tracing/ftrace: separate events tracing and stats tracing engine

Impact: tracing's Api change

Currently, the stat tracing depends on the events tracing.
When you switch to a new tracer, the stats files of the previous tracer
will disappear. But it's more scalable to separate those two engines.
This way, we can keep the stat files of one or several tracers when we
want, without bothering of multiple tracer stat files or tracer switching.

To build/destroys its stats files, a tracer just have to call
register_stat_tracer/unregister_stat_tracer everytimes it wants to.

Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
Signed-off-by: Steven Rostedt <srostedt@redhat.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

1 files changed, 0 insertions, 2 deletions

diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c
index 0418fc338b5c..40217fb499ea 100644
--- a/kernel/trace/trace.c
+++ b/kernel/trace/trace.c
@@ -2353,7 +2353,6 @@ static int tracing_set_tracer(char *buf)
                 if (ret)
                         goto out;
         }
-        init_tracer_stat(t);
 
         trace_branch_enable(tr);
  out:
@@ -3218,7 +3217,6 @@ __init static int tracer_alloc_buffers(void)
 #else
         current_trace = &nop_trace;
 #endif
-        init_tracer_stat(current_trace);
         /* All seems OK, enable tracing */
         tracing_disabled = 0;