trace: split trace_init_events out of trace_init_backends

This is cleaner and has two advantages.  First, it improves error
reporting with -daemonize.  Second, multiple "-trace events" options
now cumulate.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Denis V. Lunev <den@openvz.org>
Acked-by: Christian Borntraeger <borntraeger@de.ibm.com>
Message-id: 1452174932-28657-3-git-send-email-den@openvz.org
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>

1 files changed, 12 insertions, 3 deletions

diff --git a/trace/control.h b/trace/control.h
index 6af7ddc628..7905917213 100644
--- a/trace/control.h
+++ b/trace/control.h
@@ -150,8 +150,6 @@ static void trace_event_set_state_dynamic(TraceEvent *ev, bool state);
 
 /**
  * trace_init_backends:
- * @events: Name of file with events to be enabled at startup; may be NULL.
- *          Corresponds to commandline option "-trace events=...".
  * @file:   Name of trace output file; may be NULL.
  *          Corresponds to commandline option "-trace file=...".
  *
@@ -159,7 +157,18 @@ static void trace_event_set_state_dynamic(TraceEvent *ev, bool state);
  *
  * Returns: Whether the backends could be successfully initialized.
  */
-bool trace_init_backends(const char *events, const char *file);
+bool trace_init_backends(const char *file);
+
+/**
+ * trace_init_events:
+ * @events: Name of file with events to be enabled at startup; may be NULL.
+ *          Corresponds to commandline option "-trace events=...".
+ *
+ * Read the list of enabled tracing events.
+ *
+ * Returns: Whether the backends could be successfully initialized.
+ */
+void trace_init_events(const char *file);
 
 
 #include "trace/control-internal.h"