Index: Include/ceval.h
===================================================================
--- Include/ceval.h	(revision 83761)
+++ Include/ceval.h	(working copy)
@@ -22,6 +22,8 @@
 
 PyAPI_FUNC(void) PyEval_SetProfile(Py_tracefunc, PyObject *);
 PyAPI_FUNC(void) PyEval_SetTrace(Py_tracefunc, PyObject *);
+PyAPI_FUNC(void) PyEval_SetGlobalProfile(Py_tracefunc, PyObject *);
+PyAPI_FUNC(void) PyEval_SetGlobalTrace(Py_tracefunc, PyObject *);
 
 struct _frame; /* Avoid including frameobject.h */
 
Index: Modules/_lsprof.c
===================================================================
--- Modules/_lsprof.c	(revision 83761)
+++ Modules/_lsprof.c	(working copy)
@@ -679,13 +679,14 @@
 }
 
 PyDoc_STRVAR(enable_doc, "\
-enable(subcalls=True, builtins=True)\n\
+enable(subcalls=True, builtins=True, global=False)\n\
 \n\
 Start collecting profiling information.\n\
 If 'subcalls' is True, also records for each function\n\
 statistics separated according to its current caller.\n\
 If 'builtins' is True, records the time spent in\n\
 built-in functions separately from their caller.\n\
+If 'global' is True, profiling is started on all threads.\n\
 ");
 
 static PyObject*
@@ -693,13 +694,17 @@
 {
     int subcalls = -1;
     int builtins = -1;
-    static char *kwlist[] = {"subcalls", "builtins", 0};
-    if (!PyArg_ParseTupleAndKeywords(args, kwds, "|ii:enable",
-                                     kwlist, &subcalls, &builtins))
+    int global = 0;
+    static char *kwlist[] = {"subcalls", "builtins", "global", 0};
+    if (!PyArg_ParseTupleAndKeywords(args, kwds, "|iii:enable",
+                                     kwlist, &subcalls, &builtins, &global))
         return NULL;
     if (setSubcalls(self, subcalls) < 0 || setBuiltins(self, builtins) < 0)
         return NULL;
-    PyEval_SetProfile(profiler_callback, (PyObject*)self);
+    if (global)
+        PyEval_SetGlobalProfile(profiler_callback, (PyObject*)self);
+    else
+        PyEval_SetProfile(profiler_callback, (PyObject*)self);
     self->flags |= POF_ENABLED;
     Py_INCREF(Py_None);
     return Py_None;
Index: Python/ceval.c
===================================================================
--- Python/ceval.c	(revision 83761)
+++ Python/ceval.c	(working copy)
@@ -3623,10 +3623,9 @@
     return result;
 }
 
-void
-PyEval_SetProfile(Py_tracefunc func, PyObject *arg)
+static void
+_Py_SetProfile(PyThreadState *tstate, Py_tracefunc func, PyObject *arg)
 {
-    PyThreadState *tstate = PyThreadState_GET();
     PyObject *temp = tstate->c_profileobj;
     Py_XINCREF(arg);
     tstate->c_profilefunc = NULL;
@@ -3641,9 +3640,28 @@
 }
 
 void
-PyEval_SetTrace(Py_tracefunc func, PyObject *arg)
+PyEval_SetProfile(Py_tracefunc func, PyObject *arg)
 {
     PyThreadState *tstate = PyThreadState_GET();
+    _Py_SetProfile(tstate, func, arg);
+}
+
+void
+PyEval_SetGlobalProfile(Py_tracefunc func, PyObject *arg)
+{
+    PyThreadState *head = PyThreadState_GET();
+    PyThreadState *tstate = head;
+    for(;;) {
+        _Py_SetProfile(tstate, func, arg);
+        tstate = tstate->next;
+        if (tstate == head)
+            break;
+    }
+}
+
+static void
+_Py_SetTrace(PyThreadState *tstate, Py_tracefunc func, PyObject *arg)
+{
     PyObject *temp = tstate->c_traceobj;
     _Py_TracingPossible += (func != NULL) - (tstate->c_tracefunc != NULL);
     Py_XINCREF(arg);
@@ -3659,6 +3677,26 @@
                            || (tstate->c_profilefunc != NULL));
 }
 
