Files
AstrAI/csrc/build.py
T
ViperEkura 41dcf0feb9 feat: SGLang-style paged attention kernels replace page-table path
- PagedAttentionParams uses flat KV pool + req_to_token + kv_indptr/qo_indptr instead of page_table
- MMA split-KV decode and split-Q prefill kernels with indirect ragged-batch addressing
- Prefill kernel accepts 4D mask (causal-aware); decode kernel supports 2D mask
- CudaBackend is inference-only: kv_cache=None raises, no torch fallback
- benchmark.py: required --ckpt, --backend/--compare options
- Parallel build isolates build-temp/build-lib per subprocess
- Standalone test covers decode/prefill with mask, 27 cases pass
2026-08-01 15:41:25 +08:00

77 lines
2.1 KiB
Python

from pathlib import Path
def cuda_toolkit_version() -> tuple[int, int] | None:
"""Return ``(major, minor)`` of the nvcc on PATH, or ``None``.
Used by ``setup.py`` to detect nvcc/torch CUDA version mismatches
(e.g. nvcc 13.0 with a cu128 torch wheel) which cause cryptic ABI errors.
"""
import shutil
import subprocess
nvcc = shutil.which("nvcc")
if nvcc is None:
return None
try:
out = subprocess.check_output(
[nvcc, "--version"], stderr=subprocess.STDOUT, text=True
)
for line in out.splitlines():
if "release" in line:
ver = line.split("release")[1].split(",")[0].strip()
major, minor = ver.split(".")
return (int(major), int(minor))
except Exception:
pass
return None
def _arch_flags() -> list[str]:
import torch
if torch.cuda.is_available():
cap = torch.cuda.get_device_capability()
else:
cap = (8, 0)
ver = f"{cap[0]}{cap[1]}"
flags = [f"-gencode=arch=compute_{ver},code=sm_{ver}"]
# tensor-core mma path (mma.sync.m16n8k16.bf16) requires sm_80+; decide the
# kernel dispatch at build time via this define rather than at runtime.
if cap[0] < 8:
flags.append("-DASTRAI_NO_MMA")
return flags
_kernels_dir = Path("csrc/kernels")
REGISTRY: dict[str, dict] = {}
CXX_FLAGS = ["-O3", "-funroll-loops"]
NVCC_FLAGS = [
"-O3",
"--expt-relaxed-constexpr",
"--use_fast_math",
"--ptxas-options=-O3,-v",
"--extra-device-vectorization",
"--threads=16",
]
def register(name: str, sources: list[str] | None = None, **kwargs):
if sources is None:
sources = [str(_kernels_dir / f"{name}.cu")]
REGISTRY[name] = {
"sources": sources,
"cxx_flags": [*CXX_FLAGS],
"nvcc_flags": [*NVCC_FLAGS, *_arch_flags()],
"extra_link_args": kwargs.pop("extra_link_args", []),
**kwargs,
}
register("attn_decode")
register("attn_prefill")
register("attn_paged_decode")
register("attn_paged_prefill")
register("rotary_emb")