[cuda graph] bug fix for cuda graph static mode (#43539)

python/paddle/device/cuda/graphs.py

@@ -173,7 +173,7 @@ def construct_program_and_find_ins_outs(section, origin_program, section_idx):
                 # This in var is generated from op outside this section
                 # Only record once for same input
                 ins.append(in_name)
-            elif later_ins.count(in_name) == 0:
+            elif later_ins.count(in_name) == 0 and outs.count(in_name) > 0:
                 # this is var is generated from op inside this section, and only will be used inside this section
                 outs.remove(in_name)
         for out_name in op.output_arg_names:
@@ -248,13 +248,13 @@ def get_cuda_graph_sections(program):
                         sub_block_related = (op.type == 'conditional_block'
                                              or op.type == 'while')
                         if loss_related or sub_block_related:
-                            # if loss_related is True
+                            # If loss_related is True
                             # The internal section contains loss related ops,
                             # although these ops are between two cuda graph sections with same graph id,
                             # they belong to none of these two sections.
                             # The loss related op should be wrapped by user explicitly.
 
-                            # if sub_block_related is True
+                            # If sub_block_related is True
                             # The internal section contains while op or conditional block op.
                             # These two ops are not supported by cuda graph. Won't extend the section.
                             internal_section = []
@@ -274,6 +274,7 @@ def get_cuda_graph_sections(program):
                         current_section.append(internal_section[i])
                         current_idx.append(internal_idx[i])
                 internal_section = []
+                internal_idx = []
                 current_section.append(op)
                 current_idx.append(idx)
             else: