Fixing linaro dev address

On 16 May 2013 22:18, Chris Redpath chris.redpath@arm.com wrote:

Previously, an offline CPU would always appear to have a zero load and this would distort the offload functionality used for balancing big and little domains.

Maintain a mask of online CPUs in each domain and use this instead.

Change-Id: I639b564b2f40cb659af8ceb8bd37f84b8a1fe323 Signed-off-by: Chris Redpath chris.redpath@arm.com

---

arch/arm/kernel/topology.c | 6 ++++-- include/linux/sched.h | 1 + kernel/sched/fair.c | 39 +++++++++++++++++++++++++++++++++++++-- 3 files changed, 42 insertions(+), 4 deletions(-)

diff --git a/arch/arm/kernel/topology.c b/arch/arm/kernel/topology.c index fa45fb4..93ad2cd 100644 --- a/arch/arm/kernel/topology.c +++ b/arch/arm/kernel/topology.c @@ -381,12 +381,14 @@ void __init arch_get_hmp_domains(struct list_head *hmp_domains_list) if(!cpumask_empty(&hmp_slow_cpu_mask)) { domain = (struct hmp_domain *) kmalloc(sizeof(struct hmp_domain), GFP_KERNEL);

•           cpumask_copy(&domain->cpus, &hmp_slow_cpu_mask);
  

•           cpumask_copy(&domain->possible_cpus, &hmp_slow_cpu_mask);
  

•           cpumask_and(&domain->cpus, cpu_online_mask, &domain->possible_cpus);
            list_add(&domain->hmp_domains, hmp_domains_list);
    }
    domain = (struct hmp_domain *)
            kmalloc(sizeof(struct hmp_domain), GFP_KERNEL);
  

•   cpumask_copy(&domain->cpus, &hmp_fast_cpu_mask);
  

•   cpumask_copy(&domain->possible_cpus, &hmp_fast_cpu_mask);
  

•   cpumask_and(&domain->cpus, cpu_online_mask, &domain->possible_cpus);
    list_add(&domain->hmp_domains, hmp_domains_list);
  

} #endif /* CONFIG_SCHED_HMP */ diff --git a/include/linux/sched.h b/include/linux/sched.h index ea439ab..0553d76 100644 --- a/include/linux/sched.h +++ b/include/linux/sched.h @@ -988,6 +988,7 @@ bool cpus_share_cache(int this_cpu, int that_cpu); #ifdef CONFIG_SCHED_HMP struct hmp_domain { struct cpumask cpus;

•   struct cpumask possible_cpus;
    struct list_head hmp_domains;
  

}; #endif /* CONFIG_SCHED_HMP */ diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c index 0f9941e..3a53343 100644 --- a/kernel/sched/fair.c +++ b/kernel/sched/fair.c @@ -3514,10 +3514,10 @@ static int __init hmp_cpu_mask_setup(void) dc = 0; list_for_each(pos, &hmp_domains) { domain = list_entry(pos, struct hmp_domain, hmp_domains);

•           cpulist_scnprintf(buf, 64, &domain->cpus);
  

•           cpulist_scnprintf(buf, 64, &domain->possible_cpus);
            pr_debug("  HMP domain %d: %s\n", dc, buf);
  
  

•           for_each_cpu_mask(cpu, domain->cpus) {
  

•           for_each_cpu_mask(cpu, domain->possible_cpus) {
                    per_cpu(hmp_cpu_domain, cpu) = domain;
            }
            dc++;
  

@@ -3526,6 +3526,35 @@ static int __init hmp_cpu_mask_setup(void) return 1; }

+static struct hmp_domain *hmp_get_hmp_domain_for_cpu(int cpu) +{

•   struct hmp_domain *domain;
  

•   struct list_head *pos;
  

•   list_for_each(pos, &hmp_domains) {
  

•           domain = list_entry(pos, struct hmp_domain, hmp_domains);
  

•           if(cpumask_test_cpu(cpu, &domain->possible_cpus))
  

•                   return domain;
  

•   }
  

•   return NULL;
  

+}

+static void hmp_online_cpu(int cpu) +{

•   struct hmp_domain *domain = hmp_get_hmp_domain_for_cpu(cpu);
  

•   if(domain)
  

•           cpumask_set_cpu(cpu, &domain->cpus);
  

+}

+static void hmp_offline_cpu(int cpu) +{

•   struct hmp_domain *domain = hmp_get_hmp_domain_for_cpu(cpu);
  

•   if(domain)
  

•           cpumask_clear_cpu(cpu, &domain->cpus);
  

+}

/*

• Migration thresholds should be in the range [0..1023]
• hmp_up_threshold: min. load required for migrating tasks to a faster cpu

@@ -6570,11 +6599,17 @@ void trigger_load_balance(struct rq *rq, int cpu)

static void rq_online_fair(struct rq *rq) { +#ifdef CONFIG_SCHED_HMP

•   hmp_online_cpu(rq->cpu);
  

+#endif update_sysctl(); }

static void rq_offline_fair(struct rq *rq) { +#ifdef CONFIG_SCHED_HMP

•   hmp_offline_cpu(rq->cpu);
  

+#endif update_sysctl();

    /* Ensure any throttled groups are reachable by pick_next_task */

-- 1.7.9.5