Remove dataloader v2 usage in data/benchmarks (#1351)

* lint

* run pre-commit again

benchmarks/torchvision_classification/helpers.py

@@ -5,16 +5,13 @@
 # LICENSE file in the root directory of this source tree.
 
 import itertools
-import os
 import random
-from functools import partial
 from pathlib import Path
 
 import torch
 import torch.distributed as dist
 import torchvision
 from PIL import Image
-from torchdata.datapipes.iter import FileLister, IterDataPipe
 
 
 # TODO: maybe infinite buffer can / is already natively supported by torchdata?
@@ -24,26 +21,6 @@
 IMAGENET_TEST_LEN = 50_000
 
 
-class _LenSetter(IterDataPipe):
-    # TODO: Ideally, we woudn't need this extra class
-    def __init__(self, dp, root):
-        self.dp = dp
-
-        if "train" in str(root):
-            self.size = IMAGENET_TRAIN_LEN
-        elif "val" in str(root):
-            self.size = IMAGENET_TEST_LEN
-        else:
-            raise ValueError("oops?")
-
-    def __iter__(self):
-        yield from self.dp
-
-    def __len__(self):
-        # TODO The // world_size part shouldn't be needed. See https://github.com/pytorch/data/issues/533
-        return self.size // dist.get_world_size()
-
-
 def _decode(path, root, category_to_int):
     category = Path(path).relative_to(root).parts[0]
 
@@ -58,22 +35,6 @@ def _apply_tranforms(img_and_label, transforms):
     return transforms(img), label
 
 
-def make_dp(root, transforms):
-
-    root = Path(root).expanduser().resolve()
-    categories = sorted(entry.name for entry in os.scandir(root) if entry.is_dir())
-    category_to_int = {category: i for (i, category) in enumerate(categories)}
-
-    dp = FileLister(str(root), recursive=True, masks=["*.JPEG"])
-
-    dp = dp.shuffle(buffer_size=INFINITE_BUFFER_SIZE).set_shuffle(False).sharding_filter()
-    dp = dp.map(partial(_decode, root=root, category_to_int=category_to_int))
-    dp = dp.map(partial(_apply_tranforms, transforms=transforms))
-
-    dp = _LenSetter(dp, root=root)
-    return dp
-
-
 class PreLoadedMapStyle:
     # All the data is pre-loaded and transformed in __init__, so the DataLoader should be crazy fast.
     # This is just to assess how fast a model could theoretically be trained if there was no data bottleneck at all.
@@ -89,27 +50,6 @@ def __getitem__(self, idx):
         return self.samples[idx % len(self.samples)]
 
 
-class _PreLoadedDP(IterDataPipe):
-    # Same as above, but this is a DataPipe
-    def __init__(self, root, transforms, buffer_size=100):
-        dataset = torchvision.datasets.ImageFolder(root, transform=transforms)
-        self.size = len(dataset)
-        self.samples = [dataset[torch.randint(0, len(dataset), size=(1,)).item()] for i in range(buffer_size)]
-        # Note: the rng might be different across DDP workers so they'll all have different samples.
-        # But we don't care about accuracy here so whatever.
-
-    def __iter__(self):
-        for idx in range(self.size):
-            yield self.samples[idx % len(self.samples)]
-
-
-def make_pre_loaded_dp(root, transforms):
-    dp = _PreLoadedDP(root=root, transforms=transforms)
-    dp = dp.shuffle(buffer_size=INFINITE_BUFFER_SIZE).set_shuffle(False).sharding_filter()
-    dp = _LenSetter(dp, root=root)
-    return dp
-
-
 class MapStyleToIterable(torch.utils.data.IterableDataset):
     # This converts a MapStyle dataset into an iterable one.
     # Not sure this kind of Iterable dataset is actually useful to benchmark. It

benchmarks/torchvision_classification/train.py

@@ -16,7 +16,6 @@
 import torchvision
 import utils
 from torch import nn
-from torchdata.dataloader2 import adapter, DataLoader2, MultiProcessingReadingService
 
 
 def train_one_epoch(model, criterion, optimizer, data_loader, device, epoch, args):
@@ -111,23 +110,19 @@ def create_data_loaders(args):
     train_dir = os.path.join(dataset_dir, "train")
     val_dir = os.path.join(dataset_dir, "val")
 
