import math
import warnings
from typing import Dict, List, Optional, Tuple, Union
import torch
import torch.distributed
import torch.nn.functional as F
import torch.utils.checkpoint
from torch import nn
from torch.nn import BCEWithLogitsLoss, CrossEntropyLoss, MSELoss
from transformers.cache_utils import Cache, DynamicCache
from transformers.modeling_outputs import (
BaseModelOutputWithPast,
CausalLMOutputWithPast,
SequenceClassifierOutputWithPast,
)
from transformers.models.llama.modeling_llama import (
LlamaForCausalLM,
LlamaForSequenceClassification,
LlamaModel,
StaticCache,
apply_rotary_pos_emb,
repeat_kv,
)
from transformers.utils import logging
from colossalai.pipeline.stage_manager import PipelineStageManager
from colossalai.shardformer.layer import AttnMaskType
from colossalai.shardformer.layer._operation import all_to_all_comm, gather_sp_output, split_forward_gather_backward
from colossalai.shardformer.layer.utils import is_share_sp_tp, split_batch_zigzag
from colossalai.shardformer.shard import ShardConfig
from ..layer import ColoAttention, RingAttention, dist_cross_entropy
_SUPPORTED_SP_MODE = ["all_to_all", "split_gather", "ring", "ring_attn"]
class LlamaPipelineForwards:
"""
This class serves as a micro library for forward function substitution of Llama models
under pipeline setting.
"""
@staticmethod
def llama_model_forward(
self: LlamaModel,
input_ids: torch.LongTensor = None,
attention_mask: Optional[torch.Tensor] = None,
position_ids: Optional[torch.LongTensor] = None,
past_key_values: Optional[List[torch.FloatTensor]] = None,
inputs_embeds: Optional[torch.FloatTensor] = None,
use_cache: Optional[bool] = None,
output_attentions: Optional[bool] = None,
output_hidden_states: Optional[bool] = None,
return_dict: Optional[bool] = None,
cache_position: Optional[torch.LongTensor] = None,
stage_manager: Optional[PipelineStageManager] = None,
hidden_states: Optional[torch.FloatTensor] = None,
stage_index: Optional[List[int]] = None,
shard_config: ShardConfig = None,
# Split output only when computing cross entropy using llama_for_causal_lm_forward
# or get_lm_forward_with_dist_cross_entropy
# Default to True to avoid bug when calling classification forward from huggingface
force_sp_output_gather: bool = True,
):
logger = logging.get_logger(__name__)
output_attentions = output_attentions if output_attentions is not None else self.config.output_attentions
output_hidden_states = (
output_hidden_states if output_hidden_states is not None else self.config.output_hidden_states
)
use_cache = use_cache if use_cache is not None else self.config.use_cache
if use_cache:
logger.warning_once(
"`use_cache=True` is incompatible with pipeline parallelism. Setting `use_cache=False`..."
)
use_cache = False
return_dict = return_dict if return_dict is not None else self.config.use_return_dict
# retrieve input_ids and inputs_embeds
if stage_manager.is_first_stage():
if input_ids is not None and inputs_embeds is not None:
raise ValueError("You cannot specify both input_ids and inputs_embeds at the same time")
elif input_ids is not None:
batch_size, seq_length = input_ids.shape[:2]
elif inputs_embeds is not None:
batch_size, seq_length, _ = inputs_embeds.shape[:2]
else:
raise ValueError("You have to specify either input_ids or inputs_embeds")
device = input_ids.device if input_ids is not None else inputs_embeds.device
if inputs_embeds is None:
inputs_embeds = self.embed_tokens(input_ids)
hidden_states = inputs_embeds
else:
input_shape = hidden_states.shape[:-1]
batch_size, seq_length = input_shape
device = hidden_states.device
# Support SP + PP
sp_mode = shard_config.sequence_parallelism_mode
sp_group = shard_config.sequence_parallel_process_group
sp_size = shard_config.sequence_parallel_size
if sp_mode == "all_to_all" and not stage_manager.is_first_stage():
# For generating full positions ids, as the states will be gather along the seq dim in the attention layer later.
seq_length *= sp_size
past_seen_tokens = 0
if use_cache: # kept for BC (cache positions)
if not isinstance(past_key_values, StaticCache):
past_key_values = DynamicCache.from_legacy_cache(past_key_values)
past_seen_tokens = past_key_values.get_seq_length()
if cache_position is None:
if isinstance(past_key_values, StaticCache):
raise ValueError("cache_position is a required argument when using StaticCache.")
