trace: let boot trace be chosen by command line

Now that we have a working ftrace=<tracer> function, make the boot
tracer get activated by it. This way we can turn it on or off without
recompiling the kernel, as well as keeping the selftests on. The
selftests are disabled whenever a default tracer starts running.

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

1 files changed, 1 insertions, 4 deletions

diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c
index 2c720c79bc60..40edef4255c5 100644
--- a/kernel/trace/trace.c
+++ b/kernel/trace/trace.c
@@ -3167,12 +3167,9 @@ __init static int tracer_alloc_buffers(void)
         trace_init_cmdlines();
 
         register_tracer(&nop_trace);
+        current_trace = &nop_trace;
 #ifdef CONFIG_BOOT_TRACER
         register_tracer(&boot_tracer);
-        current_trace = &boot_tracer;
-        current_trace->init(&global_trace);
-#else
-        current_trace = &nop_trace;
 #endif
         /* All seems OK, enable tracing */
         tracing_disabled = 0;