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Merge branch 'sched/urgent' into sched/core

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Merge reason: Pick up fixes that did not make it into .32.0

Signed-off-by: Ingo Molnar <mingo@elte.hu>
This commit is contained in:
Ingo Molnar
2009-11-26 10:50:39 +01:00
parent f6630114d9 047106adcc
commit 16bc67edeb
810 changed files with 15400 additions and 9762 deletions
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74
kernel/sched_fair.c
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@@ -822,6 +822,26 @@ check_preempt_tick(struct cfs_rq *cfs_rq, struct sched_entity *curr)
* re-elected due to buddy favours.
*/
clear_buddies(cfs_rq, curr);
return;
}
/*
* Ensure that a task that missed wakeup preemption by a
* narrow margin doesn't have to wait for a full slice.
* This also mitigates buddy induced latencies under load.
*/
if (!sched_feat(WAKEUP_PREEMPT))
return;
if (delta_exec < sysctl_sched_min_granularity)
return;
if (cfs_rq->nr_running > 1) {
struct sched_entity *se = __pick_next_entity(cfs_rq);
s64 delta = curr->vruntime - se->vruntime;
if (delta > ideal_runtime)
resched_task(rq_of(cfs_rq)->curr);
}
}
@@ -861,12 +881,18 @@ wakeup_preempt_entity(struct sched_entity *curr, struct sched_entity *se);
static struct sched_entity *pick_next_entity(struct cfs_rq *cfs_rq)
{
struct sched_entity *se = __pick_next_entity(cfs_rq);
struct sched_entity *left = se;
if (cfs_rq->next && wakeup_preempt_entity(cfs_rq->next, se) < 1)
return cfs_rq->next;
if (cfs_rq->next && wakeup_preempt_entity(cfs_rq->next, left) < 1)
se = cfs_rq->next;
if (cfs_rq->last && wakeup_preempt_entity(cfs_rq->last, se) < 1)
return cfs_rq->last;
/*
* Prefer last buddy, try to return the CPU to a preempted task.
*/
if (cfs_rq->last && wakeup_preempt_entity(cfs_rq->last, left) < 1)
se = cfs_rq->last;
clear_buddies(cfs_rq, se);
return se;
}
@@ -1623,6 +1649,7 @@ static void check_preempt_wakeup(struct rq *rq, struct task_struct *p, int wake_
struct sched_entity *se = &curr->se, *pse = &p->se;
struct cfs_rq *cfs_rq = task_cfs_rq(curr);
int sync = wake_flags & WF_SYNC;
int scale = cfs_rq->nr_running >= sched_nr_latency;
update_curr(cfs_rq);
@@ -1637,18 +1664,7 @@ static void check_preempt_wakeup(struct rq *rq, struct task_struct *p, int wake_
if (unlikely(se == pse))
return;
/*
* Only set the backward buddy when the current task is still on the
* rq. This can happen when a wakeup gets interleaved with schedule on
* the ->pre_schedule() or idle_balance() point, either of which can
* drop the rq lock.
*
* Also, during early boot the idle thread is in the fair class, for
* obvious reasons its a bad idea to schedule back to the idle thread.
*/
if (sched_feat(LAST_BUDDY) && likely(se->on_rq && curr != rq->idle))
set_last_buddy(se);
if (sched_feat(NEXT_BUDDY) && !(wake_flags & WF_FORK))
if (sched_feat(NEXT_BUDDY) && scale && !(wake_flags & WF_FORK))
set_next_buddy(pse);
/*
@@ -1694,8 +1710,22 @@ static void check_preempt_wakeup(struct rq *rq, struct task_struct *p, int wake_
BUG_ON(!pse);
if (wakeup_preempt_entity(se, pse) == 1)
if (wakeup_preempt_entity(se, pse) == 1) {
resched_task(curr);
/*
* Only set the backward buddy when the current task is still
* on the rq. This can happen when a wakeup gets interleaved
* with schedule on the ->pre_schedule() or idle_balance()
* point, either of which can * drop the rq lock.
*
* Also, during early boot the idle thread is in the fair class,
* for obvious reasons its a bad idea to schedule back to it.
*/
if (unlikely(!se->on_rq || curr == rq->idle))
return;
if (sched_feat(LAST_BUDDY) && scale && entity_is_task(se))
set_last_buddy(se);
}
}
static struct task_struct *pick_next_task_fair(struct rq *rq)
@@ -1709,16 +1739,6 @@ static struct task_struct *pick_next_task_fair(struct rq *rq)
do {
se = pick_next_entity(cfs_rq);
/*
* If se was a buddy, clear it so that it will have to earn
* the favour again.
*
* If se was not a buddy, clear the buddies because neither
* was elegible to run, let them earn it again.
*
* IOW. unconditionally clear buddies.
*/
__clear_buddies(cfs_rq, NULL);
set_next_entity(cfs_rq, se);
cfs_rq = group_cfs_rq(se);
} while (cfs_rq);