[perf] introduce deep gemm group_gemm_masked as bmm (#5432)

2025-04-20 15:38:27 +08:00
parent d07e797ace
commit 99456bcacb
3 changed files with 361 additions and 20 deletions
--- a/python/sglang/srt/layers/quantization/fp8_kernel.py
+++ b/python/sglang/srt/layers/quantization/fp8_kernel.py
@@ -44,6 +44,7 @@ else:
 fp8_min = -fp8_max

 _enable_jit_deepgemm = False
+_enable_jit_deepgemm_bmm = False
 if _is_cuda:
    import deep_gemm
    from sgl_kernel import (
@@ -53,10 +54,11 @@ if _is_cuda:
    )

    sm_version = get_device_sm()
-    if sm_version == 90 and get_bool_env_var(
-        "SGL_ENABLE_JIT_DEEPGEMM", default="false"
-    ):
-        _enable_jit_deepgemm = True
+    if sm_version == 90:
+        if get_bool_env_var("SGL_ENABLE_JIT_DEEPGEMM", default="false"):
+            _enable_jit_deepgemm = True
+        if get_bool_env_var("SGL_ENABLE_JIT_DEEPGEMM_BMM", default="false"):
+            _enable_jit_deepgemm_bmm = True

 logger = logging.getLogger(__name__)

@@ -940,6 +942,108 @@ def per_tensor_quant_mla_fp8(
    return x_q, x_s_out


+@triton.jit
+def _per_token_group_quant_mla_deep_gemm_masked_fp8(
+    y_ptr,
+    y_q_ptr,
+    y_s_ptr,
+    masked_m_ptr,
+    group_size,
+    y_stride_b,
+    y_stride_t,
+    y_q_stride_b,
+    y_q_stride_t,
+    y_s_stride_b,
+    y_s_stride_g,
+    eps,
+    fp8_min,
+    fp8_max,
+    NUM_GROUP: tl.constexpr,
+    BLOCK: tl.constexpr,
+):
+    """A Triton-accelerated function to perform per-token-group
+    quantization on a tensor for deep_gemm grouped_gemm_masked.
+    This function converts the tensor values into float8 values.
+    y and y_q: (b, t, k)
+    y_s: (b, k//group_size, t)
+    """
+    t_id = tl.program_id(0)
+    b_id = tl.program_id(1)
+
+    y_ptr += b_id * y_stride_b + t_id * y_stride_t
+    y_q_ptr += b_id * y_q_stride_b + t_id * y_q_stride_t
+    y_s_ptr += b_id * y_s_stride_b + t_id
+
+    if t_id == 0:
+        tl.store(masked_m_ptr + b_id, tl.num_programs(0))
+
+    cols = tl.arange(0, BLOCK)  # group_size <= BLOCK
+    mask = cols < group_size
+
+    for gid in range(NUM_GROUP):
+        y = tl.load(y_ptr + gid * group_size + cols, mask=mask, other=0.0).to(
+            tl.float32
+        )
+        _absmax = tl.maximum(tl.max(tl.abs(y)), eps)
+        y_s = _absmax / fp8_max
+        y_q = tl.clamp(y / y_s, fp8_min, fp8_max).to(y_q_ptr.dtype.element_ty)
+
+        tl.store(y_q_ptr + gid * group_size + cols, y_q, mask=mask)
+        tl.store(y_s_ptr + gid * y_s_stride_g, y_s)
+
+
+def per_tensor_quant_mla_deep_gemm_masked_fp8(
+    x: torch.Tensor,
+    group_size: int = 128,
+    eps: float = 1e-12,
+    dtype: torch.dtype = torch.float8_e4m3fn,
+) -> Tuple[torch.Tensor, torch.Tensor]:
+    """
+    This function quantizes input values to float8 values with per-token-group-quantization
+    for deep_gemm grouped_gemm_masked and specialized for mla absorbed case.
+    """
+    assert x.dim() == 3, "`x` is not a 3d-tensor"
+
+    finfo = torch.finfo(dtype)
+    fp8_max = finfo.max
+    if _is_hip:
+        dtype = torch.float8_e4m3fnuz
+        fp8_max = 224.0
+
+    b, m, k = x.shape
+    aligned_m = (m + 255) // 256 * 256  # 256 is the max block_m of the gemm kernel
+    num_tiles_k = k // group_size
+    assert num_tiles_k * group_size == k, f"k % {group_size} must be zero"
+
+    x_q = x.new_empty((b, aligned_m, k), dtype=dtype)
+    x_s = x.new_empty((b, num_tiles_k, aligned_m), dtype=torch.float32)
+    masked_m = x.new_empty((b,), dtype=torch.int32)
+
+    BLOCK_SIZE = triton.next_power_of_2(group_size)
+    grid = (m, b)
+
+    _per_token_group_quant_mla_deep_gemm_masked_fp8[grid](
+        x,
+        x_q,
+        x_s,
+        masked_m,
+        group_size,
+        x.stride(0),
+        x.stride(1),
+        x_q.stride(0),
+        x_q.stride(1),
+        x_s.stride(0),
+        x_s.stride(1),
+        eps,
+        -fp8_max,
+        fp8_max,
+        num_tiles_k,
+        BLOCK_SIZE,
+    )
+
+    return x_q, x_s.transpose(1, 2), masked_m, m, aligned_m
+
+
 def scaled_fp8_quant(
    input: torch.Tensor,
    scale: Optional[torch.Tensor] = None,
--- a/python/sglang/srt/models/deepseek_v2.py
+++ b/python/sglang/srt/models/deepseek_v2.py
@@ -57,7 +57,11 @@ from sglang.srt.layers.moe.ep_moe.token_dispatcher import DeepEPDispatcher
 from sglang.srt.layers.moe.fused_moe_triton import FusedMoE
 from sglang.srt.layers.moe.topk import select_experts
 from sglang.srt.layers.quantization.base_config import QuantizationConfig
-from sglang.srt.layers.quantization.fp8_kernel import per_tensor_quant_mla_fp8
+from sglang.srt.layers.quantization.fp8_kernel import (
+    _enable_jit_deepgemm_bmm,
+    per_tensor_quant_mla_deep_gemm_masked_fp8,
+    per_tensor_quant_mla_fp8,
+)
 from sglang.srt.layers.quantization.fp8_utils import (
    block_quant_to_tensor_quant,
    channel_quant_to_tensor_quant,
@@ -82,6 +86,7 @@ _is_hip = is_hip()
 _is_cuda = is_cuda()

