aboutsummaryrefslogtreecommitdiff
path: root/kernel/sched_fair.c
diff options
context:
space:
mode:
authorIngo Molnar <mingo@elte.hu>2008-07-06 14:23:39 +0200
committerIngo Molnar <mingo@elte.hu>2008-07-06 14:23:39 +0200
commit68083e05d72d94f347293d8cc0067050ba904bfa (patch)
tree842e71365bd90866be7add181661a4039d891564 /kernel/sched_fair.c
parent7baac8b91f9871ba8cb09af84de4ae1d86d07812 (diff)
parentb7279469d66b55119784b8b9529c99c1955fe747 (diff)
Merge commit 'v2.6.26-rc9' into cpus4096
Diffstat (limited to 'kernel/sched_fair.c')
-rw-r--r--kernel/sched_fair.c254
1 files changed, 91 insertions, 163 deletions
diff --git a/kernel/sched_fair.c b/kernel/sched_fair.c
index e398318f101..74774bde526 100644
--- a/kernel/sched_fair.c
+++ b/kernel/sched_fair.c
@@ -334,34 +334,6 @@ int sched_nr_latency_handler(struct ctl_table *table, int write,
#endif
/*
- * delta *= w / rw
- */
-static inline unsigned long
-calc_delta_weight(unsigned long delta, struct sched_entity *se)
-{
- for_each_sched_entity(se) {
- delta = calc_delta_mine(delta,
- se->load.weight, &cfs_rq_of(se)->load);
- }
-
- return delta;
-}
-
-/*
- * delta *= rw / w
- */
-static inline unsigned long
-calc_delta_fair(unsigned long delta, struct sched_entity *se)
-{
- for_each_sched_entity(se) {
- delta = calc_delta_mine(delta,
- cfs_rq_of(se)->load.weight, &se->load);
- }
-
- return delta;
-}
-
-/*
* The idea is to set a period in which each task runs once.
*
* When there are too many tasks (sysctl_sched_nr_latency) we have to stretch
@@ -390,54 +362,47 @@ static u64 __sched_period(unsigned long nr_running)
*/
static u64 sched_slice(struct cfs_rq *cfs_rq, struct sched_entity *se)
{
- return calc_delta_weight(__sched_period(cfs_rq->nr_running), se);
+ u64 slice = __sched_period(cfs_rq->nr_running);
+
+ for_each_sched_entity(se) {
+ cfs_rq = cfs_rq_of(se);
+
+ slice *= se->load.weight;
+ do_div(slice, cfs_rq->load.weight);
+ }
+
+
+ return slice;
}
/*
* We calculate the vruntime slice of a to be inserted task
*
- * vs = s*rw/w = p
+ * vs = s/w = p/rw
*/
static u64 sched_vslice_add(struct cfs_rq *cfs_rq, struct sched_entity *se)
{
unsigned long nr_running = cfs_rq->nr_running;
+ unsigned long weight;
+ u64 vslice;
if (!se->on_rq)
nr_running++;
- return __sched_period(nr_running);
-}
-
-/*
- * The goal of calc_delta_asym() is to be asymmetrically around NICE_0_LOAD, in
- * that it favours >=0 over <0.
- *
- * -20 |
- * |
- * 0 --------+-------
- * .'
- * 19 .'
- *
- */
-static unsigned long
-calc_delta_asym(unsigned long delta, struct sched_entity *se)
-{
- struct load_weight lw = {
- .weight = NICE_0_LOAD,
- .inv_weight = 1UL << (WMULT_SHIFT-NICE_0_SHIFT)
- };
+ vslice = __sched_period(nr_running);
for_each_sched_entity(se) {
- struct load_weight *se_lw = &se->load;
+ cfs_rq = cfs_rq_of(se);
- if (se->load.weight < NICE_0_LOAD)
- se_lw = &lw;
+ weight = cfs_rq->load.weight;
+ if (!se->on_rq)
+ weight += se->load.weight;
- delta = calc_delta_mine(delta,
- cfs_rq_of(se)->load.weight, se_lw);
+ vslice *= NICE_0_LOAD;
+ do_div(vslice, weight);
}
- return delta;
+ return vslice;
}
/*
@@ -454,7 +419,11 @@ __update_curr(struct cfs_rq *cfs_rq, struct sched_entity *curr,
curr->sum_exec_runtime += delta_exec;
schedstat_add(cfs_rq, exec_clock, delta_exec);
- delta_exec_weighted = calc_delta_fair(delta_exec, curr);
+ delta_exec_weighted = delta_exec;
+ if (unlikely(curr->load.weight != NICE_0_LOAD)) {
+ delta_exec_weighted = calc_delta_fair(delta_exec_weighted,
+ &curr->load);
+ }
curr->vruntime += delta_exec_weighted;
}
@@ -541,27 +510,10 @@ update_stats_curr_start(struct cfs_rq *cfs_rq, struct sched_entity *se)
