[PATCH v2 08/12] xen/sched: Clean up trace handling

[Andrew Cooper <andrew.cooper3@xxxxxxxxxx>]

There is no need for bitfields anywhere - use more sensible types.  There is
also no need to cast 'd' to (unsigned char *) before passing it to a function
taking void *.

No functional change.

Signed-off-by: Andrew Cooper <andrew.cooper3@xxxxxxxxxx>
---
CC: George Dunlap <George.Dunlap@xxxxxxxxxxxxx>
CC: Ian Jackson <iwj@xxxxxxxxxxxxxx>
CC: Jan Beulich <JBeulich@xxxxxxxx>
CC: Stefano Stabellini <sstabellini@xxxxxxxxxx>
CC: Wei Liu <wl@xxxxxxx>
CC: Julien Grall <julien@xxxxxxx>
CC: Juergen Gross <jgross@xxxxxxxx>
CC: Dario Faggioli <dfaggioli@xxxxxxxx>

v2:
 * New
---
 xen/common/sched/core.c   |  4 ++--
 xen/common/sched/credit.c | 38 ++++++++++++++++++--------------------
 xen/common/sched/null.c   | 42 +++++++++++++++++++++++++-----------------
 3 files changed, 45 insertions(+), 39 deletions(-)

diff --git a/xen/common/sched/core.c b/xen/common/sched/core.c
index 8f4b1ca10d1c..fe133cbf117c 100644
--- a/xen/common/sched/core.c
+++ b/xen/common/sched/core.c
@@ -205,7 +205,7 @@ static inline struct scheduler *vcpu_scheduler(const struct 
vcpu *v)
 
 static inline void trace_runstate_change(const struct vcpu *v, int new_state)
 {
-    struct { uint32_t vcpu:16, domain:16; } d;
+    struct { uint16_t vcpu, domain; } d;
     uint32_t event;
 
     if ( likely(!tb_init_done) )
@@ -223,7 +223,7 @@ static inline void trace_runstate_change(const struct vcpu 
*v, int new_state)
 
 static inline void trace_continue_running(const struct vcpu *v)
 {
-    struct { uint32_t vcpu:16, domain:16; } d;
+    struct { uint16_t vcpu, domain; } d;
 
     if ( likely(!tb_init_done) )
         return;
diff --git a/xen/common/sched/credit.c b/xen/common/sched/credit.c
index d0aa017c643e..f277fa37a8b1 100644
--- a/xen/common/sched/credit.c
+++ b/xen/common/sched/credit.c
@@ -1828,21 +1828,18 @@ static void csched_schedule(
     SCHED_STAT_CRANK(schedule);
     CSCHED_UNIT_CHECK(unit);
 
-    /*
-     * Here in Credit1 code, we usually just call TRACE_nD() helpers, and
-     * don't care about packing. But scheduling happens very often, so it
-     * actually is important that the record is as small as possible.
-     */
     if ( unlikely(tb_init_done) )
     {
         struct {
-            unsigned cpu:16, tasklet:8, idle:8;
-        } d;
-        d.cpu = cur_cpu;
-        d.tasklet = tasklet_work_scheduled;
-        d.idle = is_idle_unit(unit);
-        __trace_var(TRC_CSCHED_SCHEDULE, 1, sizeof(d),
-                    (unsigned char *)&d);
+            uint16_t cpu;
+            uint8_t tasklet, idle;
+        } d = {
+            .cpu     = cur_cpu,
+            .tasklet = tasklet_work_scheduled,
+            .idle    = is_idle_unit(unit),
+        };
+
+        __trace_var(TRC_CSCHED_SCHEDULE, 1, sizeof(d), &d);
     }
 
     runtime = now - unit->state_entry_time;
@@ -1904,14 +1901,15 @@ static void csched_schedule(
         if ( unlikely(tb_init_done) )
         {
             struct {
-                unsigned unit:16, dom:16;
-                unsigned runtime;
-            } d;
-            d.dom = unit->domain->domain_id;
-            d.unit = unit->unit_id;
-            d.runtime = runtime;
-            __trace_var(TRC_CSCHED_RATELIMIT, 1, sizeof(d),
-                        (unsigned char *)&d);
+                uint16_t unit, dom;
+                uint32_t runtime;
+            } d = {
+                .dom     = unit->domain->domain_id,
+                .unit    = unit->unit_id,
+                .runtime = runtime,
+            };
+
+            __trace_var(TRC_CSCHED_RATELIMIT, 1, sizeof(d), &d);
         }
 
         goto out;
diff --git a/xen/common/sched/null.c b/xen/common/sched/null.c
index 82d5d1baab85..deb59747fbe8 100644
--- a/xen/common/sched/null.c
+++ b/xen/common/sched/null.c
@@ -329,10 +329,12 @@ pick_res(const struct null_private *prv, const struct 
sched_unit *unit)
         struct {
             uint16_t unit, dom;
             uint32_t new_cpu;
-        } d;
-        d.dom = unit->domain->domain_id;
-        d.unit = unit->unit_id;
-        d.new_cpu = new_cpu;
+        } d = {
+            .unit    = unit->unit_id,
+            .dom     = unit->domain->domain_id,
+            .new_cpu = new_cpu,
+        };
+
         __trace_var(TRC_SNULL_PICKED_CPU, 1, sizeof(d), &d);
     }
 
@@ -357,10 +359,12 @@ static void unit_assign(struct null_private *prv, struct 
sched_unit *unit,
         struct {
             uint16_t unit, dom;
             uint32_t cpu;
-        } d;
-        d.dom = unit->domain->domain_id;
-        d.unit = unit->unit_id;
-        d.cpu = cpu;
+        } d = {
+            .unit = unit->unit_id,
+            .dom  = unit->domain->domain_id,
+            .cpu  = cpu,
+        };
+
         __trace_var(TRC_SNULL_UNIT_ASSIGN, 1, sizeof(d), &d);
     }
 }
@@ -388,10 +392,12 @@ static bool unit_deassign(struct null_private *prv, const 
struct sched_unit *uni
         struct {
             uint16_t unit, dom;
             uint32_t cpu;
-        } d;
-        d.dom = unit->domain->domain_id;
-        d.unit = unit->unit_id;
-        d.cpu = cpu;
+        } d = {
+            .unit = unit->unit_id,
+            .dom  = unit->domain->domain_id,
+            .cpu  = cpu,
+        };
+
         __trace_var(TRC_SNULL_UNIT_DEASSIGN, 1, sizeof(d), &d);
     }
 
@@ -691,11 +697,13 @@ static void null_unit_migrate(const struct scheduler *ops,
         struct {
             uint16_t unit, dom;
             uint16_t cpu, new_cpu;
-        } d;
-        d.dom = unit->domain->domain_id;
-        d.unit = unit->unit_id;
-        d.cpu = sched_unit_master(unit);
-        d.new_cpu = new_cpu;
+        } d = {
+            .unit    = unit->unit_id,
+            .dom     = unit->domain->domain_id,
+            .cpu     = sched_unit_master(unit),
+            .new_cpu = new_cpu,
+        };
+
         __trace_var(TRC_SNULL_MIGRATE, 1, sizeof(d), &d);
     }
 
-- 
2.11.0