=${CUDA_HOME}/bin:${PATH}
+          export LD_LIBRARY_PATH=${CUDA_HOME}/lib64:$LD_LIBRARY_PATH
+          
+          # Verify installation
+          gcc --version
+          g++ --version
+          clang-11 --version
+          nvcc --version
+
+      - name: Install PyTorch ${{ matrix.torch-version }}+cu${{ matrix.cuda-version }}
+        run: |
+          pip install --upgrade pip
+          # With python 3.13 and torch 2.5.1, unless we update typing-extensions, we get error
+          # AttributeError: attribute '__default__' of 'typing.ParamSpec' objects is not writable
+          pip install typing-extensions==4.12.2
+          # We want to figure out the CUDA version to download pytorch
+          # e.g. we can have system CUDA version being 11.7 but if torch==1.12 then we need to download the wheel from cu116
+          # see https://github.com/pytorch/pytorch/blob/main/RELEASE.md#release-compatibility-matrix
+          export TORCH_CUDA_VERSION=124
+          pip install --no-cache-dir torch==${{ matrix.torch-version }} --index-url https://download.pytorch.org/whl/cu${TORCH_CUDA_VERSION}
+          nvcc --version
+          python --version
+          python -c "import torch; print('PyTorch:', torch.__version__)"
+          python -c "import torch; print('CUDA:', torch.version.cuda)"
+          python -c "from torch.utils import cpp_extension; print (cpp_extension.CUDA_HOME)"
+
+      - name: Build wheel
+        run: |
+          # We want setuptools >= 49.6.0 otherwise we can't compile the extension if system CUDA version is 11.7 and pytorch cuda version is 11.6
+          # https://github.com/pytorch/pytorch/blob/664058fa83f1d8eede5d66418abff6e20bd76ca8/torch/utils/cpp_extension.py#L810
+          # However this still fails so I'm using a newer version of setuptools
+          pip install setuptools
+          pip install ninja packaging wheel
+
+          cd csrc/sliding_tile_attention  # Move into the correct folder
+          git submodule update --init --recursive tk # Ensure ThunderKittens submodule is initialized
+          python setup.py bdist_wheel --dist-dir=dist
+
+      - name: Rename wheel file
+        run: |
+          cd csrc/sliding_tile_attention
+
+          CUDA_SHORT_VERSION=$(echo ${{ matrix.cuda-version }} | cut -d. -f1,2 | sed 's/\.//g')
+          TORCH_SHORT_VERSION=$(echo ${{ matrix.torch-version }} | cut -d. -f1,2)
+          # Get the correct version format
+          tmpname=cu${CUDA_SHORT_VERSION}torch${TORCH_SHORT_VERSION}
+          wheel_name=$(ls dist/*whl | xargs -n 1 basename | sed "s/-/+$tmpname-/2")
+          # Rename with version information
+          ls dist/*whl |xargs -I {} mv {} dist/${wheel_name}
+          echo "wheel_name=${wheel_name}" >> $GITHUB_ENV
+
+      - name: Upload wheel artifact
+        uses: actions/upload-artifact@v4
+        with:
+          name: ${{ env.wheel_name }}
+          path: csrc/sliding_tile_attention/dist/*.whl
+          retention-days: 90
+
+  publish_package:
+    name: Publish package
+    needs: [build_wheels]
+    if: needs.check-version-change.outputs.version-changed == 'true'
+    runs-on: ubuntu-22.04
+    permissions:
+      id-token: write  # Needed for OIDC Trusted Publishing
