A high-throughput and memory-efficient inference and serving engine for LLMs
Mirrored from https://github.com/tduncan-lum/Nvidia-Optimization-Stack---VLLM.git
Synced Nov 14, 05:30 UTC
[Feature] Add `VLLM_USE_DEEP_GEMM_E8M0` Env to Control E8M0 Scale (#21968)
Signed-off-by: yewentao256 <zhyanwentao@126.com>
Wentao Ye committed
Aug 11, 2025 at 12:39 UTC
f7dcce7a4aabb1445c2827ac5d978a9c5e18be30
9 files changed
+65
-39
tests/kernels/moe/test_block_fp8.py
+3
-2
@@ -16,7 +16,7 @@ from vllm.model_executor.layers.fused_moe.fused_moe import (
16
fused_topk, modular_triton_fused_moe)
17
from vllm.platforms import current_platform
18
from vllm.utils import has_deep_gemm
19
-from vllm.utils.deep_gemm import is_blackwell_deep_gemm_used
19
+from vllm.utils.deep_gemm import is_blackwell_deep_gemm_e8m0_used
20
21
dg_available = has_deep_gemm()
22
@@ -224,7 +224,8 @@ def test_w8a8_block_fp8_fused_moe(M, N, K, E, topk, block_size, dtype, seed,
224
@pytest.mark.parametrize("topk", TOP_KS)
225
@pytest.mark.parametrize("seed", SEEDS)
226
@pytest.mark.skipif(not dg_available, reason="DeepGemm kernels not available.")
227
-@pytest.mark.skipif(is_blackwell_deep_gemm_used(), reason="Not E8M0 scale MOE")
227
+@pytest.mark.skipif(is_blackwell_deep_gemm_e8m0_used(),
228
+ reason="Not E8M0 scale MOE")
229
@torch.inference_mode()
230
def test_w8a8_block_fp8_deep_gemm_fused_moe(M, N, K, E, topk, seed,
231
monkeypatch):
tests/kernels/moe/test_deepep_deepgemm_moe.py
+3
-3
@@ -20,7 +20,7 @@ from vllm.model_executor.layers.fused_moe.modular_kernel import (
20
FusedMoEModularKernel)
21
from vllm.platforms import current_platform
22
from vllm.utils import has_deep_ep, has_deep_gemm
23
-from vllm.utils.deep_gemm import (is_blackwell_deep_gemm_used,
23
+from vllm.utils.deep_gemm import (is_blackwell_deep_gemm_e8m0_used,
24
is_deep_gemm_supported)
25
26
from .parallel_utils import ProcessGroupInfo, parallel_launch
@@ -370,7 +370,7 @@ NUM_EXPERTS = [32]
370
@pytest.mark.parametrize("world_dp_size", [(2, 1)])
371
@requires_deep_ep
372
@requires_deep_gemm
373
-@pytest.mark.skipif(is_blackwell_deep_gemm_used(),
373
+@pytest.mark.skipif(is_blackwell_deep_gemm_e8m0_used(),
374
reason="Skipping test for Blackwell DeepGEMM")
375
def test_ht_deepep_deepgemm_moe(mnk: tuple[int, int, int], num_experts: int,
376
topk: int, world_dp_size: tuple[int, int]):
@@ -427,7 +427,7 @@ USE_FP8_DISPATCH = [False]
427
@pytest.mark.parametrize("world_dp_size", [(2, 1)])
428
@requires_deep_ep
429
@requires_deep_gemm
430
-@pytest.mark.skipif(is_blackwell_deep_gemm_used(),
430
+@pytest.mark.skipif(is_blackwell_deep_gemm_e8m0_used(),
431
reason="Skipping test for Blackwell DeepGEMM")
432
def test_ll_deepep_deepgemm_moe(
433
mnk: tuple[int, int, int],
vllm/envs.py
+5
@@ -127,6 +127,7 @@ if TYPE_CHECKING:
127
VLLM_TPU_MOST_MODEL_LEN: Optional[int] = None
128
VLLM_TPU_USING_PATHWAYS: bool = False
129
VLLM_USE_DEEP_GEMM: bool = False
130
+ VLLM_USE_DEEP_GEMM_E8M0: bool = True
131
VLLM_SKIP_DEEP_GEMM_WARMUP: bool = False
132
VLLM_USE_FLASHINFER_MOE_FP8: bool = False
133
VLLM_USE_FLASHINFER_MOE_FP4: bool = False
@@ -925,6 +926,10 @@ environment_variables: dict[str, Callable[[], Any]] = {
926
"VLLM_USE_DEEP_GEMM":
927
lambda: bool(int(os.getenv("VLLM_USE_DEEP_GEMM", "0"))),
928
929
+ # Whether to use E8M0 scaling when DeepGEMM is used on Blackwell GPUs.