cache_position = torch.arange(past_seen_tokens, past_seen_tokens + seq_length, device=device)
seq_length_with_past = seq_length + past_seen_tokens
# TODO(jianghai): left the recording kv-value tensors as () or None type, this feature may be added in the future.
if output_attentions:
logger.warning_once("output_attentions=True is not supported for pipeline models at the moment.")
output_attentions = False
if output_hidden_states:
logger.warning_once("output_hidden_states=True is not supported for pipeline models at the moment.")
output_hidden_states = False
if use_cache:
logger.warning_once("use_cache=True is not supported for pipeline models at the moment.")
use_cache = False
if position_ids is None:
position_ids = cache_position.unsqueeze(0)
# embed positions, for the first stage, hidden_states is the input embeddings,
# for the other stages, hidden_states is the output of the previous stage
if not stage_manager.is_first_stage() and sp_mode == "ring_attn":
_, attn_kwargs, _ = RingAttention.prepare_varlen_batch(attention_mask, sp_group)
elif shard_config.enable_flash_attention:
# in this case, attention_mask is a dict rather than a tensor
mask_shape = (batch_size, 1, seq_length_with_past, seq_length_with_past)
attn_kwargs = ColoAttention.prepare_attn_kwargs(
mask_shape,
hidden_states.dtype,
hidden_states.device,
q_padding_mask=attention_mask,
is_causal=True,
invert=(sp_mode != "ring_attn"),
)
else:
attn_kwargs = self._update_causal_mask(attention_mask, hidden_states, cache_position)
# Support SP + PP
# TODO: support padded casual cu_seqlens across stages
if stage_manager.is_first_stage():
# Ring Attention zigzag batch processing
if sp_mode == "ring_attn":
assert shard_config.enable_flash_attention, "Ring Attention inherently requires Flash Attention."
if attn_kwargs["attention_mask_type"] == AttnMaskType.PADDED_CAUSAL:
hidden_states, attn_kwargs, position_ids = RingAttention.prepare_varlen_batch(
attention_mask, sp_group, hidden_states, position_ids
)
else:
hidden_states, position_ids = split_batch_zigzag([hidden_states, position_ids], sp_group)
elif is_share_sp_tp(sp_mode):
hidden_states = split_forward_gather_backward(
hidden_states, 1, sp_group, fp8_communication=shard_config.fp8_communication
)
elif sp_mode == "all_to_all":
hidden_states = split_forward_gather_backward(
hidden_states, 1, sp_group, 1 / sp_size, fp8_communication=shard_config.fp8_communication
)
if self.gradient_checkpointing and self.training and use_cache:
if use_cache:
logger.warning_once(
"`use_cache=True` is incompatible with gradient checkpointing. Setting `use_cache=False`..."
)
use_cache = False
# decoder layers
all_hidden_states = () if output_hidden_states else None
all_self_attns = () if output_attentions else None
next_decoder_cache = None
start_idx, end_idx = stage_index[0], stage_index[1]
num_ckpt_layers = 0
if self.gradient_checkpointing and self.training:
num_ckpt_layers = end_idx - start_idx
# TODO: We can replace `gradient_checkpointing_enable` fn and initialize a gradient_checkpointing (List[bool]) for each layer
if shard_config.gradient_checkpoint_config is not None:
num_ckpt_layers = shard_config.gradient_checkpoint_config.get_num_ckpt_layers(
stage=stage_manager.stage,
num_stages=stage_manager.num_stages,
num_layers=end_idx - start_idx,
model_chunk_id=(stage_manager.model_chunk_id if stage_manager.is_interleave else 0),
num_model_chunks=stage_manager.num_model_chunks,
)
assert num_ckpt_layers <= end_idx - start_idx
for idx, decoder_layer in enumerate(self.layers[start_idx:end_idx], start=start_idx):
if output_hidden_states:
all_hidden_states += (hidden_states,)
if idx - start_idx < num_ckpt_layers:
layer_outputs = self._gradient_checkpointing_func(
decoder_layer.__call__,
hidden_states,
attn_kwargs,
position_ids,
past_key_values,
