Commit e7ad2031 authored Feb 05, 2018 by Wen Yang Committed by Ingo Molnar Feb 06, 2018

sched/rt: Make update_curr_rt() more accurate



rq->clock_task may be updated between the two calls of
rq_clock_task() in update_curr_rt(). Calling rq_clock_task() only
once makes it more accurate and efficient, taking update_curr() as
reference.

Signed-off-by: Wen Yang <wen.yang99@zte.com.cn>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Jiang Biao <jiang.biao2@zte.com.cn>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: zhong.weidong@zte.com.cn
Link: http://lkml.kernel.org/r/1517800721-42092-1-git-send-email-wen.yang99@zte.com.cn


Signed-off-by: Ingo Molnar <mingo@kernel.org>

parent 364f5665

kernel/sched/rt.c

+3 −2

Original line number	Diff line number	Diff line
		@@ -950,12 +950,13 @@ static void update_curr_rt(struct rq *rq)
		{
		struct task_struct *curr = rq->curr;
		struct sched_rt_entity *rt_se = &curr->rt;
		u64 now = rq_clock_task(rq);
		u64 delta_exec;

		if (curr->sched_class != &rt_sched_class)
		return;

		delta_exec = rq_clock_task(rq) - curr->se.exec_start;
		delta_exec = now - curr->se.exec_start;
		if (unlikely((s64)delta_exec <= 0))
		return;

		@@ -968,7 +969,7 @@ static void update_curr_rt(struct rq *rq)
		curr->se.sum_exec_runtime += delta_exec;
		account_group_exec_runtime(curr, delta_exec);

		curr->se.exec_start = rq_clock_task(rq);
		curr->se.exec_start = now;
		cgroup_account_cputime(curr, delta_exec);

		sched_rt_avg_update(rq, delta_exec);