mm: mmap_lock: use DECLARE_EVENT_CLASS and DEFINE_EVENT_FN

By using DECLARE_EVENT_CLASS and TRACE_EVENT_FN, we can save a lot of
space from duplicate code.

Link: https://lkml.kernel.org/r/20211009071243.70286-1-ligang.bdlg@bytedance.comSigned-off-by: Gang Li <ligang.bdlg@bytedance.com>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Reviewed-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Cc: Axel Rasmussen <axelrasmussen@google.com>
Cc: Ingo Molnar <mingo@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

include/trace/events/mmap_lock.h

@@ -13,7 +13,7 @@ struct mm_struct;
 extern int trace_mmap_lock_reg(void);
 extern void trace_mmap_lock_unreg(void);
 
-TRACE_EVENT_FN(mmap_lock_start_locking,
+DECLARE_EVENT_CLASS(mmap_lock,
 
 	TP_PROTO(struct mm_struct *mm, const char *memcg_path, bool write),
 
@@ -36,11 +36,19 @@ TRACE_EVENT_FN(mmap_lock_start_locking,
 		__entry->mm,
 		__get_str(memcg_path),
 		__entry->write ? "true" : "false"
-	),
-
-	trace_mmap_lock_reg, trace_mmap_lock_unreg
+	)
 );
 
+#define DEFINE_MMAP_LOCK_EVENT(name)                                    \
+	DEFINE_EVENT_FN(mmap_lock, name,                                \
+		TP_PROTO(struct mm_struct *mm, const char *memcg_path,  \
+			bool write),                                    \
+		TP_ARGS(mm, memcg_path, write),                         \
+		trace_mmap_lock_reg, trace_mmap_lock_unreg)
+
+DEFINE_MMAP_LOCK_EVENT(mmap_lock_start_locking);
+DEFINE_MMAP_LOCK_EVENT(mmap_lock_released);
+
 TRACE_EVENT_FN(mmap_lock_acquire_returned,
 
 	TP_PROTO(struct mm_struct *mm, const char *memcg_path, bool write,
@@ -73,34 +81,6 @@ TRACE_EVENT_FN(mmap_lock_acquire_returned,
 	trace_mmap_lock_reg, trace_mmap_lock_unreg
 );
 
-TRACE_EVENT_FN(mmap_lock_released,
-
-	TP_PROTO(struct mm_struct *mm, const char *memcg_path, bool write),
-
-	TP_ARGS(mm, memcg_path, write),
-
-	TP_STRUCT__entry(
-		__field(struct mm_struct *, mm)
-		__string(memcg_path, memcg_path)
-		__field(bool, write)
-	),
-
-	TP_fast_assign(
-		__entry->mm = mm;
-		__assign_str(memcg_path, memcg_path);
-		__entry->write = write;
-	),
-
-	TP_printk(
-		"mm=%p memcg_path=%s write=%s",
-		__entry->mm,
-		__get_str(memcg_path),
-		__entry->write ? "true" : "false"
-	),
-
-	trace_mmap_lock_reg, trace_mmap_lock_unreg
-);
-
 #endif /* _TRACE_MMAP_LOCK_H */
 
 /* This part must be outside protection */