mlx-examples/llms/mlx_lm/models/deepseek_v3.py

496 lines
17 KiB
Python

# Copyright © 2024 Apple Inc.
import math
from dataclasses import dataclass
from functools import partial
from typing import Any, Dict, Optional, Tuple
import mlx.core as mx
import mlx.nn as nn
from .base import BaseModelArgs, create_attention_mask, scaled_dot_product_attention
from .switch_layers import SwitchGLU
@dataclass
class ModelArgs(BaseModelArgs):
model_type: str = "deepseek_v3"
vocab_size: int = 102400
hidden_size: int = 4096
intermediate_size: int = 11008
moe_intermediate_size: int = 1407
num_hidden_layers: int = 30
num_attention_heads: int = 32
num_key_value_heads: int = 32
n_shared_experts: Optional[int] = None
n_routed_experts: Optional[int] = None
routed_scaling_factor: float = 1.0
kv_lora_rank: int = 512
q_lora_rank: int = 1536
qk_rope_head_dim: int = 64
v_head_dim: int = 128
qk_nope_head_dim: int = 128
topk_method: str = "noaux_tc"
scoring_func: str = "sigmoid"
norm_topk_prob: bool = True
n_group: Optional[int] = None
topk_group: Optional[int] = None
num_experts_per_tok: Optional[int] = None
moe_layer_freq: int = 1
first_k_dense_replace: int = 0
max_position_embeddings: int = 2048
rms_norm_eps: float = 1e-6
rope_theta: float = 10000.0
rope_scaling: Dict = None
attention_bias: bool = False
def yarn_find_correction_dim(
num_rotations, dim, base=10000, max_position_embeddings=2048
):
return (dim * math.log(max_position_embeddings / (num_rotations * 2 * math.pi))) / (
2 * math.log(base)
)
def yarn_find_correction_range(
low_rot, high_rot, dim, base=10000, max_position_embeddings=2048
):
low = math.floor(
yarn_find_correction_dim(low_rot, dim, base, max_position_embeddings)
)
high = math.ceil(
yarn_find_correction_dim(high_rot, dim, base, max_position_embeddings)
)
return max(low, 0), min(high, dim - 1)
def yarn_get_mscale(scale=1, mscale=1):
if scale <= 1:
return 1.0
return 0.1 * mscale * math.log(scale) + 1.0
def yarn_linear_ramp_mask(min_val, max_val, dim):
if min_val == max_val:
max_val += 0.001 # Prevent singularity
linear_func = (mx.arange(dim, dtype=mx.float32) - min_val) / (max_val - min_val)
return mx.clip(linear_func, 0, 1)
class DeepseekV3YarnRotaryEmbedding(nn.Module):
def __init__(
self,
dim,
max_position_embeddings=2048,
base=10000,
scaling_factor=1.0,
original_max_position_embeddings=4096,
beta_fast=32,
beta_slow=1,
mscale=1,
mscale_all_dim=0,
):
super().__init__()
self.mscale = yarn_get_mscale(scaling_factor, mscale) / yarn_get_mscale(
scaling_factor, mscale_all_dim
)
freq_extra = base ** (mx.arange(0, dim, 2, dtype=mx.float32) / dim)
freq_inter = scaling_factor * base ** (
mx.arange(0, dim, 2, dtype=mx.float32) / dim
)
low, high = yarn_find_correction_range(
beta_fast,
beta_slow,
dim,
base,
original_max_position_embeddings,
)
freq_mask = 1.0 - yarn_linear_ramp_mask(low, high, dim // 2)
self._freqs = (freq_inter * freq_extra) / (
freq_inter * freq_mask + freq_extra * (1 - freq_mask)
)
def __call__(self, x, offset=0):
if self.mscale != 1.0:
x = self.mscale * x
return mx.fast.rope(
x,
x.shape[-1],
traditional=True,
base=None,
scale=1.0,
offset=offset,
freqs=self._freqs,
)
# A clipped silu to prevent fp16 from overflowing
@partial(mx.compile, shapeless=True)
def clipped_silu(x):
return mx.clip(x * mx.sigmoid(x), a_min=-100, a_max=100)
class DeepseekV3Attention(nn.Module):
def __init__(self, config: ModelArgs):
super().__init__()
