diff options
| -rw-r--r-- | include/linux/sched.h | 1 | ||||
| -rw-r--r-- | kernel/sched.c | 4 | ||||
| -rw-r--r-- | kernel/sched_fair.c | 14 |
3 files changed, 15 insertions, 4 deletions
diff --git a/include/linux/sched.h b/include/linux/sched.h index 04233c8974d..8be5b57768c 100644 --- a/include/linux/sched.h +++ b/include/linux/sched.h @@ -912,6 +912,7 @@ struct sched_entity { struct load_weight load; /* for load-balancing */ struct rb_node run_node; unsigned int on_rq; + int peer_preempt; u64 exec_start; u64 sum_exec_runtime; diff --git a/kernel/sched.c b/kernel/sched.c index 0bd8f2c0fb4..e8051bd59ac 100644 --- a/kernel/sched.c +++ b/kernel/sched.c @@ -445,6 +445,7 @@ enum { 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 = @@ -452,7 +453,8 @@ const_debug unsigned int sysctl_sched_features = 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) diff --git a/kernel/sched_fair.c b/kernel/sched_fair.c index 3843ec71aad..f819f943fb8 100644 --- a/kernel/sched_fair.c +++ b/kernel/sched_fair.c @@ -526,6 +526,7 @@ dequeue_entity(struct cfs_rq *cfs_rq, struct sched_entity *se, int sleep) update_stats_dequeue(cfs_rq, se); if (sleep) { + se->peer_preempt = 0; #ifdef CONFIG_SCHEDSTATS if (entity_is_task(se)) { struct task_struct *tsk = task_of(se); @@ -553,8 +554,10 @@ check_preempt_tick(struct cfs_rq *cfs_rq, struct sched_entity *curr) 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); + curr->peer_preempt = 0; } static void @@ -839,8 +842,12 @@ static void check_preempt_wakeup(struct rq *rq, struct task_struct *p) 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); + } } } @@ -1034,6 +1041,7 @@ static void task_new_fair(struct rq *rq, struct task_struct *p) check_spread(cfs_rq, curr); __enqueue_entity(cfs_rq, se); account_entity_enqueue(cfs_rq, se); + se->peer_preempt = 0; resched_task(rq->curr); } |