 if _is_cuda:
+    from deep_gemm import m_grouped_gemm_fp8_fp8_bf16_nt_masked
    from sgl_kernel import awq_dequantize, bmm_fp8, merge_state_v2
 else:
    from vllm._custom_ops import awq_dequantize
@@ -530,6 +535,10 @@ class DeepseekV2AttentionMLA(nn.Module):
        self.w_vc = None
        self.w_scale = None

+        self.w_scale_k = None
+        self.w_scale_v = None
+        self.use_deep_gemm_bmm = False
+
        self.flashinfer_mla_disable_ragged = global_server_args_dict[
            "flashinfer_mla_disable_ragged"
        ]
@@ -684,7 +693,24 @@ class DeepseekV2AttentionMLA(nn.Module):
            )
        q_nope, q_pe = q.split([self.qk_nope_head_dim, self.qk_rope_head_dim], dim=-1)

-        if self.w_kc.dtype == torch.float8_e4m3fnuz:
+        if self.use_deep_gemm_bmm:
+            q_nope_val, q_nope_scale, masked_m, expected_m, aligned_m = (
+                per_tensor_quant_mla_deep_gemm_masked_fp8(
+                    q_nope.transpose(0, 1), dtype=torch.float8_e4m3fn
+                )
+            )
+            q_nope_out = q_nope.new_empty(
+                (self.num_local_heads, aligned_m, self.kv_lora_rank)
+            )
+            m_grouped_gemm_fp8_fp8_bf16_nt_masked(
+                (q_nope_val, q_nope_scale),
+                (self.w_kc, self.w_scale_k),
+                q_nope_out,
+                masked_m,
+                expected_m,
+            )
+            q_nope_out = q_nope_out[:, :expected_m, :]
+        elif self.w_kc.dtype == torch.float8_e4m3fnuz:
            # TODO(kernel): add bmm_fp8 for torch.float8_e4m3fnuz
            q_nope_out = torch.bmm(
                q_nope.to(torch.bfloat16).transpose(0, 1),
@@ -716,7 +742,24 @@ class DeepseekV2AttentionMLA(nn.Module):
        attn_output = self.attn_mqa(q_input, k_input, v_input, forward_batch)
        attn_output = attn_output.view(-1, self.num_local_heads, self.kv_lora_rank)

