[LLM] Optimize kv_cache for gptj model family (#9010)

* optimize gptj model family attention

* add license and comment for dolly-model

* remove xpu mentioned

* remove useless info

* code sytle

* style fix

* code style in gptj fix

* remove gptj arch

* move apply_rotary_pos_emb into utils

* kv_seq_length update

* use hidden_states instead of query layer to reach batch size
This commit is contained in:
SONG Ge 2023-09-21 10:42:08 +08:00 committed by GitHub
parent 3913ba4577
commit fa47967583
3 changed files with 210 additions and 0 deletions

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@ -173,6 +173,14 @@ def optimize(model):
module.SelfAttention,
chatglm_attention_forward
)
elif "gptj" in model.config.model_type:
# dolly-v1-6b
modeling_module_name = model.__class__.__module__
module = importlib.import_module(modeling_module_name)
from bigdl.llm.transformers.models.gptj import gptj_attention_forward
convert_forward(model,
module.GPTJAttention,
gptj_attention_forward)
elif "bloom" in model.config._name_or_path:
modeling_module_name = model.__class__.__module__
module = importlib.import_module(modeling_module_name)

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@ -0,0 +1,189 @@
#
# Copyright 2016 The BigDL Authors.
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
# http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.
#
# This file is adapted from
# https://github.com/huggingface/transformers/blob/main/src/transformers/models/gptj/modeling_gptj.py
#
import torch
from typing import Optional, Tuple, Union
from bigdl.llm.transformers.models.utils import create_kv_cache, append_kv_cache, \
apply_rotary_pos_emb
from transformers.utils.import_utils import is_torch_fx_proxy
KV_CACHE_ALLOC_BLOCK_LENGTH = 256
def _get_embed_positions(self, position_ids):
embed_positions = self.embed_positions
if embed_positions.device != position_ids.device:
embed_positions = embed_positions.to(position_ids.device)
self.embed_positions = embed_positions
return embed_positions.repeat(position_ids.shape[0], 1, 1)
def _attn(
self,
query,
key,
value,
attention_mask=None,
head_mask=None,
):
# compute causal mask from causal mask buffer
query_length, key_length = query.size(-2), key.size(-2)
causal_mask = self.bias[:, :, key_length - query_length: key_length, :key_length]
# Keep the attention weights computation in fp32 to avoid overflow issues
query = query.to(torch.float32)
key = key.to(torch.float32)
attn_weights = torch.matmul(query, key.transpose(-1, -2))
mask_value = torch.finfo(attn_weights.dtype).min
# Need to be a tensor, otherwise we get error:
# `RuntimeError: expected scalar type float but found double`.
# Need to be on the same device, otherwise `RuntimeError: ..., x and y to be on the same device`
mask_value = torch.tensor(mask_value, dtype=attn_weights.dtype).to(attn_weights.device)
attn_weights = torch.where(causal_mask, attn_weights, mask_value)
attn_weights = attn_weights / self.scale_attn
if attention_mask is not None:
# Apply the attention mask
attn_weights = attn_weights + attention_mask
attn_weights = nn.functional.softmax(attn_weights, dim=-1)
attn_weights = attn_weights.to(value.dtype)
attn_weights = self.attn_dropout(attn_weights)
# Mask heads if we want to
if head_mask is not None:
attn_weights = attn_weights * head_mask
attn_output = torch.matmul(attn_weights, value)
return attn_output, attn_weights
def gptj_attention_forward(
self,
hidden_states: torch.FloatTensor,
layer_past: Optional[Tuple[torch.Tensor]] = None,
attention_mask: Optional[torch.FloatTensor] = None,
position_ids: Optional[torch.LongTensor] = None,
head_mask: Optional[torch.FloatTensor] = None,
use_cache: Optional[bool] = False,
output_attentions: Optional[bool] = False,
) -> Union[
Tuple[torch.Tensor, Tuple[torch.Tensor]],
Optional[Tuple[torch.Tensor, Tuple[torch.Tensor], Tuple[torch.Tensor, ...]]],
]:
query = self.q_proj(hidden_states)
key = self.k_proj(hidden_states)
value = self.v_proj(hidden_states)
query = self._split_heads(query, self.num_attention_heads, self.head_dim, True)
key = self._split_heads(key, self.num_attention_heads, self.head_dim, True)
value = self._split_heads(value, self.num_attention_heads, self.head_dim, False)
if is_torch_fx_proxy(position_ids) or torch.jit.is_tracing():
# The logic to conditionally copy to GPU could not be traced, so we do this
# every time in the torch.fx case
embed_positions = get_embed_positions(self.embed_positions, position_ids)
else:
embed_positions = self._get_embed_positions(position_ids)
repeated_position_ids = position_ids.unsqueeze(-1).repeat(1, 1, embed_positions.shape[-1])
sincos = torch.gather(embed_positions, 1, repeated_position_ids)
sin, cos = torch.split(sincos, sincos.shape[-1] // 2, dim=-1)
if self.rotary_dim is not None:
k_rot = key[:, :, :, : self.rotary_dim]
k_pass = key[:, :, :, self.rotary_dim:]
q_rot = query[:, :, :, : self.rotary_dim]
q_pass = query[:, :, :, self.rotary_dim:]
q_rot, k_rot = apply_rotary_pos_emb(q_rot, k_rot, cos, sin, position_ids, "gptj")
key = torch.cat([k_rot, k_pass], dim=-1)
query = torch.cat([q_rot, q_pass], dim=-1)
else:
query, key = apply_rotary_pos_emb(query, k_rot, cos, sin, position_ids, "gptj")
batch_size, q_len, _ = hidden_states.size()
key = key.permute(0, 2, 1, 3).contiguous()
query = query.permute(0, 2, 1, 3).contiguous()
kv_seq_len = key.size(-2)
device = hidden_states.device
if layer_past is not None:
kv_seq_len += layer_past[0].size(-2)
if layer_past is not None:
cache_k = layer_past[0]
cache_v = layer_past[1]
cache_k = cache_k.permute(0, 2, 1, 3)
cache_v = cache_v.permute(0, 2, 1, 3)
past_length = cache_k.size(2)
if cache_k.stride()[1] <= cache_k.size(2) * cache_k.size(3):
new_cache_k, new_cache_v = create_kv_cache(batch_size,
self.num_attention_heads,
self.head_dim,
past_length,
kv_seq_len + KV_CACHE_ALLOC_BLOCK_LENGTH,
dtype=cache_k.dtype,
device=device)
new_cache_k[:] = cache_k
new_cache_v[:] = cache_v
cache_k = new_cache_k
cache_v = new_cache_v
key, value = append_kv_cache(cache_k, cache_v, key, value)
elif use_cache:
key_cache, value_cache = create_kv_cache(batch_size,
self.num_attention_heads,
self.head_dim,
kv_seq_len,
kv_seq_len + KV_CACHE_ALLOC_BLOCK_LENGTH,
dtype=key.dtype,
device=device)
key_cache[:] = key
value_cache[:] = value
key = key_cache
value = value_cache
if use_cache is True:
present = (key.permute(0, 2, 1, 3), value.permute(0, 2, 1, 3))
else:
present = None
# compute self-attention: V x Softmax(QK^T)
attn_output, attn_weights = self._attn(query, key, value, attention_mask, head_mask)
attn_output = self._merge_heads(attn_output, self.num_attention_heads, self.head_dim)
attn_output = self.out_proj(attn_output)
attn_output = self.resid_dropout(attn_output)
outputs = (attn_output, present)
if output_attentions:
outputs += (attn_weights,)
return outputs # a, present, (attentions)

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@ -58,6 +58,13 @@ def rotate_half(x):
return torch.cat((-x2, x1), dim=-1)
def rotate_every_two(x):
x1 = x[:, :, :, ::2]
x2 = x[:, :, :, 1::2]
x = torch.stack((-x2, x1), dim=-1)
return x.flatten(-2) # in einsum notation: rearrange(x, '... d j -> ... (d j)')
def apply_rotary_pos_emb(q, k, cos, sin, position_ids, model_family):
if model_family in ["llama", "baichuan"]:
# The first two dimensions of cos and sin are always 1, so we can `squeeze` them.
@ -68,6 +75,12 @@ def apply_rotary_pos_emb(q, k, cos, sin, position_ids, model_family):
q_embed = (q * cos) + (rotate_half(q) * sin)
k_embed = (k * cos) + (rotate_half(k) * sin)
return q_embed, k_embed
elif model_family == "gptj":
cos = torch.repeat_interleave(cos[:, :, None, :], 2, 3)
sin = torch.repeat_interleave(sin[:, :, None, :], 2, 3)
q_embed = (q * cos) + (rotate_every_two(q) * sin)
k_embed = (k * cos) + (rotate_every_two(k) * sin)
return q_embed, k_embed
elif model_family == "gpt_neox":
gather_indices = position_ids[:, None, :, None] # [bs, 1, seq_len, 1]
gather_indices = gather_indices.repeat(1, cos.shape[1], 1, cos.shape[3])