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chore: import upstream snapshot with attribution
2026-07-13 13:23:58 +08:00

418 lines
16 KiB
Python

"""
Implementation for GPTNeoX architecture.
"""
import dataclasses
import logging
from typing import Any, Dict, Optional # noqa: UP035
from tvm import tirx
from tvm.relax.frontend import nn
from tvm.relax.frontend.nn import Tensor, op
from mlc_llm import op as op_ext
from mlc_llm.model.model_utils import index_last_token
from mlc_llm.nn import PagedKVCache, RopeMode
from mlc_llm.support import tensor_parallel as tp
from mlc_llm.support.config import ConfigBase
from mlc_llm.support.style import bold
logger = logging.getLogger(__name__)
@dataclasses.dataclass
class GPTNeoXConfig(ConfigBase):
"""Configuration of the GPTNeoX model."""
use_parallel_residual: bool
hidden_size: int
intermediate_size: int
num_attention_heads: int
num_hidden_layers: int
layer_norm_eps: float
vocab_size: int
rotary_pct: float
position_embedding_base: int = 0
context_window_size: int = 0
head_dim: int = 0
prefill_chunk_size: int = 0
tensor_parallel_shards: int = 1
ffn_out_dtype: str = "float32"
max_batch_size: int = 1
kwargs: Dict[str, Any] = dataclasses.field(default_factory=dict) # noqa: UP006
def __post_init__(self):
if self.context_window_size == 0:
for name in ["max_position_embeddings", "max_sequence_length"]:
if name in self.kwargs:
self.context_window_size = self.kwargs.pop(name)
logger.info(
"%s not found in config.json. Falling back to %s (%d)",
bold("context_window_size"),
bold(name),
self.context_window_size,
)
break
else:
raise ValueError(
"Unable to determine the maximum sequence length, because none of "
"`context_window_size`, `max_position_embeddings` or `max_sequence_length` is "
"provided in `config.json`."
)
if self.position_embedding_base == 0:
if "rope_theta" in self.kwargs:
self.position_embedding_base = self.kwargs.pop("rope_theta")
else:
self.position_embedding_base = 10000
if self.head_dim == 0:
self.head_dim = self.hidden_size // self.num_attention_heads
assert self.head_dim * self.num_attention_heads == self.hidden_size
if self.prefill_chunk_size == 0:
logger.info(
"%s defaults to %d",
bold("prefill_chunk_size"),
min(self.context_window_size, 8192),
)
self.prefill_chunk_size = min(self.context_window_size, 8192)
elif self.prefill_chunk_size > self.context_window_size:
logger.info(
"Overriding %s from %d to %d",
bold("prefill_chunk_size"),
self.prefill_chunk_size,
min(self.context_window_size, 8192),
)
self.prefill_chunk_size = min(self.context_window_size, 8192)
class GPTNeoXAttention(nn.Module):
"""Multi-headed attention from 'Attention Is All You Need' paper"""
def __init__(self, config: GPTNeoXConfig):
self.rope_theta = config.position_embedding_base
self.hidden_size = config.hidden_size
if config.num_attention_heads % config.tensor_parallel_shards != 0:
raise ValueError(
f"Cannot split {config.num_attention_heads} attention heads "
f"evenly to {config.tensor_parallel_shards} GPUs."
)
self.num_attention_heads = config.num_attention_heads // config.tensor_parallel_shards
self.head_dim = config.head_dim
self.query_key_value = nn.Linear(
in_features=self.hidden_size,
out_features=3 * self.num_attention_heads * self.head_dim,
bias=True,
)
self.dense = nn.Linear(
self.num_attention_heads * self.head_dim, self.hidden_size, bias=True
)
def forward(self, hidden_states: Tensor, paged_kv_cache: PagedKVCache, layer_id: int):
# hidden_states: [batch_size, seq_len, hidden_size]
batch_size, seq_len, _ = hidden_states.shape
# q/k/v states: [batch_size, seq_len, hidden_size]
qkv = self.query_key_value(hidden_states)
qkv = op.reshape(qkv, (batch_size, seq_len, 3 * self.num_attention_heads, self.head_dim))
# Attention
output = op.reshape(
paged_kv_cache.attention_with_fused_qkv(
layer_id, qkv, self.num_attention_heads, sm_scale=self.head_dim**-0.5
),
(batch_size, seq_len, self.head_dim * self.num_attention_heads),
)
attn_output = self.dense(output)
return attn_output
class GPTNeoXMLP(nn.Module):
def __init__(self, config: GPTNeoXConfig):
super().__init__()
out_dtype = config.ffn_out_dtype
if config.intermediate_size % config.tensor_parallel_shards != 0:
raise ValueError(
f"Cannot split MLP intermediate size {config.intermediate_size} "
f"evenly to {config.tensor_parallel_shards} GPUs."
