commit 93977402441405055500ff0389b49f6bbac9d50b
author Daniel P. Berrange <berrange@redhat.com> Tue Oct 04 14:35:45 2016 +0100
committer Stefan Hajnoczi <stefanha@redhat.com> Wed Oct 12 09:35:54 2016 +0200
tree 3a1e1ded1e54db71d2576460552faae5d0f32136
parent 599ab2f241ee6693ea0a2700210718327b346f7f

trace: remove global 'uint16 dstate[]' array

Instead of having a global dstate array, declare a single
'uint16 TRACE_${EVENT_NAME}_DSTATE' variable for each
trace event. Record a pointer to this variable in the
TraceEvent struct too.

By turning trace_event_get_state_dynamic_by_id into a
macro, this still hits the fast path, and cache affinity
is ensured by declaring all the uint16 vars adjacent to
each other.

Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Reviewed-by: Lluís Vilanova <vilanova@ac.upc.edu>
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
Message-id: 1475588159-30598-7-git-send-email-berrange@redhat.com
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>

trace/control-target.c

diff --git a/trace/control-target.c b/trace/control-target.c
index 50bac4f..3b55941 100644
--- a/trace/control-target.c
+++ b/trace/control-target.c
@@ -16,21 +16,20 @@
 
 void trace_event_set_state_dynamic_init(TraceEvent *ev, bool state)
 {
-    TraceEventID id = trace_event_get_id(ev);
     bool state_pre;
     assert(trace_event_get_state_static(ev));
     /*
      * We ignore the "vcpu" property here, since no vCPUs have been created
      * yet. Then dstate can only be 1 or 0.
      */
-    state_pre = trace_events_dstate[id];
+    state_pre = *ev->dstate;
     if (state_pre != state) {
         if (state) {
             trace_events_enabled_count++;
-            trace_events_dstate[id] = 1;
+            *ev->dstate = 1;
         } else {
             trace_events_enabled_count--;
-            trace_events_dstate[id] = 0;
+            *ev->dstate = 0;
         }
     }
 }
@@ -45,15 +44,14 @@
         }
     } else {
         /* Without the "vcpu" property, dstate can only be 1 or 0 */
-        TraceEventID id = trace_event_get_id(ev);
-        bool state_pre = trace_events_dstate[id];
+        bool state_pre = *ev->dstate;
         if (state_pre != state) {
             if (state) {
                 trace_events_enabled_count++;
-                trace_events_dstate[id] = 1;
+                *ev->dstate = 1;
             } else {
                 trace_events_enabled_count--;
-                trace_events_dstate[id] = 0;
+                *ev->dstate = 0;
             }
         }
     }
@@ -62,23 +60,21 @@
 void trace_event_set_vcpu_state_dynamic(CPUState *vcpu,
                                         TraceEvent *ev, bool state)
 {
-    TraceEventID id;
     TraceEventVCPUID vcpu_id;
     bool state_pre;
     assert(trace_event_get_state_static(ev));
     assert(trace_event_is_vcpu(ev));
-    id = trace_event_get_id(ev);
     vcpu_id = trace_event_get_vcpu_id(ev);
     state_pre = test_bit(vcpu_id, vcpu->trace_dstate);
     if (state_pre != state) {
         if (state) {
             trace_events_enabled_count++;
             set_bit(vcpu_id, vcpu->trace_dstate);
-            trace_events_dstate[id]++;
+            (*ev->dstate)++;
         } else {
             trace_events_enabled_count--;
             clear_bit(vcpu_id, vcpu->trace_dstate);
-            trace_events_dstate[id]--;
+            (*ev->dstate)--;
         }
     }
 }
@@ -105,12 +101,11 @@
         if (trace_event_is_vcpu(ev) &&
             trace_event_get_state_static(ev) &&
             trace_event_get_state_dynamic(ev)) {
-            TraceEventID id = trace_event_get_id(ev);
             if (adding_first_cpu()) {
                 /* check preconditions */
-                assert(trace_events_dstate[id] == 1);
+                assert(*ev->dstate == 1);
                 /* disable early-init state ... */
-                trace_events_dstate[id] = 0;
+                *ev->dstate = 0;
                 trace_events_enabled_count--;
                 /* ... and properly re-enable */
                 trace_event_set_vcpu_state_dynamic(vcpu, ev, true);