+
+    steps:
+      - uses: actions/checkout@v4
+
+      - uses: actions/setup-python@v5
+        with:
+          python-version: '3.10'
+      
+      - name: Install CUDA 12.4.1
+        uses: Jimver/cuda-toolkit@v0.2.21
+        id: cuda-toolkit
+        with:
+          cuda: 12.4.1
+          linux-local-args: '["--toolkit"]'
+          method: 'network'
+          sub-packages: '["nvcc"]'
+
+      - name: Install dependencies (GCC, Clang, CUDA Paths, Git)
+        run: |
+          sudo apt update
+          sudo apt install -y git patchelf gcc-11 g++-11 clang-11
+          sudo update-alternatives --install /usr/bin/gcc gcc /usr/bin/gcc-11 100 --slave /usr/bin/g++ g++ /usr/bin/g++-11
+
+          # Allow Git to Access Safe Directory
+          git config --global --add safe.directory /__w/FastVideo/FastVideo
+
+          # Set CUDA environment variables
+          export CUDA_HOME=/usr/local/cuda-12.4.1
+          export PATH=${CUDA_HOME}/bin:${PATH}
+          export LD_LIBRARY_PATH=${CUDA_HOME}/lib64:$LD_LIBRARY_PATH
+          
+          # Verify installation
+          gcc --version
+          g++ --version
+          clang-11 --version
+          nvcc --version
+
+      - name: Install PyTorch 2.5.1+cu12.4.1
+        run: |
+          pip install --upgrade pip
+          # With python 3.13 and torch 2.5.1, unless we update typing-extensions, we get error
+          # AttributeError: attribute '__default__' of 'typing.ParamSpec' objects is not writable
+          pip install typing-extensions==4.12.2
+          # We want to figure out the CUDA version to download pytorch
+          # e.g. we can have system CUDA version being 11.7 but if torch==1.12 then we need to download the wheel from cu116
+          # see https://github.com/pytorch/pytorch/blob/main/RELEASE.md#release-compatibility-matrix
+          export TORCH_CUDA_VERSION=124
+          pip install --no-cache-dir torch==2.5.1 --index-url https://download.pytorch.org/whl/cu${TORCH_CUDA_VERSION}
+          nvcc --version
+          python --version
+          python -c "import torch; print('PyTorch:', torch.__version__)"
+          python -c "import torch; print('CUDA:', torch.version.cuda)"
+          python -c "from torch.utils import cpp_extension; print (cpp_extension.CUDA_HOME)"
+
+      - name: Build source distribution
+        run: |
+          # We want setuptools >= 49.6.0 otherwise we can't compile the extension if system CUDA version is 11.7 and pytorch cuda version is 11.6
+          # https://github.com/pytorch/pytorch/blob/664058fa83f1d8eede5d66418abff6e20bd76ca8/torch/utils/cpp_extension.py#L810
+          # However this still fails so I'm using a newer version of setuptools
+          pip install setuptools
+          pip install ninja packaging wheel
+
+          cd csrc/sliding_tile_attention  # Move into the correct folder
+          git submodule update --init --recursive tk # Ensure ThunderKittens submodule is initialized
+          python setup.py sdist --dist-dir=dist
+
+      - name: Publish release distributions to PyPI
+        uses: pypa/gh-action-pypi-publish@release/v1
+        with:
+          packages-dir: csrc/sliding_tile_attention/dist/

