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ce6c131)
Prevent wakeup over-scheduling. Once a task has been preempted by a
task of the same or lower priority, it becomes ineligible for repeated
preemption by same until it has been ticked, or slept. Instead, the
task is marked for preemption at the next tick. Tasks of higher
priority still preempt immediately.
Signed-off-by: Mike Galbraith <efault@gmx.de>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
struct load_weight load; /* for load-balancing */
struct rb_node run_node;
unsigned int on_rq;
struct load_weight load; /* for load-balancing */
struct rb_node run_node;
unsigned int on_rq;
u64 exec_start;
u64 sum_exec_runtime;
u64 exec_start;
u64 sum_exec_runtime;
SCHED_FEAT_TREE_AVG = 4,
SCHED_FEAT_APPROX_AVG = 8,
SCHED_FEAT_WAKEUP_PREEMPT = 16,
SCHED_FEAT_TREE_AVG = 4,
SCHED_FEAT_APPROX_AVG = 8,
SCHED_FEAT_WAKEUP_PREEMPT = 16,
+ SCHED_FEAT_PREEMPT_RESTRICT = 32,
};
const_debug unsigned int sysctl_sched_features =
};
const_debug unsigned int sysctl_sched_features =
SCHED_FEAT_START_DEBIT *1 |
SCHED_FEAT_TREE_AVG *0 |
SCHED_FEAT_APPROX_AVG *0 |
SCHED_FEAT_START_DEBIT *1 |
SCHED_FEAT_TREE_AVG *0 |
SCHED_FEAT_APPROX_AVG *0 |
- SCHED_FEAT_WAKEUP_PREEMPT *1;
+ SCHED_FEAT_WAKEUP_PREEMPT *1 |
+ SCHED_FEAT_PREEMPT_RESTRICT *1;
#define sched_feat(x) (sysctl_sched_features & SCHED_FEAT_##x)
#define sched_feat(x) (sysctl_sched_features & SCHED_FEAT_##x)
update_stats_dequeue(cfs_rq, se);
if (sleep) {
update_stats_dequeue(cfs_rq, se);
if (sleep) {
#ifdef CONFIG_SCHEDSTATS
if (entity_is_task(se)) {
struct task_struct *tsk = task_of(se);
#ifdef CONFIG_SCHEDSTATS
if (entity_is_task(se)) {
struct task_struct *tsk = task_of(se);
ideal_runtime = sched_slice(cfs_rq, curr);
delta_exec = curr->sum_exec_runtime - curr->prev_sum_exec_runtime;
ideal_runtime = sched_slice(cfs_rq, curr);
delta_exec = curr->sum_exec_runtime - curr->prev_sum_exec_runtime;
- if (delta_exec > ideal_runtime)
+ if (delta_exec > ideal_runtime ||
+ (sched_feat(PREEMPT_RESTRICT) && curr->peer_preempt))
resched_task(rq_of(cfs_rq)->curr);
resched_task(rq_of(cfs_rq)->curr);
+ curr->peer_preempt = 0;
if (unlikely(se->load.weight != NICE_0_LOAD))
gran = calc_delta_fair(gran, &se->load);
if (unlikely(se->load.weight != NICE_0_LOAD))
gran = calc_delta_fair(gran, &se->load);
- if (delta > gran)
- resched_task(curr);
+ if (delta > gran) {
+ int now = !sched_feat(PREEMPT_RESTRICT);
+
+ if (now || p->prio < curr->prio || !se->peer_preempt++)
+ resched_task(curr);
+ }
check_spread(cfs_rq, curr);
__enqueue_entity(cfs_rq, se);
account_entity_enqueue(cfs_rq, se);
check_spread(cfs_rq, curr);
__enqueue_entity(cfs_rq, se);
account_entity_enqueue(cfs_rq, se);
resched_task(rq->curr);
}
resched_task(rq->curr);
}