MiniGPT-4/minigpt4/models/moe/test_moe_layer.py

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import copy
import pickle
import torch
import torch.nn as nn
import torch.nn.functional as F
import copy
import pickle
import torch
import torch.nn as nn
import torch.nn.functional as F
class MoELayer(nn.Module):
def __init__(self, hidden_size, expert, num_experts, route_method, topk=1, use_balance_loss=True, weight_type='raw_prob, topk(softmax)'):
# remove hash list
nn.Module.__init__(self)
self.num_experts = num_experts
self.experts = nn.ModuleList([copy.deepcopy(expert) for i in range(num_experts)])
self.route_method = route_method
self.topk = topk
self.use_balance_loss = use_balance_loss
self.weight_type = weight_type
if route_method in ["gate-token", "gate-sentence"]:
self.gate = nn.Linear(hidden_size, num_experts, bias=False).float()
elif route_method in ["gate-sentence-post"]:
gate = nn.Linear(hidden_size, 1, bias=False).float()
# self.gates = nn.ModuleList([copy.deepcopy(gate) for i in range(num_experts)])
self.gate = gate
else:
raise KeyError("Routing method not supported.")
def _balancing_loss(self, prob_gate, num_tokens):
# From MOEBERT
# compute the load balancing loss
# prob_gate是 [bz, num_expert]每个样本被分配给每个expert的概率
# 等价于 VMOE 中 _gshard_auxiliary_loss
P = prob_gate.mean(0) # torch.Size([num_expert]) 每个expert被分配到样本的平均概率
temp = num_tokens.float()
f = temp / temp.sum(0, keepdim=True) # 每个expert被分配的sample比例
balance_loss = self.num_experts * torch.sum(P * f)
return balance_loss
def _importance_auxiliary_loss(self, prob_gate):
# From VMOE
# _importance_auxiliary_loss
axis = tuple(range(prob_gate.ndim - 1)) # All except last.
importance_per_expert = torch.sum(prob_gate, dim=axis)
std_importance_per_expert = torch.std(importance_per_expert)
mean_importance_per_expert = torch.mean(importance_per_expert)
# Compute coefficient of variation (i.e. std/mean) squared.
return (std_importance_per_expert / mean_importance_per_expert)**2
def _forward_gate_token(self, x):
bsz, seq_len, dim = x.size()
x = x.view(-1, dim)
logits_gate = self.gate(x)
prob_gate = F.softmax(logits_gate, dim=-1)
gate = torch.argmax(prob_gate, dim=-1)
order = gate.argsort(0)
num_tokens = F.one_hot(gate, self.num_experts).gt(0).sum(0)
gate_load = num_tokens.clone()
x = x[order] # reorder according to expert number
x = x.split(num_tokens.tolist(), dim=0) # a list of length self.num_experts
# compute the load balancing loss
P = prob_gate.mean(0)
temp = num_tokens.float()
f = temp / temp.sum(0, keepdim=True)
balance_loss = self.num_experts * torch.sum(P * f)
prob_gate = prob_gate.gather(dim=1, index=gate.unsqueeze(1))
prob_gate = prob_gate[order]
prob_gate = prob_gate.split(num_tokens.tolist(), dim=0)
def forward_expert(input_x, prob_x, expert_idx):
input_x = self.experts[expert_idx].forward(input_x)
input_x = input_x * prob_x
return input_x
x = [forward_expert(x[i], prob_gate[i], i) for i in range(self.num_experts)]
x = torch.vstack(x)
x = x[order.argsort(0)] # restore original order
x = x.view(bsz, seq_len, dim)
return x, balance_loss, gate_load
def _forward_gate_sentence_post(self, x, attention_mask):
"""
x: query_attention_output; torch.Size([bz, 32, 768])
attention_mask: torch.ones([bz, 32])
bz = 4
x = torch.randn(bz,32,768)
attention_mask = torch.ones([bz, 32])
"""
# Prepare Input x
attention_mask = torch.ones(attention_mask.shape[0], attention_mask.shape[1]).to(x.device)
x_masked = x * attention_mask.unsqueeze(-1) # torch.Size([bz, 32, 768])
# FeedForward(x) & Forward Gate
outputs = list()
logits_gate_lst = list()
for expert_idx in range(self.num_experts):
output_x = self.experts[expert_idx].forward(x_masked)
outputs.append(output_x.unsqueeze(0))
output_x_aver = torch.mean(output_x, dim=1)
# gate_acore = self.gates[expert_idx](output_x_aver)
gate_score = self.gate(output_x_aver)
logits_gate_lst.append(gate_score)
candidate_output = torch.cat(outputs) # torch.Size([num_expert, bz, 32, 768])
logits_gate = torch.cat(logits_gate_lst,dim=1)# torch.Size([bz, num_expert])
