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

523 lines
21 KiB
Python

"""
Implementation for Nemotron architecture.
"""
import dataclasses
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 logging
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 NemotronConfig(ConfigBase):
"""Configuration of the Nemotron model."""
vocab_size: int
max_position_embeddings: int
hidden_size: int
intermediate_size: int
num_hidden_layers: int
num_attention_heads: int
num_key_value_heads: int
rope_theta: int = 10000
partial_rotary_factor: float = 0.5
rope_scaling: Optional[Dict[str, Any]] = None # noqa: UP006
norm_eps: float = 1e-5
head_dim: int = 0
tie_word_embeddings: bool = False
mlp_bias: bool = False
context_window_size: int = 0
prefill_chunk_size: int = 0
tensor_parallel_shards: int = 1
pipeline_parallel_stages: int = 1
max_batch_size: int = 1
disaggregation: bool = False
kwargs: Dict[str, Any] = dataclasses.field(default_factory=dict) # noqa: UP006
def __post_init__(self):
if self.context_window_size == 0:
self.context_window_size = self.max_position_embeddings
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
self.rotary_dim = int(self.partial_rotary_factor * self.head_dim)
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 NemotronMLP(nn.Module):
"""Nemotron MLP module."""
def __init__(self, config: NemotronConfig):
super().__init__()
self.hidden_size = config.hidden_size
self.intermediate_size = config.intermediate_size
self.up_proj = nn.Linear(config.hidden_size, config.intermediate_size, bias=config.mlp_bias)
self.down_proj = nn.Linear(
config.intermediate_size, config.hidden_size, bias=config.mlp_bias
)
def forward(self, x: Tensor) -> Tensor:
"""Forward pass of the MLP module."""
out = self.up_proj(x)
out = op.square(op.relu(out))
out = self.down_proj(out)
return out
class NemotronEmbedding(nn.Embedding):
"""The embedding module that can be shared with the final head. From Qwen2Embedding."""
def lm_head_forward(self, x: Tensor):
"""The lm_head forwarding, which transposes the weight and multiplies
with the input tensor.
"""
weight = nn.op.permute_dims(self.weight)
return nn.op.matmul(x, weight, out_dtype="float32")
class NemotronLayerNorm1P(nn.LayerNorm):
"""Nemotron LayerNorm1P module."""
def __init__(self, normalized_shape: int, eps: float = 1e-5, elementwise_affine: bool = True):
super().__init__(normalized_shape, eps, elementwise_affine)
def forward(self, x: Tensor) -> Tensor:
"""Forward pass of the tweaked LayerNorm module."""
return op.layer_norm(
x,
normalized_shape=self.normalized_shape,
weight=self.weight + 1,
bias=self.bias,
eps=self.eps,
)
class NemotronAttention(nn.Module):
def __init__(self, config: NemotronConfig):
self.head_dim = config.head_dim
self.num_q_heads = config.num_attention_heads // config.tensor_parallel_shards
assert config.num_key_value_heads % config.tensor_parallel_shards == 0, (
f"num_kv_heads({config.num_key_value_heads}) must be divisible by tensor_parallel_shards" # noqa: E501
)
assert config.num_key_value_heads >= config.tensor_parallel_shards, (
f"Too large tensor_parallel_shards, must be smaller than {config.num_key_value_heads}"
)
self.num_kv_heads = config.num_key_value_heads // config.tensor_parallel_shards
self.qkv_proj = nn.Linear(
in_features=config.hidden_size,
out_features=(self.num_q_heads + 2 * self.num_kv_heads) * self.head_dim,
bias=False,
)
self.o_proj = nn.Linear(self.num_q_heads * self.head_dim, config.hidden_size, bias=False)
def forward(self, hidden_states: Tensor, paged_kv_cache: PagedKVCache, layer_id: int):
d, h_q, h_kv = self.head_dim, self.num_q_heads, self.num_kv_heads
b, s, _ = hidden_states.shape
# QKV Projection
qkv = self.qkv_proj(hidden_states)
qkv = op.reshape(qkv, (b, s, h_q + h_kv + h_kv, d))
# Attention
output = op.reshape(
paged_kv_cache.attention_with_fused_qkv(
layer_id, qkv, self.num_q_heads, sm_scale=self.head_dim**-0.5
),
(b, s, h_q * d),
)
return self.o_proj(output)
class NemotronDecoderLayer(nn.Module):
def __init__(self, config: NemotronConfig):
self.self_attn = NemotronAttention(config)
self.mlp = NemotronMLP(config)
self.input_layernorm = NemotronLayerNorm1P(config.hidden_size, config.norm_eps)
self.post_attention_layernorm = NemotronLayerNorm1P(config.hidden_size, config.norm_eps)
def _set_tp():
def _set(layer, hint):
