409 lines
19 KiB
Python
409 lines
19 KiB
Python
# Copyright (c) ModelScope Contributors. All rights reserved.
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# Part of the implementation is borrowed from dvlab-research/LongLoRA.
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import math
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import torch
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import torch.nn.functional as F
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from torch import nn
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from transformers import Cache, StaticCache
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from transformers.models.llama.modeling_llama import apply_rotary_pos_emb, repeat_kv
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from types import MethodType
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from typing import Optional, Tuple
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from swift.utils import get_logger
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logger = get_logger()
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def _preprocess_qkv_fa2(attn_module, query_states, key_states, value_states, attention_mask):
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if attn_module.training:
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bsz, q_len = query_states.shape[:2]
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group_size = int(q_len * attn_module.config.group_size_ratio)
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if q_len % group_size != 0:
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raise ValueError(f'The sequence length {q_len} should'
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f'be able to be split by the group_ratio {attn_module.config.group_size_ratio}')
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num_group = q_len // group_size
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def shift(qkv, bsz, q_len, group_size, num_heads, head_dim):
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qkv[:, :, num_heads // 2:] = qkv[:, :, num_heads // 2:].roll(-group_size // 2, dims=1)
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qkv = qkv.reshape(bsz * num_group, group_size, num_heads, head_dim)
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return qkv
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query_states = shift(query_states, bsz, q_len, group_size, attn_module.num_heads, attn_module.head_dim)
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key_states = shift(key_states, bsz, q_len, group_size, attn_module.num_heads, attn_module.head_dim)
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value_states = shift(value_states, bsz, q_len, group_size, attn_module.num_heads, attn_module.head_dim)
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if attention_mask is not None:
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attention_mask = attention_mask[:, :group_size].repeat(num_group, 1)
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return query_states, key_states, value_states, attention_mask
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def _preprocess_qkv(attn_module, query_states, key_states, value_states, attention_mask):
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if attn_module.training:
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bsz, _, q_len = query_states.shape[:3]
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group_size = int(q_len * attn_module.config.group_size_ratio)
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if q_len % group_size != 0:
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raise ValueError(f'The sequence length {q_len} should'
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f'be able to be split by the group_ratio {attn_module.config.group_size_ratio}')
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num_group = q_len // group_size
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def shift(qkv, bsz, q_len, group_size, num_heads, head_dim):
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qkv[:, num_heads // 2:] = qkv[:, num_heads // 2:].roll(-group_size // 2, dims=2)
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qkv = qkv.transpose(1, 2)
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qkv = qkv.reshape(bsz * num_group, group_size, num_heads, head_dim)
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return qkv.transpose(1, 2)
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query_states = shift(query_states, bsz, q_len, group_size, attn_module.num_heads, attn_module.head_dim)
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key_states = shift(key_states, bsz, q_len, group_size, attn_module.num_heads, attn_module.head_dim)
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value_states = shift(value_states, bsz, q_len, group_size, attn_module.num_heads, attn_module.head_dim)
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if attention_mask is not None:
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attention_mask = attention_mask[:, :, :group_size, :group_size].repeat(num_group, 1, 1, 1)
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return query_states, key_states, value_states, attention_mask
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def _postprocess_qkv(attn_module, attn_output, q_len):
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if attn_module.training:
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group_size = int(q_len * attn_module.config.group_size_ratio)
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attn_output = attn_output.transpose(1, 2)
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attn_output = attn_output.reshape(-1, q_len, attn_module.num_heads, attn_module.head_dim)
