| /* Copyright (c) 2012, 2015, The Linux Foundation. All rights reserved. |
| * |
| * This program is free software; you can redistribute it and/or modify |
| * it under the terms of the GNU General Public License version 2 and |
| * only version 2 as published by the Free Software Foundation. |
| * |
| * This program is distributed in the hope that it will be useful, |
| * but WITHOUT ANY WARRANTY; without even the implied warranty of |
| * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| * GNU General Public License for more details. |
| */ |
| |
| /* |
| * Scheduler hook for average runqueue determination |
| */ |
| #include <linux/module.h> |
| #include <linux/percpu.h> |
| #include <linux/hrtimer.h> |
| #include <linux/sched.h> |
| #include <linux/math64.h> |
| #include <trace/events/sched.h> |
| |
| #include "sched.h" |
| |
| static DEFINE_PER_CPU(u64, nr_prod_sum); |
| static DEFINE_PER_CPU(u64, last_time); |
| static DEFINE_PER_CPU(u64, nr_big_prod_sum); |
| static DEFINE_PER_CPU(u64, nr); |
| |
| static DEFINE_PER_CPU(unsigned long, iowait_prod_sum); |
| static DEFINE_PER_CPU(spinlock_t, nr_lock) = __SPIN_LOCK_UNLOCKED(nr_lock); |
| static s64 last_get_time; |
| |
| /** |
| * sched_get_nr_running_avg |
| * @return: Average nr_running, iowait and nr_big_tasks value since last poll. |
| * Returns the avg * 100 to return up to two decimal points |
| * of accuracy. |
| * |
| * Obtains the average nr_running value since the last poll. |
| * This function may not be called concurrently with itself |
| */ |
| void sched_get_nr_running_avg(int *avg, int *iowait_avg, int *big_avg) |
| { |
| int cpu; |
| u64 curr_time = sched_clock(); |
| u64 diff = curr_time - last_get_time; |
| u64 tmp_avg = 0, tmp_iowait = 0, tmp_big_avg = 0; |
| |
| *avg = 0; |
| *iowait_avg = 0; |
| *big_avg = 0; |
| |
| if (!diff) |
| return; |
| |
| /* read and reset nr_running counts */ |
| for_each_possible_cpu(cpu) { |
| unsigned long flags; |
| |
| spin_lock_irqsave(&per_cpu(nr_lock, cpu), flags); |
| curr_time = sched_clock(); |
| tmp_avg += per_cpu(nr_prod_sum, cpu); |
| tmp_avg += per_cpu(nr, cpu) * |
| (curr_time - per_cpu(last_time, cpu)); |
| |
| tmp_big_avg += per_cpu(nr_big_prod_sum, cpu); |
| tmp_big_avg += nr_eligible_big_tasks(cpu) * |
| (curr_time - per_cpu(last_time, cpu)); |
| |
| tmp_iowait += per_cpu(iowait_prod_sum, cpu); |
| tmp_iowait += nr_iowait_cpu(cpu) * |
| (curr_time - per_cpu(last_time, cpu)); |
| |
| per_cpu(last_time, cpu) = curr_time; |
| |
| per_cpu(nr_prod_sum, cpu) = 0; |
| per_cpu(nr_big_prod_sum, cpu) = 0; |
| per_cpu(iowait_prod_sum, cpu) = 0; |
| |
| spin_unlock_irqrestore(&per_cpu(nr_lock, cpu), flags); |
| } |
| |
| diff = curr_time - last_get_time; |
| last_get_time = curr_time; |
| |
| *avg = (int)div64_u64(tmp_avg * 100, diff); |
| *big_avg = (int)div64_u64(tmp_big_avg * 100, diff); |
| *iowait_avg = (int)div64_u64(tmp_iowait * 100, diff); |
| |
| trace_sched_get_nr_running_avg(*avg, *big_avg, *iowait_avg); |
| |
| BUG_ON(*avg < 0 || *big_avg < 0 || *iowait_avg < 0); |
| pr_debug("%s - avg:%d big_avg:%d iowait_avg:%d\n", |
| __func__, *avg, *big_avg, *iowait_avg); |
| } |
| EXPORT_SYMBOL(sched_get_nr_running_avg); |
| |
| /** |
| * sched_update_nr_prod |
| * @cpu: The core id of the nr running driver. |
| * @delta: Adjust nr by 'delta' amount |
| * @inc: Whether we are increasing or decreasing the count |
| * @return: N/A |
| * |
| * Update average with latest nr_running value for CPU |
| */ |
| void sched_update_nr_prod(int cpu, long delta, bool inc) |
| { |
| int diff; |
| s64 curr_time; |
| unsigned long flags, nr_running; |
| |
| spin_lock_irqsave(&per_cpu(nr_lock, cpu), flags); |
| nr_running = per_cpu(nr, cpu); |
| curr_time = sched_clock(); |
| diff = curr_time - per_cpu(last_time, cpu); |
| per_cpu(last_time, cpu) = curr_time; |
| per_cpu(nr, cpu) = nr_running + (inc ? delta : -delta); |
| |
| BUG_ON((s64)per_cpu(nr, cpu) < 0); |
| |
| per_cpu(nr_prod_sum, cpu) += nr_running * diff; |
| per_cpu(nr_big_prod_sum, cpu) += nr_eligible_big_tasks(cpu) * diff; |
| per_cpu(iowait_prod_sum, cpu) += nr_iowait_cpu(cpu) * diff; |
| spin_unlock_irqrestore(&per_cpu(nr_lock, cpu), flags); |
| } |
| EXPORT_SYMBOL(sched_update_nr_prod); |