[PATCH] sched/fair: Fix the wrong throttled clock time for cfs_rq_clock_task()

From: Xunlei Pang
Date: Tue May 10 2016 - 09:03:35 EST


Two minor fixes for cfs_rq_clock_task().
1) If cfs_rq is currently being throttled, we need to subtract the cfs
throttled clock time.

2) Make "throttled_clock_task_time" update SMP unrelated. Now UP cases
need it as well.

Signed-off-by: Xunlei Pang <xlpang@xxxxxxxxxx>
---
kernel/sched/fair.c | 4 +---
1 file changed, 1 insertion(+), 3 deletions(-)

diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c
index 1708729e..fb80a12 100644
--- a/kernel/sched/fair.c
+++ b/kernel/sched/fair.c
@@ -3655,7 +3655,7 @@ static inline struct cfs_bandwidth *tg_cfs_bandwidth(struct task_group *tg)
static inline u64 cfs_rq_clock_task(struct cfs_rq *cfs_rq)
{
if (unlikely(cfs_rq->throttle_count))
- return cfs_rq->throttled_clock_task;
+ return cfs_rq->throttled_clock_task - cfs_rq->throttled_clock_task_time;

return rq_clock_task(rq_of(cfs_rq)) - cfs_rq->throttled_clock_task_time;
}
@@ -3793,13 +3793,11 @@ static int tg_unthrottle_up(struct task_group *tg, void *data)
struct cfs_rq *cfs_rq = tg->cfs_rq[cpu_of(rq)];

cfs_rq->throttle_count--;
-#ifdef CONFIG_SMP
if (!cfs_rq->throttle_count) {
/* adjust cfs_rq_clock_task() */
cfs_rq->throttled_clock_task_time += rq_clock_task(rq) -
cfs_rq->throttled_clock_task;
}
-#endif

return 0;
}
--
1.8.3.1