layer.weight.attrs["shard_strategy"] = hint
hd = config.head_dim
q = self.self_attn.num_q_heads * hd
k = self.self_attn.num_kv_heads * hd
v = self.self_attn.num_kv_heads * hd
_set(
self.self_attn.qkv_proj,
tp.ShardSingleDim("_shard_qkv", segs=[q, k, v], dim=0),
)
_set(self.self_attn.o_proj, tp.ShardSingleDim("_shard_o", dim=1))
_set(self.mlp.up_proj, tp.ShardSingleDim("_shard_mlp_up", dim=1))
_set(self.mlp.down_proj, tp.ShardSingleDim("_shard_mlp_down", 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):
out = self.self_attn(self.input_layernorm(hidden_states), paged_kv_cache, layer_id)
hidden_states = self._apply_residual(out, residual=hidden_states)
out = self.mlp(self.post_attention_layernorm(hidden_states))
hidden_states = self._apply_residual(out, residual=hidden_states)
return hidden_states
def _apply_residual(self, out, residual):
if self.tensor_parallel_shards > 1:
return op.ccl_allreduce(out, "sum") + residual
return out + residual
class NemotronModel(nn.Module):
def __init__(self, config: NemotronConfig):
assert config.hidden_size % config.num_attention_heads == 0
self.embed_tokens = NemotronEmbedding("vocab_size", config.hidden_size)
self.layers = nn.ModuleList(
[NemotronDecoderLayer(config) for _ in range(config.num_hidden_layers)]
)
self.norm = NemotronLayerNorm1P(config.hidden_size, config.norm_eps)
self.num_layers_per_stage = (
config.num_hidden_layers + config.pipeline_parallel_stages - 1
) // config.pipeline_parallel_stages
# Compute pipeline layer partition.
layers_per_stage = (
config.num_hidden_layers + config.pipeline_parallel_stages - 1
) // config.pipeline_parallel_stages
self.layer_partition = [
i * layers_per_stage for i in range(config.pipeline_parallel_stages)
] + [config.num_hidden_layers]
def forward(self, input_embed: Tensor, paged_kv_cache: PagedKVCache):
hidden_states = input_embed
for layer_id, layer in enumerate(self.layers):
if layer_id != 0 and layer_id in self.layer_partition:
hidden_states = op_ext.pipeline_stage_boundary(hidden_states)
hidden_states = layer(hidden_states, paged_kv_cache, layer_id)
hidden_states = self.norm(hidden_states)
return hidden_states
class NemotronForCausalLM(nn.Module):
def __init__(self, config: NemotronConfig):
self.model = NemotronModel(config)
self.tie_word_embeddings = config.tie_word_embeddings
if not config.tie_word_embeddings:
self.lm_head = nn.Linear(config.hidden_size, "vocab_size", bias=False)
self.num_hidden_layers = config.num_hidden_layers
self.num_attention_heads = config.num_attention_heads
self.num_key_value_heads = config.num_key_value_heads
self.head_dim = config.head_dim
self.hidden_size = config.hidden_size
self.vocab_size = config.vocab_size
self.rope_scaling = config.rope_scaling
self.rope_theta = config.rope_theta
self.rotary_dim = config.rotary_dim
self.tensor_parallel_shards = config.tensor_parallel_shards
self.disaggregation = config.disaggregation
self.dtype = "float32"
def _set_pp():
# hidden layers
for layer_id in range(config.num_hidden_layers):
stage = layer_id // (config.num_hidden_layers // config.pipeline_parallel_stages)
for _, param in self.model.layers[layer_id].named_parameters():
param.attrs["pipeline_stages"] = [stage]
# last stage
last_stage = config.pipeline_parallel_stages - 1
self.model.norm.weight.attrs["pipeline_stages"] = [last_stage]
# embedding table and lm_head is required by all stages
all_stages = list(range(config.pipeline_parallel_stages))
self.model.embed_tokens.weight.attrs["pipeline_stages"] = all_stages
if not config.tie_word_embeddings:
self.lm_head.weight.attrs["pipeline_stages"] = all_stages
_set_pp()
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.model(input_embeds, paged_kv_cache)
if logit_positions is not None:
if self.tensor_parallel_shards > 1:
logit_positions = op.ccl_broadcast_from_worker0(logit_positions)
hidden_states = op.take(hidden_states, logit_positions, axis=1)
return self.get_logits(hidden_states)
def batch_forward_to_last_hidden_states(
self,
input_embeds: Tensor,
paged_kv_cache: PagedKVCache,
):
op_ext.configure()
hidden_states = self.model(input_embeds, paged_kv_cache)
return hidden_states
def embed(self, input_ids: Tensor):
if self.tensor_parallel_shards > 1:
input_ids = op.ccl_broadcast_from_worker0(input_ids)
return self.model.embed_tokens(input_ids)
