adding OLMoE architecture (#1321)

* initial commit

* udpate ACKNOWLEDGMENTS.md

* adding olmoe to training

* clean up

* faster generation

* remove sanitize method

* more clean ups

* adding SwitchGLU

* clean up

* a little faster and adding norm_topk_prob

* formated

ACKNOWLEDGMENTS.md

@@ -14,4 +14,4 @@ MLX Examples was developed with contributions from the following individuals:
 - Markus Enzweiler: Added the `cvae` examples.
 - Prince Canuma: Helped add support for `Starcoder2` models.
 - Shiyu Li: Added the `Segment Anything Model`.
-- Gökdeniz Gülmez: Added support for `MiniCPM`, `Helium`, `Mamba version 1` and support for `full-fine-tuning`.
+- Gökdeniz Gülmez: Added support for `MiniCPM`, `Helium`, `Mamba version 1`, `OLMoE` archtectures and support for `full-fine-tuning`.

llms/mlx_lm/models/olmoe.py

@@ -0,0 +1,217 @@
+# Copyright © 2023-2024 Apple Inc.
+
+from dataclasses import dataclass
+from typing import Any, Dict, Optional, Union
+
+import mlx.core as mx
+import mlx.nn as nn
+
+from .base import BaseModelArgs, create_attention_mask, scaled_dot_product_attention
+from .rope_utils import initialize_rope
+from .switch_layers import SwitchGLU
+
+
+@dataclass
+class ModelArgs(BaseModelArgs):
+    model_type: str
+    hidden_size: int
+    num_hidden_layers: int
+    intermediate_size: int
+    num_attention_heads: int
+    rms_norm_eps: float
+    vocab_size: int
+    num_experts: int
+    num_experts_per_tok: int
+    norm_topk_prob: bool = False
+    head_dim: Optional[int] = None
+    max_position_embeddings: Optional[int] = None
+    num_key_value_heads: Optional[int] = None
+    attention_bias: bool = False
+    mlp_bias: bool = False
+    rope_theta: float = 10000
+    rope_traditional: bool = False
+    rope_scaling: Optional[Dict[str, Union[float, str]]] = None
+    tie_word_embeddings: bool = True
+
+    def __post_init__(self):
+        if self.num_key_value_heads is None:
+            self.num_key_value_heads = self.num_attention_heads
+
+
+class Attention(nn.Module):
+    def __init__(self, args: ModelArgs):
+        super().__init__()
+
+        dim = args.hidden_size
+        self.n_heads = n_heads = args.num_attention_heads
+        self.n_kv_heads = n_kv_heads = args.num_key_value_heads
+
+        self.head_dim = head_dim = args.head_dim or args.hidden_size // n_heads
+
+        self.scale = head_dim**-0.5
+
+        self.q_proj = nn.Linear(dim, n_heads * head_dim, bias=args.attention_bias)
+        self.k_proj = nn.Linear(dim, n_kv_heads * head_dim, bias=args.attention_bias)
+        self.v_proj = nn.Linear(dim, n_kv_heads * head_dim, bias=args.attention_bias)
+        self.o_proj = nn.Linear(n_heads * head_dim, dim, bias=args.attention_bias)
+
+        self.rope = initialize_rope(
+            self.head_dim,
+            args.rope_theta,
+            args.rope_traditional,
+            args.rope_scaling,
+            args.max_position_embeddings,
+        )
+
+        self.q_norm = nn.RMSNorm(n_heads * head_dim, args.rms_norm_eps)
+        self.k_norm = nn.RMSNorm(n_kv_heads * head_dim, args.rms_norm_eps)
+
+    def __call__(
+        self,
+        x: mx.array,
+        mask: Optional[mx.array] = None,
+        cache: Optional[Any] = None,
+    ) -> mx.array:
+        B, L, D = x.shape
+        queries, keys, values = self.q_proj(x), self.k_proj(x), self.v_proj(x)
+        queries = self.q_norm(queries)
+        keys = self.k_norm(keys)
+        queries = queries.reshape(B, L, self.n_heads, -1).transpose(0, 2, 1, 3)
+        keys = keys.reshape(B, L, self.n_kv_heads, -1).transpose(0, 2, 1, 3)
+        values = values.reshape(B, L, self.n_kv_heads, -1).transpose(0, 2, 1, 3)
+        if cache is not None:
+            queries = self.rope(queries, offset=cache.offset)
+            keys = self.rope(keys, offset=cache.offset)
+            keys, values = cache.update_and_fetch(keys, values)
+        else:
+            queries = self.rope(queries)
+            keys = self.rope(keys)
+        output = scaled_dot_product_attention(
+            queries, keys, values, cache=cache, scale=self.scale, mask=mask
+        )
+        output = output.transpose(0, 2, 1, 3).reshape(B, L, -1)
+        return self.o_proj(output)
+
+
+class OlmoeSparseMoeBlock(nn.Module):
+    def __init__(self, args: ModelArgs):
+        super().__init__()
+        self.num_experts = args.num_experts
+        self.top_k = args.num_experts_per_tok
+        self.norm_topk_prob = args.norm_topk_prob
+
+        self.gate = nn.Linear(args.hidden_size, self.num_experts, bias=False)
