Update train.py with some flags related to scheduler tweaks, fix best checkpoint bug.

timm/bits/checkpoint_manager.py

@@ -193,7 +193,7 @@ class CheckpointManager:
                 best_save_path = os.path.join(self.checkpoint_dir, 'best' + self.extension)
                 self._duplicate(last_save_path, best_save_path)
 
-        return None if self.best_checkpoint is None else curr_checkpoint
+        return curr_checkpoint if self.best_checkpoint is None else self.best_checkpoint
 
     def save_recovery(self, train_state: TrainState):
         tmp_save_path = os.path.join(self.recovery_dir, 'recovery_tmp' + self.extension)

train.py

@@ -33,7 +33,7 @@ from timm.bits import initialize_device, setup_model_and_optimizer, DeviceEnv, M
 from timm.data import create_dataset, create_transform_v2, create_loader_v2, resolve_data_config,\
     PreprocessCfg, AugCfg, MixupCfg, AugMixDataset
 from timm.models import create_model, safe_model_name, convert_splitbn_model
-from timm.loss import LabelSmoothingCrossEntropy, SoftTargetCrossEntropy, JsdCrossEntropy
+from timm.loss import *
 from timm.optim import optimizer_kwargs
 from timm.scheduler import create_scheduler
 from timm.utils import setup_default_logging, random_seed, get_outdir, unwrap_model
@@ -121,8 +121,12 @@ parser.add_argument('--lr-noise-std', type=float, default=1.0, metavar='STDDEV',
                     help='learning rate noise std-dev (default: 1.0)')
 parser.add_argument('--lr-cycle-mul', type=float, default=1.0, metavar='MULT',
                     help='learning rate cycle len multiplier (default: 1.0)')
+parser.add_argument('--lr-cycle-decay', type=float, default=0.5, metavar='MULT',
+                    help='amount to decay each learning rate cycle (default: 0.5)')
 parser.add_argument('--lr-cycle-limit', type=int, default=1, metavar='N',
-                    help='learning rate cycle limit')
+                    help='learning rate cycle limit, cycles enabled if > 1')
+parser.add_argument('--lr-k-decay', type=float, default=1.0,
+                    help='learning rate k-decay for cosine/poly (default: 1.0)')
 parser.add_argument('--warmup-lr', type=float, default=0.0001, metavar='LR',
                     help='warmup learning rate (default: 0.0001)')
 parser.add_argument('--min-lr', type=float, default=1e-5, metavar='LR',
@@ -161,8 +165,10 @@ parser.add_argument('--aa', type=str, default=None, metavar='NAME',
                     help='Use AutoAugment policy. "v0" or "original". (default: None)'),
 parser.add_argument('--aug-splits', type=int, default=0,
                     help='Number of augmentation splits (default: 0, valid: 0 or >=2)')
-parser.add_argument('--jsd', action='store_true', default=False,
+parser.add_argument('--jsd-loss', action='store_true', default=False,
                     help='Enable Jensen-Shannon Divergence + CE loss. Use with `--aug-splits`.')
+parser.add_argument('--bce-loss', action='store_true', default=False,
+                    help='Enable BCE loss w/ Mixup/CutMix use.')
 parser.add_argument('--reprob', type=float, default=0., metavar='PCT',
                     help='Random erase prob (default: 0.)')
 parser.add_argument('--remode', type=str, default='const',
@@ -448,13 +454,19 @@ def setup_train_task(args, dev_env: DeviceEnv, mixup_active: bool):
         lr_scheduler.step(train_state.epoch)
 
     # setup loss function
-    if args.jsd:
+    if args.jsd_loss:
         assert args.aug_splits > 1  # JSD only valid with aug splits set
         train_loss_fn = JsdCrossEntropy(num_splits=args.aug_splits, smoothing=args.smoothing)
     elif mixup_active:
         # smoothing is handled with mixup target transform
+        if args.bce_loss:
+            train_loss_fn = nn.BCEWithLogitsLoss()
+        else:
             train_loss_fn = SoftTargetCrossEntropy()
     elif args.smoothing:
+        if args.bce_loss:
+            train_loss_fn = DenseBinaryCrossEntropy(smoothing=args.smoothing)
+        else:
             train_loss_fn = LabelSmoothingCrossEntropy(smoothing=args.smoothing)
     else:
         train_loss_fn = nn.CrossEntropyLoss()