* Scheduling class queueing methods:
*/
-#if defined CONFIG_SMP && defined CONFIG_FAIR_GROUP_SCHED
-static void
-add_cfs_task_weight(struct cfs_rq *cfs_rq, unsigned long weight)
-{
- cfs_rq->task_weight += weight;
-}
-#else
-static inline void
-add_cfs_task_weight(struct cfs_rq *cfs_rq, unsigned long weight)
-{
-}
-#endif
-
static void
account_entity_enqueue(struct cfs_rq *cfs_rq, struct sched_entity *se)
{
update_load_add(&cfs_rq->load, se->load.weight);
- if (!parent_entity(se))
- inc_cpu_load(rq_of(cfs_rq), se->load.weight);
- if (entity_is_task(se))
- add_cfs_task_weight(cfs_rq, se->load.weight);
cfs_rq->nr_running++;
se->on_rq = 1;
list_add(&se->group_node, &cfs_rq->tasks);
@@ -571,10 +523,6 @@ static void
account_entity_dequeue(struct cfs_rq *cfs_rq, struct sched_entity *se)
{
update_load_sub(&cfs_rq->load, se->load.weight);
- if (!parent_entity(se))
- dec_cpu_load(rq_of(cfs_rq), se->load.weight);
- if (entity_is_task(se))
- add_cfs_task_weight(cfs_rq, -se->load.weight);
cfs_rq->nr_running--;
se->on_rq = 0;
list_del_init(&se->group_node);
@@ -661,17 +609,8 @@ place_entity(struct cfs_rq *cfs_rq, struct sched_entity *se, int initial)
if (!initial) {
/* sleeps upto a single latency don't count. */
- if (sched_feat(NEW_FAIR_SLEEPERS)) {
- unsigned long thresh = sysctl_sched_latency;
-
- /*
- * convert the sleeper threshold into virtual time
- */
- if (sched_feat(NORMALIZED_SLEEPER))
- thresh = calc_delta_fair(thresh, se);
-
- vruntime -= thresh;
- }
+ if (sched_feat(NEW_FAIR_SLEEPERS))
+ vruntime -= sysctl_sched_latency;
/* ensure we never gain time by being placed backwards. */
vruntime = max_vruntime(se->vruntime, vruntime);
@@ -1057,16 +996,27 @@ wake_affine(struct rq *rq, struct sched_domain *this_sd, struct rq *this_rq,
struct task_struct *curr = this_rq->curr;
unsigned long tl = this_load;
unsigned long tl_per_task;
+ int balanced;
- if (!(this_sd->flags & SD_WAKE_AFFINE))
+ if (!(this_sd->flags & SD_WAKE_AFFINE) || !sched_feat(AFFINE_WAKEUPS))
return 0;
/*
+ * If sync wakeup then subtract the (maximum possible)
+ * effect of the currently running task from the load
+ * of the current CPU:
+ */
+ if (sync)
+ tl -= current->se.load.weight;
+
+ balanced = 100*(tl + p->se.load.weight) <= imbalance*load;
+
+ /*
* If the currently running task will sleep within
* a reasonable amount of time then attract this newly
* woken task:
*/
- if (sync && curr->sched_class == &fair_sched_class) {
+ if (sync && balanced && curr->sched_class == &fair_sched_class) {
if (curr->se.avg_overlap < sysctl_sched_migration_cost &&
p->se.avg_overlap < sysctl_sched_migration_cost)
return 1;
@@ -1075,16 +1025,8 @@ wake_affine(struct rq *rq, struct sched_domain *this_sd, struct rq *this_rq,
schedstat_inc(p, se.nr_wakeups_affine_attempts);
tl_per_task = cpu_avg_load_per_task(this_cpu);
- /*
- * If sync wakeup then subtract the (maximum possible)
- * effect of the currently running task from the load
- * of the current CPU:
- */
- if (sync)
- tl -= current->se.load.weight;
-
if ((tl <= load && tl + target_load(prev_cpu, idx) <= tl_per_task) ||
- 100*(tl + p->se.load.weight) <= imbalance*load) {
+ balanced) {
/*
* This domain has SD_WAKE_AFFINE and
* p is cache cold in this domain, and
@@ -1169,10 +1111,11 @@ static unsigned long wakeup_gran(struct sched_entity *se)
unsigned long gran = sysctl_sched_wakeup_granularity;
/*
- * More easily preempt - nice tasks, while not making it harder for
- * + nice tasks.
+ * More easily preempt - nice tasks, while not making
+ * it harder for + nice tasks.