output_attentions,
use_cache,
cache_position,
)
else:
layer_outputs = decoder_layer(
hidden_states,
attention_mask=attn_kwargs,
position_ids=position_ids,
past_key_value=past_key_values,
output_attentions=output_attentions,
use_cache=use_cache,
cache_position=cache_position,
)
hidden_states = layer_outputs[0]
if use_cache:
next_decoder_cache = layer_outputs[2 if output_attentions else 1]
if output_attentions:
all_self_attns += (layer_outputs[1],)
if stage_manager.is_last_stage():
hidden_states = self.norm(hidden_states)
if (not shard_config.parallel_output) or force_sp_output_gather or is_share_sp_tp(sp_mode):
hidden_states = gather_sp_output(
hidden_states, sp_group, sp_mode, fp8_communication=shard_config.fp8_communication
)
# add hidden states from the last decoder layer
if output_hidden_states:
all_hidden_states += (hidden_states,)
next_cache = next_decoder_cache if use_cache else None
if stage_manager.is_last_stage():
if not return_dict:
return tuple(
v
for v in [
hidden_states,
next_cache,
all_hidden_states,
all_self_attns,
]
if v is not None
)
return BaseModelOutputWithPast(
last_hidden_state=hidden_states,
past_key_values=next_cache,
hidden_states=all_hidden_states,
attentions=all_self_attns,
)
# always return dict for imediate stage
return {"hidden_states": hidden_states}
@staticmethod
def llama_for_causal_lm_forward(
self: LlamaForCausalLM,
input_ids: torch.LongTensor = None,
attention_mask: Optional[torch.Tensor] = None,
position_ids: Optional[torch.LongTensor] = None,
past_key_values: Optional[List[torch.FloatTensor]] = None,
inputs_embeds: Optional[torch.FloatTensor] = None,
labels: Optional[torch.LongTensor] = None,
use_cache: Optional[bool] = None,
output_attentions: Optional[bool] = None,
output_hidden_states: Optional[bool] = None,
return_dict: Optional[bool] = None,
cache_position: Optional[torch.LongTensor] = None,
stage_manager: Optional[PipelineStageManager] = None,
hidden_states: Optional[torch.FloatTensor] = None,
stage_index: Optional[List[int]] = None,
shard_config: ShardConfig = None,
):
r"""
Args:
labels (`torch.LongTensor` of shape `(batch_size, sequence_length)`, *optional*):
Labels for computing the masked language modeling loss. Indices should either be in `[0, ...,
config.vocab_size]` or -100 (see `input_ids` docstring). Tokens with indices set to `-100` are ignored
(masked), the loss is only computed for the tokens with labels in `[0, ..., config.vocab_size]`.
Returns:
Example:
```python
>>> from transformers import AutoTokenizer, LlamaForCausalLM
>>> model = LlamaForCausalLM.from_pretrained(PATH_TO_CONVERTED_WEIGHTS)
>>> tokenizer = AutoTokenizer.from_pretrained(PATH_TO_CONVERTED_TOKENIZER)
>>> prompt = "Hey, are you conscious? Can you talk to me?"
>>> inputs = tokenizer(prompt, return_tensors="pt")
>>> # Generate
>>> generate_ids = model.generate(inputs.input_ids, max_length=30)
>>> tokenizer.batch_decode(generate_ids, skip_special_tokens=True, clean_up_tokenization_spaces=False)[0]
"Hey, are you conscious? Can you talk to me?\nI'm not conscious, but I can talk to you."
```"""
logger = logging.get_logger(__name__)
output_attentions = output_attentions if output_attentions is not None else self.config.output_attentions
output_hidden_states = (
output_hidden_states if output_hidden_states is not None else self.config.output_hidden_states
)
return_dict = return_dict if return_dict is not None else self.config.use_return_dict
# TODO(jianghai): left the recording kv-value tensors as () or None type, this feature may be added in the future.
if output_attentions:
logger.warning_once("output_attentions=True is not supported for pipeline models at the moment.")
output_attentions = False
if output_hidden_states:
logger.warning_once("output_hidden_states=True is not supported for pipeline models at the moment.")
