#!/usr/bin/env python import os import json import torch import numpy as np import queue import pprint import random import argparse import importlib import threading import traceback import torch.distributed as dist import torch.multiprocessing as mp from tqdm import tqdm from torch.multiprocessing import Process, Queue, Pool from core.dbs import datasets from core.utils import stdout_to_tqdm from core.config import SystemConfig from core.sample import data_sampling_func from core.nnet.py_factory import NetworkFactory torch.backends.cudnn.enabled = True torch.backends.cudnn.benchmark = True # 命令行参数 def parse_args(): parser = argparse.ArgumentParser(description="Training Script") parser.add_argument("cfg_file", help="config file", type=str) #训练用的配置文件 parser.add_argument("--iter", dest="start_iter", help="train at iteration i", default=0, type=int) #指定训练从第i次迭代开始 parser.add_argument("--workers", default=4, type=int) parser.add_argument("--initialize", action="store_true") parser.add_argument("--distributed", action="store_true") # 分布式训练 parser.add_argument("--world-size", default=-1, type=int, help="number of nodes of distributed training") # 分布式节点的数量 parser.add_argument("--rank", default=0, type=int, help="node rank for distributed training") # 分布式训练节点的等级 parser.add_argument("--dist-url", default=None, type=str, help="url used to set up distributed training") parser.add_argument("--dist-backend", default="nccl", type=str) args = parser.parse_args() return args def prefetch_data(system_config, db, queue, sample_data, data_aug): ind = 0 print("start prefetching data...") # 用pid[进程id]做随机数种子 np.random.seed(os.getpid()) while True: try: data, ind = sample_data(system_config, db, ind, data_aug=data_aug) queue.put(data) except Exception as e: traceback.print_exc() raise e def _pin_memory(ts): if type(ts) is list: return [t.pin_memory() for t in ts] return ts.pin_memory() def pin_memory(data_queue, pinned_data_queue, sema): while True: data = data_queue.get() data["xs"] = [_pin_memory(x) for x in data["xs"]] data["ys"] = [_pin_memory(y) for y in data["ys"]] pinned_data_queue.put(data) if sema.acquire(blocking=False): return def init_parallel_jobs(system_config, dbs, queue, fn, data_aug): tasks = [Process(target=prefetch_data, args=(system_config, db, queue, fn, data_aug)) for db in dbs] for task in tasks: task.daemon = True task.start() return tasks def terminate_tasks(tasks): for task in tasks: task.terminate() # 训练函数(训练数据,验证数据,系统参数,模型,参数) def train(training_dbs, validation_db, system_config, model, args): # reading arguments from command start_iter = args.start_iter distributed = args.distributed world_size = args.world_size initialize = args.initialize gpu = args.gpu rank = args.rank # reading arguments from json file batch_size = system_config.batch_size learning_rate = system_config.learning_rate max_iteration = system_config.max_iter pretrained_model = system_config.pretrain stepsize = system_config.stepsize snapshot = system_config.snapshot val_iter = system_config.val_iter display = system_config.display decay_rate = system_config.decay_rate stepsize = system_config.stepsize print("Process {}: building model...".format(rank)) nnet = NetworkFactory(system_config, model, distributed=distributed, gpu=gpu) # 构建模型 if initialize: nnet.save_params(0) exit(0) # 开4个队列去存数据 # queues storing data for training training_queue = Queue(system_config.prefetch_size) validation_queue = Queue(5) # queues storing pinned data for training pinned_training_queue = queue.Queue(system_config.prefetch_size) pinned_validation_queue = queue.Queue(5) # allocating resources for parallel reading training_tasks = init_parallel_jobs(system_config, training_dbs, training_queue, data_sampling_func, True) if val_iter: validation_tasks = init_parallel_jobs(system_config, [validation_db], validation_queue, data_sampling_func, False) training_pin_semaphore = threading.Semaphore() validation_pin_semaphore = threading.Semaphore() training_pin_semaphore.acquire() validation_pin_semaphore.acquire() training_pin_args = (training_queue, pinned_training_queue, training_pin_semaphore) training_pin_thread = threading.Thread(target=pin_memory, args=training_pin_args) training_pin_thread.daemon = True training_pin_thread.start() validation_pin_args = (validation_queue, pinned_validation_queue, validation_pin_semaphore) validation_pin_thread = threading.Thread(target=pin_memory, args=validation_pin_args) validation_pin_thread.daemon = True validation_pin_thread.start() # 看是否有预训练的模型 if pretrained_model is not None: if not os.path.exists(pretrained_model): raise ValueError("pretrained model does not exist") print("Process {}: loading from pretrained model".format(rank)) nnet.load_pretrained_params(pretrained_model) # 看有没有开始的迭代器 if start_iter: nnet.load_params(start_iter) learning_rate /= (decay_rate ** (start_iter // stepsize)) nnet.set_lr(learning_rate) print("Process {}: training starts from iteration {} with learning_rate {}".format(rank, start_iter + 1, learning_rate)) else: nnet.set_lr(learning_rate) # 训练模型 if rank == 0: print("training start...") nnet.cuda() nnet.train_mode() # with stdout_to_tqdm() as save_stdout: # Tqdm 是一个快速,可扩展的Python进度条,可以在 Python 长循环中添加一个进度提示信息 for iteration in tqdm(range(start_iter + 1, max_iteration + 1), file=save_stdout, ncols=80): training = pinned_training_queue.get(block=True) training_loss = nnet.train(**training) # 如果设置了display的步长,我们在步长整数倍时展示损失函数的值 if display and iteration % display == 0: print("Process {}: training loss at iteration {}: {}".format(rank, iteration, training_loss.item())) del training_loss # 如果设置了变量迭代器步长[这边是验证集了] if val_iter and validation_db.db_inds.size and iteration % val_iter == 0: nnet.eval_mode() validation = pinned_validation_queue.get(block=True) validation_loss = nnet.validate(**validation) print("Process {}: validation loss at iteration {}: {}".format(rank, iteration, validation_loss.item())) nnet.train_mode() # 快照步长 if iteration % snapshot == 0 and rank == 0: nnet.save_params(iteration) # 学习率更新步长 if iteration % stepsize == 0: learning_rate /= decay_rate nnet.set_lr(learning_rate) # sending signal to kill the thread # 杀掉进程的消息 training_pin_semaphore.release() validation_pin_semaphore.release() # terminating data fetching processes # 结束任务的消息 terminate_tasks(training_tasks) terminate_tasks(validation_tasks) # 主函数main def main(gpu, ngpus_per_node, args): # 将gpu复制到args里 args.gpu = gpu if args.distributed: args.rank = args.rank * ngpus_per_node + gpu dist.init_process_group(backend=args.dist_backend, init_method=args.dist_url, world_size=args.world_size, rank=args.rank) rank = args.rank # 读取配置文件 # cfg_file是必须传入的要训练模型名字 cfg_file = os.path.join("./configs", args.cfg_file + ".json") #配置文件的路径! with open(cfg_file, "r") as f: config = json.load(f) # 上面的读取的单独模型配置的"system"里添加一项 config["system"]["snapshot_name"] = args.cfg_file # 更新参数配置 system_config = SystemConfig().update_config(config["system"]) # 模型的名字作为模型导入 model_file = "core.models.{}".format(args.cfg_file) # 模型路径 model_file = importlib.import_module(model_file) # importlib.import_module,导入模型。 model = model_file.model() # 从i系统配置里取出的参数 train_split = system_config.train_split val_split = system_config.val_split print("Process {}: loading all datasets...".format(rank)) # 用了几个worker dataset = system_config.dataset workers = args.workers print("Process {}: using {} workers".format(rank, workers)) training_dbs = [datasets[dataset](config["db"], split=train_split, sys_config=system_config) for _ in range(workers)] ## 涉及图片读取,标注文件读取 validation_db = datasets[dataset](config["db"], split=val_split, sys_config=system_config) ## 打印1次“start prefetching data...” if rank == 0: print("system config...") pprint.pprint(system_config.full) # 打印system config print("db config...") pprint.pprint(training_dbs[0].configs) # 打印db config print("len of db: {}".format(len(training_dbs[0].db_inds))) #训练集的图片数 print("distributed: {}".format(args.distributed)) #是否分布式训练 # 调用train训练函数 train(training_dbs, validation_db, system_config, model, args) if __name__ == "__main__": # 先parse参数 args = parse_args() # 分布式的选项以及节点数量 distributed = args.distributed world_size = args.world_size # 分布式节点必须大于0 if distributed and world_size < 0: raise ValueError("world size must be greater than 0 in distributed training") # 每个节点上的gpu的数量 ngpus_per_node = torch.cuda.device_count() # torch 下分布式运行 if distributed: args.world_size = ngpus_per_node * args.world_size mp.spawn(main, nprocs=ngpus_per_node, args=(ngpus_per_node, args)) else: main(None, ngpus_per_node, args)