diff --git a/colossalai/zero/gemini/chunk/manager.py b/colossalai/zero/gemini/chunk/manager.py
index c7bdd5e1f..341790a72 100644
--- a/colossalai/zero/gemini/chunk/manager.py
+++ b/colossalai/zero/gemini/chunk/manager.py
@@ -83,7 +83,7 @@ class ChunkManager:
             if chunk_group:
                 # the chunk group is not empty
                 # close the last chunk
-                self.__close_one_chunk(chunk_group[-1])
+                self.__close_one_chunk(chunk_group[-1])  # chunk[-1] 满了，所以关闭，不能再添加，然后同时scatter到ZeRO PG中
 
             if tensor.numel() > chunk_size:
                 chunk_size = tensor.numel()
diff --git a/colossalai/zero/gemini/gemini_hook.py b/colossalai/zero/gemini/gemini_hook.py
index 27a19c132..bf990d127 100644
--- a/colossalai/zero/gemini/gemini_hook.py
+++ b/colossalai/zero/gemini/gemini_hook.py
@@ -33,19 +33,22 @@ class GeminiZeROHook(ColoParamOpHook):
         all_chunks = self._chunk_manager.get_chunks(params)
 
         # wait for prefetched chunks, filter those are not prefetched
-        chunks_fetch_sync = self._gemini_manager.wait_chunks(all_chunks)
+        chunks_fetch_sync = self._gemini_manager.wait_chunks(all_chunks)  # 当前要fetch的chunk
 
         # transfer state
         for p in params:
+            # TODO(haze188): check状态转换
             self._chunk_manager.trans_tensor_state(p, TensorState.COMPUTE)
         self._gemini_manager.sample_overall_data()
 
         # evit chunks, aware of async fetched
+        # TODO(haze188): 可能我们prefetch的又被淘汰掉, check一下
         self._gemini_manager.adjust_layout(
             all_chunks, record_anyway=self._gemini_manager.placement_policy.max_prefetch > 0
         )
 
         # fetch the rest synchronously
+        # TODO(haze188): 1. 先prefetch还是先fetch（prefetch是异步，fetch是同步）
         for chunk in chunks_fetch_sync:
             self._chunk_manager.access_chunk(chunk)
 
diff --git a/colossalai/zero/gemini/gemini_mgr.py b/colossalai/zero/gemini/gemini_mgr.py
index 11bde789c..2e96c22f3 100644
--- a/colossalai/zero/gemini/gemini_mgr.py
+++ b/colossalai/zero/gemini/gemini_mgr.py
@@ -125,7 +125,7 @@ class GeminiManager:
                 self._async_works[chunk].wait()
                 del self._async_works[chunk]
             else:
-                non_prefetched_chunks.append(chunk)
+                non_prefetched_chunks.append(chunk)  # 没在之前prefetch过，现在要prefetch的chunk
         return tuple(non_prefetched_chunks)
 
     def add_work(self, chunk: Chunk, work: dist.Work):
@@ -154,6 +154,7 @@ class GeminiManager:
 
     def _record_warmup_chunks_order(self, chunks: Tuple[Chunk, ...], record_anyway: bool = False) -> None:
         self._compute_idx += 1
+        # TODO(haze188): _compute_list 记录块的访问顺序
         if self._warmup and (self._placement_policy.need_mem_stats or record_anyway):
             self._compute_list.append(chunks)
 
diff --git a/colossalai/zero/gemini/placement_policy.py b/colossalai/zero/gemini/placement_policy.py
index c0f92fa50..4c3d8dbe2 100644
--- a/colossalai/zero/gemini/placement_policy.py
+++ b/colossalai/zero/gemini/placement_policy.py
@@ -45,9 +45,9 @@ class PlacementPolicy(ABC):
         raise NotImplementedError
 
 
-import os
-
-rank = int(os.environ["RANK"])
+# import torch.distributed as dist
+# # rank = int(os.environ["RANK"])
+# rank = dist.get_rank()
 
 
 class StaticPlacementPolicy(PlacementPolicy):
@@ -118,8 +118,10 @@ class StaticPlacementPolicy(PlacementPolicy):
     def get_prefetch_chunks(self) -> List[Chunk]:
         if self.gemini_manager.is_warmup():  # no prefetch during warmup since we need compute_list
             return []
+        # 最多有多少个异步的work
         can_prefetch = self.max_prefetch - len(self.gemini_manager._async_works)
         prefetch = []
+        # static炸就炸了，dynamic可能需要我们要先分析当前运行时的内存情况，分配空间或者淘汰块
         for i in range(self.gemini_manager.compute_idx + 1, len(self.gemini_manager.compute_list)):
             for chunk in self.gemini_manager.compute_list[i]:
                 if len(prefetch) >= can_prefetch:
@@ -238,7 +240,9 @@ class AutoPlacementPolicy(PlacementPolicy):
                 grads_device_map[p] = torch.device("cpu")
 
     def get_prefetch_chunks(self, max_prefetch: int) -> List[Chunk]:
-        return []  # TODO @botbw: implement prefetching for auto
+        # TODO @haze188 @botbw: implement prefetching for auto
+
+        return []
 
 
 class PlacementPolicyFactory: