tracing/events: Move TRACE_SYSTEM outside of include guard

If TRACE_INCLDUE_FILE is defined, <trace/events/TRACE_INCLUDE_FILE.h>
will be included and compiled, otherwise it will be
<trace/events/TRACE_SYSTEM.h>

So TRACE_SYSTEM should be defined outside of #if proctection,
just like TRACE_INCLUDE_FILE.

Imaging this scenario:

 #include <trace/events/foo.h>
    -> TRACE_SYSTEM == foo
 ...
 #include <trace/events/bar.h>
    -> TRACE_SYSTEM == bar
 ...
 #define CREATE_TRACE_POINTS
 #include <trace/events/foo.h>
    -> TRACE_SYSTEM == bar !!!

and then bar.h will be included and compiled.
Signed-off-by: Li Zefan <lizf@cn.fujitsu.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
LKML-Reference: <4A5A9CF1.2010007@cn.fujitsu.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

fs/gfs2/trace_gfs2.h

+#undef TRACE_SYSTEM
+#define TRACE_SYSTEM gfs2
+
 #if !defined(_TRACE_GFS2_H) || defined(TRACE_HEADER_MULTI_READ)
 #define _TRACE_GFS2_H
 
 #include <linux/tracepoint.h>
 
-#undef TRACE_SYSTEM
-#define TRACE_SYSTEM gfs2
-#define TRACE_INCLUDE_FILE trace_gfs2
-
 #include <linux/fs.h>
 #include <linux/buffer_head.h>
 #include <linux/dlmconstants.h>
@@ -403,5 +402,6 @@ TRACE_EVENT(gfs2_block_alloc,
 /* This part must be outside protection */
 #undef TRACE_INCLUDE_PATH
 #define TRACE_INCLUDE_PATH .
+#define TRACE_INCLUDE_FILE trace_gfs2
 #include <trace/define_trace.h>
 

include/trace/events/block.h

+#undef TRACE_SYSTEM
+#define TRACE_SYSTEM block
+
 #if !defined(_TRACE_BLOCK_H) || defined(TRACE_HEADER_MULTI_READ)
 #define _TRACE_BLOCK_H
 
@@ -5,9 +8,6 @@
 #include <linux/blkdev.h>
 #include <linux/tracepoint.h>
 
-#undef TRACE_SYSTEM
-#define TRACE_SYSTEM block
-
 TRACE_EVENT(block_rq_abort,
 
 	TP_PROTO(struct request_queue *q, struct request *rq),

include/trace/events/ext4.h

-#if !defined(_TRACE_EXT4_H) || defined(TRACE_HEADER_MULTI_READ)
-#define _TRACE_EXT4_H
-
 #undef TRACE_SYSTEM
 #define TRACE_SYSTEM ext4
 
+#if !defined(_TRACE_EXT4_H) || defined(TRACE_HEADER_MULTI_READ)
+#define _TRACE_EXT4_H
+
 #include <linux/writeback.h>
 #include "../../../fs/ext4/ext4.h"
 #include "../../../fs/ext4/mballoc.h"

include/trace/events/irq.h

+#undef TRACE_SYSTEM
+#define TRACE_SYSTEM irq
+
 #if !defined(_TRACE_IRQ_H) || defined(TRACE_HEADER_MULTI_READ)
 #define _TRACE_IRQ_H
 
 #include <linux/tracepoint.h>
 #include <linux/interrupt.h>
 
-#undef TRACE_SYSTEM
-#define TRACE_SYSTEM irq
-
 #define softirq_name(sirq) { sirq##_SOFTIRQ, #sirq }
 #define show_softirq_name(val)			\
 	__print_symbolic(val,			\

include/trace/events/jbd2.h

+#undef TRACE_SYSTEM
+#define TRACE_SYSTEM jbd2
+
 #if !defined(_TRACE_JBD2_H) || defined(TRACE_HEADER_MULTI_READ)
 #define _TRACE_JBD2_H
 
 #include <linux/jbd2.h>
 #include <linux/tracepoint.h>
 
-#undef TRACE_SYSTEM
-#define TRACE_SYSTEM jbd2
-
 TRACE_EVENT(jbd2_checkpoint,
 
 	TP_PROTO(journal_t *journal, int result),

include/trace/events/kmem.h

+#undef TRACE_SYSTEM
+#define TRACE_SYSTEM kmem
+
 #if !defined(_TRACE_KMEM_H) || defined(TRACE_HEADER_MULTI_READ)
 #define _TRACE_KMEM_H
 
