Merge branch 'sched-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip

* 'sched-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
  sched: re-tune balancing
  sched: fix buddies for group scheduling
  sched: backward looking buddy
  sched: fix fair preempt check
  sched: cleanup fair task selection
This commit is contained in:
Linus Torvalds 2008-11-06 15:45:40 -08:00
commit 067ab19923
5 changed files with 60 additions and 34 deletions

View File

@ -154,7 +154,7 @@ extern unsigned long node_remap_size[];
#endif
/* sched_domains SD_NODE_INIT for NUMAQ machines */
/* sched_domains SD_NODE_INIT for NUMA machines */
#define SD_NODE_INIT (struct sched_domain) { \
.min_interval = 8, \
.max_interval = 32, \
@ -169,8 +169,9 @@ extern unsigned long node_remap_size[];
.flags = SD_LOAD_BALANCE \
| SD_BALANCE_EXEC \
| SD_BALANCE_FORK \
| SD_SERIALIZE \
| SD_WAKE_BALANCE, \
| SD_WAKE_AFFINE \
| SD_WAKE_BALANCE \
| SD_SERIALIZE, \
.last_balance = jiffies, \
.balance_interval = 1, \
}

View File

@ -146,10 +146,10 @@ void arch_update_cpu_topology(void);
.wake_idx = 1, \
.forkexec_idx = 1, \
.flags = SD_LOAD_BALANCE \
| SD_BALANCE_NEWIDLE \
| SD_BALANCE_FORK \
| SD_BALANCE_EXEC \
| SD_BALANCE_FORK \
| SD_WAKE_AFFINE \
| SD_WAKE_BALANCE \
| BALANCE_FOR_PKG_POWER,\
.last_balance = jiffies, \
.balance_interval = 1, \

View File

@ -397,7 +397,7 @@ struct cfs_rq {
* 'curr' points to currently running entity on this cfs_rq.
* It is set to NULL otherwise (i.e when none are currently running).
*/
struct sched_entity *curr, *next;
struct sched_entity *curr, *next, *last;
unsigned long nr_spread_over;
@ -1805,7 +1805,9 @@ task_hot(struct task_struct *p, u64 now, struct sched_domain *sd)
/*
* Buddy candidates are cache hot:
*/
if (sched_feat(CACHE_HOT_BUDDY) && (&p->se == cfs_rq_of(&p->se)->next))
if (sched_feat(CACHE_HOT_BUDDY) &&
(&p->se == cfs_rq_of(&p->se)->next ||
&p->se == cfs_rq_of(&p->se)->last))
return 1;
if (p->sched_class != &fair_sched_class)

View File

@ -341,23 +341,20 @@ static void __dequeue_entity(struct cfs_rq *cfs_rq, struct sched_entity *se)
cfs_rq->rb_leftmost = next_node;
}
if (cfs_rq->next == se)
cfs_rq->next = NULL;
rb_erase(&se->run_node, &cfs_rq->tasks_timeline);
}
static inline struct rb_node *first_fair(struct cfs_rq *cfs_rq)
{
return cfs_rq->rb_leftmost;
}
static struct sched_entity *__pick_next_entity(struct cfs_rq *cfs_rq)
{
return rb_entry(first_fair(cfs_rq), struct sched_entity, run_node);
struct rb_node *left = cfs_rq->rb_leftmost;
if (!left)
return NULL;
return rb_entry(left, struct sched_entity, run_node);
}
static inline struct sched_entity *__pick_last_entity(struct cfs_rq *cfs_rq)
static struct sched_entity *__pick_last_entity(struct cfs_rq *cfs_rq)
{
struct rb_node *last = rb_last(&cfs_rq->tasks_timeline);
@ -741,6 +738,12 @@ dequeue_entity(struct cfs_rq *cfs_rq, struct sched_entity *se, int sleep)
#endif
}
if (cfs_rq->last == se)
cfs_rq->last = NULL;
if (cfs_rq->next == se)
cfs_rq->next = NULL;
if (se != cfs_rq->curr)
__dequeue_entity(cfs_rq, se);
account_entity_dequeue(cfs_rq, se);
@ -794,24 +797,15 @@ set_next_entity(struct cfs_rq *cfs_rq, struct sched_entity *se)
static int
wakeup_preempt_entity(struct sched_entity *curr, struct sched_entity *se);
static struct sched_entity *
pick_next(struct cfs_rq *cfs_rq, struct sched_entity *se)
{
if (!cfs_rq->next || wakeup_preempt_entity(cfs_rq->next, se) == 1)
return se;
return cfs_rq->next;
}
static struct sched_entity *pick_next_entity(struct cfs_rq *cfs_rq)
{
struct sched_entity *se = NULL;
struct sched_entity *se = __pick_next_entity(cfs_rq);
if (first_fair(cfs_rq)) {
se = __pick_next_entity(cfs_rq);
se = pick_next(cfs_rq, se);
set_next_entity(cfs_rq, se);
}
if (cfs_rq->next && wakeup_preempt_entity(cfs_rq->next, se) < 1)
return cfs_rq->next;
if (cfs_rq->last && wakeup_preempt_entity(cfs_rq->last, se) < 1)
return cfs_rq->last;
return se;
}
@ -1325,26 +1319,53 @@ wakeup_preempt_entity(struct sched_entity *curr, struct sched_entity *se)
return 0;
}
static void set_last_buddy(struct sched_entity *se)
{
for_each_sched_entity(se)
cfs_rq_of(se)->last = se;
}
static void set_next_buddy(struct sched_entity *se)
{
for_each_sched_entity(se)
cfs_rq_of(se)->next = se;
}
/*
* Preempt the current task with a newly woken task if needed:
*/
static void check_preempt_wakeup(struct rq *rq, struct task_struct *p, int sync)
{
struct task_struct *curr = rq->curr;
struct cfs_rq *cfs_rq = task_cfs_rq(curr);
struct sched_entity *se = &curr->se, *pse = &p->se;
if (unlikely(rt_prio(p->prio))) {
struct cfs_rq *cfs_rq = task_cfs_rq(curr);
update_rq_clock(rq);
update_curr(cfs_rq);
resched_task(curr);
return;
}
if (unlikely(p->sched_class != &fair_sched_class))
return;
if (unlikely(se == pse))
return;
cfs_rq_of(pse)->next = pse;
/*
* 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);
set_next_buddy(pse);
/*
* We can come here with TIF_NEED_RESCHED already set from new task
@ -1396,6 +1417,7 @@ static struct task_struct *pick_next_task_fair(struct rq *rq)
do {
se = pick_next_entity(cfs_rq);
set_next_entity(cfs_rq, se);
cfs_rq = group_cfs_rq(se);
} while (cfs_rq);

View File

@ -12,3 +12,4 @@ SCHED_FEAT(LB_BIAS, 1)
SCHED_FEAT(LB_WAKEUP_UPDATE, 1)
SCHED_FEAT(ASYM_EFF_LOAD, 1)
SCHED_FEAT(WAKEUP_OVERLAP, 0)
SCHED_FEAT(LAST_BUDDY, 1)