Move SCHED2 trace points to post_schedule()

Linux's post_schedule() scheduling class hook more closely matches
what SCHED2 is supposed to trace, namely any scheduling overhead after
the context switch. The prior trace points caught timers being armed
from finish_switch(), which is already included in the context switch
cost CXS.

(This patch essentially reverts 8fe2fb8bb1c1cd0194608bc783d0ce7029e8d869).

2 files changed, 7 insertions, 11 deletions

diff --git a/kernel/sched.c b/kernel/sched.c
index 1d7b38a7ff25..c4b6bd5151ff 100644
--- a/kernel/sched.c
+++ b/kernel/sched.c
@@ -4417,14 +4417,20 @@ litmus_need_resched_nonpreemptible:
                 raw_spin_unlock_irq(&rq->lock);
         }
 
+        TS_SCHED2_START(prev);
         sched_trace_task_switch_to(current);
 
         post_schedule(rq);
 
-        if (sched_state_validate_switch())
+        if (sched_state_validate_switch()) {
+                TS_SCHED2_END(prev);
                 goto litmus_need_resched_nonpreemptible;
+        }
 
         preempt_enable_no_resched();
+
+        TS_SCHED2_END(prev);
+
         if (need_resched())
                 goto need_resched;
 
diff --git a/litmus/rt_domain.c b/litmus/rt_domain.c
index d0b796611bea..1683d3847560 100644
--- a/litmus/rt_domain.c
+++ b/litmus/rt_domain.c
@@ -331,12 +331,7 @@ void __add_release_on(rt_domain_t* rt, struct task_struct *task,
         list_add(&tsk_rt(task)->list, &rt->tobe_released);
         task->rt_param.domain = rt;
 
-        /* start release timer */
-        TS_SCHED2_START(task);
-
         arm_release_timer_on(rt, target_cpu);
-
-        TS_SCHED2_END(task);
 }
 #endif
 
@@ -349,11 +344,6 @@ void __add_release(rt_domain_t* rt, struct task_struct *task)
         list_add(&tsk_rt(task)->list, &rt->tobe_released);
         task->rt_param.domain = rt;
 
-        /* start release timer */
-        TS_SCHED2_START(task);
-
         arm_release_timer(rt);
-
-        TS_SCHED2_END(task);
 }