.github/workflows/test.yml

@@ -23,8 +23,11 @@ jobs:
           python -m pip install --upgrade pip setuptools wheel
           pip install torch
           pip install packaging ninja
+          # remove st-attn dependency because no cuda environment
+          sed -i '/st_attn/d' pyproject.toml
           pip install -e .
           pip install pytest
+
       - name: Run Pytest
         run: |
           pytest --ignore csrc/sliding_tile_attention/test

.gitmodules

@@ -1,3 +1,3 @@
 [submodule "csrc/sliding_tile_attention/tk"]
-	path = csrc/sliding_tile_attention/tk
+	path = sta_kernel/thunderkitten/tk
 	url = https://github.com/HazyResearch/ThunderKittens.git

fastvideo/distill.py

@@ -160,7 +160,7 @@ def distill_one_step(
                         uncond_prompt_mask.unsqueeze(0).expand(bsz, -1),
                         return_dict=False,
                     )[0].float()
-            teacher_output = cond_teacher_output + w * (cond_teacher_output - uncond_teacher_output)
+            teacher_output = uncond_teacher_output + w * (cond_teacher_output - uncond_teacher_output)
             x_prev = solver.euler_step(noisy_model_input, teacher_output, index)
 
         # 20.4.12. Get target LCM prediction on x_prev, w, c, t_n

fastvideo/models/hunyuan/modules/models.py

@@ -524,8 +524,7 @@ class HYVideoDiffusionTransformer(ModelMixin, ConfigMixin):
         if guidance is None:
             guidance = torch.tensor([6016.0], device=hidden_states.device, dtype=torch.bfloat16)
         if mask_strategy is None:
-            mask_strategy = [[None] * len(self.heads_num)
+            mask_strategy = [[None] * self.heads_num for _ in range(len(self.double_blocks) + len(self.single_blocks))]
-                             for _ in range(len(self.double_blocks) + len(self.single_blocks))]
         img = x = hidden_states
         text_mask = encoder_attention_mask
         t = timestep

pyproject.toml

@@ -4,7 +4,7 @@ build-backend = "setuptools.build_meta"
 
 [project]
 name = "fastvideo"
-version = "0.0.1"
+version = "0.0.1.dev1"
 description = "FastVideo"
 readme = "README.md"
 requires-python = ">=3.8"
@@ -39,7 +39,10 @@ dependencies = [
     "gpustat", "watch",
     
     # Kernel & Packaging
-    "wheel"
+    "wheel",
+
+    # Sliding Tile Atteniton Kernel
+    "st_attn>=0.0.1"
 ]
 
 

sta_kernel/thunderkitten/MANIFEST.in

@@ -0,0 +1,2 @@
+recursive-include tk *
+include config.py

sta_kernel/thunderkitten/setup.py

@@ -7,6 +7,13 @@ from torch.utils.cpp_extension import BuildExtension, CUDAExtension
 
 target = target.lower()
 
+# Package metadata
+PACKAGE_NAME = "st_attn"
+VERSION = "0.0.2"
+AUTHOR = "Hao AI Lab"
+DESCRIPTION = "Sliding Tile Atteniton Kernel Used in FastVideo"
+URL = "https://github.com/hao-ai-lab/FastVideo/tree/main/csrc/sliding_tile_attention"
+
 # Set environment variables
 tk_root = os.getenv('THUNDERKITTENS_ROOT', os.path.abspath(os.path.join(os.getcwd(), 'tk/')))
 python_include = subprocess.check_output(['python', '-c',
@@ -44,8 +51,11 @@ for k in kernels:
         source_files.append(sources[k]['source_files'][target])
     cpp_flags.append(f'-DTK_COMPILE_{k.replace(" ", "_").upper()}')
 
-setup(name='st_attn',
+setup(name=PACKAGE_NAME,
-      version="0.0.0",
+      version=VERSION,
+      author=AUTHOR,
+      description=DESCRIPTION,
+      url=URL,
       packages=find_packages(),
       ext_modules=[
           CUDAExtension('st_attn_cuda',
@@ -56,4 +66,11 @@ setup(name='st_attn',
                         },
                         libraries=['cuda'])
       ],
-      cmdclass={'build_ext': BuildExtension})
+      cmdclass={'build_ext': BuildExtension},
+      classifiers=[
+          "Programming Language :: Python :: 3",
+          "Environment :: GPU :: NVIDIA CUDA :: 12",
+          "License :: OSI Approved :: Apache Software License",
+      ],
+      python_requires='>=3.10',
+      install_requires=["torch>=2.5.0"])