930
+ # E8M0 is faster on B200 but may reduce accuracy.
931
+ "VLLM_USE_DEEP_GEMM_E8M0":
932
+ lambda: bool(int(os.getenv("VLLM_USE_DEEP_GEMM_E8M0", "1"))),
933
# DeepGemm JITs the kernels on-demand. The warmup attempts to make DeepGemm
934
# JIT all the required kernels before model execution so there is no
935
# JIT'ing in the hot-path. However, this warmup increases the engine
vllm/model_executor/layers/fused_moe/batched_deep_gemm_moe.py
+2
-2
@@ -12,7 +12,7 @@ from vllm.model_executor.layers.fused_moe.topk_weight_and_reduce import (
12
from vllm.model_executor.layers.fused_moe.utils import _resize_cache
13
from vllm.triton_utils import tl, triton
14
from vllm.utils.deep_gemm import (fp8_m_grouped_gemm_nt_masked,
15
- is_blackwell_deep_gemm_used)
15
+ is_blackwell_deep_gemm_e8m0_used)
16
17
logger = init_logger(__name__)
18
@@ -176,7 +176,7 @@ def silu_mul_fp8_quant_deep_gemm(
176
eps,
177
fp8_min,
178
fp8_max,
179
- is_blackwell_deep_gemm_used(),
179
+ is_blackwell_deep_gemm_e8m0_used(),
180
BLOCK=group_size,
181
NUM_STAGES=8,
182
num_warps=1,
vllm/model_executor/layers/fused_moe/fused_moe.py
+3
-3
@@ -40,7 +40,7 @@ from vllm.model_executor.layers.quantization.utils.mxfp4_utils import (
40
from vllm.platforms import current_platform
41
from vllm.triton_utils import tl, triton
42
from vllm.utils import direct_register_custom_op, is_torch_equal_or_newer
43
-from vllm.utils.deep_gemm import is_blackwell_deep_gemm_used
43
+from vllm.utils.deep_gemm import is_blackwell_deep_gemm_e8m0_used
44
45
from .rocm_aiter_fused_moe import is_rocm_aiter_moe_enabled
46
@@ -1387,8 +1387,8 @@ def fused_experts(hidden_states: torch.Tensor,
1387
# E8M0 scale, which means we requantize the weight and input to the specific
1388
# scale. Fallen back to cutlass or triton for some cases would cause
1389
# accuracy issue.
1390
- should_use_deep_gemm = is_blackwell_deep_gemm_used() or _valid_deep_gemm(
1391
- hidden_states, w1, w2)
1390
+ should_use_deep_gemm = is_blackwell_deep_gemm_e8m0_used(
1391
+ ) or _valid_deep_gemm(hidden_states, w1, w2)
1392
if (allow_deep_gemm and use_fp8_w8a8 and should_use_deep_gemm):
1393
assert apply_router_weight_on_input is False
1394
assert is_act_and_mul, (
vllm/model_executor/layers/fused_moe/triton_deep_gemm_moe.py
+3
-3
@@ -10,7 +10,7 @@ from vllm.model_executor.layers.fused_moe.deep_gemm_moe import (
10
DeepGemmExperts, _valid_deep_gemm, _valid_deep_gemm_shape,
11
deep_gemm_block_shape)
12
from vllm.model_executor.layers.fused_moe.fused_moe import TritonExperts
13
-from vllm.utils.deep_gemm import is_blackwell_deep_gemm_used
13
+from vllm.utils.deep_gemm import is_blackwell_deep_gemm_e8m0_used
14
15
16
class TritonOrDeepGemmExperts(mk.FusedMoEPermuteExpertsUnpermute):
@@ -107,7 +107,7 @@ class TritonOrDeepGemmExperts(mk.FusedMoEPermuteExpertsUnpermute):
