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vllm-npu-plugin/vllm_npu/ops/expert_load_balancer.py
2026-02-10 23:08:39 +08:00

120 lines
4.7 KiB
Python

import json
import random
from typing import Dict, List
import torch
import torch.distributed as dist
class ExpertLoadBalancer(object):
def __init__(self, expert_map_path, num_experts):
self.expert_map_path = expert_map_path
self.num_experts = num_experts
self.tensor_data = []
self.expert_map_tensor, self.layers_num, self.ranks_num = (
self._expert_file_to_tensor())
self.global_expert_num = num_experts + self.get_global_redundant_expert_num(
)
self.expert_placement_map = self.generate_expert_placement_map()
def _expert_file_to_tensor(self):
with open(self.expert_map_path, "r") as f:
data = json.load(f)
layers_num = data["moe_layer_count"]
gpus_num = data["layer_list"][0]["device_count"]
for layer in data["layer_list"]:
device_data = []
for device in layer["device_list"]:
device_data.append(device["device_expert"])
self.tensor_data.append(device_data)
expert_map_tensor = torch.tensor(self.tensor_data, dtype=torch.int32)
return expert_map_tensor, layers_num, gpus_num
def generate_index_dicts(self, tensor_2d):
dict_list = []
current_idx = 0
for row in tensor_2d:
value_to_index = {}
for i in range(row.size(0)):
value = row[i].item()
value_to_index[value] = current_idx + i
dict_list.append(value_to_index)
current_idx += row.size(0)
return dict_list
def generate_expert_placement_map(self):
expert_placement_map = torch.full(
(self.layers_num, self.ranks_num, self.num_experts),
-1,
dtype=torch.int32,
)
for layer_id in range(self.layers_num):
for gpu_id in range(self.ranks_num):
e_ids = self.expert_map_tensor[layer_id, gpu_id]
expert_placement_map[layer_id, gpu_id,
e_ids] = torch.arange(len(e_ids),
dtype=torch.int32)
return expert_placement_map
def generate_log2phy_expert_map(self, layer_id):
concatenated = torch.flatten(self.expert_map_tensor[layer_id])
rank_expert_to_global = self.generate_index_dicts(
self.expert_map_tensor[layer_id])
result_dict: Dict[int, List[int]] = {}
for idx, value in enumerate(concatenated):
key = value.item()
if key not in result_dict:
result_dict[key] = []
result_dict[key].append(idx)
log2phy_map = torch.full((self.ranks_num, self.num_experts),
-1,
dtype=torch.int32)
for rank in range(self.ranks_num):
for key in result_dict:
indices_in_concat = result_dict[key]
if key in rank_expert_to_global[rank]:
log2phy_map[rank][key] = rank_expert_to_global[rank][key]
else:
chosen_index = random.choice(indices_in_concat)
log2phy_map[rank][key] = chosen_index
return log2phy_map
def get_rank_placement_map(self, layer_id, rank_id):
layer_expert_map = self.expert_placement_map[layer_id]
rank_expert_map = layer_expert_map[rank_id].to(
torch.npu.current_device())
rank_local_expert_num = torch.sum(torch.ne(rank_expert_map, -1)).item()
return rank_local_expert_num, rank_expert_map
def get_rank_log2phy_map(self, layer_id, rank_id):
layer_log2phy_map = self.generate_log2phy_expert_map(layer_id)
return layer_log2phy_map[rank_id]
def get_global_redundant_expert_num(self):
global_redundant_expert_num = (
len(self.expert_map_tensor[0][0]) * self.ranks_num -
self.num_experts)
return global_redundant_expert_num
def check_expert_map_tensor(self):
if dist.is_initialized():
try:
rank = dist.get_rank()
world_size = dist.get_world_size()
all_expert_maps = [None for _ in range(world_size)]
dist.all_gather_object(all_expert_maps, self.tensor_data)
for rank_id, expert_map_tensor in enumerate(all_expert_maps):
if self.tensor_data != expert_map_tensor:
raise ValueError(
f"The expert map of rank{rank} is not equal to rank{rank_id}"
)
return True
except Exception as e:
raise ValueError(
f"The expert maps of all ranks are inconsistency: {e}")