| From | Morten Rasmussen <> | Subject | [RFCv3 PATCH 06/48] sched: add per rq cpu_capacity_orig | Date | Wed, 4 Feb 2015 18:30:43 +0000 |
| |
From: Vincent Guittot <vincent.guittot@linaro.org>
This new field cpu_capacity_orig reflects the original capacity of a CPU before being altered by rt tasks and/or IRQ
The cpu_capacity_orig will be used: - to detect when the capacity of a CPU has been noticeably reduced so we can trig load balance to look for a CPU with better capacity. As an example, we can detect when a CPU handles a significant amount of irq (with CONFIG_IRQ_TIME_ACCOUNTING) but this CPU is seen as an idle CPU by scheduler whereas CPUs, which are really idle, are available. - evaluate the available capacity for CFS tasks
Signed-off-by: Vincent Guittot <vincent.guittot@linaro.org> Reviewed-by: Kamalesh Babulal <kamalesh@linux.vnet.ibm.com> Acked-by: Morten Rasmussen <morten.rasmussen@arm.com> --- kernel/sched/core.c | 2 +- kernel/sched/fair.c | 8 +++++++- kernel/sched/sched.h | 1 + 3 files changed, 9 insertions(+), 2 deletions(-)
diff --git a/kernel/sched/core.c b/kernel/sched/core.c index e628cb1..48f9053 100644 --- a/kernel/sched/core.c +++ b/kernel/sched/core.c @@ -7212,7 +7212,7 @@ void __init sched_init(void) #ifdef CONFIG_SMP rq->sd = NULL; rq->rd = NULL; - rq->cpu_capacity = SCHED_CAPACITY_SCALE; + rq->cpu_capacity = rq->cpu_capacity_orig = SCHED_CAPACITY_SCALE; rq->post_schedule = 0; rq->active_balance = 0; rq->next_balance = jiffies; diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c index cfe3aea..3fdad38 100644 --- a/kernel/sched/fair.c +++ b/kernel/sched/fair.c @@ -4351,6 +4351,11 @@ static unsigned long capacity_of(int cpu) return cpu_rq(cpu)->cpu_capacity; } +static unsigned long capacity_orig_of(int cpu) +{ + return cpu_rq(cpu)->cpu_capacity_orig; +} + static unsigned long cpu_avg_load_per_task(int cpu) { struct rq *rq = cpu_rq(cpu); @@ -6028,6 +6033,7 @@ static void update_cpu_capacity(struct sched_domain *sd, int cpu) capacity >>= SCHED_CAPACITY_SHIFT; + cpu_rq(cpu)->cpu_capacity_orig = capacity; sdg->sgc->capacity_orig = capacity; capacity *= scale_rt_capacity(cpu); @@ -6082,7 +6088,7 @@ void update_group_capacity(struct sched_domain *sd, int cpu) * Runtime updates will correct capacity_orig. */ if (unlikely(!rq->sd)) { - capacity_orig += capacity_of(cpu); + capacity_orig += capacity_orig_of(cpu); capacity += capacity_of(cpu); continue; } diff --git a/kernel/sched/sched.h b/kernel/sched/sched.h index e61f00e..09bb18b 100644 --- a/kernel/sched/sched.h +++ b/kernel/sched/sched.h @@ -604,6 +604,7 @@ struct rq { struct sched_domain *sd; unsigned long cpu_capacity; + unsigned long cpu_capacity_orig; unsigned char idle_balance; /* For active balancing */ -- 1.9.1
|