*/
- gran = calc_delta_asym(sysctl_sched_wakeup_granularity, se);
+ if (unlikely(se->load.weight > NICE_0_LOAD))
+ gran = calc_delta_fair(gran, &se->load);
return gran;
}
@@ -1366,90 +1309,75 @@ static struct task_struct *load_balance_next_fair(void *arg)
return __load_balance_iterator(cfs_rq, cfs_rq->balance_iterator);
}
-static unsigned long
-__load_balance_fair(struct rq *this_rq, int this_cpu, struct rq *busiest,
- unsigned long max_load_move, struct sched_domain *sd,
- enum cpu_idle_type idle, int *all_pinned, int *this_best_prio,
- struct cfs_rq *cfs_rq)
+#ifdef CONFIG_FAIR_GROUP_SCHED
+static int cfs_rq_best_prio(struct cfs_rq *cfs_rq)
{
- struct rq_iterator cfs_rq_iterator;
+ struct sched_entity *curr;
+ struct task_struct *p;
- cfs_rq_iterator.start = load_balance_start_fair;
- cfs_rq_iterator.next = load_balance_next_fair;
- cfs_rq_iterator.arg = cfs_rq;
+ if (!cfs_rq->nr_running || !first_fair(cfs_rq))
+ return MAX_PRIO;
+
+ curr = cfs_rq->curr;
+ if (!curr)
+ curr = __pick_next_entity(cfs_rq);
+
+ p = task_of(curr);
- return balance_tasks(this_rq, this_cpu, busiest,
- max_load_move, sd, idle, all_pinned,
- this_best_prio, &cfs_rq_iterator);
+ return p->prio;
}
+#endif
-#ifdef CONFIG_FAIR_GROUP_SCHED
static unsigned long
load_balance_fair(struct rq *this_rq, int this_cpu, struct rq *busiest,
unsigned long max_load_move,
struct sched_domain *sd, enum cpu_idle_type idle,
int *all_pinned, int *this_best_prio)
{
+ struct cfs_rq *busy_cfs_rq;
long rem_load_move = max_load_move;
- int busiest_cpu = cpu_of(busiest);
- struct task_group *tg;
-
- rcu_read_lock();
- list_for_each_entry(tg, &task_groups, list) {
- long imbalance;
- unsigned long this_weight, busiest_weight;
- long rem_load, max_load, moved_load;
-
- /*
- * empty group
- */
- if (!aggregate(tg, sd)->task_weight)
- continue;
-
- rem_load = rem_load_move * aggregate(tg, sd)->rq_weight;
- rem_load /= aggregate(tg, sd)->load + 1;
-
- this_weight = tg->cfs_rq[this_cpu]->task_weight;
- busiest_weight = tg->cfs_rq[busiest_cpu]->task_weight;
+ struct rq_iterator cfs_rq_iterator;
- imbalance = (busiest_weight - this_weight) / 2;
+ cfs_rq_iterator.start = load_balance_start_fair;
+ cfs_rq_iterator.next = load_balance_next_fair;
- if (imbalance < 0)
- imbalance = busiest_weight;
+ for_each_leaf_cfs_rq(busiest, busy_cfs_rq) {
+#ifdef CONFIG_FAIR_GROUP_SCHED
+ struct cfs_rq *this_cfs_rq;
+ long imbalance;
+ unsigned long maxload;
- max_load = max(rem_load, imbalance);
- moved_load = __load_balance_fair(this_rq, this_cpu, busiest,
- max_load, sd, idle, all_pinned, this_best_prio,
- tg->cfs_rq[busiest_cpu]);
+ this_cfs_rq = cpu_cfs_rq(busy_cfs_rq, this_cpu);
- if (!moved_load)
+ imbalance = busy_cfs_rq->load.weight - this_cfs_rq->load.weight;
+ /* Don't pull if this_cfs_rq has more load than busy_cfs_rq */
+ if (imbalance <= 0)
continue;
- move_group_shares(tg, sd, busiest_cpu, this_cpu);
+ /* Don't pull more than imbalance/2 */
+ imbalance /= 2;
+ maxload = min(rem_load_move, imbalance);
- moved_load *= aggregate(tg, sd)->load;
- moved_load /= aggregate(tg, sd)->rq_weight + 1;
+ *this_best_prio = cfs_rq_best_prio(this_cfs_rq);
+#else
+# define maxload rem_load_move
+#endif
+ /*
+ * pass busy_cfs_rq argument into
+ * load_balance_[start|next]_fair iterators
+ */
+ cfs_rq_iterator.arg = busy_cfs_rq;
+ rem_load_move -= balance_tasks(this_rq, this_cpu, busiest,
+ maxload, sd, idle, all_pinned,
+ this_best_prio,
+ &cfs_rq_iterator);
- rem_load_move -= moved_load;
- if (rem_load_move < 0)
+ if (rem_load_move <= 0)
break;
}
- rcu_read_unlock();
return max_load_move - rem_load_move;
}
-#else
-static unsigned long
-load_balance_fair(struct rq *this_rq, int this_cpu, struct rq *busiest,
- unsigned long max_load_move,
- struct sched_domain *sd, enum cpu_idle_type idle,
- int *all_pinned, int *this_best_prio)
-{
- return __load_balance_fair(this_rq, this_cpu, busiest,
- max_load_move, sd, idle, all_pinned,
- this_best_prio, &busiest->cfs);
-}
-#endif
static int
move_one_task_fair(struct rq *this_rq, int this_cpu, struct rq *busiest,