[Backend Tester] Report PTE size (pytorch#13249)

Add a field to the test report for PTE size (in Kb).

Author: GregoryComer

backends/test/suite/reporting.py

@@ -131,6 +131,9 @@ class TestCaseSummary:
     undelegated_op_counts: Counter | None = None
     """ The number of undelegated occurances of each operator in the graph. """
 
+    pte_size_bytes: int | None = None
+    """ The size of the PTE file in bytes. """
+
 
 class TestSessionState:
     test_case_summaries: list[TestCaseSummary]
@@ -302,6 +305,7 @@ def generate_csv_report(summary: RunSummary, output: TextIO):
             "Undelegated Nodes",
             "Delegated Ops",
             "Undelegated Ops",
+            "PTE Size (Kb)",
         ]
     )
 
@@ -336,5 +340,8 @@ def generate_csv_report(summary: RunSummary, output: TextIO):
         row["Undelegated Nodes"] = _sum_op_counts(record.undelegated_op_counts)
         row["Delegated Ops"] = _serialize_op_counts(record.delegated_op_counts)
         row["Undelegated Ops"] = _serialize_op_counts(record.undelegated_op_counts)
+        row["PTE Size (Kb)"] = (
+            record.pte_size_bytes / 1000.0 if record.pte_size_bytes else ""
+        )
 
         writer.writerow(row)

backends/test/suite/runner.py

@@ -129,6 +129,7 @@ def build_result(
     if is_delegated:
         try:
             tester.to_executorch().serialize()
+            extra_stats["pte_size_bytes"] = len(tester.get_artifact())
         except Exception as e:
             # We could introduce a result value for this, but I'm not sure it's necessary.
             # We can do this if we ever see to_executorch() or serialize() fail due a backend issue.