diff options
author | Morten Rasmussen <Morten.Rasmussen@arm.com> | 2012-09-14 14:38:11 +0100 |
---|---|---|
committer | Viresh Kumar <viresh.kumar@linaro.org> | 2012-10-08 08:56:53 +0530 |
commit | eff98df853d3253f05f243ab990ce27ed65453e4 (patch) | |
tree | a07e054a5a0a8102c41c14541db6ca41077c1848 | |
parent | 99232a0b5cbec2a874d4ff732f66586322eca8e6 (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 72bf6b188bb..44affe14935 100644 --- a/arch/arm/Kconfig +++ b/arch/arm/Kconfig @@ -1570,6 +1570,19 @@ 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 5d405283421..673992ec48b 100644 --- a/kernel/sched/fair.c +++ b/kernel/sched/fair.c @@ -3151,9 +3151,14 @@ 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); @@ -5513,6 +5518,12 @@ 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) { @@ -5529,6 +5540,12 @@ 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) { |