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author | Wen Yang <wen.yang99@zte.com.cn> | 2018-02-06 09:53:28 +0800 |
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committer | Ingo Molnar <mingo@kernel.org> | 2018-02-13 11:44:41 +0100 |
commit | a7711602c7b79950ea437178f601b52ab08ef659 (patch) | |
tree | aaa36c553654b2cd4499c8f3be505e173d03ff16 /kernel | |
parent | 6fe0ce1eb04f99a1eb1eb6e7f775666966cf6c80 (diff) | |
download | linux-stable-a7711602c7b79950ea437178f601b52ab08ef659.tar.gz linux-stable-a7711602c7b79950ea437178f601b52ab08ef659.tar.bz2 linux-stable-a7711602c7b79950ea437178f601b52ab08ef659.zip |
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: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: zhong.weidong@zte.com.cn
Link: http://lkml.kernel.org/r/1517882008-44552-1-git-send-email-wen.yang99@zte.com.cn
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Diffstat (limited to 'kernel')
-rw-r--r-- | kernel/sched/rt.c | 3 |
1 files changed, 2 insertions, 1 deletions
diff --git a/kernel/sched/rt.c b/kernel/sched/rt.c index 663b2355a3aa..aad49451584e 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; + u64 now; if (curr->sched_class != &rt_sched_class) return; + now = rq_clock_task(rq); delta_exec = now - curr->se.exec_start; if (unlikely((s64)delta_exec <= 0)) return; |