+void
+PyEval_SetTrace(Py_tracefunc func, PyObject *arg)
+{
+    PyThreadState *tstate = PyThreadState_GET();
+    _Py_SetTrace(tstate, func, arg);
+}
+
+void
+PyEval_SetGlobalTrace(Py_tracefunc func, PyObject *arg)
+{
+    PyThreadState *head = PyThreadState_GET();
+    PyThreadState *tstate = head;
+    for(;;) {
+        _Py_SetTrace(tstate, func, arg);
+        tstate = tstate->next;
+        if (tstate == head)
+            break;
+    }
+}
+
 PyObject *
 PyEval_GetBuiltins(void)
 {
Index: Python/sysmodule.c
===================================================================
--- Python/sysmodule.c	(revision 83761)
+++ Python/sysmodule.c	(working copy)
@@ -353,6 +353,7 @@
         return 0;
     result = call_trampoline(tstate, callback, frame, what, arg);
     if (result == NULL) {
+        PyEval_SetGlobalTrace(NULL, NULL);
         PyEval_SetTrace(NULL, NULL);
         Py_XDECREF(frame->f_trace);
         frame->f_trace = NULL;
@@ -371,23 +372,34 @@
 }
 
 static PyObject *
-sys_settrace(PyObject *self, PyObject *args)
+sys_settrace(PyObject *self, PyObject *args, PyObject *kwds)
 {
+    PyObject *tracefunc, *global = Py_False;
+    char *kwlist[] = {"function", "global", NULL};
+    if (!PyArg_ParseTupleAndKeywords(args, kwds, "O|O:settrace", kwlist,
+                                     &tracefunc, &global))
+        return NULL;
     if (trace_init() == -1)
         return NULL;
-    if (args == Py_None)
+    if (args == Py_None) {
+        PyEval_SetGlobalTrace(NULL, NULL);
         PyEval_SetTrace(NULL, NULL);
-    else
-        PyEval_SetTrace(trace_trampoline, args);
+    } else {
+        if (PyObject_IsTrue(global))
+            PyEval_SetGlobalTrace(trace_trampoline, tracefunc);
+        else
+            PyEval_SetTrace(trace_trampoline, tracefunc);
+    }
     Py_INCREF(Py_None);
     return Py_None;
 }
 
 PyDoc_STRVAR(settrace_doc,
-"settrace(function)\n\
+"settrace(function[, global])\n\
 \n\
 Set the global debug tracing function.  It will be called on each\n\
-function call.  See the debugger chapter in the library manual."
+function call.  See the debugger chapter in the library manual.\n\
+If 'global' is True, the call is effective for all threads."
 );
 
 static PyObject *
@@ -410,23 +422,34 @@
 );
 
 static PyObject *
-sys_setprofile(PyObject *self, PyObject *args)
+sys_setprofile(PyObject *self, PyObject *args, PyObject *kwds)
 {
+    PyObject *profilefunc, *global=Py_False;
+    char *kwlist[] = {"function", "global", NULL};
+    if (!PyArg_ParseTupleAndKeywords(args, kwds, "O|O:setprofile", kwlist,
+                                     &profilefunc, &global))
+        return NULL;
     if (trace_init() == -1)
         return NULL;
-    if (args == Py_None)
+    if (args == Py_None) {
+        PyEval_SetGlobalProfile(NULL, NULL);
         PyEval_SetProfile(NULL, NULL);
-    else
-        PyEval_SetProfile(profile_trampoline, args);
+    } else {
+        if (PyObject_IsTrue(global))
+            PyEval_SetGlobalProfile(profile_trampoline, args);
+        else
+            PyEval_SetProfile(profile_trampoline, args);
+    }
     Py_INCREF(Py_None);
     return Py_None;
 }
 
 PyDoc_STRVAR(setprofile_doc,
-"setprofile(function)\n\
+"setprofile(function[, global])\n\
 \n\
 Set the profiling function.  It will be called on each function call\n\
-and return.  See the profiler chapter in the library manual."
+and return.  See the profiler chapter in the library manual.\n\
+If 'global' is True, the call is effective for all threads."
 );
 
 static PyObject *
@@ -1048,14 +1071,14 @@
     {"setdlopenflags", sys_setdlopenflags, METH_VARARGS,
      setdlopenflags_doc},
 #endif
-    {"setprofile",      sys_setprofile, METH_O, setprofile_doc},
+    {"setprofile",      (PyCFunction)sys_setprofile, METH_KEYWORDS, setprofile_doc},
     {"getprofile",      sys_getprofile, METH_NOARGS, getprofile_doc},
     {"setrecursionlimit", sys_setrecursionlimit, METH_VARARGS,
      setrecursionlimit_doc},
 #ifdef WITH_TSC
     {"settscdump", sys_settscdump, METH_VARARGS, settscdump_doc},
 #endif
-    {"settrace",        sys_settrace, METH_O, settrace_doc},
+    {"settrace",        (PyCFunction)sys_settrace, METH_KEYWORDS, settrace_doc},
     {"gettrace",        sys_gettrace, METH_NOARGS, gettrace_doc},
     {"call_tracing", sys_call_tracing, METH_VARARGS, call_tracing_doc},
     {NULL,              NULL}           /* sentinel */