# Probabilities for each sample of what expert it should be sent to.
prob_gate = F.softmax(logits_gate, dim=-1) # torch.Size([bz, num_experts])
if 'softmax(topk)' in self.weight_type:
prob_gate1, gate = torch.topk(logits_gate, self.topk, dim=1)
select_prob_gate = F.softmax(prob_gate1, dim=-1)
else:
select_prob_gate, gate = torch.topk(prob_gate, self.topk, dim=1) # gate, 每个样本被分配的expert: torch.Size([bz, topk])
# Calculate Balancing Loss
if self.use_balance_loss:
num_sentences = F.one_hot(gate, self.num_experts).sum(1).gt(0).sum(0) # 每个expert被分配的样本数 torch.Size([num_expert])
balance_loss = self._balancing_loss(prob_gate, num_sentences)
else:
balance_loss = 0.0
# Calculate Importance Loss
importance_loss = self._importance_auxiliary_loss(prob_gate)
# Reshap Prob_gate & Gate
# expert_mask: [batch_size, topk, num_experts]
# expert_gate: [batch_size, topk, num_experts]
# combine_tensor: [batch_size, num_experts]
expert_mask = F.one_hot(gate, self.num_experts)
expert_gate = select_prob_gate.unsqueeze(-1) * expert_mask
combine_tensor = torch.sum(expert_gate, dim=1)
# combine_tensor = torch.zeros_like(prob_gate)
# combine_tensor.scatter_(1, gate, select_prob_gate) # 等价操作,但可能不可导
candidate_output_ad = torch.permute(candidate_output, (1, 0, 2, 3)) # torch.Size([bz, num_expert, 32, 768])
results = candidate_output_ad * combine_tensor.unsqueeze(-1).unsqueeze(-1) # torch.Size([bz, num_expert, 32, 768])
outputs = torch.sum(results, dim=1) # torch.Size([bz, 32, 768])
import pdb;pdb.set_trace()
return outputs, (balance_loss+importance_loss), combine_tensor
def pre_router(self, x, attention_mask):
# Prepare input x
attention_mask = torch.ones(attention_mask.shape[0], attention_mask.shape[1]).to(x.device)
x_masked = x * attention_mask.unsqueeze(-1) # torch.Size([bz, 32, 768])
x_average = torch.mean(x_masked, dim=1) # torch.Size([bz, 768])
# Forward Gate
# logits_gate: [bz, num_experts]
logits_gate = self.gate(x_average)
