sched: Add update_current_exec_runtime helper

Wrap repeated code in helper function update_current_exec_runtime for
update the exec time of the current.
Signed-off-by: Shang XiaoJing <shangxiaojing@huawei.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lkml.kernel.org/r/20220824082856.15674-1-shangxiaojing@huawei.com

kernel/sched/deadline.c

@@ -1333,11 +1333,7 @@ static void update_curr_dl(struct rq *rq)
 
 	trace_sched_stat_runtime(curr, delta_exec, 0);
 
-	curr->se.sum_exec_runtime += delta_exec;
-	account_group_exec_runtime(curr, delta_exec);
-
-	curr->se.exec_start = now;
-	cgroup_account_cputime(curr, delta_exec);
+	update_current_exec_runtime(curr, now, delta_exec);
 
 	if (dl_entity_is_special(dl_se))
 		return;

kernel/sched/rt.c

@@ -1062,11 +1062,7 @@ static void update_curr_rt(struct rq *rq)
 
 	trace_sched_stat_runtime(curr, delta_exec, 0);
 
-	curr->se.sum_exec_runtime += delta_exec;
-	account_group_exec_runtime(curr, delta_exec);
-
-	curr->se.exec_start = now;
-	cgroup_account_cputime(curr, delta_exec);
+	update_current_exec_runtime(curr, now, delta_exec);
 
 	if (!rt_bandwidth_enabled())
 		return;

kernel/sched/sched.h

@@ -3158,4 +3158,14 @@ extern int sched_dynamic_mode(const char *str);
 extern void sched_dynamic_update(int mode);
 #endif
 
+static inline void update_current_exec_runtime(struct task_struct *curr,
+						u64 now, u64 delta_exec)
+{
+	curr->se.sum_exec_runtime += delta_exec;
+	account_group_exec_runtime(curr, delta_exec);
+
+	curr->se.exec_start = now;
+	cgroup_account_cputime(curr, delta_exec);
+}
+
 #endif /* _KERNEL_SCHED_SCHED_H */

kernel/sched/stop_task.c

@@ -71,20 +71,17 @@ static void yield_task_stop(struct rq *rq)
 static void put_prev_task_stop(struct rq *rq, struct task_struct *prev)
 {
 	struct task_struct *curr = rq->curr;
-	u64 delta_exec;
+	u64 now, delta_exec;
 
-	delta_exec = rq_clock_task(rq) - curr->se.exec_start;
+	now = rq_clock_task(rq);
+	delta_exec = now - curr->se.exec_start;
 	if (unlikely((s64)delta_exec < 0))
 		delta_exec = 0;
 
 	schedstat_set(curr->stats.exec_max,
 		      max(curr->stats.exec_max, delta_exec));
 
-	curr->se.sum_exec_runtime += delta_exec;
-	account_group_exec_runtime(curr, delta_exec);
-
-	curr->se.exec_start = rq_clock_task(rq);
-	cgroup_account_cputime(curr, delta_exec);
+	update_current_exec_runtime(curr, now, delta_exec);
 }
 
 /*