tracing: Drop lock_acquired waittime field

Drop the waittime field from the lock_acquired event, we can
calculate it by substracting the lock_acquired event timestamp
with the matching lock_acquire one.

It is not needed and takes useless space in the traces.

Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Hitoshi Mitake <mitake@dcl.info.waseda.ac.jp>
Cc: Steven Rostedt <rostedt@goodmis.org>

2 files changed, 5 insertions, 8 deletions

diff --git a/include/trace/events/lock.h b/include/trace/events/lock.h
index 5c1dcfc16c60..17ca287ae176 100644
--- a/include/trace/events/lock.h
+++ b/include/trace/events/lock.h
@@ -78,24 +78,21 @@ TRACE_EVENT(lock_contended,
 );
 
 TRACE_EVENT(lock_acquired,
-        TP_PROTO(struct lockdep_map *lock, unsigned long ip, s64 waittime),
+        TP_PROTO(struct lockdep_map *lock, unsigned long ip),
 
-        TP_ARGS(lock, ip, waittime),
+        TP_ARGS(lock, ip),
 
         TP_STRUCT__entry(
                 __string(name, lock->name)
-                __field(s64, wait_nsec)
                 __field(void *, lockdep_addr)
         ),
 
         TP_fast_assign(
                 __assign_str(name, lock->name);
-                __entry->wait_nsec = waittime;
                 __entry->lockdep_addr = lock;
         ),
-        TP_printk("%p %s (%llu ns)", __entry->lockdep_addr,
-                  __get_str(name),
-                  __entry->wait_nsec)
+        TP_printk("%p %s", __entry->lockdep_addr,
+                  __get_str(name))
 );
 
 #endif
diff --git a/kernel/lockdep.c b/kernel/lockdep.c
index 2594e1ce41cb..31e22e742368 100644
--- a/kernel/lockdep.c
+++ b/kernel/lockdep.c
@@ -3380,7 +3380,7 @@ found_it:
                 hlock->holdtime_stamp = now;
         }
 
-        trace_lock_acquired(lock, ip, waittime);
+        trace_lock_acquired(lock, ip);
 
         stats = get_lock_stats(hlock_class(hlock));
         if (waittime) {