diff options
Diffstat (limited to 'kernel/sched/fair.c')
| -rw-r--r-- | kernel/sched/fair.c | 32 |
1 files changed, 25 insertions, 7 deletions
diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c index be47ce6da2a..cea2fa85327 100644 --- a/kernel/sched/fair.c +++ b/kernel/sched/fair.c @@ -3132,6 +3132,8 @@ task_hot(struct task_struct *p, u64 now, struct sched_domain *sd) } #define LBF_ALL_PINNED 0x01 +#define LBF_NEED_BREAK 0x02 +#define LBF_ABORT 0x04 /* * can_migrate_task - may task p from runqueue rq be migrated to this_cpu? @@ -3237,8 +3239,10 @@ balance_tasks(struct rq *this_rq, int this_cpu, struct rq *busiest, goto out; list_for_each_entry_safe(p, n, &busiest_cfs_rq->tasks, se.group_node) { - if (loops++ > sysctl_sched_nr_migrate) + if (loops++ > sysctl_sched_nr_migrate) { + *lb_flags |= LBF_NEED_BREAK; break; + } if ((p->se.load.weight >> 1) > rem_load_move || !can_migrate_task(p, busiest, this_cpu, sd, idle, @@ -3255,8 +3259,10 @@ balance_tasks(struct rq *this_rq, int this_cpu, struct rq *busiest, * kernels will stop after the first task is pulled to minimize * the critical section. */ - if (idle == CPU_NEWLY_IDLE) + if (idle == CPU_NEWLY_IDLE) { + *lb_flags |= LBF_ABORT; break; + } #endif /* @@ -3374,6 +3380,9 @@ load_balance_fair(struct rq *this_rq, int this_cpu, struct rq *busiest, unsigned long busiest_weight = busiest_cfs_rq->load.weight; u64 rem_load, moved_load; + if (*lb_flags & (LBF_NEED_BREAK|LBF_ABORT)) + break; + /* * empty group or part of a throttled hierarchy */ @@ -3440,18 +3449,19 @@ static int move_tasks(struct rq *this_rq, int this_cpu, struct rq *busiest, total_load_moved += load_moved; + if (*lb_flags & (LBF_NEED_BREAK|LBF_ABORT)) + break; + #ifdef CONFIG_PREEMPT /* * NEWIDLE balancing is a source of latency, so preemptible * kernels will stop after the first task is pulled to minimize * the critical section. */ - if (idle == CPU_NEWLY_IDLE && this_rq->nr_running) - break; - - if (raw_spin_is_contended(&this_rq->lock) || - raw_spin_is_contended(&busiest->lock)) + if (idle == CPU_NEWLY_IDLE && this_rq->nr_running) { + *lb_flags |= LBF_ABORT; break; + } #endif } while (load_moved && max_load_move > total_load_moved); @@ -4496,6 +4506,14 @@ redo: if (ld_moved && this_cpu != smp_processor_id()) resched_cpu(this_cpu); + if (lb_flags & LBF_ABORT) + goto out_balanced; + + if (lb_flags & LBF_NEED_BREAK) { + lb_flags &= ~LBF_NEED_BREAK; + goto redo; + } + /* All tasks on this runqueue were pinned by CPU affinity */ if (unlikely(lb_flags & LBF_ALL_PINNED)) { cpumask_clear_cpu(cpu_of(busiest), cpus); |