sta_kernel/tilelang/sta_tilelang.py

@@ -0,0 +1,252 @@
+# Copyright (c) Tile-AI Corporation.
+# Licensed under the MIT License.
+import math
+import torch
+
+import tilelang
+import tilelang.language as T
+import torch.nn.functional as F
+
+def get_sta_mask(x, canvas_size=(32, 48, 80), tile_size=(4, 8, 8), kernel_size=(1, 1, 1), has_text=False):
+    bsz, num_head, downsample_len, _ = x.shape
+    device = x.device
+    CT, CH, CW = canvas_size
+    TT, TH, TW = tile_size
+    NT, NH, NW = CT // TT, CH // TH, CW // TW
+    KT, KH, KW = kernel_size
+    DT, DH, DW = KT // 2, KH // 2, KW // 2
+    
+    dense_mask = torch.full([bsz, num_head, downsample_len, downsample_len],
+                           False,
+                           dtype=torch.bool,
+                           device=device)
+    indices = torch.arange(downsample_len, device=device)
+    q_t = (indices // (NT * NH * NW)).unsqueeze(-1)
+    q_h = ((indices // (NW)) % NH).unsqueeze(-1)
+    q_w = ((indices // 1) % NW).unsqueeze(-1)
+    
+    q_t = torch.clamp(q_t, DT, NT-DT-1)
+    q_h = torch.clamp(q_h, DH, NH-DH-1)
+    q_w = torch.clamp(q_w, DW, NW-DW-1)
+    
+    k_indices = torch.arange(downsample_len, device=device)
+    k_t = (k_indices // (NT * NH * NW)).unsqueeze(0)
+    k_h = ((k_indices // (NW)) % NH).unsqueeze(0)
+    k_w = ((k_indices // 1) % NW).unsqueeze(0)
+    
+    t_dist = torch.abs(q_t - k_t)
+    h_dist = torch.abs(q_h - k_h)
+    w_dist = torch.abs(q_w - k_w)
+    mask = (t_dist <= DT) & (h_dist <= DH) & (w_dist <= DW)
+    
+    for b in range(bsz):
+        for h in range(num_head):
+            dense_mask[b, h] = mask
+    
+    # for text mask
+    if has_text:
+        text_start = downsample_len - 3
+        dense_mask[:, :, text_start:, :text_start] = True
+        dense_mask[:, :, text_start:, text_start:] = torch.tril(
+            torch.ones(3, 3, device=device, dtype=torch.bool)
+        )
+    return dense_mask
+
+def blocksparse_flashattn(batch, heads, seq_len, dim, downsample_len, is_causal):
+    block_M = 64
+    block_N = 64
+    num_stages = 1
+    threads = 128
+    scale = (1.0 / dim)**0.5 * 1.44269504  # log2(e)
+    shape = [batch, heads, seq_len, dim]
+    block_mask_shape = [batch, heads, downsample_len, downsample_len]
+
+    dtype = "float16"
+    accum_dtype = "float"
+    block_mask_dtype = "bool"
+
+    def kernel_func(block_M, block_N, num_stages, threads):
+
+        @T.macro
+        def MMA0(
+            K: T.Buffer(shape, dtype),
+            Q_shared: T.Buffer([block_M, dim], dtype),
+            K_shared: T.Buffer([block_N, dim], dtype),
+            acc_s: T.Buffer([block_M, block_N], accum_dtype),
+            k: T.int32,
+            bx: T.int32,
+            by: T.int32,
+            bz: T.int32,
+        ):
+            T.copy(K[bz, by, k * block_N:(k + 1) * block_N, :], K_shared)
+            if is_causal:
+                for i, j in T.Parallel(block_M, block_N):
+                    acc_s[i, j] = T.if_then_else(bx * block_M + i >= k * block_N + j, 0,
+                                                 -T.infinity(acc_s.dtype))
+            else:
+                T.clear(acc_s)
+            T.gemm(Q_shared, K_shared, acc_s, transpose_B=True, policy=T.GemmWarpPolicy.FullRow)
+
+        @T.macro
+        def MMA1(
+                V: T.Buffer(shape, dtype),
+                V_shared: T.Buffer([block_M, dim], dtype),
+                acc_s_cast: T.Buffer([block_M, block_N], dtype),
+                acc_o: T.Buffer([block_M, dim], accum_dtype),
+                k: T.int32,
+                by: T.int32,
+                bz: T.int32,
+        ):