# Probabilities for each sample of what expert it should be sent to.
# prob_gate: [bz, num_experts]
prob_gate = F.softmax(logits_gate, dim=-1)
if 'softmax(topk)' in self.weight_type:
prob_gate1, gate = torch.topk(logits_gate, self.topk, dim=1)
select_prob_gate = F.softmax(prob_gate1, dim=-1)
else:
# topk(softmax)
# Get Top-K experts for each sample
# gate: [bz, topk]
# select_prob_gate: [bz, topk]
select_prob_gate, gate = torch.topk(prob_gate, self.topk, dim=1)
# Reshap Prob_gate & Gate
# expert_mask: [batch_size, topk, num_experts]
# expert_gate: [batch_size, topk, num_experts]
# combine_tensor: [batch_size, num_experts]
expert_mask = F.one_hot(gate, self.num_experts)
expert_gate = select_prob_gate.unsqueeze(-1) * expert_mask
combine_tensor = torch.sum(expert_gate, dim=1)
# Calculate Balancing Loss
if self.use_balance_loss:
num_sentences = F.one_hot(gate, self.num_experts).sum(1).gt(0).sum(0) # 每个expert被分配的样本数 torch.Size([num_expert])
balance_loss = self._balancing_loss(prob_gate, num_sentences)
else:
balance_loss = 0.0
# Calculate Importance Loss
importance_loss = self._importance_auxiliary_loss(prob_gate)
import pdb; pdb.set_trace()
return expert_mask, combine_tensor, balance_loss, importance_loss
def _forward_gate_sentence(self, x, attention_mask):
"""
x: query_attention_output , torch.Size([bz, 32, 768])
attention_mask: torch.ones([bz, 32])
### Notice:
the raw version of expert_attention_mask is the extended_attention_mask,
which will be add to attention_score directly
the values of extended_attention_mask are -0.0 or -10000
it should be adjust to 1/0 version to be processed by experts
"""
# Forward Router
expert_mask, combine_tensor, balance_loss, importance_loss = self.pre_router(x, attention_mask)
# Forward Expert FFN
result = []
for expert_idx in range(self.num_experts):
output_x = self.experts[expert_idx].forward(x)
result.append(output_x.unsqueeze(0))
expert_output = torch.cat(result).permute(1,0,2,3) # torch.Size([batch_size, num_expert, num_tokens, hidden_states])
# multiply outputs of experts by the routing probability
expert_outputs_combined = expert_output * combine_tensor.unsqueeze(-1).unsqueeze(-1) # torch.Size([batch_size, num_expert, num_tokens, hidden_states])
outputs = torch.sum(expert_outputs_combined, dim=1) # torch.Size([batch_size, num_tokens, hidden_states])
import pdb; pdb.set_trace()
return outputs, (balance_loss+importance_loss), combine_tensor
def forward(self, x, attention_mask):
if self.route_method == "gate-token":
x, balance_loss, gate_load = self._forward_gate_token(x)
elif self.route_method == "gate-sentence":
x, balance_loss, gate_load = self._forward_gate_sentence(x, attention_mask)
elif self.route_method == "gate-sentence-post":
x, balance_loss, gate_load = self._forward_gate_sentence_post(x, attention_mask)
else:
raise KeyError("Routing method not supported.")
# import pdb; pdb.set_trace()
return x, balance_loss, gate_load
if __name__ == '__main__':
import sys
sys.path.append("/mnt/pfs-guan-ssai/nlu/wanghanzi/multimodal/PromptMoE")
from minigpt4.models.QformerRouteMoE import BertConfig
from minigpt4.models.QformerRouteMoE import FeedForward
from minigpt4.models.moe.utils import (
moe_layer_judge,
)
vision_width = 1408
cross_attention_freq = 2
num_query_token = 32
# init_QformerMoE
config = BertConfig.from_pretrained("/mnt/pfs-guan-ssai/nlu/wanghanzi/models/bert-base-uncased")
config.encoder_width = vision_width
# insert cross-attention layer every other block
config.add_cross_attention = True
config.cross_attention_freq = cross_attention_freq
config.query_length = num_query_token
config.moebert_expert_num = 3
config.moebert_num_beams = 2
config.moebert_route_method = 'gate-sentence-post'
config.moe_topk = 1
config.use_balance_loss = False
# config.moe_weight_type = 'raw_prob, softmax(topk)'
config.moe_weight_type = 'raw_prob, topk(softmax)'
batch_size = 4
x2 = torch.randn(batch_size, 32, 768)
beam_scores, expert_route = None, None
for layer_num in [6, 8, 10]:
layer_judge = moe_layer_judge(layer_num)
ffn = FeedForward(config)
gate = nn.Linear(768, config.moebert_expert_num, bias=False).float()
experts_moe = MoELayer(
hidden_size=config.hidden_size,
expert=ffn,
num_experts=config.moebert_expert_num,
route_method=config.moebert_route_method,
topk=config.moe_topk,
use_balance_loss=config.use_balance_loss,
weight_type=config.moe_weight_type,
)
attn_mask = torch.ones([batch_size, 32])
layer_output = experts_moe(x2, attn_mask)
hidden_states3, aux_loss, combine_tensor = layer_output
print(combine_tensor)
print(aux_loss)
x2 = hidden_states3
print("------------------------------------")
import pdb; pdb.set_trace()