output_hidden_states = False
if shard_config.sequence_parallelism_mode == "ring_attn" and shard_config.parallel_output:
# Split labels in a zigzag fashion too
sp_group = shard_config.sequence_parallel_process_group
if attention_mask.bool().all():
labels = split_batch_zigzag(labels, sp_group, seq_dim=1)
else:
# [B, max_seqlen // sp_size]
labels, _, _ = RingAttention.prepare_varlen_batch(attention_mask, sp_group, labels, is_label=True)
# decoder outputs consists of (dec_features, layer_state, dec_hidden, dec_attn)
outputs = LlamaPipelineForwards.llama_model_forward(
self.model,
input_ids=input_ids,
attention_mask=attention_mask,
position_ids=position_ids,
past_key_values=past_key_values,
inputs_embeds=inputs_embeds,
use_cache=use_cache,
output_attentions=output_attentions,
output_hidden_states=output_hidden_states,
return_dict=return_dict,
cache_position=cache_position,
stage_manager=stage_manager,
hidden_states=hidden_states,
stage_index=stage_index,
shard_config=shard_config,
force_sp_output_gather=False,
)
past_key_values = None
if stage_manager.is_last_stage():
hidden_states = outputs[0]
logits = self.lm_head(hidden_states)
loss = dist_cross_entropy(
labels, logits, shard_config, self.lm_head.out_features, self.config.vocab_size, self.model.dtype
)
if not return_dict:
output = (logits,) + outputs[1:]
return (loss,) + output if loss is not None else output
return CausalLMOutputWithPast(
loss=loss,
logits=logits,
past_key_values=outputs.past_key_values,
hidden_states=outputs.hidden_states,
attentions=outputs.attentions,
)
else:
hidden_states = outputs.get("hidden_states")
return {"hidden_states": hidden_states}
@staticmethod
def llama_for_sequence_classification_forward(
self: LlamaForSequenceClassification,
input_ids: torch.LongTensor = None,
attention_mask: Optional[torch.Tensor] = None,
position_ids: Optional[torch.LongTensor] = None,
past_key_values: Optional[List[torch.FloatTensor]] = None,
inputs_embeds: Optional[torch.FloatTensor] = None,
labels: Optional[torch.LongTensor] = None,
use_cache: Optional[bool] = None,
output_attentions: Optional[bool] = None,
output_hidden_states: Optional[bool] = None,
return_dict: Optional[bool] = None,
cache_position: Optional[torch.LongTensor] = None,
stage_manager: Optional[PipelineStageManager] = None,
hidden_states: Optional[torch.FloatTensor] = None,
stage_index: Optional[List[int]] = None,
shard_config: ShardConfig = None,
):
r"""
labels (`torch.LongTensor` of shape `(batch_size,)`, *optional*):
Labels for computing the sequence classification/regression loss. Indices should be in `[0, ...,
config.num_labels - 1]`. If `config.num_labels == 1` a regression loss is computed (Mean-Square loss), If
`config.num_labels > 1` a classification loss is computed (Cross-Entropy).
"""
logger = logging.get_logger(__name__)
return_dict = return_dict if return_dict is not None else self.config.use_return_dict
# TODO(jianghai): left the recording kv-value tensors as () or None type, this feature may be added in the future.
if output_attentions:
logger.warning_once("output_attentions=True is not supported for pipeline models at the moment.")
output_attentions = False
if output_hidden_states:
logger.warning_once("output_hidden_states=True is not supported for pipeline models at the moment.")
output_hidden_states = False
transformer_outputs = LlamaPipelineForwards.llama_model_forward(
self.model,
input_ids,
attention_mask=attention_mask,
position_ids=position_ids,
past_key_values=past_key_values,
inputs_embeds=inputs_embeds,
use_cache=use_cache,
output_attentions=output_attentions,
output_hidden_states=output_hidden_states,
return_dict=return_dict,
cache_position=cache_position,
stage_manager=stage_manager,
hidden_states=hidden_states,
stage_index=stage_index,
shard_config=shard_config,
)
if input_ids is not None:
batch_size = input_ids.shape[0]
elif inputs_embeds is not None:
batch_size = inputs_embeds.shape[0]
else:
batch_size = hidden_states.shape[0]
if stage_manager.is_last_stage():
hidden_states = transformer_outputs[0]
logits = self.score(hidden_states)
if self.config.pad_token_id is None and batch_size != 1:
raise ValueError("Cannot handle batch sizes > 1 if no padding token is defined.")
