Commit Graph
6 Commits
Author SHA1 Message Date
ViperEkura 1b1f1a0707 fix: add dtype guard to FlashAttnBackend capability check
- _backend_supports now rejects fp32 for FlashAttnBackend (flash-attn only supports fp16/bf16), preventing runtime crash on fallback chain
- rename test_default_backend_is_torch_native to reflect multi-backend reality
- scheduler test fixture uses bf16 model (matches production, avoids unnecessary 3-step fallback chain)
2026-08-07 23:08:22 +08:00
ViperEkura 02469887f5 refactor: simplify inference engine and backend dispatch
- merge _generate_streaming/_generate_non_streaming into single _generate() with stream flag
- delete dead GenerationRequest class and generate_with_request method
- inline _next_token helper into generate_async
- replace flash-attn double-checked locking with functools.lru_cache
- extract _write_and_gather_kv helper shared by TorchNative/FlashAttn backends
- inline _kv_cache_is_contiguous into its sole call site in FlashAttnBackend
- change default backend priority from flash>cuda>torch to cuda>flash>torch
- add ASTR_BACKEND env var to override default backend at resolve time
- add supports_graph() static method to AttentionBackend ABC, override in CudaBackend
- replace isinstance(get_backend(), CudaBackend) with get_backend().supports_graph() in executor
- add torch.cuda.is_available() guard to CudaBackend.supports()
2026-08-07 22:28:48 +08:00
ViperEkura 55ee258e95 style: fix ruff lint warnings
- Remove unused local variable b in attention_backend.py
- Remove unused variable rank0_sd in test_broadcast_state_dict.py
- Remove unused imports across test files
2026-08-07 14:17:48 +08:00
ViperEkura 6f49738991 feat: auto-select best available attention backend
- Default backend resolves to highest-priority available: flash -> cuda -> torch
- attention() falls back per-call for training/fp32/unsupported head_dim
- Re-apply index_copy_ for CUDA KV cache writes (index_put_ race mitigation)
2026-08-07 13:48:59 +08:00
ViperEkura 8152760b5f refactor : use factory for attention backends
- register built-in backends through BaseFactory
- derive benchmark choices from registered backends
- cover string selection and invalid backend names
2026-08-05 15:37:22 +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