Add SCHED, SCHED2, TICK, and CXS overhead tracepoints

This patch integrates the overhead tracepoints into the Linux
scheduler that are compatible with plain vanilla Linux (i.e., not
specific to LITMUS^RT plugins).  This can be used to measure the
overheads of an otherwise unmodified kernel.

1 files changed, 15 insertions, 1 deletions

diff --git a/kernel/sched/core.c b/kernel/sched/core.c
index f286554e3395..50f9f4c45ce9 100644
--- a/kernel/sched/core.c
+++ b/kernel/sched/core.c
@@ -87,6 +87,8 @@
 #include "../workqueue_internal.h"
 #include "../smpboot.h"
 
+#include <litmus/trace.h>
+
 #define CREATE_TRACE_POINTS
 #include <trace/events/sched.h>
 
@@ -2748,6 +2750,8 @@ static void __sched __schedule(void)
         rcu_note_context_switch();
         prev = rq->curr;
 
+        TS_SCHED_START;
+
         schedule_debug(prev);
 
         if (sched_feat(HRTICK))
@@ -2800,14 +2804,24 @@ static void __sched __schedule(void)
                 rq->curr = next;
                 ++*switch_count;
 
+                TS_SCHED_END(next);
+                TS_CXS_START(next);
                 rq = context_switch(rq, prev, next); /* unlocks the rq */
+                TS_CXS_END(current);
+
                 cpu = cpu_of(rq);
-        } else
+        } else {
+                TS_SCHED_END(prev);
                 raw_spin_unlock_irq(&rq->lock);
+        }
+
+        TS_SCHED2_START(prev);
 
         post_schedule(rq);
 
         sched_preempt_enable_no_resched();
+
+        TS_SCHED2_END(prev);
 }
 
 static inline void sched_submit_work(struct task_struct *tsk)