if self.config.pad_token_id is None:
sequence_lengths = -1
else:
if input_ids is not None:
sequence_lengths = (torch.ne(input_ids, self.config.pad_token_id).sum(-1) - 1).to(logits.device)
else:
sequence_lengths = -1
pooled_logits = logits[torch.arange(batch_size, device=logits.device), sequence_lengths]
loss = None
if labels is not None:
labels = labels.to(logits.device)
if self.config.problem_type is None:
if self.num_labels == 1:
self.config.problem_type = "regression"
elif self.num_labels > 1 and (labels.dtype == torch.long or labels.dtype == torch.int):
self.config.problem_type = "single_label_classification"
else:
self.config.problem_type = "multi_label_classification"
if self.config.problem_type == "regression":
loss_fct = MSELoss()
if self.num_labels == 1:
loss = loss_fct(pooled_logits.squeeze(), labels.squeeze())
else:
loss = loss_fct(pooled_logits, labels)
elif self.config.problem_type == "single_label_classification":
loss_fct = CrossEntropyLoss()
loss = loss_fct(pooled_logits.view(-1, self.num_labels), labels.view(-1))
elif self.config.problem_type == "multi_label_classification":
loss_fct = BCEWithLogitsLoss()
loss = loss_fct(pooled_logits, labels)
if not return_dict:
output = (pooled_logits,) + transformer_outputs[1:]
return ((loss,) + output) if loss is not None else output
return SequenceClassifierOutputWithPast(
loss=loss,
logits=pooled_logits,
past_key_values=transformer_outputs.past_key_values,
hidden_states=transformer_outputs.hidden_states,
attentions=transformer_outputs.attentions,
)
else:
hidden_states = transformer_outputs.get("hidden_states")
return {"hidden_states": hidden_states}
def get_llama_flash_attention_forward(shard_config: ShardConfig, sp_mode=None, sp_size=None, sp_group=None):
def forward(
self,
hidden_states: torch.Tensor,
attention_mask: Optional[Union[torch.Tensor, Dict]] = None,
position_ids: Optional[torch.LongTensor] = None,
past_key_value: Optional[Cache] = None,
output_attentions: bool = False,
use_cache: bool = False,
cache_position: Optional[torch.LongTensor] = None,
**kwargs,
) -> Tuple[torch.Tensor, Optional[torch.Tensor], Optional[Cache]]:
if sp_mode is not None:
assert sp_mode in _SUPPORTED_SP_MODE, f"SP mode {sp_mode} is not supported by {type(self)} yet"
assert (sp_size is not None) and (
sp_group is not None
), "Must specify sp_size and sp_group for sequence parallel"
if "padding_mask" in kwargs:
warnings.warn(
"Passing `padding_mask` is deprecated and will be removed in v4.37. Please make sure use `attention_mask` instead.`"
)
bsz, q_len, _ = hidden_states.size()
# sp: modify sp_len when sequence parallel mode is ring
if is_share_sp_tp(sp_mode):
q_len *= sp_size
if self.config.pretraining_tp > 1:
key_value_slicing = (self.num_key_value_heads * self.head_dim) // self.config.pretraining_tp
query_slices = self.q_proj.weight.split(
(self.num_heads * self.head_dim) // self.config.pretraining_tp, dim=0
)
key_slices = self.k_proj.weight.split(key_value_slicing, dim=0)
value_slices = self.v_proj.weight.split(key_value_slicing, dim=0)
query_states = [F.linear(hidden_states, query_slices[i]) for i in range(self.config.pretraining_tp)]
query_states = torch.cat(query_states, dim=-1)
key_states = [F.linear(hidden_states, key_slices[i]) for i in range(self.config.pretraining_tp)]
key_states = torch.cat(key_states, dim=-1)
value_states = [F.linear(hidden_states, value_slices[i]) for i in range(self.config.pretraining_tp)]
value_states = torch.cat(value_states, dim=-1)
else:
query_states = self.q_proj(hidden_states)
key_states = self.k_proj(hidden_states)
value_states = self.v_proj(hidden_states)
# sp: all-to-all comminucation when introducing sequence parallel
if sp_mode == "all_to_all":
query_states = all_to_all_comm(query_states, sp_group, fp8_communication=shard_config.fp8_communication)
key_states = all_to_all_comm(key_states, sp_group, fp8_communication=shard_config.fp8_communication)
value_states = all_to_all_comm(value_states, sp_group, fp8_communication=shard_config.fp8_communication)
bsz, q_len, _ = query_states.size()
query_states = query_states.view(bsz, q_len, self.num_heads, self.head_dim).transpose(1, 2)
key_states = key_states.view(bsz, q_len, self.num_key_value_heads, self.head_dim).transpose(1, 2)
value_states = value_states.view(bsz, q_len, self.num_key_value_heads, self.head_dim).transpose(1, 2)
kv_seq_len = key_states.shape[-2]
if past_key_value is not None:
if self.layer_idx is None:
raise ValueError(
f"The cache structure has changed since version v4.36. If you are using {self.__class__.__name__} "
"for auto-regressive decoding with k/v caching, please make sure to initialize the attention class "
"with a layer index."