self.config = config
self.hidden_size = config.hidden_size
self.num_heads = config.num_attention_heads
self.max_position_embeddings = config.max_position_embeddings
self.rope_theta = config.rope_theta
self.q_lora_rank = config.q_lora_rank
self.qk_rope_head_dim = config.qk_rope_head_dim
self.kv_lora_rank = config.kv_lora_rank
self.v_head_dim = config.v_head_dim
self.qk_nope_head_dim = config.qk_nope_head_dim
self.q_head_dim = config.qk_nope_head_dim + config.qk_rope_head_dim
self.scale = self.q_head_dim**-0.5
if self.q_lora_rank is None:
self.q_proj = nn.Linear(
self.hidden_size, self.num_heads * self.q_head_dim, bias=False
)
else:
self.q_a_proj = nn.Linear(
self.hidden_size, self.q_lora_rank, bias=config.attention_bias
)
self.q_a_layernorm = nn.RMSNorm(self.q_lora_rank)
self.q_b_proj = nn.Linear(
self.q_lora_rank, self.num_heads * self.q_head_dim, bias=False
)
self.kv_a_proj_with_mqa = nn.Linear(
self.hidden_size,
self.kv_lora_rank + self.qk_rope_head_dim,
bias=config.attention_bias,
)
self.kv_a_layernorm = nn.RMSNorm(self.kv_lora_rank)
self.kv_b_proj = nn.Linear(
self.kv_lora_rank,
self.num_heads
* (self.q_head_dim - self.qk_rope_head_dim + self.v_head_dim),
bias=False,
)
self.o_proj = nn.Linear(
self.num_heads * self.v_head_dim,
self.hidden_size,
bias=config.attention_bias,
)
mscale_all_dim = self.config.rope_scaling.get("mscale_all_dim", 0)
scaling_factor = self.config.rope_scaling["factor"]
if mscale_all_dim:
mscale = yarn_get_mscale(scaling_factor, mscale_all_dim)
self.scale = self.scale * mscale * mscale
rope_kwargs = {
key: self.config.rope_scaling[key]
for key in [
"original_max_position_embeddings",
"beta_fast",
"beta_slow",
"mscale",
"mscale_all_dim",
]
if key in self.config.rope_scaling
}
self.rope = DeepseekV3YarnRotaryEmbedding(
dim=self.qk_rope_head_dim,
max_position_embeddings=self.max_position_embeddings,
scaling_factor=scaling_factor,
base=self.rope_theta,
**rope_kwargs,
)
def __call__(
self,
x: mx.array,
mask: Optional[mx.array] = None,
cache: Optional[Any] = None,
) -> mx.array:
B, L, D = x.shape
if self.q_lora_rank is None:
q = self.q_proj(x)
else:
q = self.q_b_proj(self.q_a_layernorm(self.q_a_proj(x)))
q = q.reshape(B, L, self.num_heads, self.q_head_dim).transpose(0, 2, 1, 3)
q_nope, q_pe = mx.split(q, [self.qk_nope_head_dim], axis=-1)
compressed_kv = self.kv_a_proj_with_mqa(x)
compressed_kv, k_pe = mx.split(compressed_kv, [self.kv_lora_rank], axis=-1)
k_pe = k_pe.reshape(B, L, 1, self.qk_rope_head_dim).transpose(0, 2, 1, 3)
kv = self.kv_b_proj(self.kv_a_layernorm(compressed_kv))
kv = kv.reshape(B, L, self.num_heads, -1).transpose(0, 2, 1, 3)
k_nope, values = mx.split(kv, [self.qk_nope_head_dim], axis=-1)
if cache is not None:
q_pe = self.rope(q_pe, cache.offset)
k_pe = self.rope(k_pe, cache.offset)
k_pe = mx.repeat(k_pe, self.num_heads, axis=1)
keys, values = cache.update_and_fetch(
mx.concatenate([k_nope, k_pe], axis=-1), values
)
else:
q_pe = self.rope(q_pe)
k_pe = self.rope(k_pe)
k_pe = mx.repeat(k_pe, self.num_heads, axis=1)
keys = mx.concatenate([k_nope, k_pe], axis=-1)
queries = mx.concatenate([q_nope, q_pe], axis=-1)
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 DeepseekV3MLP(nn.Module):
def __init__(
self, config: ModelArgs, hidden_size: int = None, intermediate_size: int = None
):
super().__init__()
self.config = config
self.hidden_size = config.hidden_size if hidden_size is None else hidden_size