-        if self.w_vc.dtype == torch.float8_e4m3fnuz:
+        if self.use_deep_gemm_bmm:
+            attn_output_val, attn_output_scale, masked_m, expected_m, aligned_m = (
+                per_tensor_quant_mla_deep_gemm_masked_fp8(
+                    attn_output.transpose(0, 1), dtype=torch.float8_e4m3fn
+                )
+            )
+            attn_bmm_output = attn_output.new_empty(
+                (self.num_local_heads, aligned_m, self.v_head_dim)
+            )
+            m_grouped_gemm_fp8_fp8_bf16_nt_masked(
+                (attn_output_val, attn_output_scale),
+                (self.w_vc, self.w_scale_v),
+                attn_bmm_output,
+                masked_m,
+                expected_m,
+            )
+            attn_bmm_output = attn_bmm_output[:, :expected_m, :]
+        elif self.w_vc.dtype == torch.float8_e4m3fnuz:
            # TODO(kernel): add bmm_fp8 for torch.float8_e4m3fnuz
            attn_bmm_output = torch.bmm(
                attn_output.to(torch.bfloat16).transpose(0, 1),
@@ -1439,6 +1482,10 @@ class DeepseekV2ForCausalLM(nn.Module):
                w = self_attn.kv_b_proj.weight
            # NOTE(HandH1998): Since `bmm_fp8` only supports per-tensor scale, we have to requantize `self_attn.kv_b_proj`.
            # This may affect the accuracy of fp8 model.
+            # Fix deepseek v3 blockwise bmm by using deep_gemm
+            use_deep_gemm_bmm = False
+            model_dtype = torch.get_default_dtype()
+
            if w.dtype in (
                torch.float8_e4m3fn,
                torch.float8_e4m3fnuz,
@@ -1457,10 +1504,20 @@ class DeepseekV2ForCausalLM(nn.Module):
                            weight = w
                            weight_scale = self_attn.kv_b_proj.weight_scale_inv

-                        w, scale = block_quant_to_tensor_quant(
-                            weight, weight_scale, weight_block_size
-                        )
-                        self_attn.w_scale = scale
+                        if (
+                            _is_cuda
+                            and _enable_jit_deepgemm_bmm
+                            and weight_block_size[0] == 128
+                            and weight_block_size[1] == 128
+                            and model_dtype == torch.bfloat16
+                        ):
+                            block_scale = weight_scale
+                            use_deep_gemm_bmm = True
+                        else:
+                            w, scale = block_quant_to_tensor_quant(
+                                weight, weight_scale, weight_block_size
+                            )
+                            self_attn.w_scale = scale
                else:
                    weight = w
                    weight_scale = self_attn.kv_b_proj.weight_scale
@@ -1483,18 +1540,31 @@ class DeepseekV2ForCausalLM(nn.Module):
                    w = w.to(torch.bfloat16) * self_attn.kv_b_proj.weight_scale.to(
                        torch.bfloat16
                    )
+
            w_kc, w_vc = w.unflatten(
                0, (-1, self_attn.qk_nope_head_dim + self_attn.v_head_dim)
            ).split([self_attn.qk_nope_head_dim, self_attn.v_head_dim], dim=1)
-            self_attn.w_kc = w_kc.transpose(1, 2).contiguous().transpose(1, 2)
-            self_attn.w_vc = w_vc.contiguous().transpose(1, 2)
-            if (
-                hasattr(self_attn.kv_b_proj, "weight_scale")
-                and self_attn.w_scale is None
-            ):
-                self_attn.w_scale = self_attn.kv_b_proj.weight_scale
-                if _is_hip:
-                    self_attn.w_scale *= 2.0
+            if not use_deep_gemm_bmm:
+                self_attn.w_kc = w_kc.transpose(1, 2).contiguous().transpose(1, 2)
+                self_attn.w_vc = w_vc.contiguous().transpose(1, 2)
+                if (
+                    hasattr(self_attn.kv_b_proj, "weight_scale")
+                    and self_attn.w_scale is None
+                ):
+                    self_attn.w_scale = self_attn.kv_b_proj.weight_scale
+                    if _is_hip:
+                        self_attn.w_scale *= 2.0
+            else:
+                num_tiles_k = self_attn.qk_nope_head_dim // weight_block_size[1]
+                num_tiles_n = self_attn.v_head_dim // weight_block_size[0]
+                ws_kc, ws_vc = block_scale.unflatten(
+                    0, (-1, (num_tiles_k + num_tiles_n))
+                ).split([num_tiles_k, num_tiles_n], dim=1)
+                self_attn.w_scale_k = ws_kc.transpose(1, 2).contiguous()
+                self_attn.w_scale_v = ws_vc.contiguous()
+                self_attn.w_kc = w_kc.transpose(1, 2).contiguous()
+                self_attn.w_vc = w_vc.contiguous()
+                self_attn.use_deep_gemm_bmm = True