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# shift back
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attn_output_clone = attn_output.clone()
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attn_output_clone[:, :, attn_module.num_heads // 2:] = attn_output[:, :, attn_module.num_heads // 2:].roll(
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group_size // 2, dims=1)
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attn_output = attn_output_clone
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return attn_output.transpose(1, 2)
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def _postprocess_qkv_fa2(attn_module, attn_output, q_len):
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if attn_module.training:
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group_size = int(q_len * attn_module.config.group_size_ratio)
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attn_output = attn_output.reshape(-1, q_len, attn_module.num_heads, attn_module.head_dim)
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attn_output_clone = attn_output.clone()
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# shift back
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attn_output_clone[:, :, attn_module.num_heads // 2:] = attn_output[:, :, attn_module.num_heads // 2:].roll(
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group_size // 2, dims=1)
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attn_output = attn_output_clone
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return attn_output
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# code borrowed from https://github.com/huggingface/transformers/blob/main/src/transformers/models/llama/modeling_llama.py # noqa
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def eager_forward(
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self,
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hidden_states: torch.Tensor,
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attention_mask: Optional[torch.Tensor] = None,
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position_ids: Optional[torch.LongTensor] = None,
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past_key_value: Optional[Cache] = None,
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output_attentions: bool = False,
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use_cache: bool = False,
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cache_position: Optional[torch.LongTensor] = None,
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position_embeddings: Optional[Tuple[torch.Tensor, torch.Tensor]] = None, # will become mandatory in v4.46
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**kwargs,
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) -> Tuple[torch.Tensor, Optional[torch.Tensor], Optional[Tuple[torch.Tensor]]]:
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bsz, q_len, _ = hidden_states.size()
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if self.config.pretraining_tp > 1:
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key_value_slicing = (self.num_key_value_heads * self.head_dim) // self.config.pretraining_tp
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query_slices = self.q_proj.weight.split((self.num_heads * self.head_dim) // self.config.pretraining_tp, dim=0)
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key_slices = self.k_proj.weight.split(key_value_slicing, dim=0)
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value_slices = self.v_proj.weight.split(key_value_slicing, dim=0)
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query_states = [F.linear(hidden_states, query_slices[i]) for i in range(self.config.pretraining_tp)]
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query_states = torch.cat(query_states, dim=-1)
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key_states = [F.linear(hidden_states, key_slices[i]) for i in range(self.config.pretraining_tp)]
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key_states = torch.cat(key_states, dim=-1)
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value_states = [F.linear(hidden_states, value_slices[i]) for i in range(self.config.pretraining_tp)]
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value_states = torch.cat(value_states, dim=-1)
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else:
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query_states = self.q_proj(hidden_states)
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key_states = self.k_proj(hidden_states)
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value_states = self.v_proj(hidden_states)
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query_states = query_states.view(bsz, q_len, self.num_heads, self.head_dim).transpose(1, 2)
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key_states = key_states.view(bsz, q_len, self.num_key_value_heads, self.head_dim).transpose(1, 2)
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value_states = value_states.view(bsz, q_len, self.num_key_value_heads, self.head_dim).transpose(1, 2)
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if position_embeddings is None:
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logger.warning_once(
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'The attention layers in this model are transitioning from computing the RoPE embeddings internally '
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'through `position_ids` (2D tensor with the indexes of the tokens), to using externally computed '
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'`position_embeddings` (Tuple of tensors, containing cos and sin). In v4.46 `position_ids` will be '
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'removed and `position_embeddings` will be mandatory.')
