Commit-ID: 6fe0ce1eb04f99a1eb1eb6e7f775666966cf6c80
Gitweb: https://git.kernel.org/tip/6fe0ce1eb04f99a1eb1eb6e7f775666966cf6c80
Author: Wen Yang <wen.yang99@xxxxxxxxxx>
AuthorDate: Tue, 6 Feb 2018 09:55:48 +0800
Committer: Ingo Molnar <mingo@xxxxxxxxxx>
CommitDate: Tue, 13 Feb 2018 11:44:40 +0100
sched/deadline: Make update_curr_dl() more accurate
rq->clock_task may be updated between the two calls of
rq_clock_task() in update_curr_dl(). Calling rq_clock_task() only
once makes it more accurate and efficient, taking update_curr() as
reference.
Suggested-by: Peter Zijlstra <peterz@xxxxxxxxxxxxx>
Signed-off-by: Wen Yang <wen.yang99@xxxxxxxxxx>
Signed-off-by: Peter Zijlstra (Intel) <peterz@xxxxxxxxxxxxx>
Reviewed-by: Jiang Biao <jiang.biao2@xxxxxxxxxx>
Cc: Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxxx>
Cc: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
Cc: zhong.weidong@xxxxxxxxxx
Link: http://lkml.kernel.org/r/1517882148-44599-1-git-send-email-wen.yang99@xxxxxxxxxx
Signed-off-by: Ingo Molnar <mingo@xxxxxxxxxx>
---
kernel/sched/deadline.c | 6 ++++--
1 file changed, 4 insertions(+), 2 deletions(-)
diff --git a/kernel/sched/deadline.c b/kernel/sched/deadline.c
index 9bb0e0c..9df0978 100644
--- a/kernel/sched/deadline.c
+++ b/kernel/sched/deadline.c
@@ -1153,6 +1153,7 @@ static void update_curr_dl(struct rq *rq)
struct sched_dl_entity *dl_se = &curr->dl;
u64 delta_exec, scaled_delta_exec;
int cpu = cpu_of(rq);
+ u64 now;
if (!dl_task(curr) || !on_dl_rq(dl_se))
return;
@@ -1165,7 +1166,8 @@ static void update_curr_dl(struct rq *rq)
* natural solution, but the full ramifications of this
* approach need further study.
*/
- 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)) {
if (unlikely(dl_se->dl_yielded))
goto throttle;
@@ -1178,7 +1180,7 @@ static void update_curr_dl(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);
--
To unsubscribe from this list: send the line "unsubscribe linux-tip-commits" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
|