No need to use atomics here

Author: brandtbucher

Python/gc.c

@@ -2074,7 +2074,7 @@ _PyGC_Collect(PyThreadState *tstate, int generation, _PyGC_Reason reason)
         // Don't start a garbage collection if one is already in progress.
         return 0;
     }
-    _Py_atomic_store_ptr(&gcstate->frame, tstate->current_frame);
+    gcstate->frame = tstate->current_frame;
 
     struct gc_collection_stats stats = { 0 };
     if (reason != _Py_GC_REASON_SHUTDOWN) {
@@ -2120,7 +2120,7 @@ _PyGC_Collect(PyThreadState *tstate, int generation, _PyGC_Reason reason)
     }
 #endif
     validate_spaces(gcstate);
-    _Py_atomic_store_ptr(&gcstate->frame, NULL);
+    gcstate->frame = NULL;
     _Py_atomic_store_int(&gcstate->collecting, 0);
 
     if (gcstate->debug & _PyGC_DEBUG_STATS) {

Python/gc_free_threading.c

@@ -2358,7 +2358,7 @@ gc_collect_main(PyThreadState *tstate, int generation, _PyGC_Reason reason)
         _Py_atomic_store_int(&gcstate->collecting, 0);
         return 0;
     }
-    _Py_atomic_store_ptr(&gcstate->frame, tstate->current_frame);
+    gcstate->frame = tstate->current_frame;
 
     assert(generation >= 0 && generation < NUM_GENERATIONS);
 
@@ -2447,7 +2447,7 @@ gc_collect_main(PyThreadState *tstate, int generation, _PyGC_Reason reason)
     }
 
     assert(!_PyErr_Occurred(tstate));
-    _Py_atomic_store_ptr(&gcstate->frame, NULL);
+    gcstate->frame = NULL;
     _Py_atomic_store_int(&gcstate->collecting, 0);
     return n + m;
 }