)
self.intermediate_size = config.intermediate_size // config.tensor_parallel_shards
self.dense_h_to_4h = nn.Linear(
config.hidden_size,
self.intermediate_size,
out_dtype=out_dtype,
)
self.dense_4h_to_h = nn.Linear(
self.intermediate_size,
config.hidden_size,
out_dtype=out_dtype,
)
def forward(self, hidden_states: Tensor):
dtype = hidden_states.dtype
if hidden_states.dtype != dtype:
hidden_states = hidden_states.astype(dtype)
hidden_states = self.dense_h_to_4h(hidden_states)
hidden_states = op.gelu(hidden_states)
if hidden_states.dtype != dtype:
hidden_states = hidden_states.astype(dtype)
hidden_states = self.dense_4h_to_h(hidden_states)
if hidden_states.dtype != dtype:
hidden_states = hidden_states.astype(dtype)
return hidden_states
class GPTNeoXLayer(nn.Module):
def __init__(self, config: GPTNeoXConfig):
self.input_layernorm = nn.LayerNorm(config.hidden_size, eps=config.layer_norm_eps)
self.post_attention_layernorm = nn.LayerNorm(config.hidden_size, eps=config.layer_norm_eps)
self.attention = GPTNeoXAttention(config)
self.mlp = GPTNeoXMLP(config)
self.use_parallel_residual = config.use_parallel_residual
def _set_tp():
def _set(param, hint):
param.attrs["shard_strategy"] = hint
hd = config.head_dim
q = k = v = self.attention.num_attention_heads * hd
_set(
self.attention.query_key_value.weight,
tp.ShardSingleDim("_shard_qkv_weight", dim=0, segs=[q, k, v]),
)
_set(
self.attention.query_key_value.bias,
tp.ShardSingleDim("_shard_qkv_bias", dim=0, segs=[q, k, v]),
)
_set(self.attention.dense.weight, tp.ShardSingleDim("_shard_dense", dim=1))
_set(
self.mlp.dense_h_to_4h.weight,
tp.ShardSingleDim("_shard_dense_h_to_4h_weight", dim=0),
)
_set(
self.mlp.dense_h_to_4h.bias,
tp.ShardSingleDim("_shard_dense_h_to_4h_bias", dim=0),
)
_set(
self.mlp.dense_4h_to_h.weight,
tp.ShardSingleDim("_shard_dense_4h_to_h", dim=1),
)
self.tensor_parallel_shards = config.tensor_parallel_shards
_set_tp()
def forward(self, hidden_states: Tensor, paged_kv_cache: PagedKVCache, layer_id: int):
dtype = hidden_states.dtype
attn_input = self.input_layernorm(hidden_states)
with tp.shard_bias(self.attention.dense, self.tensor_parallel_shards):
attn_output = self.attention(
attn_input,
paged_kv_cache,
layer_id,
)
if self.use_parallel_residual:
mlp_input = self.post_attention_layernorm(hidden_states)
mlp_output = self.mlp(mlp_input)
hidden_states = mlp_output + attn_output + hidden_states
else:
attn_output = self._apply_residual(attn_output, hidden_states)
mlp_input = self.post_attention_layernorm(attn_output)
with tp.shard_bias(self.mlp.dense_4h_to_h, self.tensor_parallel_shards):
mlp_output = self.mlp(mlp_input)
hidden_states = self._apply_residual(mlp_output.astype(dtype), attn_output)
return hidden_states
def _apply_residual(self, out, residual):
if self.tensor_parallel_shards > 1:
return op.ccl_allreduce(out + residual / self.tensor_parallel_shards, "sum")
return out + residual
class GPTNeoXModel(nn.Module):
def __init__(self, config: GPTNeoXConfig):
self.embed_in = nn.Embedding(num="vocab_size", dim=config.hidden_size)
self.layers = nn.ModuleList([GPTNeoXLayer(config) for _ in range(config.num_hidden_layers)])
self.final_layer_norm = nn.LayerNorm(config.hidden_size, eps=config.layer_norm_eps)
def forward(self, inputs: Tensor, paged_kv_cache: PagedKVCache):
hidden_states = inputs
for layer_id, layer in enumerate(self.layers):
hidden_states = layer(hidden_states, paged_kv_cache, layer_id)
hidden_states = self.final_layer_norm(hidden_states)
return hidden_states
class GPTNeoXForCausalLM(nn.Module):
def __init__(self, config: GPTNeoXConfig):
self.gpt_neox = GPTNeoXModel(config)
self.embed_out = nn.Linear(
in_features=config.hidden_size,
out_features="vocab_size",
bias=False,
dtype="float32",
)
self.num_hidden_layers = config.num_hidden_layers
self.hidden_size = config.hidden_size
self.num_attention_heads = config.num_attention_heads
self.head_dim = config.head_dim
self.vocab_size = config.vocab_size
self.rope_theta = config.position_embedding_base
self.tensor_parallel_shards = config.tensor_parallel_shards
self.dtype = "float32"
self.rotary_pct = config.rotary_pct
def to(self, dtype: Optional[str] = None):
super().to(dtype=dtype)
if dtype is not None:
