mm: get rid of unnecessary overhead of trace_mm_page_alloc_extfrag()

In general, every tracepoint should be zero overhead if it is disabled.
However, trace_mm_page_alloc_extfrag() is one of exception.  It evaluate
"new_type == start_migratetype" even if tracepoint is disabled.

However, the code can be moved into tracepoint's TP_fast_assign() and
TP_fast_assign exist exactly such purpose.  This patch does it.

Signed-off-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Acked-by: Mel Gorman <mgorman@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 4 insertions, 6 deletions

diff --git a/include/trace/events/kmem.h b/include/trace/events/kmem.h
index d0c613476620..aece1346ceb7 100644
--- a/include/trace/events/kmem.h
+++ b/include/trace/events/kmem.h
@@ -267,14 +267,12 @@ DEFINE_EVENT_PRINT(mm_page, mm_page_pcpu_drain,
 TRACE_EVENT(mm_page_alloc_extfrag,
 
         TP_PROTO(struct page *page,
-                        int alloc_order, int fallback_order,
-                        int alloc_migratetype, int fallback_migratetype,
-                        int change_ownership),
+                int alloc_order, int fallback_order,
+                int alloc_migratetype, int fallback_migratetype, int new_migratetype),
 
         TP_ARGS(page,
                 alloc_order, fallback_order,
-                alloc_migratetype, fallback_migratetype,
-                change_ownership),
+                alloc_migratetype, fallback_migratetype, new_migratetype),
 
         TP_STRUCT__entry(
                 __field(        struct page *,  page                    )
@@ -291,7 +289,7 @@ TRACE_EVENT(mm_page_alloc_extfrag,
                 __entry->fallback_order         = fallback_order;
                 __entry->alloc_migratetype      = alloc_migratetype;
                 __entry->fallback_migratetype   = fallback_migratetype;
-                __entry->change_ownership       = change_ownership;
+                __entry->change_ownership       = (new_migratetype == alloc_migratetype);
         ),
 
         TP_printk("page=%p pfn=%lu alloc_order=%d fallback_order=%d pageblock_order=%d alloc_migratetype=%d fallback_migratetype=%d fragmenting=%d change_ownership=%d",