+        self.switch_mlp = SwitchGLU(
+            args.hidden_size,
+            args.intermediate_size,
+            self.num_experts,
+            bias=args.mlp_bias,
+        )
+
+    def __call__(self, x: mx.array) -> mx.array:
+        B, L, D = x.shape
+        x_flat = x.reshape(-1, D)
+        router_logits = self.gate(x_flat)
+        routing_weights = mx.softmax(router_logits, axis=1, precise=True)
+        k = self.top_k
+        indices = mx.stop_gradient(
+            mx.argpartition(-routing_weights, kth=k - 1, axis=-1)[..., :k]
+        )
+        scores = mx.take_along_axis(routing_weights, indices, axis=-1)
+        if self.norm_topk_prob:
+            scores = scores / scores.sum(axis=-1, keepdims=True)
+        y = self.switch_mlp(x_flat, indices)
+        y = (y * scores[..., None]).sum(axis=-2)
+        return y.reshape(B, L, D)
+
+
+class TransformerBlock(nn.Module):
+    def __init__(self, args: ModelArgs):
+        super().__init__()
+        self.self_attn = Attention(args)
+        self.mlp = OlmoeSparseMoeBlock(args)
+        self.input_layernorm = nn.RMSNorm(args.hidden_size, eps=args.rms_norm_eps)
+        self.post_attention_layernorm = nn.RMSNorm(
+            args.hidden_size, eps=args.rms_norm_eps
+        )
+
+    def __call__(
+        self,
+        x: mx.array,
+        mask: Optional[mx.array] = None,
+        cache: Optional[Any] = None,
+    ) -> mx.array:
+        x = x + self.self_attn(self.input_layernorm(x), mask, cache)
+        x = x + self.mlp(self.post_attention_layernorm(x))
+        return x
+
+
+class OlmoeModel(nn.Module):
+    def __init__(self, args: ModelArgs):
+        super().__init__()
+        self.args = args
+        self.vocab_size = args.vocab_size
+        self.num_hidden_layers = args.num_hidden_layers
+        assert self.vocab_size > 0
+        self.embed_tokens = nn.Embedding(args.vocab_size, args.hidden_size)
+        self.layers = [
+            TransformerBlock(args=args) for _ in range(args.num_hidden_layers)
+        ]
+        self.norm = nn.RMSNorm(args.hidden_size, eps=args.rms_norm_eps)
+
+    def __call__(
+        self,
+        inputs: mx.array,
+        cache=None,
+        mask=None,
+    ):
+        h = self.embed_tokens(inputs)
+        if mask is None:
+            mask = create_attention_mask(h, cache)
+        if cache is None:
+            cache = [None] * len(self.layers)
+        for layer, c in zip(self.layers, cache):
+            h = layer(h, mask, cache=c)
+        return self.norm(h)
+
+
+class Model(nn.Module):
+    def __init__(self, args: ModelArgs):
+        super().__init__()
+        self.args = args
+        self.model_type = args.model_type
+        self.model = OlmoeModel(args)
+        if not args.tie_word_embeddings:
+            self.lm_head = nn.Linear(args.hidden_size, args.vocab_size, bias=False)
+
+    def __call__(
+        self,
+        inputs: mx.array,
+        cache=None,
+        mask=None,
+    ):
+        out = self.model(inputs, cache, mask)
+        if self.args.tie_word_embeddings:
+            out = self.model.embed_tokens.as_linear(out)
+        else:
+            out = self.lm_head(out)
+        return out
+
+    def sanitize(self, weights):
+        if "model.layers.0.mlp.experts.0.up_proj.weight" not in weights:
+            return weights
+        for l in range(self.args.num_hidden_layers):
+            prefix = f"model.layers.{l}"
+            for n in ["up_proj", "down_proj", "gate_proj"]:
+                for k in ["weight", "scales", "biases"]:
+                    if f"{prefix}.mlp.experts.0.{n}.{k}" in weights:
+                        to_join = [
+                            weights.pop(f"{prefix}.mlp.experts.{e}.{n}.{k}")
+                            for e in range(self.args.num_experts)
+                        ]
+                        weights[f"{prefix}.mlp.switch_mlp.{n}.{k}"] = mx.stack(to_join)
+        return weights
+
+    @property
+    def layers(self):
+        return self.model.layers

llms/mlx_lm/tuner/utils.py

@@ -98,6 +98,7 @@ def linear_to_lora_layers(
         "minicpm",
         "deepseek",
         "olmo2",
+        "olmoe",
         "internlm3",
     ]:
         keys = set(["self_attn.q_proj", "self_attn.v_proj"])
@@ -106,6 +107,8 @@ def linear_to_lora_layers(
         if model.model_type == "qwen2_moe":
             keys.add("mlp.gate")
             keys.add("mlp.shared_expert_gate")
+        if model.model_type == "olmoe":
+            keys.add("mlp.gate")
 
     elif model.model_type == "gpt_bigcode":
         keys = set(["attn.c_attn"])