107
# Note: the deep gemm workspaces are strictly larger than the triton
108
# workspaces so we can be pessimistic here and allocate for DeepGemm
109
# even if we fall back to triton later, e.g. if expert maps are set.
110
- if self.allow_deep_gemm and (is_blackwell_deep_gemm_used()
110
+ if self.allow_deep_gemm and (is_blackwell_deep_gemm_e8m0_used()
111
or _valid_deep_gemm_shape(M, N, K)):
112
assert self.deep_gemm_expert is not None
113
return self.deep_gemm_expert.workspace_shapes(
@@ -133,7 +133,7 @@ class TritonOrDeepGemmExperts(mk.FusedMoEPermuteExpertsUnpermute):
133
extra_expert_args: Optional[dict[str, Any]]):
134
use_deep_gemm = (self.allow_deep_gemm
135
and (_valid_deep_gemm(hidden_states, w1, w2)
136
- or is_blackwell_deep_gemm_used()))
136
+ or is_blackwell_deep_gemm_e8m0_used()))
137
138
experts = self.deep_gemm_expert if use_deep_gemm else self.triton_expert
139
assert experts is not None
vllm/model_executor/layers/quantization/fp8.py
+7
-12
@@ -45,7 +45,8 @@ from vllm.model_executor.utils import set_weight_attrs
45
from vllm.platforms import current_platform
46
from vllm.scalar_type import scalar_types
47
from vllm.utils import has_deep_gemm
48
-from vllm.utils.deep_gemm import is_blackwell_deep_gemm_used
48
+from vllm.utils.deep_gemm import (is_blackwell_deep_gemm_e8m0_used,
49
+ is_deep_gemm_supported)
50
from vllm.utils.flashinfer import has_flashinfer_moe
51
52
if TYPE_CHECKING:
@@ -415,10 +416,10 @@ class Fp8LinearMethod(LinearMethodBase):
416
# Activations not quantized for marlin.
417
del layer.input_scale
418
418
- # On B200, DeepGemm only support E8M0 scale, which means we need to
419
+ # On B200, if E8M0 for DeepGemm is used, we need to
420
# requantize the weight and input to the specific scale
421
# at the same time.
421
- if is_blackwell_deep_gemm_used():
422
+ if is_blackwell_deep_gemm_e8m0_used():
423
assert layer.weight_block_size is not None
424
block_sz = tuple(layer.weight_block_size)
425
requant_weight_ue8m0_inplace(
@@ -505,15 +506,9 @@ class Fp8MoEMethod(FusedMoEMethodBase):
506
elif not self.block_quant:
507
logger.warning_once("Model is not block quantized. Not using "
508
"DeepGemm kernels")
508
- elif (current_platform.is_cuda()
509
- and current_platform.is_device_capability(90)):
509
+ elif (is_deep_gemm_supported()):
510
logger.info_once("Using DeepGemm kernels for Fp8MoEMethod.")
511
self.allow_deep_gemm = True
512
- elif (current_platform.is_cuda()
513
- and is_blackwell_deep_gemm_used()):
514
- logger.info_once("Using DeepGemm SM100 kernels for "
515
- "Fp8MoEMethod.")
516
- self.allow_deep_gemm = True
512
else:
513
logger.warning_once(
514
"DeepGemm not supported on the current platform.")
@@ -725,7 +720,7 @@ class Fp8MoEMethod(FusedMoEMethodBase):
720
721
# DeepGemm scales need to be transposed and aligned. We try to do
722
# it ahead of time for performance reasons.
728
- if self.allow_deep_gemm and not is_blackwell_deep_gemm_used():
723
+ if self.allow_deep_gemm and not is_blackwell_deep_gemm_e8m0_used():
724
# Lazy import to avoid CUDA initialization problems.
725
if _is_col_major(layer.w13_weight_scale_inv):
726
layer.w13_weight_scale_inv = \
@@ -851,7 +846,7 @@ class Fp8MoEMethod(FusedMoEMethodBase):
846
del layer.w13_input_scale
847
del layer.w2_input_scale
848
854
- if is_blackwell_deep_gemm_used():
849
+ if is_blackwell_deep_gemm_e8m0_used():
850
assert layer.weight_block_size is not None
851
# Re-quantise the expert weights so their scales are UE8M0.
852
block_sz = tuple(layer.weight_block_size)
vllm/model_executor/layers/quantization/utils/fp8_utils.py
+2
-4
@@ -20,7 +20,7 @@ from vllm.model_executor.layers.quantization.utils.w8a8_utils import (
20
from vllm.platforms import current_platform
21
from vllm.triton_utils import tl, triton
22
from vllm.utils import cdiv, direct_register_custom_op, has_deep_gemm
23
-from vllm.utils.deep_gemm import is_blackwell_deep_gemm_used
23
+from vllm.utils.deep_gemm import is_blackwell_deep_gemm_e8m0_used
24
25
logger = init_logger(__name__)
26
@@ -394,10 +394,8 @@ def per_token_group_quant_fp8(
394
tuple[torch.Tensor, torch.Tensor]: The quantized tensor and the
395
scaling factor.