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cos, sin = self.rotary_emb(value_states, position_ids)
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else:
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cos, sin = position_embeddings
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query_states, key_states = apply_rotary_pos_emb(query_states, key_states, cos, sin)
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if past_key_value is not None:
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# sin and cos are specific to RoPE models; cache_position needed for the static cache
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cache_kwargs = {'sin': sin, 'cos': cos, 'cache_position': cache_position}
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key_states, value_states = past_key_value.update(key_states, value_states, self.layer_idx, cache_kwargs)
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key_states = repeat_kv(key_states, self.num_key_value_groups)
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value_states = repeat_kv(value_states, self.num_key_value_groups)
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# patch position rolling
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query_states, key_states, value_states, causal_mask = _preprocess_qkv(self, query_states, key_states, value_states,
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attention_mask)
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attn_weights = torch.matmul(query_states, key_states.transpose(2, 3)) / math.sqrt(self.head_dim)
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if attention_mask is not None: # no matter the length, we just slice it
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causal_mask = attention_mask[:, :, :, :key_states.shape[-2]]
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attn_weights = attn_weights + causal_mask
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# upcast attention to fp32
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attn_weights = nn.functional.softmax(attn_weights, dim=-1, dtype=torch.float32).to(query_states.dtype)
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attn_weights = nn.functional.dropout(attn_weights, p=self.attention_dropout, training=self.training)
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attn_output = torch.matmul(attn_weights, value_states)
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if attn_output.size() != (bsz, self.num_heads, q_len, self.head_dim):
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raise ValueError(f'`attn_output` should be of size {(bsz, self.num_heads, q_len, self.head_dim)}, but is'
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f' {attn_output.size()}')
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# patch position unrolling
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attn_output = _postprocess_qkv(self, attn_output, q_len)
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attn_output = attn_output.transpose(1, 2).contiguous()
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attn_output = attn_output.reshape(bsz, q_len, -1)
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if self.config.pretraining_tp > 1:
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attn_output = attn_output.split(self.hidden_size // self.config.pretraining_tp, dim=2)
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o_proj_slices = self.o_proj.weight.split(self.hidden_size // self.config.pretraining_tp, dim=1)
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attn_output = sum([F.linear(attn_output[i], o_proj_slices[i]) for i in range(self.config.pretraining_tp)])
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else:
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attn_output = self.o_proj(attn_output)
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if not output_attentions:
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attn_weights = None
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return attn_output, attn_weights, past_key_value
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# code borrowed from https://github.com/huggingface/transformers/blob/main/src/transformers/models/llama/modeling_llama.py # noqa
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def fa2_forward(
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self,
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hidden_states: torch.Tensor,
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attention_mask: Optional[torch.LongTensor] = None,
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position_ids: Optional[torch.LongTensor] = None,
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past_key_value: Optional[Cache] = None,
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output_attentions: bool = False,
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use_cache: bool = False,
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cache_position: Optional[torch.LongTensor] = None,
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position_embeddings: Optional[Tuple[torch.Tensor, torch.Tensor]] = None, # will become mandatory in v4.46
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) -> Tuple[torch.Tensor, Optional[torch.Tensor], Optional[Tuple[torch.Tensor]]]:
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if isinstance(past_key_value, StaticCache):
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raise ValueError(
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'`static` cache implementation is not compatible with `attn_implementation==flash_attention_2` '
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'make sure to use `sdpa` in the mean time, and open an issue at https://github.com/huggingface/transformers'
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)
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output_attentions = False
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bsz, q_len, _ = hidden_states.size()
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query_states = self.q_proj(hidden_states)
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key_states = self.k_proj(hidden_states)
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value_states = self.v_proj(hidden_states)
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# Flash attention requires the input to have the shape
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# batch_size x seq_length x head_dim x hidden_dim
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# therefore we just need to keep the original shape
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query_states = query_states.view(bsz, q_len, self.num_heads, self.head_dim).transpose(1, 2)
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key_states = key_states.view(bsz, q_len, self.num_key_value_heads, self.head_dim).transpose(1, 2)
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value_states = value_states.view(bsz, q_len, self.num_key_value_heads, self.head_dim).transpose(1, 2)
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if position_embeddings is None:
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logger.warning_once(
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'The attention layers in this model are transitioning from computing the RoPE embeddings internally '
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'through `position_ids` (2D tensor with the indexes of the tokens), to using externally computed '
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'`position_embeddings` (Tuple of tensors, containing cos and sin). In v4.46 `position_ids` will be '
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'removed and `position_embeddings` will be mandatory.')