+            T.copy(V[bz, by, k * block_N:(k + 1) * block_N, :], V_shared)
+            T.gemm(acc_s_cast, V_shared, acc_o, policy=T.GemmWarpPolicy.FullRow)
+
+        @T.macro
+        def Softmax(
+                acc_s: T.Buffer([block_M, block_N], accum_dtype),
+                acc_s_cast: T.Buffer([block_M, block_N], dtype),
+                scores_max: T.Buffer([block_M], accum_dtype),
+                scores_max_prev: T.Buffer([block_M], accum_dtype),
+                scores_scale: T.Buffer([block_M], accum_dtype),
+                scores_sum: T.Buffer([block_M], accum_dtype),
+                logsum: T.Buffer([block_M], accum_dtype),
+        ):
+            T.copy(scores_max, scores_max_prev)
+            T.fill(scores_max, -T.infinity(accum_dtype))
+            T.reduce_max(acc_s, scores_max, dim=1, clear=False)
+            # To do causal softmax, we need to set the scores_max to 0 if it is -inf
+            # This process is called Check_inf in FlashAttention3 code, and it only need to be done
+            # in the first ceil_div(kBlockM, kBlockN) steps.
+            # for i in T.Parallel(block_M):
+            #     scores_max[i] = T.if_then_else(scores_max[i] == -T.infinity(accum_dtype), 0, scores_max[i])
+            for i in T.Parallel(block_M):
+                scores_scale[i] = T.exp2(scores_max_prev[i] * scale - scores_max[i] * scale)
+            for i, j in T.Parallel(block_M, block_N):
+                # Instead of computing exp(x - max), we compute exp2(x * log_2(e) -
+                # max * log_2(e)) This allows the compiler to use the ffma
+                # instruction instead of fadd and fmul separately.
+                acc_s[i, j] = T.exp2(acc_s[i, j] * scale - scores_max[i] * scale)
+            T.reduce_sum(acc_s, scores_sum, dim=1)
+            for i in T.Parallel(block_M):
+                logsum[i] = logsum[i] * scores_scale[i] + scores_sum[i]
+            T.copy(acc_s, acc_s_cast)
+
+        @T.macro
+        def Rescale(
+                acc_o: T.Buffer([block_M, dim], accum_dtype),
+                scores_scale: T.Buffer([block_M], accum_dtype),
+        ):
+            for i, j in T.Parallel(block_M, dim):
+                acc_o[i, j] *= scores_scale[i]
+
+        @T.prim_func
+        def main(
+                Q: T.Buffer(shape, dtype),
+                K: T.Buffer(shape, dtype),
+                V: T.Buffer(shape, dtype),
+                BlockSparseMask: T.Buffer(block_mask_shape, block_mask_dtype),
+                Output: T.Buffer(shape, dtype),
+        ):
+            with T.Kernel(
+                    T.ceildiv(seq_len, block_M), heads, batch, threads=threads) as (bx, by, bz):
+                Q_shared = T.alloc_shared([block_M, dim], dtype)
+                K_shared = T.alloc_shared([block_N, dim], dtype)
+                V_shared = T.alloc_shared([block_N, dim], dtype)
+                O_shared = T.alloc_shared([block_M, dim], dtype)
+                acc_s = T.alloc_fragment([block_M, block_N], accum_dtype)
+                acc_s_cast = T.alloc_fragment([block_M, block_N], dtype)
+                acc_o = T.alloc_fragment([block_M, dim], accum_dtype)
+                scores_max = T.alloc_fragment([block_M], accum_dtype)
+                scores_max_prev = T.alloc_fragment([block_M], accum_dtype)
+                scores_scale = T.alloc_fragment([block_M], accum_dtype)
+                scores_sum = T.alloc_fragment([block_M], accum_dtype)
+                logsum = T.alloc_fragment([block_M], accum_dtype)
+                block_mask = T.alloc_local([downsample_len], block_mask_dtype)
+
+                T.copy(Q[bz, by, bx * block_M:(bx + 1) * block_M, :], Q_shared)
