From 053646a8f65fd40bb022dfe943ba92b7a0e6cafb Mon Sep 17 00:00:00 2001
From: Konstantin Gulin <66528950+KSGulin@users.noreply.github.com>
Date: Fri, 27 May 2022 18:44:43 +0100
Subject: [PATCH] Fix DataParallel validation forward signatures (#47)

* Fix: DataParallel validation forward signatures

* Update: generalize forward_fn selection

* nit: space
---
 src/transformers/trainer.py | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/src/transformers/trainer.py b/src/transformers/trainer.py
index 6129fa6af9f975..73f6c7b55d82b5 100755
--- a/src/transformers/trainer.py
+++ b/src/transformers/trainer.py
@@ -2435,11 +2435,12 @@ def evaluation_loop(
 
         observed_num_examples = 0
         # Main evaluation loop
+        module_forward_fn = model.module.forward if isinstance(model, nn.DataParallel) else model.forward
         for step, inputs in enumerate(dataloader):
             inputs = {
                 k: inputs[k]
                 for k in inputs
-                if k in list(inspect.signature(model.forward).parameters.keys())
+                if k in list(inspect.signature(module_forward_fn).parameters.keys())
             }
 
             # Update the observed num examples