self.dtype = dtype
def batch_forward(
self,
input_embeds: Tensor,
paged_kv_cache: PagedKVCache,
logit_positions: Optional[Tensor] = None,
):
op_ext.configure()
hidden_states = self.gpt_neox(input_embeds, paged_kv_cache)
if logit_positions is not None:
hidden_states = op.take(hidden_states, logit_positions, axis=1)
logits = self.embed_out(hidden_states)
if logits.dtype != "float32":
logits = logits.astype("float32")
return logits
def embed(self, input_ids: Tensor):
if self.tensor_parallel_shards > 1:
input_ids = op.ccl_broadcast_from_worker0(input_ids)
return self.gpt_neox.embed_in(input_ids)
def prefill(self, input_embed: Tensor, paged_kv_cache: PagedKVCache):
op_ext.configure()
hidden_states = self.gpt_neox(input_embed, paged_kv_cache)
hidden_states = index_last_token(hidden_states)
logits = self.embed_out(hidden_states)
if logits.dtype != "float32":
logits = logits.astype("float32")
return logits, paged_kv_cache
def decode(self, input_embed: Tensor, paged_kv_cache: PagedKVCache):
op_ext.configure()
hidden_states = self.gpt_neox(input_embed, paged_kv_cache)
logits = self.embed_out(hidden_states)
if logits.dtype != "float32":
logits = logits.astype("float32")
return logits, paged_kv_cache
def batch_prefill(
self,
input_embeds: Tensor,
logit_positions: Tensor,
paged_kv_cache: PagedKVCache,
):
if self.tensor_parallel_shards > 1:
logit_positions = op.ccl_broadcast_from_worker0(logit_positions)
logits = self.batch_forward(input_embeds, paged_kv_cache, logit_positions)
return logits, paged_kv_cache
def batch_decode(self, input_embeds: Tensor, paged_kv_cache: PagedKVCache):
logits = self.batch_forward(input_embeds, paged_kv_cache)
return logits, paged_kv_cache
def batch_verify(self, input_embeds: Tensor, paged_kv_cache: PagedKVCache):
logits = self.batch_forward(input_embeds, paged_kv_cache)
return logits, paged_kv_cache
def create_paged_kv_cache(
self,
max_batch_size: tirx.Var,
max_total_seq_len: tirx.Var,
prefill_chunk_size: tirx.Var,
page_size: tirx.Var,
support_sliding_window: tirx.Var,
) -> PagedKVCache:
return PagedKVCache.create_generic(
attn_kind="mha",
max_batch_size=max_batch_size,
max_total_seq_len=max_total_seq_len,
prefill_chunk_size=prefill_chunk_size,
page_size=page_size,
support_sliding_window=support_sliding_window,
num_hidden_layers=self.num_hidden_layers,
num_attention_heads=self.num_attention_heads // self.tensor_parallel_shards,
num_key_value_heads=self.num_attention_heads // self.tensor_parallel_shards,
qk_head_dim=self.head_dim,
v_head_dim=self.head_dim,
rope_mode=RopeMode.NORMAL,
rope_scale=1,
rope_theta=self.rope_theta,
dtype=self.dtype,
rotary_dim=int(self.head_dim * self.rotary_pct),
)
def get_default_spec(self):
mod_spec = {
"embed": {
"input_ids": nn.spec.Tensor(["seq_len"], "int32"),
"$": {
"param_mode": "packed",
"effect_mode": "none",
},
},
"prefill": {
"input_embed": nn.spec.Tensor([1, "seq_len", self.hidden_size], self.dtype),
"paged_kv_cache": nn.spec.Object(object_type=PagedKVCache),
"$": {
"param_mode": "packed",
"effect_mode": "none",
},
},
"decode": {
"input_embed": nn.spec.Tensor([1, 1, self.hidden_size], self.dtype),
"paged_kv_cache": nn.spec.Object(object_type=PagedKVCache),
"$": {
"param_mode": "packed",
"effect_mode": "none",
},
},
"batch_prefill": {
"input_embeds": nn.spec.Tensor([1, "seq_len", self.hidden_size], self.dtype),
"logit_positions": nn.spec.Tensor(["batch_size"], "int32"),
"paged_kv_cache": nn.spec.Object(object_type=PagedKVCache),
"$": {
"param_mode": "packed",
"effect_mode": "none",
},
},
"batch_decode": {
"input_embeds": nn.spec.Tensor(["batch_size", 1, self.hidden_size], self.dtype),
"paged_kv_cache": nn.spec.Object(object_type=PagedKVCache),
"$": {
"param_mode": "packed",
"effect_mode": "none",
},
},
"batch_verify": {
"input_embeds": nn.spec.Tensor([1, "seq_len", self.hidden_size], self.dtype),
"paged_kv_cache": nn.spec.Object(object_type=PagedKVCache),
"$": {
"param_mode": "packed",
"effect_mode": "none",
},
},
"create_paged_kv_cache": {
"max_batch_size": int,
"max_total_seq_len": int,
"prefill_chunk_size": int,
"page_size": int,
"support_sliding_window": int,
"$": {
"param_mode": "none",
"effect_mode": "none",
},
},
}
return nn.spec.ModuleSpec.from_raw(mod_spec, self)