fix: w4a8 marlin 中 weight重排接入lightop算子

vllm/model_executor/layers/quantization/slimquant_w4a8_marlin.py

@@ -10,7 +10,7 @@ from vllm.model_executor.layers.quantization import QuantizationMethods
 from vllm.model_executor.layers.linear import (LinearBase,LinearMethodBase)
 from vllm.model_executor.layers.quantization.base_config import (QuantizationConfig,
                                                                  QuantizeMethodBase)
-from vllm.model_executor.layers.quantization.utils.w4a8_utils import w4a8_2_marlin_weight
+from vllm.model_executor.layers.quantization.utils.w4a8_utils import w4a8_weight_repack_impl
 from vllm.model_executor.layers.fused_moe import (FusedMoE, FusedMoEMethodBase,
                                                   FusedMoeWeightScaleSupported)
 from vllm.model_executor.parameter import (ChannelQuantScaleParameter,
@@ -205,16 +205,8 @@ class SlimQuantW4A8Int8MarlinMoEMethod:
             layer.w2_weight_scale.data, requires_grad=False
         )
 
-        w1_marlin_list = []
-        for e in range(layer.w13_weight.shape[0]):
-            w1_marlin_in = w4a8_2_marlin_weight(layer.w13_weight[e])
-            w1_marlin_list.append(w1_marlin_in)
-        layer.w13_weight = Parameter(torch.stack(w1_marlin_list, dim=0), requires_grad=False)
-        w2_marlin_list = []
-        for e in range(layer.w2_weight.shape[0]):
-            w2_marlin_in = w4a8_2_marlin_weight(layer.w2_weight[e])
-            w2_marlin_list.append(w2_marlin_in)
-        layer.w2_weight = Parameter(torch.stack(w2_marlin_list, dim=0), requires_grad=False)
+        layer.w13_weight = Parameter(w4a8_weight_repack_impl(layer.w13_weight), requires_grad=False)
+        layer.w2_weight = Parameter(w4a8_weight_repack_impl(layer.w2_weight), requires_grad=False)
 
     def apply(
         self,

vllm/model_executor/layers/quantization/utils/w4a8_utils.py

 import torch
 import numpy as np
 
+try:
+    from lightop import awq_marlin_repack_w4a8
+    use_lightop = True
+except Exception:
+    use_lightop = False
+
 def unpack_int8_to_int4(tensor_int8: torch.Tensor) -> torch.Tensor:
     """
     将[N, K//2]大小的torch.int8 Tensor，转换为[N, K]大小的torch.int32 Tensor。
@@ -69,3 +75,19 @@ def w4a8_2_marlin_weight(w4a8_w):
     weight_perm = get_weight_perms()
     marlin_q_w = marlin_weights(full_w4a8_w, weight_perm, k_tile=32, n_tile=64, pack_factor=8)
     return marlin_q_w
+
+def w4a8_weight_repack_impl(input):
+    if use_lightop:
+        size_batch = input.shape[0]
+        size_n = input.shape[1]
+        size_k = input.shape[2] * 2
+        output = torch.zeros((size_batch, size_k // 32, size_n * 4), device=input.device, dtype=torch.int32)
+        awq_marlin_repack_w4a8(input, output, size_batch, size_k, size_n)
+    else:
+        w_marlin_list = []
+        for e in range(input.shape[0]):
+            w_marlin_in = w4a8_2_marlin_weight(input[e])
+            w_marlin_list.append(w_marlin_in)
+        output = torch.stack(w_marlin_list, dim=0)
+
+    return output
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