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cos, sin = self.rotary_emb(value_states, position_ids)
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else:
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cos, sin = position_embeddings
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query_states, key_states = apply_rotary_pos_emb(query_states, key_states, cos, sin)
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if past_key_value is not None:
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# sin and cos are specific to RoPE models; cache_position needed for the static cache
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cache_kwargs = {'sin': sin, 'cos': cos, 'cache_position': cache_position}
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key_states, value_states = past_key_value.update(key_states, value_states, self.layer_idx, cache_kwargs)
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# TODO: These transpose are quite inefficient but Flash Attention requires the layout
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# [batch_size, sequence_length, num_heads, head_dim]. We would need to refactor the KV cache
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# to be able to avoid many of these transpose/reshape/view.
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query_states = query_states.transpose(1, 2)
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key_states = key_states.transpose(1, 2)
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value_states = value_states.transpose(1, 2)
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dropout_rate = self.attention_dropout if self.training else 0.0
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# In PEFT, usually we cast the layer norms in float32 for training stability reasons
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# therefore the input hidden states gets silently casted in float32. Hence, we need
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# cast them back in the correct dtype just to be sure everything works as expected.
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# This might slowdown training & inference so it is recommended to not cast the LayerNorms
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# in fp32. (LlamaRMSNorm handles it correctly)
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input_dtype = query_states.dtype
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if input_dtype == torch.float32:
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if torch.is_autocast_enabled():
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target_dtype = torch.get_autocast_gpu_dtype()
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# Handle the case where the model is quantized
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elif hasattr(self.config, '_pre_quantization_dtype'):
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target_dtype = self.config._pre_quantization_dtype
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else:
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target_dtype = self.q_proj.weight.dtype
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logger.warning_once(
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f'The input hidden states seems to be silently casted in float32, this might be related to'
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f' the fact you have upcasted embedding or layer norm layers in float32. We will cast back the input in'
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f' {target_dtype}.')
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query_states = query_states.to(target_dtype)
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key_states = key_states.to(target_dtype)
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value_states = value_states.to(target_dtype)
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# patch position rolling
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query_states, key_states, value_states, attention_mask = _preprocess_qkv_fa2(
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self, query_states, key_states, value_states, attention_mask)
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from transformers.modeling_flash_attention_utils import _flash_attention_forward
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attn_output = _flash_attention_forward(
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query_states,
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key_states,
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value_states,
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attention_mask,
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q_len,
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position_ids=position_ids,
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dropout=dropout_rate,
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sliding_window=getattr(self, 'sliding_window', None),
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use_top_left_mask=self._flash_attn_uses_top_left_mask,
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is_causal=self.is_causal,
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)
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# patch position unrolling
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attn_output = _postprocess_qkv_fa2(self, attn_output, q_len)
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attn_output = attn_output.reshape(bsz, q_len, -1).contiguous()
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attn_output = self.o_proj(attn_output)
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if not output_attentions:
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attn_weights = None
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return attn_output, attn_weights, past_key_value
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# code borrowed from https://github.com/huggingface/transformers/blob/main/src/transformers/models/llama/modeling_llama.py # noqa
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def sdpa_forward(
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self,
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hidden_states: torch.Tensor,
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attention_mask: Optional[torch.Tensor] = None,
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position_ids: Optional[torch.LongTensor] = None,
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past_key_value: Optional[Cache] = None,
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output_attentions: bool = False,
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use_cache: bool = False,
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cache_position: Optional[torch.LongTensor] = None,
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position_embeddings: Optional[Tuple[torch.Tensor, torch.Tensor]] = None, # will become mandatory in v4.46
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**kwargs,
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) -> Tuple[torch.Tensor, Optional[torch.Tensor], Optional[Tuple[torch.Tensor]]]:
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if output_attentions:
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return super().forward(
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hidden_states=hidden_states,
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attention_mask=attention_mask,
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position_ids=position_ids,
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past_key_value=past_key_value,
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output_attentions=output_attentions,
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use_cache=use_cache,
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cache_position=cache_position,
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position_embeddings=position_embeddings,
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)
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bsz, q_len, _ = hidden_states.size()
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query_states = self.q_proj(hidden_states)
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key_states = self.k_proj(hidden_states)
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value_states = self.v_proj(hidden_states)
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query_states = query_states.view(bsz, q_len, self.num_heads, self.head_dim).transpose(1, 2)
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key_states = key_states.view(bsz, q_len, self.num_key_value_heads, self.head_dim).transpose(1, 2)
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value_states = value_states.view(bsz, q_len, self.num_key_value_heads, self.head_dim).transpose(1, 2)
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if position_embeddings is None:
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logger.warning_once(
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'The attention layers in this model are transitioning from computing the RoPE embeddings internally '
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'through `position_ids` (2D tensor with the indexes of the tokens), to using externally computed '
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'`position_embeddings` (Tuple of tensors, containing cos and sin). In v4.46 `position_ids` will be '
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'removed and `position_embeddings` will be mandatory.')
