From 5e5c30d9ab8f1f07155eee61f2cab95a8e7cc350 Mon Sep 17 00:00:00 2001
From: fzyzcjy <5236035+fzyzcjy@users.noreply.github.com>
Date: Fri, 5 Sep 2025 19:52:32 +0800
Subject: [PATCH] Tiny let DeepGEMM scale checks cover more cases (#7182)

Co-authored-by: Yineng Zhang <me@zhyncs.com>
---
 .../deep_gemm_wrapper/entrypoint.py           | 27 +++++++++++++++++++
 .../srt/layers/quantization/fp8_utils.py      | 10 -------
 2 files changed, 27 insertions(+), 10 deletions(-)

diff --git a/python/sglang/srt/layers/quantization/deep_gemm_wrapper/entrypoint.py b/python/sglang/srt/layers/quantization/deep_gemm_wrapper/entrypoint.py
index eedaa3c9b..02945f449 100644
--- a/python/sglang/srt/layers/quantization/deep_gemm_wrapper/entrypoint.py
+++ b/python/sglang/srt/layers/quantization/deep_gemm_wrapper/entrypoint.py
@@ -11,6 +11,7 @@ from sglang.srt.layers.quantization.deep_gemm_wrapper.configurer import (
     ENABLE_JIT_DEEPGEMM,
 )
 from sglang.srt.server_args import ServerArgs
+from sglang.srt.utils import get_bool_env_var
 
 logger = logging.getLogger(__name__)
 
@@ -18,6 +19,8 @@ if ENABLE_JIT_DEEPGEMM:
     import deep_gemm
     from deep_gemm.utils.layout import get_mn_major_tma_aligned_tensor
 
+_SANITY_CHECK = get_bool_env_var("SGLANG_DEEPGEMM_SANITY_CHECK")
+
 
 # TODO maybe rename these functions
 def grouped_gemm_nt_f8f8bf16_masked(
@@ -31,6 +34,9 @@ def grouped_gemm_nt_f8f8bf16_masked(
     _, n, _ = rhs[0].shape
     kernel_type = compile_utils.DeepGemmKernelType.GROUPED_GEMM_NT_F8F8BF16_MASKED
 
+    _sanity_check_input(lhs)
+    _sanity_check_input(rhs)
+
     with compile_utils.deep_gemm_execution_hook(
         expected_m, n, k, num_groups, kernel_type
     ):
@@ -53,6 +59,9 @@ def grouped_gemm_nt_f8f8bf16_contig(
     num_groups, n, _ = rhs[0].shape
     kernel_type = compile_utils.DeepGemmKernelType.GROUPED_GEMM_NT_F8F8BF16_CONTIG
 
+    _sanity_check_input(lhs)
+    _sanity_check_input(rhs)
+
     with compile_utils.deep_gemm_execution_hook(m, n, k, num_groups, kernel_type):
         deep_gemm.m_grouped_fp8_gemm_nt_contiguous(lhs, rhs, out, m_indices)
 
@@ -67,6 +76,9 @@ def gemm_nt_f8f8bf16(
     num_groups = 1
     kernel_type = compile_utils.DeepGemmKernelType.GEMM_NT_F8F8BF16
 
+    _sanity_check_input(lhs)
+    _sanity_check_input(rhs)
+
     with compile_utils.deep_gemm_execution_hook(m, n, k, num_groups, kernel_type):
         deep_gemm.fp8_gemm_nt(
             lhs,
@@ -90,3 +102,18 @@ def configure_deep_gemm_num_sms(num_sms):
             yield
         finally:
             deep_gemm.set_num_sms(original_num_sms)
+
+
+def _sanity_check_input(x_fp8: Tuple[torch.Tensor, torch.Tensor]):
+    if not _SANITY_CHECK:
+        return
+
+    x, x_scale = x_fp8
+
+    if x_scale.dtype == torch.int:
+        return
+
+    from sglang.srt.layers.quantization.fp8_utils import ceil_to_ue8m0
+
+    x_scale_ceil = ceil_to_ue8m0(x_scale)
+    assert torch.all(x_scale == x_scale_ceil), f"{x_scale=} {x_scale_ceil=}"
diff --git a/python/sglang/srt/layers/quantization/fp8_utils.py b/python/sglang/srt/layers/quantization/fp8_utils.py
index 42c894590..e4bcbe23c 100644
--- a/python/sglang/srt/layers/quantization/fp8_utils.py
+++ b/python/sglang/srt/layers/quantization/fp8_utils.py
@@ -248,11 +248,6 @@ def deepgemm_w8a8_block_fp8_linear_with_fallback(
         scale_ue8m0=deep_gemm_wrapper.DEEPGEMM_SCALE_UE8M0,
     )
 
-    # NOTE(alcanderian): Useless when scale is packed to int32
-    # if get_bool_env_var("SGLANG_W8A8_DEEPGEMM_SANITY_CHECK_UE8M0"):
-    #     _check_ue8m0("x_scale", x_scale)
-    #     _check_ue8m0("weight_scale", ws)
-
     output = w8a8_block_fp8_matmul_deepgemm(
         q_input, weight, x_scale, weight_scale, block_size, output_dtype=output_dtype
     )
@@ -261,11 +256,6 @@ def deepgemm_w8a8_block_fp8_linear_with_fallback(
     return output.to(dtype=output_dtype).view(*output_shape)
 
 
-def _check_ue8m0(name, x):
-    x_ceil = ceil_to_ue8m0(x)
-    assert torch.all(x == x_ceil), f"{name=} {x=} {x_ceil=}"
-
-
 def aiter_w8a8_block_fp8_linear(
     input: torch.Tensor,
     weight: torch.Tensor,