self.intermediate_size = (
config.intermediate_size if intermediate_size is None else intermediate_size
)
self.gate_proj = nn.Linear(self.hidden_size, self.intermediate_size, bias=False)
self.up_proj = nn.Linear(self.hidden_size, self.intermediate_size, bias=False)
self.down_proj = nn.Linear(self.intermediate_size, self.hidden_size, bias=False)
def __call__(self, x):
down_proj = self.down_proj(nn.silu(self.gate_proj(x)) * self.up_proj(x))
return down_proj
@mx.compile
def group_expert_select(
gates,
e_score_correction_bias,
top_k,
n_group,
topk_group,
routed_scaling_factor,
norm_topk_prob,
):
k = top_k
scores = mx.sigmoid(gates.astype(mx.float32))
scores = scores + e_score_correction_bias
scores = mx.unflatten(scores, axis=-1, shape=(n_group, -1))
group_scores = mx.topk(scores, 2, axis=-1).sum(axis=-1, keepdims=True)
k = n_group - topk_group
group_idx = mx.argpartition(group_scores, kth=k - 1, axis=-2)[..., :k, :]
scores = mx.put_along_axis(scores, group_idx, mx.array(0.0), axis=-2)
scores = mx.flatten(scores, -2, -1)
k = top_k
inds = mx.argpartition(-scores, kth=k - 1, axis=-1)[..., :k]
scores = mx.take_along_axis(scores, inds, axis=-1)
if top_k > 1 and norm_topk_prob:
denominator = scores.sum(axis=-1, keepdims=True) + 1e-20
scores = scores / denominator
scores = scores * routed_scaling_factor
return inds, scores
class MoEGate(nn.Module):
def __init__(self, config: ModelArgs):
super().__init__()
self.config = config
self.top_k = config.num_experts_per_tok
self.norm_topk_prob = config.norm_topk_prob
self.n_routed_experts = config.n_routed_experts
self.routed_scaling_factor = config.routed_scaling_factor
self.n_group = config.n_group
self.topk_group = config.topk_group
self.weight = mx.zeros((self.n_routed_experts, config.hidden_size))
self.e_score_correction_bias = mx.zeros((self.n_routed_experts,))
assert config.topk_method == "noaux_tc", "Unsupported topk method."
def __call__(self, x):
return group_expert_select(
x @ self.weight.T,
self.e_score_correction_bias,
self.top_k,
self.n_group,
self.topk_group,
self.routed_scaling_factor,
self.norm_topk_prob,
)
class DeepseekV3MoE(nn.Module):
def __init__(self, config: ModelArgs):
super().__init__()
self.config = config
self.num_experts_per_tok = config.num_experts_per_tok
self.switch_mlp = SwitchGLU(
config.hidden_size,
config.moe_intermediate_size,
config.n_routed_experts,
activation=clipped_silu,
)
self.gate = MoEGate(config)
if config.n_shared_experts is not None:
intermediate_size = config.moe_intermediate_size * config.n_shared_experts
self.shared_experts = DeepseekV3MLP(
config=config, intermediate_size=intermediate_size
)
def __call__(self, x):
inds, scores = self.gate(x)
y = self.switch_mlp(x, inds)
y = (y * scores[..., None]).sum(axis=-2).astype(y.dtype)
if self.config.n_shared_experts is not None:
y = y + self.shared_experts(x)
return y
class DeepseekV3DecoderLayer(nn.Module):
def __init__(self, config: ModelArgs, layer_idx: int):
super().__init__()
self.self_attn = DeepseekV3Attention(config)
self.mlp = (
DeepseekV3MoE(config)
if (
config.n_routed_experts is not None
and layer_idx >= config.first_k_dense_replace
and layer_idx % config.moe_layer_freq == 0
)
else DeepseekV3MLP(config)
)
self.input_layernorm = nn.RMSNorm(config.hidden_size, eps=config.rms_norm_eps)
self.post_attention_layernorm = nn.RMSNorm(
config.hidden_size, eps=config.rms_norm_eps
)