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cos, sin = self.rotary_emb(value_states, position_ids)
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else:
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cos, sin = position_embeddings
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query_states, key_states = apply_rotary_pos_emb(query_states, key_states, cos, sin)
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if past_key_value is not None:
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# sin and cos are specific to RoPE models; cache_position needed for the static cache
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cache_kwargs = {'sin': sin, 'cos': cos, 'cache_position': cache_position}
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key_states, value_states = past_key_value.update(key_states, value_states, self.layer_idx, cache_kwargs)
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key_states = repeat_kv(key_states, self.num_key_value_groups)
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value_states = repeat_kv(value_states, self.num_key_value_groups)
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causal_mask = attention_mask
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if attention_mask is not None:
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causal_mask = causal_mask[:, :, :, :key_states.shape[-2]]
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if query_states.device.type == 'cuda' and causal_mask is not None:
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query_states = query_states.contiguous()
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key_states = key_states.contiguous()
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value_states = value_states.contiguous()
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is_causal = True if causal_mask is None and q_len > 1 else False
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# patch position rolling
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query_states, key_states, value_states, causal_mask = _preprocess_qkv(self, query_states, key_states, value_states,
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causal_mask)
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attn_output = torch.nn.functional.scaled_dot_product_attention(
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query_states,
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key_states,
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value_states,
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attn_mask=causal_mask,
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dropout_p=self.attention_dropout if self.training else 0.0,
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is_causal=is_causal,
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)
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# patch position unrolling
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attn_output = _postprocess_qkv(self, attn_output, q_len)
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attn_output = attn_output.transpose(1, 2).contiguous()
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|
attn_output = attn_output.view(bsz, q_len, -1)
|
|
|
|
attn_output = self.o_proj(attn_output)
|
|
|
|
return attn_output, None, past_key_value
|
|
|
|
|
|
def replace_llama_attn(model: nn.Module):
|
|
layers = None
|
|
for module in model.modules():
|
|
if isinstance(module, torch.nn.ModuleList):
|
|
layers = module
|
|
break
|
|
assert layers is not None
|
|
for idx, m in enumerate(layers):
|
|
if model.config._attn_implementation == 'flash_attention_2':
|
|
cuda_major, cuda_minor = torch.cuda.get_device_capability()
|
|
if cuda_major < 8:
|
|
logger.warn(
|
|
'Flash attention is only supported on A100 or H100 GPU during training due to head dim > 64 backward.' # noqa
|
|
'ref: https://github.com/HazyResearch/flash-attention/issues/190#issuecomment-1523359593')
|
|
m.self_attn.forward = MethodType(fa2_forward, m.self_attn)
|
|
elif model.config._attn_implementation == 'eager':
|
|
m.self_attn.forward = MethodType(eager_forward, m.self_attn)
|
|
elif model.config._attn_implementation == 'sdpa':
|
|
m.self_attn.forward = MethodType(sdpa_forward, m.self_attn)
|