 #include <linux/types.h>
 #include <linux/tracepoint.h>
 
-#undef TRACE_SYSTEM
-#define TRACE_SYSTEM kmem
-
 /*
  * The order of these masks is important. Matching masks will be seen
  * first and the left over flags will end up showing by themselves.

include/trace/events/lockdep.h

+#undef TRACE_SYSTEM
+#define TRACE_SYSTEM lockdep
+
 #if !defined(_TRACE_LOCKDEP_H) || defined(TRACE_HEADER_MULTI_READ)
 #define _TRACE_LOCKDEP_H
 
 #include <linux/lockdep.h>
 #include <linux/tracepoint.h>
 
-#undef TRACE_SYSTEM
-#define TRACE_SYSTEM lockdep
-
 #ifdef CONFIG_LOCKDEP
 
 TRACE_EVENT(lock_acquire,

include/trace/events/sched.h

+#undef TRACE_SYSTEM
+#define TRACE_SYSTEM sched
+
 #if !defined(_TRACE_SCHED_H) || defined(TRACE_HEADER_MULTI_READ)
 #define _TRACE_SCHED_H
 
 #include <linux/sched.h>
 #include <linux/tracepoint.h>
 
-#undef TRACE_SYSTEM
-#define TRACE_SYSTEM sched
-
 /*
  * Tracepoint for calling kthread_stop, performed to end a kthread:
  */

include/trace/events/skb.h

+#undef TRACE_SYSTEM
+#define TRACE_SYSTEM skb
+
 #if !defined(_TRACE_SKB_H) || defined(TRACE_HEADER_MULTI_READ)
 #define _TRACE_SKB_H
 
 #include <linux/skbuff.h>
 #include <linux/tracepoint.h>
 
-#undef TRACE_SYSTEM
-#define TRACE_SYSTEM skb
-
 /*
  * Tracepoint for free an sk_buff:
  */

include/trace/events/workqueue.h

+#undef TRACE_SYSTEM
+#define TRACE_SYSTEM workqueue
+
 #if !defined(_TRACE_WORKQUEUE_H) || defined(TRACE_HEADER_MULTI_READ)
 #define _TRACE_WORKQUEUE_H
 
@@ -5,9 +8,6 @@
 #include <linux/sched.h>
 #include <linux/tracepoint.h>
 
-#undef TRACE_SYSTEM
-#define TRACE_SYSTEM workqueue
-
 TRACE_EVENT(workqueue_insertion,
 
 	TP_PROTO(struct task_struct *wq_thread, struct work_struct *work),

samples/trace_events/trace-events-sample.h

-/*
- * Notice that this file is not protected like a normal header.
- * We also must allow for rereading of this file. The
- *
- *  || defined(TRACE_HEADER_MULTI_READ)
- *
- * serves this purpose.
- */
-#if !defined(_TRACE_EVENT_SAMPLE_H) || defined(TRACE_HEADER_MULTI_READ)
-#define _TRACE_EVENT_SAMPLE_H
-
-/*
- * All trace headers should include tracepoint.h, until we finally
- * make it into a standard header.
- */
-#include <linux/tracepoint.h>
-
 /*
  * If TRACE_SYSTEM is defined, that will be the directory created
  * in the ftrace directory under /debugfs/tracing/events/<system>
@@ -34,10 +17,30 @@
  * #define TRACE_INCLUDE_FILE trace-events-sample
  *
  * As we do an the bottom of this file.
+ *
+ * Notice that TRACE_SYSTEM should be defined outside of #if
+ * protection, just like TRACE_INCLUDE_FILE.
  */
 #undef TRACE_SYSTEM
 #define TRACE_SYSTEM sample
 
+/*
+ * Notice that this file is not protected like a normal header.
+ * We also must allow for rereading of this file. The
+ *
+ *  || defined(TRACE_HEADER_MULTI_READ)
+ *
+ * serves this purpose.
+ */
+#if !defined(_TRACE_EVENT_SAMPLE_H) || defined(TRACE_HEADER_MULTI_READ)
+#define _TRACE_EVENT_SAMPLE_H
+
+/*
+ * All trace headers should include tracepoint.h, until we finally
+ * make it into a standard header.
+ */
+#include <linux/tracepoint.h>
+
 /*
  * The TRACE_EVENT macro is broken up into 5 parts.
  *