Almost identical functions which push/pull task from/to current CPU to/from another cluster. Called when balancing between clusters is broken and we need to fix it.
Signed-off-by: Tarek Dakhran <t.dakh...@samsung.com> Signed-off-by: Sergey Dyasly <s.dya...@samsung.com> Signed-off-by: Dmitriy Safonov <d.safo...@partner.samsung.com> Signed-off-by: Arseniy Krasnov <a.kras...@samsung.com> Signed-off-by: Ilya Maximets <i.maxim...@samsung.com> --- kernel/sched/fair.c | 254 ++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 254 insertions(+) diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c index 028d329..4fda1ec 100644 --- a/kernel/sched/fair.c +++ b/kernel/sched/fair.c @@ -7519,6 +7519,260 @@ unlock: return ld_moved; } + +/* Get idlest cpu from opposite domain of this_cpu */ +static int get_idlest_cpu(struct sched_domain *sd, int this_cpu) +{ + struct sched_group *opposite_sg; + struct cpumask *opposite_mask; + unsigned long load = ULONG_MAX; + int idlest_cpu = -1; + int cpu; + + opposite_sg = get_opposite_group(sd, cpu_is_fastest(this_cpu)); + opposite_mask = sched_group_cpus(opposite_sg); + + for_each_cpu_and(cpu, opposite_mask, cpu_online_mask) { + if (cpu_rq(cpu)->load.weight < load) { + load = cpu_rq(cpu)->load.weight; + idlest_cpu = cpu; + } + } + return idlest_cpu; +} + +/** + * move_a15_to_a7(): Moves one task from A15 to A7. + * @sd: Current sched domain. + * @this_cpu: without NO_HZ same as smp_processor_id(). + * + * Returns moved weight. + * + * Chooses task to migrate by druntime. + */ +static unsigned int move_a15_to_a7(struct sched_domain *sd, int this_cpu) +{ + struct task_struct *task_to_move; + struct rq *local_rq = NULL; + struct rq *foreign_rq = NULL; + int local_stopper_flag = 0; + int foreign_stopper_flag = 0; + unsigned long local_flags; + unsigned int ld_moved = 0; + + local_rq = cpu_rq(this_cpu); + local_irq_save(local_flags); + + if (!cpu_is_fastest(this_cpu)) { + /* this A7 pulls task from A15 */ + foreign_rq = get_unfair_rq(sd, this_cpu); + + if (!foreign_rq) { + local_irq_restore(local_flags); + return 0; + } + + double_lock_balance(foreign_rq, local_rq); + + if (foreign_rq->active_balance) + goto unlock; + + if (local_rq->active_balance) + goto unlock; + + if (foreign_rq->cfs.h_nr_running <= 1) + goto unlock; + + task_to_move = get_migration_candidate(sd, foreign_rq, 0, + this_cpu); + + if (!task_to_move) + goto unlock; + + ld_moved = try_to_move_task(task_to_move, this_cpu, + &foreign_stopper_flag); + + if (!ld_moved) { + task_to_move->se.migrate_candidate = 0; + goto unlock; + } + + if (foreign_stopper_flag) { + foreign_rq->active_balance = 1; + foreign_rq->push_cpu = this_cpu; + foreign_rq->migrate_task = task_to_move; + } + } else { + /* this A15 push task to A7 */ + int dst_cpu = get_idlest_cpu(sd, this_cpu); + + if (dst_cpu == -1) { + local_irq_restore(local_flags); + return 0; + } + + foreign_rq = cpu_rq(dst_cpu); + raw_spin_lock(&foreign_rq->lock); + double_lock_balance(foreign_rq, local_rq); + + if (local_rq->cfs.h_nr_running <= 1) + goto unlock; + + if (foreign_rq->active_balance) + goto unlock; + + if (local_rq->active_balance) + goto unlock; + + task_to_move = get_migration_candidate(sd, local_rq, 0, + foreign_rq->cpu); + + if (!task_to_move) + goto unlock; + + ld_moved = try_to_move_task(task_to_move, dst_cpu, + &local_stopper_flag); + + if (!ld_moved) { + task_to_move->se.migrate_candidate = 0; + goto unlock; + } + + if (local_stopper_flag) { + local_rq->active_balance = 1; + local_rq->push_cpu = dst_cpu; + local_rq->migrate_task = task_to_move; + } + } +unlock: + double_rq_unlock(local_rq, foreign_rq); + local_irq_restore(local_flags); + + if (foreign_stopper_flag) + stop_one_cpu_nowait(foreign_rq->cpu, + active_load_balance_cpu_stop, foreign_rq, + &foreign_rq->active_balance_work); + + if (local_stopper_flag) + stop_one_cpu_nowait(local_rq->cpu, + active_load_balance_cpu_stop, local_rq, + &local_rq->active_balance_work); + + return ld_moved; +} + +/** + * move_a7_to_a15(): Moves one task from A7 to A15. + * @sd: Current sched domain. + * @this_cpu: without NO_HZ same as smp_processor_id(). + * + * Returns moved weight. + * + * Chooses task to migrate by druntime. + */ +static unsigned int move_a7_to_a15(struct sched_domain *sd, int this_cpu) +{ + struct task_struct *task_to_move; + struct rq *local_rq = NULL; + struct rq *foreign_rq = NULL; + int local_stopper_flag = 0; + int foreign_stopper_flag = 0; + unsigned long local_flags; + unsigned int ld_moved = 0; + + local_rq = cpu_rq(this_cpu); + local_irq_save(local_flags); + + if (cpu_is_fastest(this_cpu)) { + /* this A15 pulls task from A7 */ + foreign_rq = get_unfair_rq(sd, this_cpu); + + if (!foreign_rq) { + local_irq_restore(local_flags); + return 0; + } + double_lock_balance(foreign_rq, local_rq); + + if (local_rq->active_balance) + goto unlock; + + if (foreign_rq->active_balance) + goto unlock; + + task_to_move = get_migration_candidate(sd, foreign_rq, 0, + this_cpu); + + if (!task_to_move) + goto unlock; + + ld_moved = try_to_move_task(task_to_move, this_cpu, + &foreign_stopper_flag); + + if (!ld_moved) { + task_to_move->se.migrate_candidate = 0; + goto unlock; + } + + if (foreign_stopper_flag) { + foreign_rq->active_balance = 1; + foreign_rq->push_cpu = this_cpu; + foreign_rq->migrate_task = task_to_move; + } + } else { + /* this A7 push task to A15*/ + int dst_cpu = get_idlest_cpu(sd, this_cpu); + + if (dst_cpu == -1) { + local_irq_restore(local_flags); + return 0; + } + + foreign_rq = cpu_rq(dst_cpu); + raw_spin_lock(&foreign_rq->lock); + double_lock_balance(foreign_rq, local_rq); + + if (foreign_rq->active_balance) + goto unlock; + + if (local_rq->active_balance) + goto unlock; + + task_to_move = get_migration_candidate(sd, local_rq, 0, + foreign_rq->cpu); + + if (!task_to_move) + goto unlock; + + ld_moved = try_to_move_task(task_to_move, dst_cpu, + &local_stopper_flag); + + if (!ld_moved) { + task_to_move->se.migrate_candidate = 0; + goto unlock; + } + + if (local_stopper_flag) { + local_rq->active_balance = 1; + local_rq->push_cpu = dst_cpu; + local_rq->migrate_task = task_to_move; + } + } +unlock: + double_rq_unlock(local_rq, foreign_rq); + local_irq_restore(local_flags); + + if (foreign_stopper_flag) + stop_one_cpu_nowait(foreign_rq->cpu, + active_load_balance_cpu_stop, foreign_rq, + &foreign_rq->active_balance_work); + + if (local_stopper_flag) + stop_one_cpu_nowait(local_rq->cpu, + active_load_balance_cpu_stop, local_rq, + &local_rq->active_balance_work); + + return ld_moved; +} #endif /* CONFIG_HPERF_HMP */ /* -- 1.9.1 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/