def get_logits(self, hidden_states: Tensor):
op_ext.configure()
if self.tie_word_embeddings:
logits = self.model.embed_tokens.lm_head_forward(hidden_states)
else:
logits = self.lm_head(hidden_states)
if logits.dtype != "float32":
logits = logits.astype("float32")
return logits
def batch_select_last_hidden_states(self, hidden_states: Tensor, logit_positions: Tensor):
op_ext.configure()
if self.tensor_parallel_shards > 1:
logit_positions = op.ccl_broadcast_from_worker0(logit_positions)
hidden_states = op.take(hidden_states, logit_positions, axis=0)
return hidden_states
def prefill(self, input_embed: Tensor, paged_kv_cache: PagedKVCache):
op_ext.configure()
hidden_states = self.model(input_embed, paged_kv_cache)
hidden_states = index_last_token(hidden_states)
logits = self.get_logits(hidden_states)
return logits, paged_kv_cache
def decode(self, input_embed: Tensor, paged_kv_cache: PagedKVCache):
op_ext.configure()
hidden_states = self.model(input_embed, paged_kv_cache)
logits = self.get_logits(hidden_states)
return logits, paged_kv_cache
def prefill_to_last_hidden_states(self, input_embed: Tensor, paged_kv_cache: PagedKVCache):
op_ext.configure()
hidden_states = self.model(input_embed, paged_kv_cache)
return hidden_states, paged_kv_cache
def decode_to_last_hidden_states(self, input_embed: Tensor, paged_kv_cache: PagedKVCache):
op_ext.configure()
hidden_states = self.model(input_embed, paged_kv_cache)
return hidden_states, paged_kv_cache
def batch_prefill(
self,
input_embeds: Tensor,
logit_positions: Tensor,
paged_kv_cache: PagedKVCache,
):
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 batch_prefill_to_last_hidden_states(
self, input_embeds: Tensor, paged_kv_cache: PagedKVCache
):
hidden_states = self.batch_forward_to_last_hidden_states(input_embeds, paged_kv_cache)
return hidden_states, paged_kv_cache
def batch_decode_to_last_hidden_states(
self, input_embeds: Tensor, paged_kv_cache: PagedKVCache
):
hidden_states = self.batch_forward_to_last_hidden_states(input_embeds, paged_kv_cache)
return hidden_states, paged_kv_cache
def batch_verify_to_last_hidden_states(
self, input_embeds: Tensor, paged_kv_cache: PagedKVCache
):
hidden_states = self.batch_forward_to_last_hidden_states(input_embeds, paged_kv_cache)
return hidden_states, 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_key_value_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,
rope_scaling=self.rope_scaling,
rotary_dim=self.rotary_dim,
layer_partition=self.model.layer_partition,
enable_disaggregation=self.disaggregation,
dtype=self.dtype,
)
def get_default_spec(self):
mod_spec = {
"embed": {
"input_ids": nn.spec.Tensor(["seq_len"], "int32"),
"$": {
"param_mode": "packed",
"effect_mode": "none",
},
},
"get_logits": {
"hidden_states": nn.spec.Tensor(["seq_len", self.hidden_size], self.dtype),
"$": {
"param_mode": "packed",
"effect_mode": "none",
},
},
"batch_select_last_hidden_states": {
"hidden_states": nn.spec.Tensor(["seq_len", self.hidden_size], self.dtype),
"logit_positions": nn.spec.Tensor(["batch_size"], "int32"),
"$": {
"param_mode": "none",
"effect_mode": "none",
},
},
"prefill": {
"input_embed": nn.spec.Tensor([1, "seq_len", self.hidden_size], self.dtype),
"paged_kv_cache": nn.spec.Object(object_type=PagedKVCache),
"$": {
"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),
"$": {
"param_mode": "packed",
"effect_mode": "none",
},
},
"prefill_to_last_hidden_states": {
"input_embed": nn.spec.Tensor([1, "seq_len", self.hidden_size], self.dtype),
"paged_kv_cache": nn.spec.Object(object_type=PagedKVCache),
"$": {
"param_mode": "packed",
"effect_mode": "none",
},
},
"decode_to_last_hidden_states": {
"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",
},
},
"batch_prefill_to_last_hidden_states": {
"input_embeds": nn.spec.Tensor([1, "seq_len", self.hidden_size], self.dtype),
"paged_kv_cache": nn.spec.Object(object_type=PagedKVCache),
"$": {
"param_mode": "packed",
"effect_mode": "none",
},
},
"batch_decode_to_last_hidden_states": {
"input_embeds": nn.spec.Tensor(["batch_size", 1, self.hidden_size], self.dtype),
"paged_kv_cache": nn.spec.Object(object_type=PagedKVCache),
"$": {
"param_mode": "packed",
"effect_mode": "none",
},
},
"batch_verify_to_last_hidden_states": {
"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)