Three fixes:

- Fix load tracking bug/inconsistency
  - Fix a sporadic CFS bandwidth constraints enforcement bug
  - Fix a uclamp utilization tracking bug for newly woken tasks
 
 Signed-off-by: Ingo Molnar <mingo@kernel.org>
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Merge tag 'sched-urgent-2021-07-11' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull scheduler fixes from Ingo Molnar:
 "Three fixes:

   - Fix load tracking bug/inconsistency

   - Fix a sporadic CFS bandwidth constraints enforcement bug

   - Fix a uclamp utilization tracking bug for newly woken tasks"

* tag 'sched-urgent-2021-07-11' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  sched/uclamp: Ignore max aggregation if rq is idle
  sched/fair: Fix CFS bandwidth hrtimer expiry type
  sched/fair: Sync load_sum with load_avg after dequeue
This commit is contained in:
Linus Torvalds 2021-07-11 11:13:57 -07:00
commit 877029d921
2 changed files with 18 additions and 10 deletions

View File

@ -3037,8 +3037,9 @@ enqueue_load_avg(struct cfs_rq *cfs_rq, struct sched_entity *se)
static inline void static inline void
dequeue_load_avg(struct cfs_rq *cfs_rq, struct sched_entity *se) dequeue_load_avg(struct cfs_rq *cfs_rq, struct sched_entity *se)
{ {
u32 divider = get_pelt_divider(&se->avg);
sub_positive(&cfs_rq->avg.load_avg, se->avg.load_avg); sub_positive(&cfs_rq->avg.load_avg, se->avg.load_avg);
sub_positive(&cfs_rq->avg.load_sum, se_weight(se) * se->avg.load_sum); cfs_rq->avg.load_sum = cfs_rq->avg.load_avg * divider;
} }
#else #else
static inline void static inline void
@ -5081,7 +5082,7 @@ static const u64 cfs_bandwidth_slack_period = 5 * NSEC_PER_MSEC;
static int runtime_refresh_within(struct cfs_bandwidth *cfs_b, u64 min_expire) static int runtime_refresh_within(struct cfs_bandwidth *cfs_b, u64 min_expire)
{ {
struct hrtimer *refresh_timer = &cfs_b->period_timer; struct hrtimer *refresh_timer = &cfs_b->period_timer;
u64 remaining; s64 remaining;
/* if the call-back is running a quota refresh is already occurring */ /* if the call-back is running a quota refresh is already occurring */
if (hrtimer_callback_running(refresh_timer)) if (hrtimer_callback_running(refresh_timer))
@ -5089,7 +5090,7 @@ static int runtime_refresh_within(struct cfs_bandwidth *cfs_b, u64 min_expire)
/* is a quota refresh about to occur? */ /* is a quota refresh about to occur? */
remaining = ktime_to_ns(hrtimer_expires_remaining(refresh_timer)); remaining = ktime_to_ns(hrtimer_expires_remaining(refresh_timer));
if (remaining < min_expire) if (remaining < (s64)min_expire)
return 1; return 1;
return 0; return 0;

View File

@ -2818,20 +2818,27 @@ static __always_inline
unsigned long uclamp_rq_util_with(struct rq *rq, unsigned long util, unsigned long uclamp_rq_util_with(struct rq *rq, unsigned long util,
struct task_struct *p) struct task_struct *p)
{ {
unsigned long min_util; unsigned long min_util = 0;
unsigned long max_util; unsigned long max_util = 0;
if (!static_branch_likely(&sched_uclamp_used)) if (!static_branch_likely(&sched_uclamp_used))
return util; return util;
min_util = READ_ONCE(rq->uclamp[UCLAMP_MIN].value);
max_util = READ_ONCE(rq->uclamp[UCLAMP_MAX].value);
if (p) { if (p) {
min_util = max(min_util, uclamp_eff_value(p, UCLAMP_MIN)); min_util = uclamp_eff_value(p, UCLAMP_MIN);
max_util = max(max_util, uclamp_eff_value(p, UCLAMP_MAX)); max_util = uclamp_eff_value(p, UCLAMP_MAX);
/*
* Ignore last runnable task's max clamp, as this task will
* reset it. Similarly, no need to read the rq's min clamp.
*/
if (rq->uclamp_flags & UCLAMP_FLAG_IDLE)
goto out;
} }
min_util = max_t(unsigned long, min_util, READ_ONCE(rq->uclamp[UCLAMP_MIN].value));
max_util = max_t(unsigned long, max_util, READ_ONCE(rq->uclamp[UCLAMP_MAX].value));
out:
/* /*
* Since CPU's {min,max}_util clamps are MAX aggregated considering * Since CPU's {min,max}_util clamps are MAX aggregated considering
* RUNNABLE tasks with _different_ clamps, we can end up with an * RUNNABLE tasks with _different_ clamps, we can end up with an