-    val_resize_size, val_crop_size, train_crop_size = args.val_resize_size, args.val_crop_size, args.train_crop_size
+    val_resize_size, val_crop_size, train_crop_size = (
+        args.val_resize_size,
+        args.val_crop_size,
+        args.train_crop_size,
+    )
 
     if args.no_transforms:
         train_preset = val_preset = helpers.no_transforms
     else:
         train_preset = presets.ClassificationPresetTrain(crop_size=train_crop_size)
         val_preset = presets.ClassificationPresetEval(crop_size=val_crop_size, resize_size=val_resize_size)
 
-    if args.ds_type == "dp":
-        builder = helpers.make_pre_loaded_dp if args.preload_ds else helpers.make_dp
-        train_dataset = builder(train_dir, transforms=train_preset)
-        val_dataset = builder(val_dir, transforms=val_preset)
-
-        train_sampler = val_sampler = None
-        train_shuffle = True
-
-    elif args.ds_type == "iterable":
+    if args.ds_type == "iterable":
         train_dataset = torchvision.datasets.ImageFolder(train_dir, transform=train_preset)
         train_dataset = helpers.MapStyleToIterable(train_dataset, shuffle=True)
 
@@ -149,45 +144,22 @@ def create_data_loaders(args):
     else:
         raise ValueError(f"Invalid value for args.ds_type ({args.ds_type})")
 
-    data_loader_arg = args.data_loader.lower()
-    if data_loader_arg == "v1":
-        train_data_loader = torch.utils.data.DataLoader(
-            train_dataset,
-            batch_size=args.batch_size,
-            shuffle=train_shuffle,
-            sampler=train_sampler,
-            num_workers=args.workers,
-            pin_memory=True,
-            drop_last=True,
-        )
-        val_data_loader = torch.utils.data.DataLoader(
-            val_dataset,
-            batch_size=args.batch_size,
-            sampler=val_sampler,
-            num_workers=args.workers,
-            pin_memory=True,
-        )
-    elif data_loader_arg == "v2":
-        if args.ds_type != "dp":
-            raise ValueError("DataLoader2 only works with datapipes.")
-
-        # Note: we are batching and collating here *after the transforms*, which is consistent with DLV1.
-        # But maybe it would be more efficient to do that before, so that the transforms can work on batches??
-
-        train_dataset = train_dataset.batch(args.batch_size, drop_last=True).collate()
-        train_data_loader = DataLoader2(
-            train_dataset,
-            datapipe_adapter_fn=adapter.Shuffle(),
-            reading_service=MultiProcessingReadingService(num_workers=args.workers),
-        )
-
-        val_dataset = val_dataset.batch(args.batch_size, drop_last=True).collate()  # TODO: Do we need drop_last here?
-        val_data_loader = DataLoader2(
-            val_dataset,
-            reading_service=MultiProcessingReadingService(num_workers=args.workers),
-        )
-    else:
-        raise ValueError(f"invalid data-loader param. Got {args.data_loader}")
+    train_data_loader = torch.utils.data.DataLoader(
+        train_dataset,
+        batch_size=args.batch_size,
+        shuffle=train_shuffle,
+        sampler=train_sampler,
+        num_workers=args.workers,
+        pin_memory=True,
+        drop_last=True,
+    )
+    val_data_loader = torch.utils.data.DataLoader(
+        val_dataset,
+        batch_size=args.batch_size,
+        sampler=val_sampler,
+        num_workers=args.workers,
+        pin_memory=True,
+    )
 
     return train_data_loader, val_data_loader, train_sampler
 
@@ -266,17 +238,47 @@ def get_args_parser(add_help=True):
 
