From b51bf60964357edbf55d54eb01735a4bfac15d48 Mon Sep 17 00:00:00 2001
From: Zhihao Lin <36994684+LZHgrla@users.noreply.github.com>
Date: Thu, 11 Jan 2024 10:47:05 +0800
Subject: [PATCH] [Fix] Fix the resume of iteration (#1471)

---
 mmengine/runner/loops.py | 8 ++++++++
 1 file changed, 8 insertions(+)

diff --git a/mmengine/runner/loops.py b/mmengine/runner/loops.py
index 6a874a6a..1f6551ab 100644
--- a/mmengine/runner/loops.py
+++ b/mmengine/runner/loops.py
@@ -271,6 +271,14 @@ class IterBasedTrainLoop(BaseLoop):
         # In iteration-based training loop, we treat the whole training process
         # as a big epoch and execute the corresponding hook.
         self.runner.call_hook('before_train_epoch')
+        if self._iter > 0:
+            print_log(
+                f'Advance dataloader {self._iter} steps to skip data '
+                'that has already been trained',
+                logger='current',
+                level=logging.WARNING)
+            for _ in range(self._iter):
+                next(self.dataloader_iterator)
         while self._iter < self._max_iters and not self.stop_training:
             self.runner.model.train()