+                T.fill(acc_o, 0)
+                T.fill(logsum, 0)
+                T.fill(scores_max, -T.infinity(accum_dtype))
+
+                for vj in T.serial(downsample_len):
+                    block_mask[vj] = BlockSparseMask[bz, by, bx, vj]
+
+                loop_range = (
+                    T.min(T.ceildiv(seq_len, block_N), T.ceildiv(
+                        (bx + 1) * block_M, block_N)) if is_causal else T.ceildiv(seq_len, block_N))
+
+                for k in T.Pipelined(loop_range, num_stages=num_stages):
+                    if block_mask[k] != 0:
+                        MMA0(K, Q_shared, K_shared, acc_s, k, bx, by, bz)
+                        Softmax(acc_s, acc_s_cast, scores_max, scores_max_prev, scores_scale,
+                                scores_sum, logsum)
+                        Rescale(acc_o, scores_scale)
+                        MMA1(V, V_shared, acc_s_cast, acc_o, k, by, bz)
+                for i, j in T.Parallel(block_M, dim):
+                    acc_o[i, j] /= logsum[i]
+                T.copy(acc_o, O_shared)
+                T.copy(O_shared, Output[bz, by, bx * block_M:(bx + 1) * block_M, :])
+
+        return main
+
+    return kernel_func(block_M, block_N, num_stages, threads)
+
+
+def test_sta_attention():
+    # Config
+    BATCH, N_HEADS, SEQ_LEN, D_HEAD = 1, 24, 2048, 128
+    torch.manual_seed(0)
+
+    # Create inputs
+    q = torch.randn(BATCH, N_HEADS, SEQ_LEN, D_HEAD, device='cuda', dtype=torch.float16)
+    k = torch.randn(BATCH, N_HEADS, SEQ_LEN, D_HEAD, device='cuda', dtype=torch.float16)
+    v = torch.randn(BATCH, N_HEADS, SEQ_LEN, D_HEAD, device='cuda', dtype=torch.float16)
+
+    sm_scale = 1.0 / (D_HEAD**0.5)
+
+    # Create sparse mask (downsampled to block level)
+    canvas_size = (32, 48, 80)
+    tile_size = (4, 8, 8)
+    delta_size = (2, 2, 2)
+    BLOCK = tile_size[0] * tile_size[1] * tile_size[2]
+    downsample_factor = BLOCK
+    downsample_len = math.ceil(SEQ_LEN / downsample_factor)
+    x_ds = torch.randn([BATCH, N_HEADS, downsample_len, downsample_len],
+                       device='cuda',
+                       dtype=torch.bfloat16)
+    block_mask = get_sta_mask(x_ds, canvas_size, tile_size, delta_size, has_text=True)
+    # print mask density
+    print("mask density", block_mask.sum() / block_mask.numel())
+    print("block_mask", block_mask)
+
+    # Run Triton kernel
+    program = blocksparse_flashattn(BATCH, N_HEADS, SEQ_LEN, D_HEAD, downsample_len, is_causal=True)
+    kernel = tilelang.compile(program, out_idx=[4])
+    
+    cuda_source = kernel.get_kernel_source()
+    print("Generated CUDA kernel:\n", cuda_source)
+
+    tilelang_output = kernel(q, k, v, block_mask)
+
+    if True:
+        # Compute reference
+        # Expand block mask to full attention matrix
+        full_mask = torch.kron(block_mask.float(), torch.ones(BLOCK, BLOCK, device='cuda'))
+        full_mask = full_mask[..., :SEQ_LEN, :SEQ_LEN].bool()
+        full_mask = full_mask & torch.tril(torch.ones_like(full_mask))  # Apply causal
+
+        # PyTorch reference implementation
+        attn = torch.einsum('bhsd,bhtd->bhst', q, k) * sm_scale
+        attn = attn.masked_fill(~full_mask, float('-inf'))
+        attn = F.softmax(attn, dim=-1)
+        ref_output = torch.einsum('bhst,bhtd->bhsd', attn, v)
+
+        print("ref_output", ref_output)
+        print("tilelang_output", tilelang_output)
+
+        # Verify accuracy
+        torch.testing.assert_close(tilelang_output, ref_output, atol=1e-2, rtol=1e-2)
+        print("Pass topk sparse attention test with qlen == klen")
+
+
+if __name__ == "__main__":
+    test_sta_attention()