vmscan: convert direct reclaim tracepoint to DEFINE_TRACE

Mel Gorman recently added some vmscan tracepoints.  Unfortunately they are
covered only global reclaim.  But we want to trace memcg reclaim too.

Thus, this patch convert them to DEFINE_TRACE macro.  it help to reuse
tracepoint definition for other similar usage (i.e.  memcg).  This patch
have no functionally change.

Signed-off-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Reviewed-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Acked-by: Mel Gorman <mel@csn.ul.ie>
Acked-by: Balbir Singh <balbir@linux.vnet.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

include/trace/events/vmscan.h

@@ -86,7 +86,7 @@ TRACE_EVENT(mm_vmscan_wakeup_kswapd,
 		__entry->order)
 );
 
-TRACE_EVENT(mm_vmscan_direct_reclaim_begin,
+DECLARE_EVENT_CLASS(mm_vmscan_direct_reclaim_begin_template,
 
 	TP_PROTO(int order, int may_writepage, gfp_t gfp_flags),
 
@@ -110,7 +110,15 @@ TRACE_EVENT(mm_vmscan_direct_reclaim_begin,
 		show_gfp_flags(__entry->gfp_flags))
 );
 
-TRACE_EVENT(mm_vmscan_direct_reclaim_end,
+DEFINE_EVENT(mm_vmscan_direct_reclaim_begin_template, mm_vmscan_direct_reclaim_begin,
+
+	TP_PROTO(int order, int may_writepage, gfp_t gfp_flags),
+
+	TP_ARGS(order, may_writepage, gfp_flags)
+);
+
+
+DECLARE_EVENT_CLASS(mm_vmscan_direct_reclaim_end_template,
 
 	TP_PROTO(unsigned long nr_reclaimed),
 
@@ -127,6 +135,13 @@ TRACE_EVENT(mm_vmscan_direct_reclaim_end,
 	TP_printk("nr_reclaimed=%lu", __entry->nr_reclaimed)
 );
 
+DEFINE_EVENT(mm_vmscan_direct_reclaim_end_template, mm_vmscan_direct_reclaim_end,
+
+	TP_PROTO(unsigned long nr_reclaimed),
+
+	TP_ARGS(nr_reclaimed)
+);
+
 TRACE_EVENT(mm_vmscan_lru_isolate,
 
 	TP_PROTO(int order,