396
"""
397
- # TODO(wentao): refactor this
398
- # use_ue8m0 should be a global flag that could be set by user
397
if use_ue8m0 is None:
400
- use_ue8m0 = is_blackwell_deep_gemm_used()
398
+ use_ue8m0 = is_blackwell_deep_gemm_e8m0_used()
399
dtype = current_platform.fp8_dtype() if dtype is None else dtype
400
assert (x.shape[-1] % group_size == 0), (
401
f"the last dimension of `x` {x.shape[-1]} must be divisible "
vllm/utils/deep_gemm.py
+37
-10
@@ -31,19 +31,37 @@ def is_deep_gemm_supported() -> bool:
31
32
33
@functools.cache
34
-def is_blackwell_deep_gemm_used() -> bool:
35
- """Return ``True`` if vLLM is configured to use DeepGEMM on a
36
- Blackwell-class GPU.
34
+def is_blackwell_deep_gemm_e8m0_used() -> bool:
35
+ """Return ``True`` if vLLM is configured to use DeepGEMM "
36
+ "E8M0 scale on a Blackwell-class GPU.
37
"""
38
- if not (envs.VLLM_USE_DEEP_GEMM and has_deep_gemm()):
38
+ if not (envs.VLLM_USE_DEEP_GEMM):
39
+ logger.debug_once("DeepGEMM E8M0 disabled: VLLM_USE_DEEP_GEMM=0.")
40
+ return False
41
+
42
+ if not has_deep_gemm():
43
+ logger.debug_once("DeepGEMM E8M0 disabled: DeepGEMM backend missing.")
44
+ return False
45
+
46
+ if not envs.VLLM_USE_DEEP_GEMM_E8M0:
47
+ logger.debug_once("DeepGEMM E8M0 disabled: VLLM_USE_DEEP_GEMM_E8M0=0.")
48
return False
49
50
_lazy_init()
51
+
52
if _fp8_gemm_nt_impl is None:
53
+ logger.debug_once(
54
+ "DeepGEMM E8M0 disabled: _fp8_gemm_nt_impl not found")
55
return False
56
45
- return (current_platform.is_cuda()
46
- and current_platform.is_device_capability(100))
57
+ enabled = (current_platform.is_cuda()
58
+ and current_platform.has_device_capability(100))
59
+ if enabled:
60
+ logger.debug_once("DeepGEMM E8M0 enabled on Blackwell GPU.")
61
+ else:
62
+ logger.debug_once(
63
+ "DeepGEMM E8M0 disabled: not running on Blackwell GPU.")
64
+ return enabled
65
66
67
def _missing(*_: Any, **__: Any) -> NoReturn:
@@ -109,21 +127,30 @@ def fp8_gemm_nt(*args, **kwargs):
127
_lazy_init()
128
if _fp8_gemm_nt_impl is None:
129
return _missing(*args, **kwargs)
112
- return _fp8_gemm_nt_impl(*args, **kwargs)
130
+ return _fp8_gemm_nt_impl(
131
+ *args,
132
+ disable_ue8m0_cast=not is_blackwell_deep_gemm_e8m0_used(),
133
+ **kwargs)
134
135
136
def m_grouped_fp8_gemm_nt_contiguous(*args, **kwargs):
137
_lazy_init()
138
if _grouped_impl is None:
139
return _missing(*args, **kwargs)
119
- return _grouped_impl(*args, **kwargs)
140
+ return _grouped_impl(
141
+ *args,
142
+ disable_ue8m0_cast=not is_blackwell_deep_gemm_e8m0_used(),
143
+ **kwargs)
144
145
146
def fp8_m_grouped_gemm_nt_masked(*args, **kwargs):
147
_lazy_init()
148
if _grouped_masked_impl is None:
149
return _missing(*args, **kwargs)
126
- return _grouped_masked_impl(*args, **kwargs)
150
+ return _grouped_masked_impl(
151
+ *args,
152
+ disable_ue8m0_cast=not is_blackwell_deep_gemm_e8m0_used(),
153
+ **kwargs)
154
155
156
def _ceil_to_ue8m0(x: torch.Tensor):
@@ -181,6 +208,6 @@ __all__ = [
208
"m_grouped_fp8_gemm_nt_contiguous",
209
"fp8_m_grouped_gemm_nt_masked",
210
"per_block_cast_to_fp8",
184
- "is_blackwell_deep_gemm_used",
211
+ "is_blackwell_deep_gemm_e8m0_used",
212
"is_deep_gemm_supported",
213
]