diff options
| -rw-r--r-- | kernel/sched/core.c | 53 | ||||
| -rw-r--r-- | kernel/sched/fair.c | 2 | ||||
| -rw-r--r-- | kernel/sched/sched.h | 2 |
3 files changed, 41 insertions, 16 deletions
diff --git a/kernel/sched/core.c b/kernel/sched/core.c index 6883d99..860fddf 100644 --- a/kernel/sched/core.c +++ b/kernel/sched/core.c @@ -692,8 +692,6 @@ int tg_nop(struct task_group *tg, void *data) } #endif -void update_cpu_load(struct rq *this_rq); - static void set_load_weight(struct task_struct *p) { int prio = p->static_prio - MAX_RT_PRIO; @@ -2486,22 +2484,13 @@ decay_load_missed(unsigned long load, unsigned long missed_updates, int idx) * scheduler tick (TICK_NSEC). With tickless idle this will not be called * every tick. We fix it up based on jiffies. */ -void update_cpu_load(struct rq *this_rq) +static void __update_cpu_load(struct rq *this_rq, unsigned long this_load, + unsigned long pending_updates) { - unsigned long this_load = this_rq->load.weight; - unsigned long curr_jiffies = jiffies; - unsigned long pending_updates; int i, scale; this_rq->nr_load_updates++; - /* Avoid repeated calls on same jiffy, when moving in and out of idle */ - if (curr_jiffies == this_rq->last_load_update_tick) - return; - - pending_updates = curr_jiffies - this_rq->last_load_update_tick; - this_rq->last_load_update_tick = curr_jiffies; - /* Update our load: */ this_rq->cpu_load[0] = this_load; /* Fasttrack for idx 0 */ for (i = 1, scale = 2; i < CPU_LOAD_IDX_MAX; i++, scale += scale) { @@ -2526,9 +2515,45 @@ void update_cpu_load(struct rq *this_rq) sched_avg_update(this_rq); } +/* + * Called from nohz_idle_balance() to update the load ratings before doing the + * idle balance. + */ +void update_idle_cpu_load(struct rq *this_rq) +{ + unsigned long curr_jiffies = jiffies; + unsigned long load = this_rq->load.weight; + unsigned long pending_updates; + + /* + * Bloody broken means of dealing with nohz, but better than nothing.. + * jiffies is updated by one cpu, another cpu can drift wrt the jiffy + * update and see 0 difference the one time and 2 the next, even though + * we ticked at roughtly the same rate. + * + * Hence we only use this from nohz_idle_balance() and skip this + * nonsense when called from the scheduler_tick() since that's + * guaranteed a stable rate. + */ + if (load || curr_jiffies == this_rq->last_load_update_tick) + return; + + pending_updates = curr_jiffies - this_rq->last_load_update_tick; + this_rq->last_load_update_tick = curr_jiffies; + + __update_cpu_load(this_rq, load, pending_updates); +} + +/* + * Called from scheduler_tick() + */ static void update_cpu_load_active(struct rq *this_rq) { - update_cpu_load(this_rq); + /* + * See the mess in update_idle_cpu_load(). + */ + this_rq->last_load_update_tick = jiffies; + __update_cpu_load(this_rq, this_rq->load.weight, 1); calc_load_account_active(this_rq); } diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c index a259a614..124e6b6 100644 --- a/kernel/sched/fair.c +++ b/kernel/sched/fair.c @@ -5012,7 +5012,7 @@ static void nohz_idle_balance(int this_cpu, enum cpu_idle_type idle) raw_spin_lock_irq(&this_rq->lock); update_rq_clock(this_rq); - update_cpu_load(this_rq); + update_idle_cpu_load(this_rq); raw_spin_unlock_irq(&this_rq->lock); rebalance_domains(balance_cpu, CPU_IDLE); diff --git a/kernel/sched/sched.h b/kernel/sched/sched.h index 7282e7b..ba9dccf 100644 --- a/kernel/sched/sched.h +++ b/kernel/sched/sched.h @@ -876,7 +876,7 @@ extern void resched_cpu(int cpu); extern struct rt_bandwidth def_rt_bandwidth; extern void init_rt_bandwidth(struct rt_bandwidth *rt_b, u64 period, u64 runtime); -extern void update_cpu_load(struct rq *this_rq); +extern void update_idle_cpu_load(struct rq *this_rq); #ifdef CONFIG_CGROUP_CPUACCT #include <linux/cgroup.h> |