Merge branch 'linus' into cont_syslog

[safe/jmp/linux-2.6] / include / linux / preempt.h

diff --git a/include/linux/preempt.h b/include/linux/preempt.h
index 484988e..2e681d9 100644 (file)
--- a/include/linux/preempt.h
+++ b/include/linux/preempt.h
@@ -10,9 +10,9 @@
 #include <linux/linkage.h>
 #include <linux/list.h>
 
-#ifdef CONFIG_DEBUG_PREEMPT
-  extern void fastcall add_preempt_count(int val);
-  extern void fastcall sub_preempt_count(int val);
+#if defined(CONFIG_DEBUG_PREEMPT) || defined(CONFIG_PREEMPT_TRACER)
+  extern void add_preempt_count(int val);
+  extern void sub_preempt_count(int val);
 #else
 # define add_preempt_count(val)        do { preempt_count() += (val); } while (0)
 # define sub_preempt_count(val)        do { preempt_count() -= (val); } while (0)
@@ -52,6 +52,34 @@ do { \
        preempt_check_resched(); \
 } while (0)
 
+/* For debugging and tracer internals only! */
+#define add_preempt_count_notrace(val)                 \
+       do { preempt_count() += (val); } while (0)
+#define sub_preempt_count_notrace(val)                 \
+       do { preempt_count() -= (val); } while (0)
+#define inc_preempt_count_notrace() add_preempt_count_notrace(1)
+#define dec_preempt_count_notrace() sub_preempt_count_notrace(1)
+
+#define preempt_disable_notrace() \
+do { \
+       inc_preempt_count_notrace(); \
+       barrier(); \
+} while (0)
+
+#define preempt_enable_no_resched_notrace() \
+do { \
+       barrier(); \
+       dec_preempt_count_notrace(); \
+} while (0)
+
+/* preempt_check_resched is OK to trace */
+#define preempt_enable_notrace() \
+do { \
+       preempt_enable_no_resched_notrace(); \
+       barrier(); \
+       preempt_check_resched(); \
+} while (0)
+
 #else
 
 #define preempt_disable()              do { } while (0)
@@ -59,6 +87,10 @@ do { \
 #define preempt_enable()               do { } while (0)
 #define preempt_check_resched()                do { } while (0)
 
+#define preempt_disable_notrace()              do { } while (0)
+#define preempt_enable_no_resched_notrace()    do { } while (0)
+#define preempt_enable_notrace()               do { } while (0)
+
 #endif
 
 #ifdef CONFIG_PREEMPT_NOTIFIERS
@@ -73,6 +105,11 @@ struct preempt_notifier;
  * @sched_out: we've just been preempted
  *    notifier: struct preempt_notifier for the task being preempted
  *    next: the task that's kicking us out
+ *
+ * Please note that sched_in and out are called under different
+ * contexts.  sched_out is called with rq lock held and irq disabled
+ * while sched_in is called without rq lock and irq enabled.  This
+ * difference is intentional and depended upon by its users.
  */
 struct preempt_ops {
        void (*sched_in)(struct preempt_notifier *notifier, int cpu);