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Merge git://git.kernel.org/pub/scm/linux/kernel/git/mingo/linux-2.6-sched

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* git://git.kernel.org/pub/scm/linux/kernel/git/mingo/linux-2.6-sched:
  sched: clean up task_new_fair()
  sched: small schedstat fix
  sched: fix wait_start_fair condition in update_stats_wait_end()
  sched: call update_curr() in task_tick_fair()
  sched: make the scheduler converge to the ideal latency
  sched: fix sleeper bonus limit
This commit is contained in:
Linus Torvalds 2007-08-31 10:52:00 -07:00
commit 5e7a39275b
3 changed files with 37 additions and 11 deletions
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1
include/linux/sched.h
View File

@ -904,6 +904,7 @@ struct sched_entity {
u64 exec_start;
u64 sum_exec_runtime;
u64 prev_sum_exec_runtime;
u64 wait_start_fair;
u64 sleep_start_fair;

1
kernel/sched.c
View File

@ -1587,6 +1587,7 @@ static void __sched_fork(struct task_struct *p)
p->se.wait_start_fair = 0;
p->se.exec_start = 0;
p->se.sum_exec_runtime = 0;
p->se.prev_sum_exec_runtime = 0;
p->se.delta_exec = 0;
p->se.delta_fair_run = 0;
p->se.delta_fair_sleep = 0;

46
kernel/sched_fair.c
View File

@ -354,7 +354,7 @@ __update_curr(struct cfs_rq *cfs_rq, struct sched_entity *curr)
delta_fair = calc_delta_fair(delta_exec, lw);
delta_mine = calc_delta_mine(delta_exec, curr->load.weight, lw);
if (cfs_rq->sleeper_bonus > sysctl_sched_latency) {
if (cfs_rq->sleeper_bonus > sysctl_sched_min_granularity) {
delta = min((u64)delta_mine, cfs_rq->sleeper_bonus);
delta = min(delta, (unsigned long)(
(long)sysctl_sched_runtime_limit - curr->wait_runtime));
@ -489,6 +489,9 @@ update_stats_wait_end(struct cfs_rq *cfs_rq, struct sched_entity *se)
{
unsigned long delta_fair;
if (unlikely(!se->wait_start_fair))
return;
delta_fair = (unsigned long)min((u64)(2*sysctl_sched_runtime_limit),
(u64)(cfs_rq->fair_clock - se->wait_start_fair));
@ -668,7 +671,7 @@ dequeue_entity(struct cfs_rq *cfs_rq, struct sched_entity *se, int sleep)
/*
* Preempt the current task with a newly woken task if needed:
*/
static void
static int
__check_preempt_curr_fair(struct cfs_rq *cfs_rq, struct sched_entity *se,
struct sched_entity *curr, unsigned long granularity)
{
@ -679,8 +682,11 @@ __check_preempt_curr_fair(struct cfs_rq *cfs_rq, struct sched_entity *se,
* preempt the current task unless the best task has
* a larger than sched_granularity fairness advantage:
*/
if (__delta > niced_granularity(curr, granularity))
if (__delta > niced_granularity(curr, granularity)) {
resched_task(rq_of(cfs_rq)->curr);
return 1;
}
return 0;
}
static inline void
@ -725,6 +731,7 @@ static void put_prev_entity(struct cfs_rq *cfs_rq, struct sched_entity *prev)
static void entity_tick(struct cfs_rq *cfs_rq, struct sched_entity *curr)
{
unsigned long gran, ideal_runtime, delta_exec;
struct sched_entity *next;
/*
@ -741,8 +748,22 @@ static void entity_tick(struct cfs_rq *cfs_rq, struct sched_entity *curr)
if (next == curr)
return;
__check_preempt_curr_fair(cfs_rq, next, curr,
sched_granularity(cfs_rq));
gran = sched_granularity(cfs_rq);
ideal_runtime = niced_granularity(curr,
max(sysctl_sched_latency / cfs_rq->nr_running,
(unsigned long)sysctl_sched_min_granularity));
/*
* If we executed more than what the latency constraint suggests,
* reduce the rescheduling granularity. This way the total latency
* of how much a task is not scheduled converges to
* sysctl_sched_latency:
*/
delta_exec = curr->sum_exec_runtime - curr->prev_sum_exec_runtime;
if (delta_exec > ideal_runtime)
gran = 0;
if (__check_preempt_curr_fair(cfs_rq, next, curr, gran))
curr->prev_sum_exec_runtime = curr->sum_exec_runtime;
}
/**************************************************
@ -1076,31 +1097,34 @@ static void task_tick_fair(struct rq *rq, struct task_struct *curr)
static void task_new_fair(struct rq *rq, struct task_struct *p)
{
struct cfs_rq *cfs_rq = task_cfs_rq(p);
struct sched_entity *se = &p->se;
struct sched_entity *se = &p->se, *curr = cfs_rq_curr(cfs_rq);
sched_info_queued(p);
update_curr(cfs_rq);
update_stats_enqueue(cfs_rq, se);
/*
* Child runs first: we let it run before the parent
* until it reschedules once. We set up the key so that
* it will preempt the parent:
*/
p->se.fair_key = current->se.fair_key -
niced_granularity(&rq->curr->se, sched_granularity(cfs_rq)) - 1;
se->fair_key = curr->fair_key -
niced_granularity(curr, sched_granularity(cfs_rq)) - 1;
/*
* The first wait is dominated by the child-runs-first logic,
* so do not credit it with that waiting time yet:
*/
if (sysctl_sched_features & SCHED_FEAT_SKIP_INITIAL)
p->se.wait_start_fair = 0;
se->wait_start_fair = 0;
/*
* The statistical average of wait_runtime is about
* -granularity/2, so initialize the task with that:
*/
if (sysctl_sched_features & SCHED_FEAT_START_DEBIT)
p->se.wait_runtime = -(sched_granularity(cfs_rq) / 2);
if (sysctl_sched_features & SCHED_FEAT_START_DEBIT) {
se->wait_runtime = -(sched_granularity(cfs_rq) / 2);
schedstat_add(cfs_rq, wait_runtime, se->wait_runtime);
}
__enqueue_entity(cfs_rq, se);
}