    def load_weights(self, weights: Iterable[Tuple[str, torch.Tensor]]):
        stacked_params_mapping = [
--- a/python/sglang/test/test_block_fp8.py
+++ b/python/sglang/test/test_block_fp8.py
@@ -7,6 +7,7 @@ import torch
 from sglang.srt.layers.activation import SiluAndMul
 from sglang.srt.layers.moe.fused_moe_triton.fused_moe import fused_moe
 from sglang.srt.layers.quantization.fp8_kernel import (
+    per_tensor_quant_mla_deep_gemm_masked_fp8,
    per_tensor_quant_mla_fp8,
    per_token_group_quant_fp8,
    static_quant_fp8,
@@ -212,6 +213,62 @@ class TestPerTensorQuantMlaFP8(CustomTestCase):
                self._per_tensor_quant_mla_fp8(*params)


+class TestPerTokenGroupQuantMlaDeepGemmMaskedFP8(CustomTestCase):
+    DTYPES = [torch.half, torch.bfloat16, torch.float32]
+    B = [128]
+    NUM_TOKENS = [7, 83, 2048, 1024 * 16]
+    D = [512, 128]
+    GROUP_SIZE = [128]
+    SEEDS = [0]
+
+    @classmethod
+    def setUpClass(cls):
+        if not torch.cuda.is_available():
+            raise unittest.SkipTest("CUDA is not available")
+        torch.set_default_device("cuda")
+
+    def _per_token_group_quant_mla_deep_gemm_masked_fp8(
+        self, b, num_tokens, d, dtype, group_size, seed
+    ):
+        torch.manual_seed(seed)
+
+        x = torch.rand(b, num_tokens, d, dtype=dtype)
+
+        with torch.inference_mode():
+            ref_out, ref_scale = native_per_token_group_quant_fp8(x, group_size, 1e-12)
+            out, scale, _, _, _ = per_tensor_quant_mla_deep_gemm_masked_fp8(
+                x, group_size
+            )
+            out = out[:, :num_tokens, :]
+            scale = scale[:, :num_tokens, :]
+
+        self.assertTrue(
+            torch.allclose(
+                out.to(torch.float32), ref_out.to(torch.float32), rtol=0.20, atol=1e-2
+            )
+        )
+        self.assertTrue(torch.allclose(scale, ref_scale))
+
+    def test_per_token_group_quant_mla_deep_gemm_masked_fp8(self):
+        for params in itertools.product(
+            self.B,
+            self.NUM_TOKENS,
+            self.D,
+            self.DTYPES,
+            self.GROUP_SIZE,
+            self.SEEDS,
+        ):
+            with self.subTest(
+                b=params[0],
+                num_tokens=params[1],
+                d=params[2],
+                dtype=params[3],
+                group_size=params[4],
+                seed=params[5],
+            ):
+                self._per_token_group_quant_mla_deep_gemm_masked_fp8(*params)
+
+
 # For test
 def native_w8a8_block_fp8_matmul(A, B, As, Bs, block_size, output_dtype=torch.float16):
    """This function performs matrix multiplication with block-wise quantization using native torch.
@@ -485,5 +542,115 @@ class TestW8A8BlockFP8FusedMoE(CustomTestCase):
                self._w8a8_block_fp8_fused_moe(*params)


