credit2: pack trace data better for xentrace_format

when tracing runstate changes, the vcpu and domain IDs
are encoded in the lower and higher, respectively, parts
of a 32 bits integer. When decoding a trace with
xentrace_format, this makes it possible to display
such events like this:

CPU0  833435853624 (+     768)  running_to_runnable [ dom:vcpu = 0x7fff0000 ]
CPU0  833435854416 (+     792)  runnable_to_running [ dom:vcpu = 0x00000007 ]

For consistency, we should do the same when displaying
the events coming from the Credit2 scheduler (when using
the same tool), and to do that, we need to invert the
order in which the fields are being put in the trace
struct right now.

Signed-off-by: Dario Faggioli <dario.faggioli@citrix.com>
Reviewed-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Acked-by: George Dunlap <george.dunlap@citrix.com>

diff --git a/xen/common/sched_credit2.c b/xen/common/sched_credit2.c
index 78220a7ca06c3ecfe6698968e15e2ae94881ac16..cf40f68d0072851550909d914b0625dd675e952c 100644 (file)
--- a/xen/common/sched_credit2.c
+++ b/xen/common/sched_credit2.c
@@ -382,7 +382,7 @@ __update_svc_load(const struct scheduler *ops,
 
     {
         struct {
-            unsigned dom:16,vcpu:16;
+            unsigned vcpu:16, dom:16;
             unsigned v_avgload:32;
         } d;
         d.dom = svc->vcpu->domain->domain_id;
@@ -450,7 +450,7 @@ runq_insert(const struct scheduler *ops, unsigned int cpu, struct csched2_vcpu *
 
     {
         struct {
-            unsigned dom:16,vcpu:16;
+            unsigned vcpu:16, dom:16;
             unsigned pos;
         } d;
         d.dom = svc->vcpu->domain->domain_id;
@@ -536,7 +536,7 @@ runq_tickle(const struct scheduler *ops, unsigned int cpu, struct csched2_vcpu *
 
         /* TRACE */ {
             struct {
-                unsigned dom:16,vcpu:16;
+                unsigned vcpu:16, dom:16;
                 unsigned credit;
             } d;
             d.dom = cur->vcpu->domain->domain_id;
@@ -561,9 +561,9 @@ tickle:
 
     /* TRACE */ {
         struct {
-            unsigned cpu:8;
+            unsigned cpu:16, pad:16;
         } d;
-        d.cpu = ipid;
+        d.cpu = ipid; d.pad = 0;
         trace_var(TRC_CSCHED2_TICKLE, 0,
                   sizeof(d),
                   (unsigned char *)&d);
@@ -634,7 +634,7 @@ static void reset_credit(const struct scheduler *ops, int cpu, s_time_t now,
 
         /* TRACE */ {
             struct {
-                unsigned dom:16,vcpu:16;
+                unsigned vcpu:16, dom:16;
                 unsigned credit_start, credit_end;
                 unsigned multiplier;
             } d;
@@ -683,7 +683,7 @@ void burn_credits(struct csched2_runqueue_data *rqd, struct csched2_vcpu *svc, s
     /* TRACE */
     {
         struct {
-            unsigned dom:16,vcpu:16;
+            unsigned vcpu:16, dom:16;
             unsigned credit;
             int delta;
         } d;
@@ -812,7 +812,7 @@ __runq_assign(struct csched2_vcpu *svc, struct csched2_runqueue_data *rqd)
     /* TRACE */
     {
         struct {
-            unsigned dom:16,vcpu:16;
+            unsigned vcpu:16, dom:16;
             unsigned rqi:16;
         } d;
         d.dom = svc->vcpu->domain->domain_id;