)
kv_seq_len += past_key_value.get_usable_length(kv_seq_len, self.layer_idx)
cos, sin = self.rotary_emb(value_states, position_ids)
query_states, key_states = apply_rotary_pos_emb(query_states, key_states, cos, sin)
if past_key_value is not None:
cache_kwargs = {"sin": sin, "cos": cos, "cache_position": cache_position}
key_states, value_states = past_key_value.update(key_states, value_states, self.layer_idx, cache_kwargs)
# repeat k/v heads if n_kv_heads < n_heads
key_states = repeat_kv(key_states, self.num_key_value_groups)
value_states = repeat_kv(value_states, self.num_key_value_groups)
if sp_mode == "ring_attn":
attn_output = RingAttention.attention(
query_states,
key_states,
value_states,
sp_group,
**attention_mask,
inner_ring_size=shard_config.inner_ring_size,
)
elif shard_config.enable_flash_attention:
assert isinstance(attention_mask, dict), "Flash Attention Error: attention_mask should be a dict."
attn_output = ColoAttention.attention(query_states, key_states, value_states, **attention_mask)
else:
attn_weights = torch.matmul(query_states, key_states.transpose(2, 3)) / math.sqrt(self.head_dim)
if attn_weights.size() != (bsz, self.num_heads, q_len, kv_seq_len):
raise ValueError(
f"Attention weights should be of size {(bsz, self.num_heads, q_len, kv_seq_len)}, but is"
f" {attn_weights.size()}"
)
if attention_mask is not None:
if attention_mask.size() != (bsz, 1, q_len, kv_seq_len):
raise ValueError(
f"Attention mask should be of size {(bsz, 1, q_len, kv_seq_len)}, but is {attention_mask.size()}"
)
attn_weights = attn_weights + attention_mask
# upcast attention to fp32
attn_weights = nn.functional.softmax(attn_weights, dim=-1, dtype=torch.float32).to(query_states.dtype)
attn_output = torch.matmul(attn_weights, value_states)
if attn_output.size() != (bsz, self.num_heads, q_len, self.head_dim):
raise ValueError(
f"`attn_output` should be of size {(bsz, self.num_heads, q_len, self.head_dim)}, but is"
f" {attn_output.size()}"
)
attn_output = attn_output.transpose(1, 2).contiguous()
# sp: all-to-all comminucation when introducing sequence parallel
if sp_mode == "all_to_all":
attn_output = attn_output.reshape(bsz, q_len, self.num_heads * self.head_dim)
attn_output = all_to_all_comm(
attn_output, sp_group, scatter_dim=1, gather_dim=2, fp8_communication=shard_config.fp8_communication
)
else:
attn_output = attn_output.reshape(bsz, q_len, self.hidden_size)
if self.config.pretraining_tp > 1:
attn_output = attn_output.split(self.hidden_size // self.config.pretraining_tp, dim=2)
o_proj_slices = self.o_proj.weight.split(self.hidden_size // self.config.pretraining_tp, dim=1)
attn_output = sum([F.linear(attn_output[i], o_proj_slices[i]) for i in range(self.config.pretraining_tp)])
else:
attn_output = self.o_proj(attn_output)
if not output_attentions:
attn_weights = None
return attn_output, attn_weights, past_key_value
return forward
def get_llama_flash_attention_model_forward(shard_config: ShardConfig, sp_mode=None, sp_size=None, sp_group=None):
logger = logging.get_logger(__name__)
def forward(
self,
input_ids: torch.LongTensor = None,
attention_mask: Optional[torch.Tensor] = None,
position_ids: Optional[torch.LongTensor] = None,
past_key_values: Optional[List[torch.FloatTensor]] = None,
inputs_embeds: Optional[torch.FloatTensor] = None,
use_cache: Optional[bool] = None,
output_attentions: Optional[bool] = None,
output_hidden_states: Optional[bool] = None,
return_dict: Optional[bool] = None,
cache_position: Optional[torch.LongTensor] = None,
# Split output only when computing cross entropy using llama_for_causal_lm_forward
# or get_lm_forward_with_dist_cross_entropy
# Default to True to avoid bug when calling classification forward from huggingface
force_sp_output_gather: bool = True,
) -> Union[Tuple, BaseModelOutputWithPast]:
output_attentions = output_attentions if output_attentions is not None else self.config.output_attentions
output_hidden_states = (
output_hidden_states if output_hidden_states is not None else self.config.output_hidden_states
)
use_cache = use_cache if use_cache is not None else self.config.use_cache
return_dict = return_dict if return_dict is not None else self.config.use_return_dict
# retrieve input_ids and inputs_embeds
if (input_ids is None) ^ (inputs_embeds is not None):
raise ValueError(
"You cannot specify both input_ids and inputs_embeds at the same time, and must specify either one"
)
if (self.gradient_checkpointing or sp_mode in ["ring", "all_to_all"]) and self.training:
if use_cache:
logger.warning_once(
"`use_cache=True` is incompatible with gradient checkpointing. Setting `use_cache=False`..."
