From: Michael Turquette <[email protected]> Implements a very simple policy to scale cpu frequency as a function of cfs utilization. This policy is a placeholder until something better comes along. Its purpose is to illustrate how to use the cpufreq_sched_set_capacity api and allow interested parties to hack on this stuff.
Signed-off-by: Michael Turquette <[email protected]> --- Changes in v3: Split out into separate patch Capacity calculation moved from cpufreq governor to cfs Removed use of static key. Replaced with Kconfig option kernel/sched/fair.c | 41 +++++++++++++++++++++++++++++++++++++++++ 1 file changed, 41 insertions(+) diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c index 46855d0..5ccc384 100644 --- a/kernel/sched/fair.c +++ b/kernel/sched/fair.c @@ -4217,6 +4217,7 @@ enqueue_task_fair(struct rq *rq, struct task_struct *p, int flags) { struct cfs_rq *cfs_rq; struct sched_entity *se = &p->se; + unsigned long utilization, capacity; for_each_sched_entity(se) { if (se->on_rq) @@ -4252,6 +4253,19 @@ enqueue_task_fair(struct rq *rq, struct task_struct *p, int flags) update_rq_runnable_avg(rq, rq->nr_running); add_nr_running(rq, 1); } + +#ifdef CONFIG_CPU_FREQ_GOV_SCHED + /* add 25% margin to current utilization */ + utilization = rq->cfs.utilization_load_avg; + capacity = utilization + (utilization >> 2); + + /* handle rounding errors */ + capacity = (capacity > SCHED_LOAD_SCALE) ? SCHED_LOAD_SCALE : + capacity; + + cpufreq_sched_set_cap(cpu_of(rq), capacity); +#endif + hrtick_update(rq); } @@ -4267,6 +4281,7 @@ static void dequeue_task_fair(struct rq *rq, struct task_struct *p, int flags) struct cfs_rq *cfs_rq; struct sched_entity *se = &p->se; int task_sleep = flags & DEQUEUE_SLEEP; + unsigned long utilization, capacity; for_each_sched_entity(se) { cfs_rq = cfs_rq_of(se); @@ -4313,6 +4328,19 @@ static void dequeue_task_fair(struct rq *rq, struct task_struct *p, int flags) sub_nr_running(rq, 1); update_rq_runnable_avg(rq, 1); } + +#ifdef CONFIG_CPU_FREQ_GOV_SCHED + /* add 25% margin to current utilization */ + utilization = rq->cfs.utilization_load_avg; + capacity = utilization + (utilization >> 2); + + /* handle rounding errors */ + capacity = (capacity > SCHED_LOAD_SCALE) ? SCHED_LOAD_SCALE : + capacity; + + cpufreq_sched_set_cap(cpu_of(rq), capacity); +#endif + hrtick_update(rq); } @@ -7806,6 +7834,7 @@ static void task_tick_fair(struct rq *rq, struct task_struct *curr, int queued) { struct cfs_rq *cfs_rq; struct sched_entity *se = &curr->se; + unsigned long utilization, capacity; for_each_sched_entity(se) { cfs_rq = cfs_rq_of(se); @@ -7816,6 +7845,18 @@ static void task_tick_fair(struct rq *rq, struct task_struct *curr, int queued) task_tick_numa(rq, curr); update_rq_runnable_avg(rq, 1); + +#ifdef CONFIG_CPU_FREQ_GOV_SCHED + /* add 25% margin to current utilization */ + utilization = rq->cfs.utilization_load_avg; + capacity = utilization + (utilization >> 2); + + /* handle rounding errors */ + capacity = (capacity > SCHED_LOAD_SCALE) ? SCHED_LOAD_SCALE : + capacity; + + cpufreq_sched_set_cap(cpu_of(rq), capacity); +#endif } /* -- 1.9.1 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