     parser.add_argument("--fs", default="fsx", type=str)
     parser.add_argument("--model", default="resnet18", type=str, help="model name")
-    parser.add_argument("--device", default="cuda", type=str, help="device (Use cuda or cpu Default: cuda)")
     parser.add_argument(
-        "-b", "--batch-size", default=32, type=int, help="images per gpu, the total batch size is $NGPU x batch_size"
+        "--device",
+        default="cuda",
+        type=str,
+        help="device (Use cuda or cpu Default: cuda)",
     )
-    parser.add_argument("--epochs", default=90, type=int, metavar="N", help="number of total epochs to run")
     parser.add_argument(
-        "-j", "--workers", default=12, type=int, metavar="N", help="number of data loading workers (default: 16)"
+        "-b",
+        "--batch-size",
+        default=32,
+        type=int,
+        help="images per gpu, the total batch size is $NGPU x batch_size",
+    )
+    parser.add_argument(
+        "--epochs",
+        default=90,
+        type=int,
+        metavar="N",
+        help="number of total epochs to run",
+    )
+    parser.add_argument(
+        "-j",
+        "--workers",
+        default=12,
+        type=int,
+        metavar="N",
+        help="number of data loading workers (default: 16)",
     )
     parser.add_argument("--lr", default=0.1, type=float, help="initial learning rate")
-    parser.add_argument("--lr-step-size", default=30, type=int, help="decrease lr every step-size epochs")
-    parser.add_argument("--lr-gamma", default=0.1, type=float, help="decrease lr by a factor of lr-gamma")
+    parser.add_argument(
+        "--lr-step-size",
+        default=30,
+        type=int,
+        help="decrease lr every step-size epochs",
+    )
+    parser.add_argument(
+        "--lr-gamma",
+        default=0.1,
+        type=float,
+        help="decrease lr by a factor of lr-gamma",
+    )
     parser.add_argument("--momentum", default=0.9, type=float, metavar="M", help="momentum")
 
     parser.add_argument("--print-freq", default=10, type=int, help="print frequency")
@@ -291,27 +293,43 @@ def get_args_parser(add_help=True):
 
     # distributed training parameters
     parser.add_argument("--world-size", default=1, type=int, help="number of distributed processes")
-    parser.add_argument("--dist-url", default="env://", type=str, help="url used to set up distributed training")
+    parser.add_argument(
+        "--dist-url",
+        default="env://",
+        type=str,
+        help="url used to set up distributed training",
+    )
 
     parser.add_argument(
-        "--use-deterministic-algorithms", action="store_true", help="Forces the use of deterministic algorithms only."
+        "--use-deterministic-algorithms",
+        action="store_true",
+        help="Forces the use of deterministic algorithms only.",
     )
     parser.add_argument(
-        "--val-resize-size", default=256, type=int, help="the resize size used for validation (default: 256)"
+        "--val-resize-size",
+        default=256,
+        type=int,
+        help="the resize size used for validation (default: 256)",
     )
     parser.add_argument(
-        "--val-crop-size", default=224, type=int, help="the central crop size used for validation (default: 224)"
+        "--val-crop-size",
+        default=224,
+        type=int,
+        help="the central crop size used for validation (default: 224)",
     )
     parser.add_argument(
-        "--train-crop-size", default=224, type=int, help="the random crop size used for training (default: 224)"
+        "--train-crop-size",
+        default=224,
+        type=int,
+        help="the random crop size used for training (default: 224)",
     )
     parser.add_argument("--weights", default=None, type=str, help="the weights enum name to load")
 
     parser.add_argument(
         "--ds-type",
         default="mapstyle",
         type=str,
-        help="'dp' or 'iterable' or 'mapstyle' (for regular indexable datasets)",
+        help="'iterable' or 'mapstyle' (for regular indexable datasets)",
     )
 
     parser.add_argument(
@@ -341,7 +359,7 @@ def get_args_parser(add_help=True):
         "--data-loader",
         default="V1",
         type=str,
-        help="'V1' or 'V2'. V2 only works for datapipes",
+        help="'V1' or 'V2'. Last stable release with DataloaderV2 is 0.9.0.",
     )
 
     return parser