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>

diff --git a/include/trace/events/lock.h b/include/trace/events/lock.h
index 5c1dcfc16c6037019d8bcecf4e7c2fa4f3649505..17ca287ae176ceda2241b94b8b7890cd6727a870 100644 (file)
--- 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 2594e1ce41cbf12889b44deb3fc202c0a5c30fa2..31e22e742368b8c0e2d8e8051c4d08f47b6fb252 100644 (file)
--- 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) {