)
use_cache = False
if inputs_embeds is None:
inputs_embeds = self.embed_tokens(input_ids)
past_seen_tokens = 0
seq_len = inputs_embeds.shape[1]
batch_size = inputs_embeds.shape[0]
if use_cache: # kept for BC (cache positions)
if not isinstance(past_key_values, StaticCache):
past_key_values = DynamicCache.from_legacy_cache(past_key_values)
past_seen_tokens = past_key_values.get_seq_length()
if cache_position is None:
if isinstance(past_key_values, StaticCache):
raise ValueError("cache_position is a required argument when using StaticCache.")
cache_position = torch.arange(past_seen_tokens, past_seen_tokens + seq_len, device=inputs_embeds.device)
if position_ids is None:
position_ids = cache_position.unsqueeze(0)
if shard_config.enable_flash_attention:
mask_shape = (batch_size, 1, seq_len, past_seen_tokens + seq_len)
attn_kwargs: dict = ColoAttention.prepare_attn_kwargs(
mask_shape,
inputs_embeds.dtype,
inputs_embeds.device,
q_padding_mask=attention_mask,
is_causal=True,
invert=(sp_mode != "ring_attn"),
)
else:
attn_kwargs: torch.Tensor = self._update_causal_mask(attention_mask, inputs_embeds, cache_position)
# Ring Attention zigzag batch processing
if sp_mode == "ring_attn":
assert shard_config.enable_flash_attention, "Ring Attention inherently requires Flash Attention."
if attn_kwargs["attention_mask_type"] == AttnMaskType.PADDED_CAUSAL:
inputs_embeds, attn_kwargs, position_ids = RingAttention.prepare_varlen_batch(
attention_mask, sp_group, inputs_embeds, position_ids
)
else:
inputs_embeds, position_ids = split_batch_zigzag([inputs_embeds, position_ids], sp_group)
attn_kwargs = {"attention_mask_type": attn_kwargs["attention_mask_type"]} # drop redundant tensors
elif is_share_sp_tp(sp_mode):
inputs_embeds = split_forward_gather_backward(
inputs_embeds, 1, sp_group, fp8_communication=shard_config.fp8_communication
)
elif sp_mode == "all_to_all":
inputs_embeds = split_forward_gather_backward(
inputs_embeds, 1, sp_group, 1 / sp_size, fp8_communication=shard_config.fp8_communication
)
hidden_states = inputs_embeds
# decoder layers
all_hidden_states = () if output_hidden_states else None
all_self_attns = () if output_attentions else None
next_decoder_cache = None
for decoder_layer in self.layers:
if output_hidden_states:
all_hidden_states += (hidden_states,)
if self.gradient_checkpointing and self.training:
layer_outputs = self._gradient_checkpointing_func(
decoder_layer.__call__,
hidden_states,
attn_kwargs,
position_ids,
past_key_values,
output_attentions,
use_cache,
cache_position,
)
else:
layer_outputs = decoder_layer(
hidden_states,
attention_mask=attn_kwargs,
position_ids=position_ids,
past_key_value=past_key_values,
output_attentions=output_attentions,
use_cache=use_cache,
cache_position=cache_position,
)
hidden_states = layer_outputs[0]
if use_cache:
next_decoder_cache = layer_outputs[2 if output_attentions else 1]
if output_attentions:
all_self_attns += (layer_outputs[1],)
hidden_states = self.norm(hidden_states)
# Cases that don't support parallelizing cross entropy computation along sequence
if (not shard_config.parallel_output) or is_share_sp_tp(sp_mode) or force_sp_output_gather:
hidden_states = gather_sp_output(
hidden_states, sp_group, sp_mode, fp8_communication=shard_config.fp8_communication
)
# add hidden states from the last decoder layer
if output_hidden_states:
all_hidden_states += (hidden_states,)
next_cache = None
if use_cache:
next_cache = (
next_decoder_cache.to_legacy_cache() if isinstance(next_decoder_cache, Cache) else next_decoder_cache
)
if not return_dict:
return tuple(v for v in [hidden_states, next_cache, all_hidden_states, all_self_attns] if v is not None)
return BaseModelOutputWithPast(
last_hidden_state=hidden_states,
past_key_values=next_cache,
