FIX BUG

1. model parallel x_grad rescale

recognition/arcface_torch/partial_fc.py

@@ -153,10 +153,9 @@ class PartialFC(Module):
         logits.backward(grad)
         if total_features.grad is not None:
             total_features.grad.detach_()
-        x_grad: torch.Tensor = torch.zeros_like(features)
-        x_grad.mul_(self.world_size)
-
+        x_grad: torch.Tensor = torch.zeros_like(features, requires_grad=True)
         # feature gradient all-reduce
         dist.reduce_scatter(x_grad, list(total_features.grad.chunk(self.world_size, dim=0)))
+        x_grad = x_grad * self.world_size
         # backward backbone
         return x_grad, loss_v