Files
sglang/python/sglang/jit_kernel/activation.py
T

128 lines
3.8 KiB
Python

from __future__ import annotations
from typing import TYPE_CHECKING, Optional
import torch
from sglang.jit_kernel.utils import (
cache_once,
get_jit_cuda_arch,
is_arch_support_pdl,
is_hip_runtime,
load_jit,
make_cpp_args,
)
from sglang.srt.utils.custom_op import register_custom_op
if TYPE_CHECKING:
from tvm_ffi.module import Module
def _fast_math_flags() -> list[str]:
# Mirrors sgl-kernel's CMake policy: fast-math on SM90, precise on
# SM100+ (Blackwell needs bit-exact expf), off on HIP (clang rejects).
if is_hip_runtime():
return []
if get_jit_cuda_arch().major >= 10:
return []
return ["--use_fast_math"]
@cache_once
def _jit_activation_module(dtype: torch.dtype) -> Module:
args = make_cpp_args(dtype, is_arch_support_pdl())
return load_jit(
"activation",
*args,
cuda_files=["elementwise/activation.cuh"],
extra_cuda_cflags=_fast_math_flags(),
cuda_wrappers=[
("run_activation", f"ActivationKernel<{args}>::run_activation"),
(
"run_activation_filtered",
f"ActivationKernel<{args}>::run_activation_filtered",
),
],
)
SUPPORTED_ACTIVATIONS = {"silu", "gelu", "gelu_tanh"}
@register_custom_op(mutates_args=["out"])
def _run_activation_inplace(
op_name: str, input: torch.Tensor, out: torch.Tensor
) -> None:
hidden_size = input.shape[-1] // 2
module = _jit_activation_module(input.dtype)
input_2d = input.view(-1, hidden_size * 2)
out_2d = out.view(-1, hidden_size)
module.run_activation(input_2d, out_2d, op_name)
@register_custom_op(mutates_args=["out"])
def _run_activation_filtered_inplace(
op_name: str,
input: torch.Tensor,
out: torch.Tensor,
expert_ids: torch.Tensor,
expert_step: int,
) -> None:
hidden_size = input.shape[-1] // 2
module = _jit_activation_module(input.dtype)
input_2d = input.view(-1, hidden_size * 2)
out_2d = out.view(-1, hidden_size)
module.run_activation_filtered(input_2d, out_2d, expert_ids, expert_step, op_name)
def run_activation(
op_name: str,
input: torch.Tensor,
out: Optional[torch.Tensor],
expert_ids: Optional[torch.Tensor] = None,
expert_step: int = 1,
) -> torch.Tensor:
"""Apply ``op_name`` activation followed by element-wise multiplication.
When ``expert_ids`` is provided, output rows are skipped for tokens whose
routed expert id is ``-1``. ``expert_step`` is 1 for per-token routing and
``BLOCK_SIZE_M`` for sorted/TMA routing — i.e. ``expert_ids[token_id //
expert_step]`` is consulted before computing each row.
"""
assert op_name in SUPPORTED_ACTIVATIONS, f"Unsupported activation: {op_name}"
hidden_size = input.shape[-1] // 2
if out is None:
out = input.new_empty(*input.shape[:-1], hidden_size)
if expert_ids is None:
_run_activation_inplace(op_name, input, out)
else:
_run_activation_filtered_inplace(op_name, input, out, expert_ids, expert_step)
return out
def silu_and_mul(
input: torch.Tensor,
out: Optional[torch.Tensor] = None,
expert_ids: Optional[torch.Tensor] = None,
expert_step: int = 1,
) -> torch.Tensor:
return run_activation("silu", input, out, expert_ids, expert_step)
def gelu_and_mul(
input: torch.Tensor,
out: Optional[torch.Tensor] = None,
expert_ids: Optional[torch.Tensor] = None,
expert_step: int = 1,
) -> torch.Tensor:
return run_activation("gelu", input, out, expert_ids, expert_step)
def gelu_tanh_and_mul(
input: torch.Tensor,
out: Optional[torch.Tensor] = None,
expert_ids: Optional[torch.Tensor] = None,
expert_step: int = 1,
) -> torch.Tensor:
return run_activation("gelu_tanh", input, out, expert_ids, expert_step)