Increase headroom

Author: markshannon

Include/internal/pycore_ceval.h

@@ -327,6 +327,7 @@ void _Py_unset_eval_breaker_bit_all(PyInterpreterState *interp, uintptr_t bit);
 
 PyAPI_FUNC(PyObject *) _PyFloat_FromDouble_ConsumeInputs(_PyStackRef left, _PyStackRef right, double value);
 
+extern int _PyOS_CheckStack(int words);
 
 #ifdef __cplusplus
 }

Include/pythonrun.h

@@ -23,8 +23,8 @@ PyAPI_DATA(int) (*PyOS_InputHook)(void);
 
 /* Stack size, in "pointers" (so we get extra safety margins
    on 64-bit platforms).  On a 32-bit platform, this translates
-   to an 8k margin. */
-#define PYOS_STACK_MARGIN 2048
+   to an 16k margin. */
+#define PYOS_STACK_MARGIN 4096
 #define PYOS_STACK_MARGIN_BYTES (PYOS_STACK_MARGIN * sizeof(void *))
 
 #if defined(WIN32) && !defined(MS_WIN64) && !defined(_M_ARM) && defined(_MSC_VER) && _MSC_VER >= 1300

Python/bytecodes.c

@@ -1083,9 +1083,6 @@ dummy_func(
             /* Restore previous frame and return. */
             tstate->current_frame = frame->previous;
             assert(!_PyErr_Occurred(tstate));
-            // PyEval_EvalDefault is a big function, so count it twice
-            _Py_LeaveRecursiveCallTstate(tstate);
-            _Py_LeaveRecursiveCallTstate(tstate);
             PyObject *result = PyStackRef_AsPyObjectSteal(retval);
             SYNC_SP(); /* Not strictly necessary, but prevents warnings */
             return result;
@@ -5252,9 +5249,6 @@ dummy_func(
             if (frame->owner == FRAME_OWNED_BY_INTERPRETER) {
                 /* Restore previous frame and exit */
                 tstate->current_frame = frame->previous;
-                // PyEval_EvalDefault is a big function, so count it twice
-                _Py_LeaveRecursiveCallTstate(tstate);
-                _Py_LeaveRecursiveCallTstate(tstate);
                 return NULL;
             }
             next_instr = frame->instr_ptr;

Python/ceval.c

@@ -326,7 +326,7 @@ _Py_InitializeRecursionCheck(PyThreadState *tstate)
 #ifdef USE_STACKCHECK
     if (_PyOS_CheckStack(PYOS_STACK_MARGIN * 2) == 0) {
         tstate->c_stack_soft_limit = here_addr - PYOS_STACK_MARGIN_BYTES;
-        return 0;
+        return;
     }
     int margin = PYOS_STACK_MARGIN;
     assert(tstate->c_stack_soft_limit != UINTPTR_MAX);
@@ -1033,9 +1033,6 @@ _PyEval_EvalFrameDefault(PyThreadState *tstate, _PyInterpreterFrame *frame, int
     assert(frame->owner == FRAME_OWNED_BY_INTERPRETER);
     /* Restore previous frame and exit */
     tstate->current_frame = frame->previous;
-    // PyEval_EvalDefault is a big function, so count it twice
-    _Py_LeaveRecursiveCallTstate(tstate);
-    _Py_LeaveRecursiveCallTstate(tstate);
     return NULL;
 }