Commit-ID: e7ad203166fff89b1d8253faf68fbe6966bf7181 Gitweb: https://git.kernel.org/tip/e7ad203166fff89b1d8253faf68fbe6966bf7181 Author: Wen Yang <wen.yan...@zte.com.cn> AuthorDate: Mon, 5 Feb 2018 11:18:41 +0800 Committer: Ingo Molnar <mi...@kernel.org> CommitDate: Tue, 6 Feb 2018 10:20:34 +0100
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.yan...@zte.com.cn> Signed-off-by: Peter Zijlstra (Intel) <pet...@infradead.org> Reviewed-by: Jiang Biao <jiang.bi...@zte.com.cn> Cc: Linus Torvalds <torva...@linux-foundation.org> Cc: Mike Galbraith <efa...@gmx.de> Cc: Peter Zijlstra <pet...@infradead.org> Cc: Thomas Gleixner <t...@linutronix.de> Cc: zhong.weid...@zte.com.cn Link: http://lkml.kernel.org/r/1517800721-42092-1-git-send-email-wen.yan...@zte.com.cn Signed-off-by: Ingo Molnar <mi...@kernel.org> --- kernel/sched/rt.c | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-) diff --git a/kernel/sched/rt.c b/kernel/sched/rt.c index 89a086e..663b235 100644 --- a/kernel/sched/rt.c +++ b/kernel/sched/rt.c @@ -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);
