diff options
| author | Dietmar Eggemann <dietmar.eggemann@arm.com> | 2013-06-21 17:50:08 +0100 |
|---|---|---|
| committer | Jon Medhurst <tixy@linaro.org> | 2013-07-17 11:32:41 +0100 |
| commit | 4ab2679351e9566a6b0822f2d841a902758ba066 (patch) | |
| tree | 9faea058d1beee4871c6115046bbedb21d93d659 | |
| parent | 6eada0087366d8aec6bc38348a68f721f538cc5c (diff) | |
HMP: experimental: Force all rt tasks to start on little domain.big-LITTLE-MP-13.07master-task-placement-v2-updates
This patch restricts the allowed cpu mask for rt tasks initially started
with a full cpu mask to the little domain.
An rt task is specified as real time in __setscheduler() which is finally
called for all rt tasks (kernel and user land). In this function we
restrict the allowed cpu mask to the little domain.
This also prevents that a rt tasks can later be pushed to the big domain
because the function find_lowest_rq() will only recognize the allowed cpu
mask of a task to find the new cpu the task runs on.
Current kludges of the patch:
* Since we do not have an API to get the cpu mask of the A7 cluster,
hmp_slow_cpu_mask is made global in arm/kernel/topology.c for now.
* The watchdog_enable() function calls sched_setscheduler() before
kthread_bind() for the cpu specific watchdog kernel threads. The order of
these two calls has to be changed to make this patch work.
Signed-off-by: Dietmar Eggemann <dietmar.eggemann@arm.com>
| -rw-r--r-- | arch/arm/kernel/topology.c | 3 | ||||
| -rw-r--r-- | kernel/sched/core.c | 9 |
2 files changed, 10 insertions, 2 deletions
diff --git a/arch/arm/kernel/topology.c b/arch/arm/kernel/topology.c index 9047dd1c5a1..4459c0b4e91 100644 --- a/arch/arm/kernel/topology.c +++ b/arch/arm/kernel/topology.c @@ -367,10 +367,11 @@ void __init arch_get_fast_and_slow_cpus(struct cpumask *fast, cpumask_clear(slow); } +struct cpumask hmp_slow_cpu_mask; + void __init arch_get_hmp_domains(struct list_head *hmp_domains_list) { struct cpumask hmp_fast_cpu_mask; - struct cpumask hmp_slow_cpu_mask; struct hmp_domain *domain; arch_get_fast_and_slow_cpus(&hmp_fast_cpu_mask, &hmp_slow_cpu_mask); diff --git a/kernel/sched/core.c b/kernel/sched/core.c index 4c53da3781e..50d9e9849ce 100644 --- a/kernel/sched/core.c +++ b/kernel/sched/core.c @@ -3827,6 +3827,8 @@ static struct task_struct *find_process_by_pid(pid_t pid) return pid ? find_task_by_vpid(pid) : current; } +extern struct cpumask hmp_slow_cpu_mask; + /* Actually do priority change: must hold rq lock. */ static void __setscheduler(struct rq *rq, struct task_struct *p, int policy, int prio) @@ -3836,8 +3838,13 @@ __setscheduler(struct rq *rq, struct task_struct *p, int policy, int prio) p->normal_prio = normal_prio(p); /* we are holding p->pi_lock already */ p->prio = rt_mutex_getprio(p); - if (rt_prio(p->prio)) + if (rt_prio(p->prio)) { p->sched_class = &rt_sched_class; +#ifdef CONFIG_SCHED_HMP + if (cpumask_equal(&p->cpus_allowed, cpu_all_mask)) + do_set_cpus_allowed(p, &hmp_slow_cpu_mask); +#endif + } else p->sched_class = &fair_sched_class; set_load_weight(p); |