fix(vram): model.to(cpu) eviction in free_cuda and run_rmu

scripts/smoke_l4.py

@@ -148,13 +148,22 @@ def reset_gpu_peak() -> None:
 
 
 def free_cuda(*objs) -> None:
+    import gc
     import torch
 
     for obj in objs:
-        del obj
+        if obj is not None and hasattr(obj, "to"):
+            try:
+                obj.to("cpu")
+            except Exception:
+                pass
     gc.collect()
     if torch.cuda.is_available():
         torch.cuda.empty_cache()
+        try:
+            torch.cuda.ipc_collect()
+        except Exception:
+            pass
 
 
 # ---------------------------------------------------------------------------
@@ -389,6 +398,18 @@ def run_rmu(model_name: str, bench_repo: str, workdir: Path, telemetry: Telemetr
         "elapsed_s": round(time.time() - t0, 1),
     }
     telemetry.push_json("rmu.json", result)
+    try:
+        model.to("cpu")
+        frozen.to("cpu")
+        updated.to("cpu")
+    except Exception:
+        pass
+    if hasattr(trainer, "model"):
+        trainer.model = None
+    if hasattr(trainer, "frozen_model"):
+        trainer.frozen_model = None
+    if hasattr(trainer, "optimizer"):
+        trainer.optimizer = None
     free_cuda(updated, model, frozen, trainer, tok)
     return result
 
@@ -451,6 +472,11 @@ def run_circuitkit(
         telemetry.push_json("circuitkit.json", result)
         return result
     finally:
+        try:
+            if tl_model is not None and hasattr(tl_model, "to"):
+                tl_model.to("cpu")
+        except Exception:
+            pass
         free_cuda(circuit, tl_model)