Commit Graph
6 Commits
Author SHA1 Message Date
ViperEkura 3439e3104e perf: launch CUDA kernels on torch's current stream
- Thread a cudaStream_t through attn dispatchers onto torch's current stream
- Scope the device guard to the entry function so kernels run on tensor device
- DISPATCH_HEAD_DIM now forwards varargs so stream reaches each dispatch
- Parallelize CPU reference kernels with OpenMP (paged test 31s -> 7s)
- Merge decode/prefill standalone tests into attn_test.cu with correctness tables
- Drop bench error column (CPU ref too slow at large sizes)
- Update cuda_kernels.md for the merged test layout
2026-08-02 13:20:14 +08:00
ViperEkura 3067a8e1a6 feat: unify attention backend with multi-dim mask support
- Add attention() functional entry delegating to active backend
- GQA/MLA forward calls attention() instead of inline cache/SDPA
- CUDA kernels support 2D/3D/4D mask via mask_h_stride field
- CudaBackend.fwd_decode builds 2D padding mask for mixed seq_lens
- KVCache.max_len precomputed in bind_tasks to avoid GPU sync
- batch==1 decode short-circuits mask=None
- Split tests into conftest, test_backend, test_backend_equivalence, test_kernel_mask
- 440 tests pass, L20 decode 1.44-1.60x speedup vs torch native
2026-07-30 20:38:34 +08:00
ViperEkura f7a16efc9d refactor: extract shared dispatcher header, unify MMA/scalar dispatch format
- Merge 3 duplicated dispatch blocks into single attn_dispatchers.cuh
- Merge compute_num_splits from attn_utils.cuh into dispatcher header
- All dim3 grid/block declarations and <<<>>> launches are single-line
- Production .cu files (35-42 loc) only handle torch wrapping + pybind11
- Test files include dispatcher header directly, removing all #ifndef ASTRAI_NO_MMA duplication
2026-07-21 22:21:39 +08:00
ViperEkura 57729fd92d refactor: stride-based attn interface with layout and causal mask
- Replace is_causal + causal_offset with unified causal_offset (-1 = off, >=0 = first Q pos)
- Causal and mask can now coexist (was mutually exclusive)
- Add stride-based addressing for Q/KV/O (layout-agnostic, zero-copy)
- Add layout param ("bhld"/"blhd") parsed in Python, passed as int to C++
- Support 2D [batch, kv_len] and 3D [batch, q_len, kv_len] mask
- Vectorize paged KV gather in Python fallback (was per-token Python loop)
- Extract shared helpers: compute_num_splits, alloc_split_partials, dispatch_head_dim
- Unify paged_decode entry via attn_pack_paged_params
- Update mma_softmax_tile for 3D mask with per-row qrow indexing
2026-07-14 21:34:42 +08:00
ViperEkura fd6d25ad86 refactor: extract bench_kernel and dispatch_by_head_dim into test_utils 2026-07-12 00:05:04 +08:00
ViperEkura 2c3cef1c87 feat: wire up paged decode CUDA kernel to Python extension
- Add attn_paged_decode wrapper in ops.py with gather fallback
- Register kernel in loader.py and export from __init__.py
- Extract test_utils.cuh shared by all attention unit tests
- Rename attn_paged_vs_contiguous.cu to attn_paged_decode_test.cu
- Refactor decode/prefill tests to use common bf16 helpers and cpu ref
- Fix k_cache dim check in attn_paged_decode.cu
2026-07-11 18:40:49 +08:00