ftrace: cleanups

factor out code and clean it up.

Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
diff --git a/kernel/trace/trace.h b/kernel/trace/trace.h
index 88edbf1..cc1d34b 100644
--- a/kernel/trace/trace.h
+++ b/kernel/trace/trace.h
@@ -53,12 +53,12 @@
  * the trace, etc.)
  */
 struct trace_array_cpu {
-	void			*trace;
 	void			*trace_current;
-	unsigned		trace_current_idx;
 	struct list_head	trace_pages;
-	unsigned long		trace_idx;
 	atomic_t		disabled;
+	/* these fields get copied into max-trace: */
+	unsigned		trace_current_idx;
+	unsigned long		trace_idx;
 	unsigned long		saved_latency;
 	unsigned long		critical_start;
 	unsigned long		critical_end;
@@ -216,4 +216,6 @@
 #endif
 #endif /* CONFIG_FTRACE_STARTUP_TEST */
 
+extern void *head_page(struct trace_array_cpu *data);
+
 #endif /* _LINUX_KERNEL_TRACE_H */