def __call__(
self,
x: mx.array,
mask: Optional[mx.array] = None,
cache: Optional[Any] = None,
) -> mx.array:
r = self.self_attn(self.input_layernorm(x), mask, cache)
h = x + r
r = self.mlp(self.post_attention_layernorm(h))
return h + r
class DeepseekV3Model(nn.Module):
def __init__(self, config: ModelArgs):
super().__init__()
self.vocab_size = config.vocab_size
self.embed_tokens = nn.Embedding(config.vocab_size, config.hidden_size)
self.layers = [
DeepseekV3DecoderLayer(config, idx)
for idx in range(config.num_hidden_layers)
]
self.start_idx = 0
self.end_idx = len(self.layers)
self.num_layers = self.end_idx
self.norm = nn.RMSNorm(config.hidden_size, eps=config.rms_norm_eps)
self.pipeline_rank = 0
self.pipeline_size = 1
def pipeline(self, group):
# Split layers in reverse so rank=0 gets the last layers and
# rank=pipeline_size-1 gets the first
self.pipeline_rank = group.rank()
self.pipeline_size = group.size()
layers_per_rank = len(self.layers) // self.pipeline_size
extra = len(self.layers) - layers_per_rank * self.pipeline_size
if self.pipeline_rank < extra:
layers_per_rank += 1
self.start_idx = (self.pipeline_size - self.pipeline_rank - 1) * layers_per_rank
self.end_idx = self.start_idx + layers_per_rank
self.layers = self.layers[: self.end_idx]
self.layers[: self.start_idx] = [None] * self.start_idx
self.num_layers = len(self.layers) - self.start_idx
def __call__(
self,
x: mx.array,
cache: Optional[Any] = None,
mask: Optional[mx.array] = None,
) -> mx.array:
h = self.embed_tokens(x)
pipeline_rank = self.pipeline_rank
pipeline_size = self.pipeline_size
# Hack to avoid time-outs during prompt-processing
dist_stream = mx.cpu if h.shape[1] > 1 else mx.gpu
if mask is None:
mask = create_attention_mask(h, cache)
if cache is None:
cache = [None] * self.num_layers
# Receive from the previous process in the pipeline
if pipeline_rank < pipeline_size - 1:
h = mx.distributed.recv_like(h, (pipeline_rank + 1), stream=dist_stream)
for i in range(self.num_layers):
h = self.layers[self.start_idx + i](h, mask, cache[i])
# Send to the next process in the pipeline
if pipeline_rank != 0:
h = mx.distributed.send(
h, (pipeline_rank - 1) % pipeline_size, stream=dist_stream
)
# Broadcast h while keeping it in the graph
h = mx.distributed.all_gather(h, stream=dist_stream)[: h.shape[0]]
return self.norm(h)
class Model(nn.Module):
def __init__(self, config: ModelArgs):
super().__init__()
self.args = config
self.model_type = config.model_type
self.model = DeepseekV3Model(config)
self.lm_head = nn.Linear(config.hidden_size, config.vocab_size, bias=False)
def __call__(
self,
inputs: mx.array,
cache: Optional[Any] = None,
mask: Optional[mx.array] = None,
):
out = self.model(inputs, cache, mask)
return self.lm_head(out)
def sanitize(self, weights):
for l in range(self.args.num_hidden_layers):
prefix = f"model.layers.{l}"
for n, m in [("w1", "gate_proj"), ("w2", "down_proj"), ("w3", "up_proj")]:
for k in ["weight", "scales", "biases"]:
if f"{prefix}.mlp.experts.0.{m}.{k}" in weights:
to_join = [
weights.pop(f"{prefix}.mlp.experts.{e}.{m}.{k}")
for e in range(self.args.n_routed_experts)
]
weights[f"{prefix}.mlp.switch_mlp.{m}.{k}"] = mx.stack(to_join)
# Remove multi-token prediction layer
return {k: v for k, v in weights.items() if not k.startswith("model.layers.61")}
@property
def layers(self):
return self.model.layers[self.model.start_idx : self.model.end_idx]