Use SparseMoELayer

server/text_generation_server/models/custom_modeling/flash_llama_modeling.py

@@ -27,6 +27,7 @@
 from torch import nn
 from transformers.activations import ACT2FN
 
+from text_generation_server.layers.moe import SparseMoELayer
 from text_generation_server.utils.import_utils import SYSTEM
 from text_generation_server.layers.attention import (
     paged_attention,
@@ -251,95 +252,32 @@ def forward(
         )
 
 
-def _load_experts(config, prefix: str, mat, weights):
-    if config.quantize is not None:
-        raise NotImplementedError("Mixtral does not support weight quantization yet.")
-
-    assert mat in ["w1", "w2", "w3"]
-
-    world_size = weights.process_group.size()
-    rank = weights.process_group.rank()
-
-    assert (
-        config.intermediate_size % world_size == 0
-    ), f"The chosen size {config.intermediate_size} is not compatible with sharding on {world_size} shards"
-
-    block_size = config.intermediate_size // world_size
-    start = rank * block_size
-    stop = (rank + 1) * block_size
-
-    tensor = torch.empty(
-        (config.num_local_experts * block_size, config.hidden_size),
-        dtype=weights.dtype,
-        device=weights.device,
-    )
-
-    for i in range(config.num_local_experts):
-        slice_ = weights._get_slice(f"{prefix}.{i}.{mat}.weight")
-
-        if mat == "w2":
-            expert_slice = slice_[:, start:stop].t().contiguous()
-        else:
-            expert_slice = slice_[start:stop]
-        tensor[i * block_size : (i + 1) * block_size] = expert_slice.to(
-            dtype=weights.dtype
-        ).to(device=weights.device)
-    return tensor
-
-
 class BlockSparseMoE(nn.Module):
     def __init__(self, prefix, config, weights):
         super().__init__()
-        self.hidden_dim = config.hidden_size
-        self.ffn_dim = config.intermediate_size // weights.process_group.size()
-        self.num_experts = config.num_local_experts
-        self.top_k = config.num_experts_per_tok
-
-        act = config.hidden_act
-        if "gelu" in act:
-            self.act = lambda x: torch.nn.functional.gelu(
-                x,
-                approximate=(
-                    "tanh" if act in ["gelu_fast", "gelu_pytorch_tanh"] else "none"
-                ),
-            )
-        elif "silu" in act:
-            self.act = torch.nn.functional.silu
-        else:
-            self.act = ACT2FN[act]
 
         # gating
         self.gate = FastLinear.load(config, f"{prefix}.gate", weights, bias=False)
 
-        # merged expert weights, all of size  (n_experts * ffn_dim, hidden_dim)
-        w1 = _load_experts(config, f"{prefix}.experts", "w1", weights).view(
-            self.num_experts, self.ffn_dim, self.hidden_dim
-        )
-        w3 = _load_experts(config, f"{prefix}.experts", "w3", weights).view(
-            self.num_experts, self.ffn_dim, self.hidden_dim
-        )
-        self.w13 = torch.cat([w1, w3], dim=1)
-        self.w2 = (
-            _load_experts(config, f"{prefix}.experts", "w2", weights)
-            .view(self.num_experts, self.ffn_dim, self.hidden_dim)
-            .transpose(1, 2)
-            .contiguous()
+        self.moe = SparseMoELayer(
+            prefix=f"{prefix}.experts",
+            n_experts=config.num_local_experts,
+            n_expert_group=None,
+            renormalize=True,
+            topk=config.num_experts_per_tok,
+            topk_group=None,
+            weights=weights,
+            gate_proj_name="w1",
+            up_proj_name="w3",
+            down_proj_name="w2",
         )
 
         self.process_group = weights.process_group
 
     def forward(self, x, adapter_data) -> torch.Tensor:
         # router_logits: (num_tokens, n_experts)
         router_logits = self.gate(x)
-        out = fused_moe(
-            x,
-            self.w13,
-            self.w2,
-            router_logits,
-            self.top_k,
-            renormalize=True,
-            inplace=True,
-        )
+        out = self.moe(x, gating_output=router_logits)
 
         # Reduce sum
         if self.process_group.size() > 1: