trace: track enabled events in a separate array

This is more cache friendly on the fast path, where we already have
the event id available.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>

1 files changed, 11 insertions, 4 deletions

diff --git a/trace/control-internal.h b/trace/control-internal.h
index 271bddb19e..07cb1c1685 100644
--- a/trace/control-internal.h
+++ b/trace/control-internal.h
@@ -14,6 +14,7 @@
 
 
 extern TraceEvent trace_events[];
+extern bool trace_events_dstate[];
 extern int trace_events_enabled_count;
 
 
@@ -52,18 +53,24 @@ static inline bool trace_event_get_state_static(TraceEvent *ev)
     return ev->sstate;
 }
 
+static inline bool trace_event_get_state_dynamic_by_id(int id)
+{
+    return unlikely(trace_events_enabled_count) && trace_events_dstate[id];
+}
+
 static inline bool trace_event_get_state_dynamic(TraceEvent *ev)
 {
-    assert(ev != NULL);
-    return unlikely(trace_events_enabled_count) && ev->dstate;
+    int id = trace_event_get_id(ev);
+    return trace_event_get_state_dynamic_by_id(id);
 }
 
 static inline void trace_event_set_state_dynamic(TraceEvent *ev, bool state)
 {
+    int id = trace_event_get_id(ev);
     assert(ev != NULL);
     assert(trace_event_get_state_static(ev));
-    trace_events_enabled_count += state - ev->dstate;
-    ev->dstate = state;
+    trace_events_enabled_count += state - trace_events_dstate[id];
+    trace_events_dstate[id] = state;
 }
 
 #endif  /* TRACE__CONTROL_INTERNAL_H */