diff options
| author | Vincent Guittot <vincent.guittot@linaro.org> | 2015-01-15 11:09:26 +0100 |
|---|---|---|
| committer | Robin Randhawa <robin.randhawa@arm.com> | 2015-04-09 12:26:12 +0100 |
| commit | efb9a9b020bcc925840d95b250038bd387d41a95 (patch) | |
| tree | 2d2071e6cbc5a5cd5db345780dd7853a75671e8d | |
| parent | 8dcf01b64567b71636ffdebfb4e39e34ee611281 (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 f70c1a19bb99..1c0df973c80f 100644 --- a/kernel/sched/core.c +++ b/kernel/sched/core.c @@ -6177,7 +6177,7 @@ 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 da6b3867e087..6a6577002dde 100644 --- a/kernel/sched/fair.c +++ b/kernel/sched/fair.c @@ -4060,6 +4060,11 @@ 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); @@ -5610,6 +5615,7 @@ 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); @@ -5664,7 +5670,7 @@ 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 fe40be0aeea2..0a522fb7ffc3 100644 --- a/kernel/sched/sched.h +++ b/kernel/sched/sched.h @@ -451,6 +451,7 @@ struct rq { struct sched_domain *sd; unsigned long cpu_capacity; + unsigned long cpu_capacity_orig; unsigned char idle_balance; /* For active balancing */ |