cgroups: add cpu_relax() calls in css_tryget() and cgroup_clear_css_refs()

[safe/jmp/linux-2.6] / kernel / marker.c

diff --git a/kernel/marker.c b/kernel/marker.c
index 348e70c..ea54f26 100644 (file)
--- a/kernel/marker.c
+++ b/kernel/marker.c
@@ -479,7 +479,7 @@ static int marker_set_format(struct marker_entry *entry, const char *format)
 static int set_marker(struct marker_entry *entry, struct marker *elem,
                int active)
 {
-       int ret;
+       int ret = 0;
        WARN_ON(strcmp(entry->name, elem->name) != 0);
 
        if (entry->format) {
@@ -531,9 +531,40 @@ static int set_marker(struct marker_entry *entry, struct marker *elem,
         */
        smp_wmb();
        elem->ptype = entry->ptype;
+
+       if (elem->tp_name && (active ^ elem->state)) {
+               WARN_ON(!elem->tp_cb);
+               /*
+                * It is ok to directly call the probe registration because type
+                * checking has been done in the __trace_mark_tp() macro.
+                */
+
+               if (active) {
+                       /*
+                        * try_module_get should always succeed because we hold
+                        * lock_module() to get the tp_cb address.
+                        */
+                       ret = try_module_get(__module_text_address(
+                               (unsigned long)elem->tp_cb));
+                       BUG_ON(!ret);
+                       ret = tracepoint_probe_register_noupdate(
+                               elem->tp_name,
+                               elem->tp_cb);
+               } else {
+                       ret = tracepoint_probe_unregister_noupdate(
+                               elem->tp_name,
+                               elem->tp_cb);
+                       /*
+                        * tracepoint_probe_update_all() must be called
+                        * before the module containing tp_cb is unloaded.
+                        */
+                       module_put(__module_text_address(
+                               (unsigned long)elem->tp_cb));
+               }
+       }
        elem->state = active;
 
-       return 0;
+       return ret;
 }
 
 /*
@@ -544,7 +575,24 @@ static int set_marker(struct marker_entry *entry, struct marker *elem,
  */
 static void disable_marker(struct marker *elem)
 {
+       int ret;
+
        /* leave "call" as is. It is known statically. */
+       if (elem->tp_name && elem->state) {
+               WARN_ON(!elem->tp_cb);
+               /*
+                * It is ok to directly call the probe registration because type
+                * checking has been done in the __trace_mark_tp() macro.
+                */
+               ret = tracepoint_probe_unregister_noupdate(elem->tp_name,
+                       elem->tp_cb);
+               WARN_ON(ret);
+               /*
+                * tracepoint_probe_update_all() must be called
+                * before the module containing tp_cb is unloaded.
+                */
+               module_put(__module_text_address((unsigned long)elem->tp_cb));
+       }
        elem->state = 0;
        elem->single.func = __mark_empty_function;
        /* Update the function before setting the ptype */
@@ -608,6 +656,7 @@ static void marker_update_probes(void)
        marker_update_probe_range(__start___markers, __stop___markers);
        /* Markers in modules. */
        module_update_markers();
+       tracepoint_probe_update_all();
 }
 
 /**
@@ -847,6 +896,8 @@ void *marker_get_private_data(const char *name, marker_probe_func *probe,
 }
 EXPORT_SYMBOL_GPL(marker_get_private_data);
 
+#ifdef CONFIG_MODULES
+
 int marker_module_notify(struct notifier_block *self,
                         unsigned long val, void *data)
 {
@@ -875,3 +926,5 @@ static int init_markers(void)
        return register_module_notifier(&marker_module_nb);
 }
 __initcall(init_markers);
+
+#endif /* CONFIG_MODULES */