+# For test
+def torch_w8a8_block_fp8_bmm(a, a_s, w, w_s, block_shape, out_dtype):
+    """This function performs bmm with block-wise quantization using native torch."""
+
+    B, N, _ = w.shape
+    _, M, _ = a.shape
+    out = torch.empty((B, M, N), dtype=out_dtype, device=a.device)
+
+    for i in range(B):
+        out[i] = native_w8a8_block_fp8_matmul(
+            a[i], w[i], a_s[i], w_s[i], block_shape, output_dtype=out_dtype
+        )
+
+    return out
+
+
+class TestW8A8BlockFP8BatchedDeepGemm(CustomTestCase):
+    DTYPES = [torch.bfloat16]
+    M = [1, 33, 64, 222, 8192]
+    N = [128, 512]
+    K = [128, 512]
+    BATCH = [128]
+    BLOCK_SIZE = [[128, 128]]
+    SEEDS = [0]
+
+    @classmethod
+    def setUpClass(cls):
+        if not torch.cuda.is_available():
+            raise unittest.SkipTest("CUDA is not available")
+        try:
+            import deep_gemm
+        except ImportError:
+            raise unittest.SkipTest("DeepGEMM is not available")
+        torch.set_default_device("cuda")
+
+    def _w8a8_block_fp8_batched_deep_gemm(self, M, N, K, B, block_size, dtype, seed):
+        torch.manual_seed(seed)
+        factor_for_scale = 1e-2
+        fp8_info = torch.finfo(torch.float8_e4m3fn)
+        fp8_max, fp8_min = fp8_info.max, fp8_info.min
+
+        a_fp32 = torch.randn((B, M, K), dtype=torch.float32) / 10
+        a = a_fp32.clamp(min=fp8_min, max=fp8_max).to(torch.float8_e4m3fn)
+
+        w_fp32 = (torch.rand((B, N, K), dtype=torch.float32) - 0.5) * 2 * fp8_max
+        w = w_fp32.clamp(min=fp8_min, max=fp8_max).to(torch.float8_e4m3fn)
+
+        block_n, block_k = block_size[0], block_size[1]
+        n_tiles_w = (N + block_n - 1) // block_n
+        k_tiles_w = (K + block_k - 1) // block_k
+
+        w_s = (
+            torch.rand((B, n_tiles_w, k_tiles_w), dtype=torch.float32)
+            * factor_for_scale
+        )
+        a_s = torch.rand((B, M, k_tiles_w), dtype=torch.float32) * factor_for_scale
+
+        ae = a.new_empty(B, (M + 255) // 256 * 256, K)
+        ae_s = a_s.new_empty(B, (M + 255) // 256 * 256, k_tiles_w)
+        oe = torch.empty((B, (M + 255) // 256 * 256, N), dtype=dtype)
+        ae[:, :M, :] = a
+        ae_s[:, :M, :] = a_s
+
+        masked_m = torch.full((B,), M, dtype=torch.int)
+        expected_m = M
+        lhs = (
+            ae,
+            ae_s,
+        )
+        rhs = (
+            w,
+            w_s,
+        )
+
+        from deep_gemm import m_grouped_gemm_fp8_fp8_bf16_nt_masked
+
+        with torch.inference_mode():
+            ref_out = torch_w8a8_block_fp8_bmm(a, a_s, w, w_s, block_size, dtype)
+            m_grouped_gemm_fp8_fp8_bf16_nt_masked(lhs, rhs, oe, masked_m, expected_m)
+            out = oe[:, :M, :]
+
+        self.assertTrue(
+            torch.mean(torch.abs(out.to(torch.float32) - ref_out.to(torch.float32)))
+            / torch.mean(torch.abs(ref_out.to(torch.float32)))
+            < 0.0001
+        )
+
+    def test_w8a8_block_fp8_batched_deep_gemm(self):
+
+        for params in itertools.product(
+            self.M,
+            self.N,
+            self.K,
+            self.BATCH,
+            self.BLOCK_SIZE,
+            self.DTYPES,
+            self.SEEDS,
+        ):
+            with self.subTest(
+                M=params[0],
+                N=params[1],
+                K=params[2],
+                B=params[3],
+                block_size=params[4],
+                dtype=params[5],
+                seed=params[6],
+            ):
+                self._w8a8_block_fp8_batched_deep_gemm(*params)
+
+
 if __name__ == "__main__":
    unittest.main(verbosity=2)