Add explicit half/fp16 support to loader and validation script

timm/data/loader.py

@@ -21,10 +21,15 @@ class PrefetchLoader:
             rand_erase_prob=0.,
             rand_erase_mode='const',
             mean=IMAGENET_DEFAULT_MEAN,
-            std=IMAGENET_DEFAULT_STD):
+            std=IMAGENET_DEFAULT_STD,
+            fp16=False):
         self.loader = loader
         self.mean = torch.tensor([x * 255 for x in mean]).cuda().view(1, 3, 1, 1)
         self.std = torch.tensor([x * 255 for x in std]).cuda().view(1, 3, 1, 1)
+        self.fp16 = fp16
+        if fp16:
+            self.mean = self.mean.half()
+            self.std = self.std.half()
         if rand_erase_prob > 0.:
             self.random_erasing = RandomErasing(
                 probability=rand_erase_prob, mode=rand_erase_mode)
@@ -39,7 +44,10 @@ class PrefetchLoader:
             with torch.cuda.stream(stream):
                 next_input = next_input.cuda(non_blocking=True)
                 next_target = next_target.cuda(non_blocking=True)
-                next_input = next_input.float().sub_(self.mean).div_(self.std)
+                if self.fp16:
+                    next_input = next_input.half().sub_(self.mean).div_(self.std)
+                else:
+                    next_input = next_input.float().sub_(self.mean).div_(self.std)
                 if self.random_erasing is not None:
                     next_input = self.random_erasing(next_input)
 
@@ -94,6 +102,7 @@ def create_loader(
         distributed=False,
         crop_pct=None,
         collate_fn=None,
+        fp16=False,
         tf_preprocessing=False,
 ):
     if isinstance(input_size, tuple):
@@ -151,6 +160,7 @@ def create_loader(
             rand_erase_prob=rand_erase_prob if is_training else 0.,
             rand_erase_mode=rand_erase_mode,
             mean=mean,
-            std=std)
+            std=std,
+            fp16=fp16)
 
     return loader

timm/utils.py

@@ -156,12 +156,7 @@ def accuracy(output, target, topk=(1,)):
     _, pred = output.topk(maxk, 1, True, True)
     pred = pred.t()
     correct = pred.eq(target.view(1, -1).expand_as(pred))
-
-    res = []
-    for k in topk:
-        correct_k = correct[:k].view(-1).float().sum(0)
-        res.append(correct_k.mul_(100.0 / batch_size))
-    return res
+    return [correct[:k].view(-1).float().sum(0) * 100. / batch_size for k in topk]
 
 
 def get_outdir(path, *paths, inc=False):

timm/version.py

@@ -1 +1 @@
-__version__ = '0.1.7'
+__version__ = '0.1.8'

validate.py

@@ -50,7 +50,11 @@ parser.add_argument('--num-gpu', type=int, default=1,
                     help='Number of GPUS to use')
 parser.add_argument('--no-test-pool', dest='no_test_pool', action='store_true',
                     help='disable test time pool')
-parser.add_argument('--tf-preprocessing', dest='tf_preprocessing', action='store_true',
+parser.add_argument('--no-prefetcher', action='store_true', default=False,
+                    help='disable fast prefetcher')
+parser.add_argument('--fp16', action='store_true', default=False,
+                    help='Use half precision (fp16)')
+parser.add_argument('--tf-preprocessing', action='store_true', default=False,
                     help='Use Tensorflow preprocessing pipeline (require CPU TF installed')
 parser.add_argument('--use-ema', dest='use_ema', action='store_true',
                     help='use ema version of weights if present')
@@ -59,6 +63,7 @@ parser.add_argument('--use-ema', dest='use_ema', action='store_true',
 def validate(args):
     # might as well try to validate something
     args.pretrained = args.pretrained or not args.checkpoint
+    args.prefetcher = not args.no_prefetcher
 
     # create model
     model = create_model(
@@ -81,6 +86,9 @@ def validate(args):
     else:
         model = model.cuda()
 
+    if args.fp16:
+        model = model.half()
+
     criterion = nn.CrossEntropyLoss().cuda()
 
     crop_pct = 1.0 if test_time_pool else data_config['crop_pct']
@@ -88,12 +96,13 @@ def validate(args):
         Dataset(args.data, load_bytes=args.tf_preprocessing),
         input_size=data_config['input_size'],
         batch_size=args.batch_size,
-        use_prefetcher=True,
+        use_prefetcher=args.prefetcher,
         interpolation=data_config['interpolation'],
         mean=data_config['mean'],
         std=data_config['std'],
         num_workers=args.workers,
         crop_pct=crop_pct,
+        fp16=args.fp16,
         tf_preprocessing=args.tf_preprocessing)
 
     batch_time = AverageMeter()
@@ -105,8 +114,11 @@ def validate(args):
     end = time.time()
     with torch.no_grad():
         for i, (input, target) in enumerate(loader):
-            target = target.cuda()
-            input = input.cuda()
+            if args.no_prefetcher:
+                target = target.cuda()
+                input = input.cuda()
+                if args.fp16:
+                    input = input.half()
 
             # compute output
             output = model(input)
@@ -125,7 +137,7 @@ def validate(args):
             if i % args.log_freq == 0:
                 logging.info(
                     'Test: [{0:>4d}/{1}]  '
-                    'Time: {batch_time.val:.3f} ({batch_time.avg:.3f})  '
+                    'Time: {batch_time.val:.3f}s ({batch_time.avg:.3f}s, {rate_avg:>7.2f}/s)  '
                     'Loss: {loss.val:>7.4f} ({loss.avg:>6.4f})  '
                     'Prec@1: {top1.val:>7.3f} ({top1.avg:>7.3f})  '
                     'Prec@5: {top5.val:>7.3f} ({top5.avg:>7.3f})'.format(