Use _PyGC_BITS_DEFERRED for all immortal objects

Author: efimov-mikhail

Include/internal/pycore_stackref.h

@@ -523,7 +523,7 @@ PyStackRef_IsHeapSafe(_PyStackRef stackref)
 {
     if (PyStackRef_IsDeferred(stackref)) {
         PyObject *obj = PyStackRef_AsPyObjectBorrow(stackref);
-        return obj == NULL || _Py_IsImmortal(obj) || _PyObject_HasDeferredRefcount(obj);
+        return obj == NULL || _PyObject_HasDeferredRefcount(obj);
     }
     return true;
 }
@@ -554,7 +554,7 @@ PyStackRef_FromPyObjectNew(PyObject *obj)
     // Make sure we don't take an already tagged value.
     assert(((uintptr_t)obj & Py_TAG_BITS) == 0);
     assert(obj != NULL);
-    if (_PyObject_HasDeferredRefcount(obj) || _Py_IsImmortal(obj)) {
+    if (_PyObject_HasDeferredRefcount(obj)) {
         return (_PyStackRef){ .bits = (uintptr_t)obj | Py_TAG_DEFERRED };
     }
     else {

Objects/object.c

@@ -2675,6 +2675,9 @@ _Py_SetImmortalUntracked(PyObject *op)
         assert(PyUnicode_CHECK_INTERNED(op) == SSTATE_INTERNED_IMMORTAL
             || PyUnicode_CHECK_INTERNED(op) == SSTATE_INTERNED_IMMORTAL_STATIC);
     }
+#endif
+#ifdef Py_GIL_DISABLED
+    _Py_atomic_or_uint8(&op->ob_gc_bits, _PyGC_BITS_DEFERRED);
 #endif
     // Check if already immortal to avoid degrading from static immortal to plain immortal
     if (_Py_IsImmortal(op)) {
@@ -2684,7 +2687,6 @@ _Py_SetImmortalUntracked(PyObject *op)
     op->ob_tid = _Py_UNOWNED_TID;
     op->ob_ref_local = _Py_IMMORTAL_REFCNT_LOCAL;
     op->ob_ref_shared = 0;
-    _Py_atomic_or_uint8(&op->ob_gc_bits, _PyGC_BITS_DEFERRED);
 #elif SIZEOF_VOID_P > 4
     op->ob_flags = _Py_IMMORTAL_FLAGS;
     op->ob_refcnt = _Py_IMMORTAL_INITIAL_REFCNT;