print('Using {} dataloader workers every process'.format(nw)) #获取一批批的数据 train_loader = torch.utils.data.DataLoader(train_dataset, batch_size=batch_size, shuffle=True, num_workers=0) #num_workers表示加载数据需要的线程个数 0表示使用主线程加载数据 validate_dataset = datasets.ImageFolder(r...
multiprocessing.Process类就是构造进程的类,这里根据设定的进程数来启动,然后赋值给self.workers。接下来的一个for循环就通过调用start方法依次启动self.workers中的进程。接下来关于self.pin_memory的判断语句,该判断语句内部主要是实现了多线程操作。self.pin_memory的含义在前面已经介绍过了,当为True的时候,就会把数据...
6、sampler：和shuffle是互斥的，一般默认即可。7、num_workers：这个参数必须大于等于0，0的话表示数据...
num_workers用于设置有多少个进程。然后每个进程都在后台做预取。取到了就用pipe发给主进程。
( dataset, batch_size=20, shuffle=True, num_workers=4, collate_fn=utils.collate_fn) data_loader_val = torch.utils.data.DataLoader( dataset_validation, batch_size=10, shuffle=False, num_workers=4, collate_fn=utils.collate_fn) # get the model using our helper function #model = get_...
num_workers (int, optional): how many subprocesses to use for data loading. 0 means that the data will be loaded in the main process. (default: 0) collate_fn (callable, optional): merges a list of samples to form a mini-batch. ...
self._iterator._reset(self) return self._iterator else: return self._get_iterator()def _get_iterator(self) -> "_BaseDataLoaderIter": if self.num_workers == 0 or self.num_workers == 1: return _SingleProcessDataLoaderIter(self) else: self.check_worker_number_rationali...
Is there an opportunity cost to picking large datasets in the main process, compared to worker process? Author slevang Nov 6, 2024 We would want to skip it if we're in a fork context. But other than that, no, because everything has to be pickled to be sent to the workers. It's...
Fixes #105203 and is a follow up PR to #141833 When in_order is True (the default), tasks are given out to workers in a round robin fashion. When in_order is False this is no longer needed, as we g...
num_workers (int, optional): 这个参数决定了有几个进程来处理data loading。0意味着所有的数据都会被load进主进程。(默认为0) collate_fn (callable, optional): 将一个list的sample组成一个mini-batch的函数 pin_memory (bool, optional): 如果设置为True,那么data loader将会在返回它们之前,将tensors拷贝到...