hidden_states=all_hidden_states,
attentions=all_self_attns,
)
return forward
def get_lm_forward_with_dist_cross_entropy(shard_config: ShardConfig):
from transformers import LlamaForCausalLM
def forward(
self: LlamaForCausalLM,
input_ids: torch.LongTensor = None,
attention_mask: Optional[torch.Tensor] = None,
position_ids: Optional[torch.LongTensor] = None,
past_key_values: Optional[List[torch.FloatTensor]] = None,
inputs_embeds: Optional[torch.FloatTensor] = None,
labels: Optional[torch.LongTensor] = None,
use_cache: Optional[bool] = None,
output_attentions: Optional[bool] = None,
output_hidden_states: Optional[bool] = None,
return_dict: Optional[bool] = None,
cache_position: Optional[torch.LongTensor] = None,
) -> Union[Tuple, CausalLMOutputWithPast]:
r"""
Args:
labels (`torch.LongTensor` of shape `(batch_size, sequence_length)`, *optional*):
Labels for computing the masked language modeling loss. Indices should either be in `[0, ...,
config.vocab_size]` or -100 (see `input_ids` docstring). Tokens with indices set to `-100` are ignored
(masked), the loss is only computed for the tokens with labels in `[0, ..., config.vocab_size]`.
Returns:
Example:
```python
>>> from transformers import AutoTokenizer, LlamaForCausalLM
>>> model = LlamaForCausalLM.from_pretrained(PATH_TO_CONVERTED_WEIGHTS)
>>> tokenizer = AutoTokenizer.from_pretrained(PATH_TO_CONVERTED_TOKENIZER)
>>> prompt = "Hey, are you conscious? Can you talk to me?"
>>> inputs = tokenizer(prompt, return_tensors="pt")
>>> # Generate
>>> generate_ids = model.generate(inputs.input_ids, max_length=30)
>>> tokenizer.batch_decode(generate_ids, skip_special_tokens=True, clean_up_tokenization_spaces=False)[0]
"Hey, are you conscious? Can you talk to me?\nI'm not conscious, but I can talk to you."
```"""
output_attentions = output_attentions if output_attentions is not None else self.config.output_attentions
output_hidden_states = (
output_hidden_states if output_hidden_states is not None else self.config.output_hidden_states
)
return_dict = return_dict if return_dict is not None else self.config.use_return_dict
if shard_config.sequence_parallelism_mode == "ring_attn" and shard_config.parallel_output:
# Special processing: Split labels in a zigzag fashion too
sp_group = shard_config.sequence_parallel_process_group
if attention_mask.bool().all():
labels = split_batch_zigzag(labels, sp_group, seq_dim=1, is_label=True)
else:
# [B, max_seq_len // sp_size]
labels, _, _ = RingAttention.prepare_varlen_batch(attention_mask, sp_group, labels, is_label=True)
# decoder outputs consists of (dec_features, layer_state, dec_hidden, dec_attn)
outputs = self.model(
input_ids=input_ids,
attention_mask=attention_mask,
position_ids=position_ids,
past_key_values=past_key_values,
inputs_embeds=inputs_embeds,
use_cache=use_cache,
output_attentions=output_attentions,
output_hidden_states=output_hidden_states,
return_dict=return_dict,
cache_position=cache_position,
force_sp_output_gather=False,
)
hidden_states = outputs[0]
if self.config.pretraining_tp > 1:
lm_head_slices = self.lm_head.weight.split(self.vocab_size // self.config.pretraining_tp, dim=0)
logits = [F.linear(hidden_states, lm_head_slices[i]) for i in range(self.config.pretraining_tp)]
logits = torch.cat(logits, dim=-1)
else:
logits = self.lm_head(hidden_states)
logits = logits.float()
loss = dist_cross_entropy(
labels, logits, shard_config, self.lm_head.out_features, self.config.vocab_size, self.model.dtype
)
if not return_dict:
output = (logits,) + outputs[1:]
return (loss,) + output if loss is not None else output
return CausalLMOutputWithPast(
loss=loss,
logits=logits,
past_key_values=outputs.past_key_values,
hidden_states=outputs.hidden_states,
attentions=outputs.attentions,
)
return forward