diff options
| author | Vincent Guittot <vincent.guittot@linaro.org> | 2014-03-05 16:39:50 +0800 |
|---|---|---|
| committer | Vincent Guittot <vincent.guittot@linaro.org> | 2014-11-03 17:05:28 +0100 |
| commit | f4bb649896a026a5489c9ec2bbdfd3db871d2a2c (patch) | |
| tree | abd7193e169504549c804c958e0456f804191f7d | |
| parent | 965224c12e4ff6a57480cf044c9ed073160b77e2 (diff) | |
sched: add per rq cpu_capacity_orig
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>
| -rw-r--r-- | kernel/sched/core.c | 2 | ||||
| -rw-r--r-- | kernel/sched/fair.c | 8 | ||||
| -rw-r--r-- | 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 c84bdc098656..45ae52db59bf 100644 --- a/kernel/sched/core.c +++ b/kernel/sched/core.c @@ -7087,7 +7087,7 @@ 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 b37c27b18839..47827334a2a5 100644 --- a/kernel/sched/fair.c +++ b/kernel/sched/fair.c @@ -4141,6 +4141,11 @@ 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); @@ -5821,6 +5826,7 @@ 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); @@ -5875,7 +5881,7 @@ 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 fc5b1523aa28..aaaa3e4db334 100644 --- a/kernel/sched/sched.h +++ b/kernel/sched/sched.h @@ -585,6 +585,7 @@ struct rq { struct sched_domain *sd; unsigned long cpu_capacity; + unsigned long cpu_capacity_orig; unsigned char idle_balance; /* For active balancing */ |