diff options
| author | Morten Rasmussen <Morten.Rasmussen@arm.com> | 2012-09-14 14:38:11 +0100 |
|---|---|---|
| committer | Jon Medhurst <tixy@linaro.org> | 2013-07-17 11:12:24 +0100 |
| commit | 943106d9437fcced79c4e48ed794410e5f750b4c (patch) | |
| tree | 0fcac4f90716d5c02e30d9192434cb27234fac5f | |
| parent | 2dd22b22c95851445c189c3d4708c027aa19cf5f (diff) | |
sched: Introduce priority-based task migration filter
Introduces a priority threshold which prevents low priority task
from migrating to faster hmp_domains (cpus). This is useful for
user-space software which assigns lower task priority to background
task.
Signed-off-by: Morten Rasmussen <Morten.Rasmussen@arm.com>
| -rw-r--r-- | arch/arm/Kconfig | 13 | ||||
| -rw-r--r-- | kernel/sched/fair.c | 17 |
2 files changed, 30 insertions, 0 deletions
diff --git a/arch/arm/Kconfig b/arch/arm/Kconfig index 5fb586f4fcf..6157ed8e0e3 100644 --- a/arch/arm/Kconfig +++ b/arch/arm/Kconfig @@ -1511,6 +1511,19 @@ config SCHED_HMP !SCHED_AUTOGROUP. Furthermore, normal load-balancing must be disabled between cpus of different type (DISABLE_CPU_SCHED_DOMAIN_BALANCE). +config SCHED_HMP_PRIO_FILTER + bool "(EXPERIMENTAL) Filter HMP migrations by task priority" + depends on SCHED_HMP + help + Enables task priority based HMP migration filter. Any task with + a NICE value above the threshold will always be on low-power cpus + with less compute capacity. + +config SCHED_HMP_PRIO_FILTER_VAL + int "NICE priority threshold" + default 5 + depends on SCHED_HMP_PRIO_FILTER + config HAVE_ARM_SCU bool help diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c index 2d88b043c9e..a6b451d9cd3 100644 --- a/kernel/sched/fair.c +++ b/kernel/sched/fair.c @@ -3392,9 +3392,14 @@ static int __init hmp_cpu_mask_setup(void) * hmp_down_threshold: max. load allowed for tasks migrating to a slower cpu * The default values (512, 256) offer good responsiveness, but may need * tweaking suit particular needs. + * + * hmp_up_prio: Only up migrate task with high priority (<hmp_up_prio) */ unsigned int hmp_up_threshold = 512; unsigned int hmp_down_threshold = 256; +#ifdef CONFIG_SCHED_HMP_PRIO_FILTER +unsigned int hmp_up_prio = NICE_TO_PRIO(CONFIG_SCHED_HMP_PRIO_FILTER_VAL); +#endif static unsigned int hmp_up_migration(int cpu, struct sched_entity *se); static unsigned int hmp_down_migration(int cpu, struct sched_entity *se); @@ -5845,6 +5850,12 @@ static unsigned int hmp_up_migration(int cpu, struct sched_entity *se) if (hmp_cpu_is_fastest(cpu)) return 0; +#ifdef CONFIG_SCHED_HMP_PRIO_FILTER + /* Filter by task priority */ + if (p->prio >= hmp_up_prio) + return 0; +#endif + if (cpumask_intersects(&hmp_faster_domain(cpu)->cpus, tsk_cpus_allowed(p)) && se->avg.load_avg_ratio > hmp_up_threshold) { @@ -5861,6 +5872,12 @@ static unsigned int hmp_down_migration(int cpu, struct sched_entity *se) if (hmp_cpu_is_slowest(cpu)) return 0; +#ifdef CONFIG_SCHED_HMP_PRIO_FILTER + /* Filter by task priority */ + if (p->prio >= hmp_up_prio) + return 1; +#endif + if (cpumask_intersects(&hmp_slower_domain(cpu)->cpus, tsk_cpus_allowed(p)) && se->avg.load_avg_ratio < hmp_down_threshold) { |